Graham Audio LS8/1 Signature Edition & a New System

tmallin

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iPad as a Streamer

I agree that using an iPad connected via USB to a good DAC like the Benchmark DAC3B is perfectly acceptable to my ears for internet music streaming. I've tried it and it sounds fine. Just keep the USB cable off the carpet and thus away from your feet when you are sitting in your chair to avoid accidental damage to the cable or the USB connections at either end.. In my room I'd need a long USB cable running along the floor from my listening seat to the equipment rack and thus it's not an acceptable long-term solution for me.

Reasons the iPad could be sonically bettered by using a "real" streamer, as well as possible ways to improve an iPad's performance as a streamer include:

1. The iPad ordinarily uses Wi-Fi to capture internet signals. Wi-Fi connections just don't sound as good (or measure as good, for that matter, in terms of speed, latency, and jitter) as ethernet connections. I've done the sonic comparisons. It's not hard to hear the improvement when a "real" streamer is connected via ethernet versus Wi-Fi. While it's possible to connect an iPad to ethernet and simultaneously output its stream to a DAC via USB, the adaptors needed for this take their sonic toll. Again, I've tried this. Real streamers have ethernet connections built in.

2. Volume control: If you use the iPad's volume control to control system volume, you are using a generic digital volume control which, if used to reduce the output significantly to accommodate ordinary listening levels, may be throwing away low level detail. You can get around this problem by leaving the iPad volume control at 100% and using the Benchmark DAC's hybrid gain control if you have the HGC model. If you have a Benchmark without a volume control, you could use an analog preamp's volume control to adjust system volume. With the Lumin streamers I've used, volume is controlled by a Leedh-processed digital volume control which, in my experience, is the most transparent means of reducing volume, bar none, even better sounding than the relay controlled analog volume control of the best Benchmark preamps. The Lumin streamer can thus ideally directly drive my power amps with no intervening electronics.

3. USB cable quality: I've talked about this in other recent posts. Keep the cable short and try to find one that is warmer sounding, less bright, and less hashy than most. This is especially important in light of 4.

4. As best I can determine by connecting headphones directly to the iPad via BlueTooth or via its Lightning or USB-C port with adaptors, the iPad tends to sound lean in the bass and a bit bright in the treble. These may just be power supply limitations. The iPad actually sounds best to me as a streamer in terms of subjective frequency balance, clearness, and cleanness of sound when used in AirPlay mode, sending its stream through the air to a "real" streamer such as my Lumin. AirPlay gets around the (to me) problematic sonic qualities of most USB connections.

5. Most electronics sound cleaner using battery power, not AC wall power. The iPad is no exception. Thus, for best sound, make sure to disconnect the charging cable when listening to streaming through the iPad. The Apple USB 3 camera adaptor allows connecting the iPad simultaneously to power and USB to the DAC, but it will sound better if the adaptor is not used when listening.

6. The iPad will sound better if you use one dedicated to your system, not one with general purpose apps on it. Disable all functions not needed for music streaming (especially BlueTooth) and remove all apps not needed for music streaming. Again, this may be power supply related or digital overhead related. Keeping the number of background general operations the iPad is performing to a bare minimum seems to improve its sonic quality as a streamer.

7. In my system, I use such a dedicated "stripped down" iPad merely for system control of my Lumin X1, not usually streaming anything through it (AirPlay being the exception). Even that system control use reduces the audio performance of my system a bit. Once I get the program and volume dialed in, if I actually turn off the iPad (not just turning off the screen), I can hear the audio spatial focus improve immediately and the background becomes "blacker." The same thing happens when I use my iPhone 14 Pro Max for system control. Why this should be, I don't know, but that's the way I hear it. If the iPad is actually used for streaming music to your Benchmark, this effect could be audible, but not bypassable since the iPad is the device doing the streaming. Perhaps the Benchmark might be immune to this effect; I have not experimented with that since I no longer use a Benchmark DAC in my audio room.

8. If Tidal MQA is important at all to you, neither the iPad nor the Benchmark does any MQA decoding or rendering. Note that something like an AudioQuest Dragonfly DAC can be used in an inexpensive streaming system. The Dragonfly is an MQA renderer. While it does not do the final unfolding/decoding, my experience with such rendering units indicates to me that the rendering is the sonically most important part of hearing MQA improvements. But, if you want to stick strictly with Qobuz Hi-Res PCM streaming, you will get no argument from me. I rarely use Tidal anymore and actually usually have the MQA processing of my Lumin X1 (which is a decoder and renderer) turned off since the Lumin's sound on regular PCM files improves a bit if I turn off the MQA functions in the options menu. This MQA thing may be a moot point anyway since Tidal Max is now making Hi-Res PCM material available.

Whether any of these issues are worth spending extra for a "real" streamer, only you can decide. If you are happy using the iPad as you do, just keep things as they are. If it ain't broke, don't try to fix it. But if you ever decide you hear problems, rest assured that there could be ways to improve the iPad's sonic performance as a streamer and reasons why a "real" streamer might sound better yet.
 

tmallin

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Roon Equalization

For any of you currently using Roon or thinking about using it, one of the lesser known Roon DSP functions which comes "for free" with the purchase of your Roon license is fairly sophisticated parametric equalization. See the description of this function here.

Roon makes a big deal about offering pre-programmed sets of parametric EQ filters designed to enhance the performance of various audiophile-oriented headphones. However, you can custom design sets of parametric filters as well and apply them just as easily to speaker listening. Also, there are numerous parametric EQ presets available and you can assign any custom EQ to one of those presets for later recall.

This function will equalize anything you play through Roon, but not otherwise. In my own internet streaming system, this includes all internet radio stations played through the Roon Live Radio function, all Tidal or Qobuz material, and all my personal music files in the music Library residing on the computer which serves as my Roon Core which I have associated with Roon. In my system, the only exclusions would be internet streaming services not available through Roon, like Jazz Radio and SiriusXM Radio.

Many bands of parametric EQ are available at once. The effect of each band is displayed on a frequency response graph and in a table with the parameters of each filter. You can draw the filters via the on-screen graph, or type the parameters into the table, which filter will then display on the graph.

This processing takes some computing "horsepower." As someone else here mentioned not too long ago, there is thus a few seconds of silent delay between enabling, disabling, or changing any filter parameter. Not an ideal situation because of the silent delay in results, but not too bad for comparisons, in my estimation. Roon will also display the processing resources used by the equalization and other DSP functions. As long as you are using a decently powerful processing chip in your Roon Core computer, there shouldn't be any problems enabling this EQ.

As far as I can tell, the EQ seems pretty transparent other than the desired frequency response changes and the silent delay in taking effect. Thus, it seems like a good electronic EQ solution as long as you are playing music via Roon. I haven't used it much yet, though, since I mostly listen to music via the Lumin App. Others who have used this EQ function regularly say it is indeed seemingly quite transparent.

With my Lumin X1 streamer, to use Roon, I enable Roon Ready in the Options menu. (If you are not using Roon, Lumin's lead designer recommends disabling this Option and all other unused Options for best sound quality from the Lumin App.) Then I use the Roon app screen to play music and adjust the volume. Roon allows you to use your streamer's controls to control the volume, however, so adjusting volume through the Roon App on my iPad system controller still uses the superb Leedh-processed digital volume control of the Lumin App to adjust the volume while allowing Roon to apply its parametric EQ function.

Lumin equipment does not offer on-board electronic equalization since, as a design choice, the Lumin App is not now and probably will never be able to do that. Lumin's lead designer recommends off-boarding the EQ function to Roon equalization if you need electronic EQ. This, he says, reduces the demands on the Lumin streamer's processing engine and power supply, keeping sound quality as high as possible.
 

tmallin

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Limitations of Streaming, But Why I Prefer It

My own experience is that reissues are wildly inconsistent compared to the originals or earlier reissues. Sometimes the newest 24/192 remasterings really do sound better to me. But if there is a trend in successive reissues, it is toward greater apparent clarity at the cost of jacked up high frequencies and very frequently reduced bass weight and warmth. For many albums, various reissues may be directly compared on Tidal and Qobuz. Of course you never know how any given reissue has been re-equalized or re-reprocessed as to phase and I think such re-equalization and phase reprocessing is usually by far the most important distinguishing characteristic from one reissue to another.

I also agree with those who say that while millions of albums are available on Qobuz and Tidal, not everything of interest is. I have run across this recently for albums of multiple genres, not just classical.

Of course, this was also true when vinyl was "replaced" by CD: not all the albums previously released on vinyl were reissued on CD. Similarly, for reasons not entirely clear to me, not all CDs make it to any of the streaming services. Sometimes, as with some audiophile-oriented releases, it's the manufacturer's choice not to stream in order to protect its vinyl and CDs sales. In other cases, however, as with many Telarc discs, they are present for a while on streaming services, only to then become unplayable with a note that the manufacturer does not allow streaming of this title, only to later reappear and be playable either in a newer reissue or as apparently the exact same release with no explanation.

Many niche internet radio stations seem to be distinguishing their programming from the major streaming services by using their deep and decades-old catalogs of vinyl and CD originals to stream material not available on the major streaming services and frequently not even available for sale anymore on sources like Amazon, eBay, or Discogs. For example, you'd have no idea how much music has been recorded for concert band unless you listen to the concert band stream of Your Classical. But the same is true for most genres. Many times niche internet radio stations play recordings of jazz and other genres you will search for in vain (to get the full CD quality version) on Qobuz, Tidal, or any of the music for sale sites.

One specific recent example I remember was a version of Gerhshwin's "An American in Paris" I heard played on Your Classical MPR with the Dallas Symphony Orchestra conducted by Eduardo Mata (the same orchestra and conductor responsible for the Rachmaninoff Symphonic Dances on the ProArte label I find truly excellent as to both sound and interpretation). The sound seemed excellent and the interpretation was unusual. But I could not find it on any of the streaming services. I did find copies available from Amazon and Discogs, however. It was an RCA Red Seal or Victrola release, so nothing exotic in terms of label. All the streaming services have huge catalogs of RCA releases, but not that one from a well-known American orchestra and conductor. The Dallas/Mata/Rachmaninoff/Symphonic Dances isn't on the streaming services either, for that matter.

****************

Still, I greatly prefer streaming to playing music from discs. Sure, most music lovers have (or at least had) substantial legacy collections of music on tape, LP, CD, SACD, and perhaps other physical media. But since the advent of streaming, there is no real need to touch those legacy music archives and no need to acquire discs containing new music except for items which have not made it to streaming platforms.

Some enjoy the ritual of LP playback or even CD playback. That's fine, but it's just ritual, not love of music. It's a sort of worship of fine quality playback of music via the mechanisms and manual processes needed for such high-quality playback. Maybe that worshipful attitude helps to maintain the respect and importance one has decided that music deserves in one's life because of its value as art. On the other hand, such worship-like rituals tend to make music into an idol.

My own music collection is about 1200 discs, not small, but not very large as music lover collections go. I no longer have the means to play the discs back directly in my audio room. I keep them because they look nice on the shelves, fulfill some useful acoustic diffusion in my audio room, and also because the legalities of playback of the music ripped from CDs is still not terribly clear unless one still owns the CDs.

I have long received more joy from music which I don't directly program than from picking music from discs. I like to be at least somewhat surprised by the playback. Thus I like attending concerts of unfamiliar works, not familiar ones. Before internet days I listened to a lot of classical and jazz FM radio, professionally curated by experts in those genres so I could explore new music. I thus owned a string of the finest FM tuners available as well as serious over-the-air antennas. I did then, and still do, primarily enjoy music as a transitory event, something which washes over and through me for current pleasure. I am not one who primarily enjoys re-listening to musical favorites over and over or even periodically. Yes, there is pleasure in being able to anticipate and re-live familiar music, but for me not usually so much as hearing something new. I think most people feel this once-and-done way about most movies or other videos, but not music. For me, music is only somewhat more enjoyable on repeat playback, and usually something new would be my choice.

Once I acquired a Logitech Squeezebox Touch in 2010, I saw the handwriting on the wall. This streaming of music from the internet was the direction music sourcing and playback was headed. FM stations were now easily accessible on the internet and, with just a couple of local exceptions, usually in fidelity comparable overall to the multipath-ridden signals from over-the-air FM transmissions. And the choice of internet radio stations was almost instantly in the tens of thousands from all over the world, rather than the meager few available decent local FM stations available over the air in even the largest cities. Then my Squeezebox and Oppo players became Tidal compatible around 2015, just about the time I moved into my current home. From that point on, buying CDs really was pointless, at least for material available on Tidal. Now, with both Tidal and Qobuz offering true high-resolution digital playback, all the hard media arguably has now been equaled if not truly surpassed in terms of playback fidelity potential.

These days the hard media is useful to me only for acquiring music which I simply must have available on call. And given my continuing joy at being surprised by new music and new interpretations of music I already know, I buy very few discs. When I buy them, I immediately rip them to music files I can play through my streamer.
 

Salectric

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I have long received more joy from music which I don't directly program than from picking music from discs. I like to be at least somewhat surprised by the playback.
Same here. I am often captivated by hearing a piece on the radio that I have in my collection but haven't pulled out to play in many years.
 

tmallin

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Streaming Sonic Tweaks, IF You Want to Go There

Back in the 1970s Enid Lumley wrote columns in The Absolute Sound about various tweaks you could perform to your home's electrical system wiring, as well as your audio system wiring and set up which went further than most people believed was necessary. Many of these are preserved not only in the back paper issues of TAS from long ago but also in Laura Dearborn's Book, "Good Sound." No one really knew why a number of her suggestions could make a sonic difference, much less an improvement, but most guessed that any truth to the suggestions were related to reducing electrical noise such as RFI and EMI.

I was a believer, then and now. I have recently been experimenting with unplugging or turning off various things around the house to see if these acts affect the sound I hear on my streaming system. The answer is a resounding "YES!"

My first experiment is documented in posts #27 and #32 above, dealing with unplugging my old Sony clock radio with two-inch tall red LEDs for a display.

Shortly after that experiment, I discovered that unplugging the Temper ERGO adjustable platform under our king mattress also improved the sound.

Then I found that eliminating the ethernet connection to one of my two TVs also improved the sound. See post #36 above.

I've also recently found that disconnecting as many internet connected devices as possible from my Wi-Fi network progressively improves the sound. Items falling into this category include my Google Nest player, both TVs, iPhones, iPads, and iWatches. Where possible, disconnect these from Wi-Fi and then power them off.

This last finding even extends to the iPad I use to control my streaming system in my audio room. Once I have the program dialed in and the volume set, the sound takes another uptick when I actually shut down the Lumin App on the iPad (leaving the program playing through my Lumin X1 streamer/DAC, of course) and then power off the iPad.

Basically, the more household electronics you can disconnect from your home's electrical system and the internet, the better your streaming system will sound.

Items which don't seem to have much audible effect on streaming sound quality are generally those which we would classify as electrical, rather than electronic. Things like fans, refrigerators (not the smart kind), electric ovens, motors, pumps, and even air conditioners (other than the audible noise from air movement) don't seem to matter much in terms of whether they are on, off, or unplugged/disconnected from power, as in turning off the circuit breaker which powers them. Some exceptions are small charging devices such as those for an electric toothbrush, iPad, or iPhone. Incandescent light bulbs are fine, but watch out for fluorescent and LED lights and any kind of dimmer switches.

I wish this were not so! But such also was the case in my prior home twenty years ago when my audio system did not involve streaming at all. High frequency electrical noise pollution of our environment has become much worse in the interim of course with the proliferation of digital electronics of all kinds and our modern digital audio electronics apparently are no more immune to such interference and the tweaks which can reduce such interference than were prior CD-based systems. See post #32 above.

How far you want to take such tweaking is up to you. Just be aware that sonic improvements are possible, but that the degree of sonic improvement is in direct proportion to the annoyance or impracticality of implementing these tweaks.

The nature of the improvements I'm mentioning generally involves more apparent low frequency warmth and weight, smoother and more integrated high frequencies, blacker background, sharper image focus, a much greater sense of three dimensionality, continuity, solidity, and envelopment of the soundstage, as well as a perception of lowered distortion and greater clarity. I do not regard these as minor or particularly subtle effects. They were easily audible as sonic improvements and not just differences 20 years ago and just as, if not more audible, with my current streaming system.
 
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Salectric

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Streaming Sonic Tweaks, IF You Want to Go There

Back in the 1970s Enid Lumley wrote columns in The Absolute Sound about various tweaks you could perform to your home's electrical system wiring, as well as your audio system wiring and set up which went further than most people believed was necessary. Many of these are preserved not only in the back paper issues of TAS from long ago but also in Laura Dearborn's Book, "Good Sound." No one really knew why a number of her suggestions could make a sonic difference, much less an improvement, but most guessed that any truth to the suggestions were related to reducing electrical noise such as RFI and EMI.

I was a believer, then and now. I have recently been experimenting with unplugging or turning off various things around the house to see if these acts affect the sound I hear on my streaming system. The answer is a resounding "YES!"

My first experiment is documented in posts #27 and #32 above, dealing with unplugging my old Sony clock radio with two-inch tall red LEDs for a display.

Shortly after that experiment, I discovered that unplugging the Temper ERGO adjustable platform under our king mattress also improved the sound.

Then I found that eliminating the ethernet connection to one of my two TVs also improved the sound. See post #36 above.

I've also recently found that disconnecting as many internet connected devices as possible from my Wi-Fi network progressively improves the sound. Items falling into this category include my Google Nest player, both TVs, iPhones, iPads, and iWatches. Where possible, disconnect these from Wi-Fi and then power them off.

This last finding even extends to the iPad I use to control my streaming system in my audio room. Once I have the program dialed in and the volume set, the sound takes another uptick when I actually shut down the Lumin App on the iPad (leaving the program playing through my Lumin X1 streamer/DAC, of course) and then power off the iPad.

Basically, the more household electronics you can disconnect from your home's electrical system and the internet, the better your streaming system will sound.

I wish this were not so! But such also was the case in my prior home twenty years ago when my audio system did not involve streaming. Electrical noise pollution of our environment has become much worse in the interim of course and our modern digital electronics apparently are no more immune to such tweaks than were prior CD-based systems. See post #32 above.

How far you want to take such tweaking is up to you. Just be aware that sonic improvements are possible, but that the degree of sonic improvement is in direct proportion to the annoyance or impracticality of implementing these tweaks.

The nature of the improvements I'm mentioning generally involve more apparent low frequency warmth and weight, smoother and more integrated high frequencies, blacker background, sharper image focus, a much greater sense of three dimensionality, continuity, solidity, and envelopment of the soundstage, as well as a perception of lowered distortion and greater clarity. I do not regard these as minor or particularly subtle effects. They were easily audible as sonic improvements and not just differences 20 years ago and just as, if not more audible, with my current streaming system.
That’s certainly been my experience as well. Unplugging unnecessary equipment from wall outlets often results in improved sound quality. One of my first experiences with this was when I set up my new Loricraft record cleaner in the music room. After cleaning a few records I sat down to listen and something was really wrong with the sound. Long story short—simply having the Loricraft power cord plugged into a wall outlet on the opposite side of the room messed up the sound. Unplugging it restored the sound to normal.

The practical implications of this for me are that I unplug everything from the music room outlets except the devices actually in use. When I listen to records, the DAC and transport are unplugged from the wall. I don’t have the same control over items in other rooms but that’s something to investigate in the future.
 

tmallin

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I don't believe that there are any more new Graham Audio LS8/1 Signature Edition pairs left for sale. I have not heard the non-signature edition so I cannot say how close it is sonically to the Signature Edition or even whether there is any sonic difference at all. At the time of sale I was told by my dealer Gene Rubin that the Signature Edition was made of different wood, by more skilled craftsman in Italy as opposed to China or England where the non-Signature version was being sourced. I have not checked with Graham to verify this.

What I do know is that several months on now, I'm still as impressed with and captivated by the Signature Edition LS8/1s as I was at the very first. Further set-up tweaks described in my prior posts have only served to make the speakers sound yet more impressive.

I'm more and more convinced that a good part of the magic of these speakers is the lack of a crossover between the low-end roll-off and 3.5 kHz. Most of the sound comes from a single driver, yielding great coherence/of-a-piece-ness to the sound. This feature probably also plays a big part in the perceived clarity and absence of distortions or "electronic" sound. It's also probably primarily responsible for how "solid" the stereo is from this pair of speakers. On good stereo recordings, the sense of a large solid block of space extending from well behind the speakers to well outside the left and right positions of the speakers, as well as coming forward from the speakers and actually enveloping and surrounding the listening position is unprecedented in my experience from a two-channel rig and actually sounds more realistic in terms of 3-D envelopment than most multichannel surround systems.

But unlike speakers where all the sound comes from a single driver or coaxial drivers, there are tweeters above the bass/midrange driver and that gives the soundstage an excellent sense of height and size while maintaining excellent image focus. Sure, a panel speaker like the Sanders 10e I used before these also yields a large soundstage, but by comparison with the Grahams there is a bit of blurring of soundstage dimensions and image focus with the Sanders.

Surely another major factor in their perceived excellence is the extremely accurate sounding tonal balance and lifelike timbre and dynamics. Instruments and voices sound like the real unamplified thing to an unprecedented degree. The Grahams reign supreme in my experience at differentiating among recordings in terms of tonal balance realism, soundstage shape and size, and image focus, as well as perceived micro and macro dynamics. You have to hear these effects to believe that statement, I'm sure, but that's what I hear.

In addition, there is never any "cringe" factor to their sound. Most likely the lack of narrow resonances noted by REG in his review is at play here. Pianos and vocals are just "there," hanging in space and completely free of artifice or unnatural transient edge, grit, or crunch.

In the coming months I may try to gild the lily a bit by swapping my 225-watt Van Alstine DVA M225 monoblock amps for the big brother 750-watt DVA M750. The size and weight of that big brother is still manageable for me and reports indicate that the added power does in fact result in better-yet sound. I hesitate only because I really hear no problems at all which I could lay at the feet of marginal power reserves in the DVA M225s I've been using from the start of my experience with the Grahams. But maybe the extra power reserve is one of those things that you can only appreciate once you hear it.

As I've said before, I'm aware that these speakers do not fully flesh out the bottom octave. But the bass extension and balance is so cannily chosen that in my small room I really don't hear the deficiency, even on orchestral power music or modern electronic music which relies on subterranean bass lines. The bass is always detailed, punchy, solid, deep and awesomely throbbing when appropriate.
 
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tmallin

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More About Speaker Stands for the Graham LS8/1

I discussed my chosen Skylan SKY-24 speaker stands in post #24 above. Understandably, however, some may prefer to use Graham's own metal stands. These came with the Signature Edition of the speakers and are optionally available from Graham for use with the non-Signature version.

At the time I ordered my Skylan stands, Noel Nolan had 30 cm x 30 cm top plates in stock. Those fit the LS8/1 perfectly as you can see from my pictures. I imagine he usually has those in stock since that is a common size to approximately fit many British stand-mounted speakers from Harbeth, Spendor, Graham, Wharfedale, etc.

My Graham metal stands are in storage in my attic and are not easily accessible to measure their height. I opened the box, looked at them, determined just by looks that they were too short, and put them in storage. I did not measure them.

If you wanted to use the Graham metal stands but increase their effective height, one way to do that would be to use taller aftermarket feet under the base rather than the stock spikes. You could also do that in combination with mounting the stands on some sort of thick wooden plinth. Harbeth recommends granite slabs for use with the Tontrager stands they recommend, so that might be another possibility for a plinth.

As to taller accessory feet for the metal stands, you would need to determine the size of the bolt holes and their threading to get a match. Possible choices of feet include, among others:

https://www.moon-audio.com/isoacous...ion-1.html?sku=Isoacoustics_Gaia_III-SI&nis=6

or the Missing Link feet described at the below link and meant for use with metal stands similar to that supplied by Graham (the Something Solid XF MkII):

https://www.decoaudio.com/deco_audio_feet.html

To increase the height of the metal stands at the top plate, you would have to mount an accessory top plate atop the four little carbon or metal tips at the top of the stand. If you are going to do that, you might as well get the Skylan stands instead since the only possible reason to use the metal stands is to provide the apparently intended open air space beneath the speakers. Putting a solid plinth atop the metal stand would defeat that design feature.
 

tmallin

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About Face: Using the Graham Stands with the Graham LS8/1 Speakers

Well, you should have at least tried that first, you're saying! Yes, you're correct. But I didn't. In my initial view, placing the speakers on stands which at 20 inches tall was necessary to sit comfortably in my regular Drexel overstuffed chair while putting my ears on axis with the lower tweeter, as clearly sounds best with these speakers, and which is the axis endorsed by Derek Hughes, the designer. The 4.25-inch taller Skylan SKY-20 stands I was using shouldn't work to the sonic detriment of the presentation, I thought.

I only got around to trying the OEM stands because a friend also bought these speakers and is thrilled with their sound on the Graham stands. At first he was tilting the stands back a bit, something I did not want to do for the reasons I've explained before. But now he purchased a new chair which is very low and gets his ears at the right vertical position, even with the lower tweeter, without tilting the stands back at all.

When mounted on the Graham stands (which are 15.75" or 400 mm tall without spikes or bumpers on top--just the metal part of the stand), when I include the little rubber bumpers (about 1/8" high) and a few felt pads beneath the base of the stands to level them, the center of the lower tweeter is about 34 inches above the carpet.

My own Drexel chair can get my ears that low if I take the seat cushion out. The seat cushion can be used as the back cushion if I want to sit most erect, or I can continue to use the back cushion for a bit more recline and less cushion near my ears (a good thing). I've used this Drexel chair many times before without sitting on the seat cushion with low floor-standing speakers, such as all the Gradient models. The chair isn't as comfortable that way since the seat is a little harder without the seat cushion and it's harder to get out of the chair, but that's a low chair for you.

Anyway, I bit the bullet and set up the speakers on the Graham stands. The supplied spikes are too short to both pierce my carpet and level the speakers on the floor. It's an old house and the floor is not exactly level. I'm using the supplied 1/8-inch-high rubber bumpers Graham supplied as the interface between the speaker bottom corners and the stands. I'm using one or more thicknesses of furniture padding felt (1-inch squares) under the corners of the stands to level the top of the speakers front to back and side to side.

Not the most rock-solid mounting, but I've most always preferred to "float" speakers atop carpet rather than spiking the stands to the floor. "Floating" minimizes nasty high frequency resonances from ringing metal stands and bass resonances from the floor. The bit of sway that can be induced in the speakers if nudged is of a very low "you can count the cycles" frequency. This "spring" mounting thus filters out all vibrations through the stand at frequencies in the audio range, 20 Hz and above, which is well above the sway-frequency resonance of just a very few cycles a second. (For a thorough treatment of spring theory as applied to audio equipment isolation and resonances, see the wonderful old treatise by Shannon Dickson in Stereophile, "Bad Vibes.")

So how does the sound of the Graham LS8/1 speakers on the OEM Graham stands compare to what I was getting with the speakers on my 20-inch-tall Skylan stands? As wonderful as the Graham speakers sounded on the Skylans, I now have to admit that Graham has it right: the speakers sound even more wonderful on the lower Graham stands!

There seems to be "more meat on the bone" with the lower stands. The overall balance is tilted a meaningful bit toward the lower ranges, perhaps because of less harmful floor bounce cancellation in the power range (100 to 300 Hz, say), which is helpful in my set up to my ears. This was clearly audible even before dialing in the speaker positioning in the ways I described earlier in this thread; see especially posts #11 and #12. Everything else about the tonal balance seemed about the same, which is good, and the focus and staging were already excellent, even before dialing things in.

After dialing in the speaker positioning, the imaging and staging achieved new levels of spectacularity. Thus, the Graham stands improved not only the perceived frequency balance, but also all the spatial aspects of the music! In addition, the sense of clarity and seeming lack of distortion further improved.

Keep in mind that only the speaker stands and seat cushion changed in this comparison. Everything else about the equipment and set-up stayed the same.

How much of the sonic change resulted from "correcting" the height of the woofer/port with respect to the floor, how much resulted from eliminating the top plate of the speaker stands so that the bottoms of the speakers are freer to vibrate, and how much resulted from the 4.25-inch change in my listening height with respect to the floor and ceiling, I do not know. I do note that a listening height of 34 inches is close to 1/3 the distance between the floor and ceiling of my listening room (the room is 103.5 inches high). The 1/3 position may more equally represent to my ears the floor-to-ceiling room modes in the lower frequencies. See the 1/3 position (labeled "B") in the attached chart of the first eight axial room modes.

In any event, my new recommendation, if your sitting comfort can accommodate it, is to sit with your ears at 34" above the floor when using these speakers and to use the LS8/1s on the Graham 400 mm/15.75-inch-high stands. If you don't mind "looking down" a bit on the soundstage--as if from the balcony at a concert hall--then you could try a more comfortable, higher chair and angle the speaker stands back a bit to aim the lower tweeters directly at your ears.

Note that while the Signature Edition of the Graham Audio LS8/1 speakers came with these Graham stands, the stands must be purchased separately from Graham if you buy the non-Signature Edition of the speakers. IMG_9783.jpg IMG_9782.jpg

STANDING WAVE MODES.JPG
 
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jonstine

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Audio by Van Alstine DVA M750 Amps Replace DVA M225 Amps

As one of the photos in the immediately prior post shows, I have also decided to replace the Audio by Van Alstine (AVA) DVA M225 amps I was using in this system with their big brothers, the AVA DVA M750 amps. The new amps are much larger, heavier and, at 750 watts per channel, much more powerful than the 225 watt DVA M225.

The amps I was using were no slouch in terms of power for these Graham LS8/1 speakers and are surely entirely adequate, you say. Yes, I thought that as well and I heard nothing which I thought was indicative of inadequate reserve power. The system sounded spectacular with them, as I've said.

But sometimes you don't know what you're missing until you hear it. That was the case with this substitution.

The new larger amps do all the excellent things the smaller ones did but seemingly add more grunt to the low end and overall yet more clarity and seemingly reduced distortion. What I thought were just minor speaker limitations (e.g., the lack of a big woofer and big cabinet) in terms of forcefulness and energy turn out to be limitations of the smaller amps. The LS8/1s now sound majestic even with the most demanding recordings. The low end is just as full as before in the power range (100 to 300 Hz), but the bottom octaves are stronger, punchier/more impactful, and better defined. There is, as one might expect, an overall increase in the "ease" of the reproduction since the larger amps are just coasting along to an even greater extent. The background seems yet a bit blacker, which was already a strong point of the smaller amps.

Here's how a reviewer of the DVA M750 amps on the AVA Audio Circle site well described one aspect of the presentation--increased energy: :



See more comments from this reviewer on this page: https://www.audiocircle.com/index.php?PHPSESSID=gsbjcq9396s4p9qvs4hpb6mst2&topic=187104.0

I don't believe any of the yet-published reviews of the AVA DVA M750 amp have compared it directly with its smaller sibling. I think I'm the first to comment on this comparison.

The DVA M225 is by no means sonically embarrassed by the comparison, but the DVA M750 does sound better, even in the context of the rather "small" Graham Audio LS8/1 speakers. If the DVA M750 is a "10" on the sonic scale with the LS8/1, then I'd rate the smaller DVA M225 as an "8.5" or even "9" on that scale as a mate for the Graham LS8/1 speakers. The price difference is substantial: $5,600 a pair for the larger amps vs. $3,400 a pair for the smaller ones. Only you can decide whether the larger amps are "worth it" to you. They definitely are "worth it" to me, but then I'm a bit or more of a perfectionist. :)

The DVA M750 does push the limits of what I can accommodate in the context of my downsized system goals. They are much larger and heavier than their smaller siblings. But they are still a bit smaller and quite a bit lighter than the Sanders Magtech amps I was using with the Sanders 10e speakers.

While the amps look basically the same except for size, I'd call the DVA M225s "cute" while the DVA M750s are "handsome."

I kept the smaller DVA M225s from direct contact with the carpet by placing them atop a pair of Bright Star Audio Little Rocks which rested flat against the carpet. Those Little Rocks are a bit too small to support the larger footprint of the DVA M750s. I have the larger amps sitting on a pair of 17" x 14" Butcher Block Acoustics 1.5-inch-thick solid maple platforms, which are themselves "handsome," I think. Again, as with the Little Rocks, these maple platforms float directly atop the carpet, with no accessory feet or spikes. The stock amp feet in both cases directly rest on the platform.

When I first unboxed the new larger amps, I noticed that the top of the chassis and heatsinks seemed to ring substantially more when tapped than the smaller chassis and heatsinks of the DVA M225. I thought I might have to place a magazine (this is the highest and best use of old issues of The Absolute Sound, I think) centered atop each chassis to damp the ringing. However, after placing the amps atop the maple platforms and allowing them to heat up to their still only slightly warm to the touch normal operating temperature, the ringing went away. Odd in my experience, but welcome.
I purchased a pair of DVA M750 monos a couple weeks ago. Should be here this weekend. I am looking forward to hearing how they sound, especially since I’ve been following your journey with the M225’s and now the M750s.

Thank you for the updates! I’ll post with impressions as soon as possible. Replacing a modded Jolida JD502B with some way too expensive NOS tubes!
 

Tim Link

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My first thought about these speakers is that 3.5 kHz seems really high for an almost 8" woofer. That said, I've experimented with pushing a 10" woofer that high and it sounded surprisingly natural. The response was smooth on my 10 to almost 6kHz, but of course it gets very directional at those frequencies. Still, at 3.5 kHz it sounded natural but dry. Worked well for orchestral recordings. Overall I like more dispersion in the midrange, so I'm now crossing it at 1.2 kHz to a waveguide, and that's providing the kind of presence and energy in the room that I enjoy more with most music. The LS8 might have wider dispersion than I think because I've been told that some of these woofers can decouple the center from the edges at higher frequencies, causing them to maintain a more constant dispersion.
 

tmallin

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The 3.5 kHz crossover, as I've mentioned in previous posts in this thread, is pretty standard in this sort of BBC-inspired monitor. It was there in the Spendor BC-1 and all the later derivatives designed by Derek Hughes, including the Spendor SP1/2 and the Stirling Broadcast LS3/6 which I owned in the past. It is also present in the original Harbeth SLH5 and subsequent variations to the present day.

As I've expressed in prior threads, I believe this relatively high initial crossover is to a great extent responsible for the feeling of hearing the coherence of a single driver system, but without the vertical smallness usually imparted by coaxial designs. The presence of tweeters above the bass/mid driver adds an impressive amount of size and height to the presentation.

Yes, a lower crossover or more traditional three-way design (e.g., a system with a woofer, midrange, and tweeter, rather than a woofer/mid and two tweeters as in the LS8/1) might result in broader horizontal dispersion. Despite the desirability of broad horizontal dispersion in some audio circles, in my experience, and especially in rooms which, like mine, are not very wide, wide horizontal dispersion in the treble is NOT an advantage. The audibility of reflections from the side walls needs to be minimized for best imaging and staging anyway, and wide dispersion up top just makes this more difficult. The narrowing dispersion of this 3.5 kHz crossover design at the top of the woofer band makes absorbing the wall reflections in the mid-treble easier. While the Graham design does not have an on-axis depression in this presence range, the off-axis depression helps with creating a sound field that is more "out there" in terms of depth perception. As you noted, this is very helpful with orchestral and indeed most other classical and acoustic music reproduction.

"Dry" is definitely NOT a description I would apply to the Graham LS8/1 or any of its predecessors, at least as I have had them set up in my listening room. The apparent "wetness" of the recorded ambient field from this sort of design needs to be heard to be appreciated. The imaging, staging, and feeling of envelopment from a two-channel stereo set up with the Grahams are the best I've ever achieved in my room. The presentation is true to the meaning of "stereo" as "solid" and is that way not only for the very best classical orchestral recordings, but also for a very wide array of commercial recordings ranging from classical to electronic.
 
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Tim Link

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Despite the desirability of broad horizontal dispersion in some audio circles, in my experience, and especially in rooms which, like mine, are not very wide, wide horizontal dispersion in the treble is NOT an advantage. The audibility of reflections from the side walls needs to be minimized for best imaging and staging anyway, and wide dispersion up top just makes this more difficult. The narrowing dispersion of this 3.5 kHz crossover design at the top of the woofer band makes absorbing the wall reflections in the mid-treble easier.
That makes a lot of sense. I've got my system playing on the long wall now so that might explain why I'm going for the wider treble dispersion at the moment. Also I'm using an unusual set up for 2 channel playback that involves 3 speakers upmixed in a crosstalk reducing array, all right next to each other in the middle of the room. The outside speakers tweeters end up about 9 feet from the side walls. I've taken all the absorption off the sidewalls for now because I think those reflections are delayed enough that they are doing more good than harm.
 

Tim Link

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I agree there's something about the coherence from the 3.5kHz crossover. The other way around is to get it down near 1kHz or lower with a waveguide. I have some 1" throat waveguides that I was able to load all the way down to 600Hz with good results, and that's without a baffle. Those have a narrower dispersion and sounded really nice mated up to a mid-woofer horn. In some ways I think that might have been the best sound I've achieved yet. I think I should try using them with 15" woofers, as they were intended to fit snugly against. Next year's project. I may also try some smaller direct radiators pushed up to 3.5kHz. The 10" woofer is a bit much for that. I've had great luck in the past with a 4" woofer at 3.5kHz. It's interesting I ended up at that number. I tried making the speaker a 3 way with a 2" dome midrange. That sounded very solid and could play really loud, but just going with a 2 way with 3.5 kHz was more pleasing overall.
 

Tim Link

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"Dry" is definitely NOT a description I would apply to the Graham LS8/1 or any of its predecessors, at least as I have had them set up in my listening room.
To clarify what I mean by "dry", it's just a cleaner, more direct sound with less perceived midrange and upper midrange reverberance from the room. Not to be confused with a lowered on-axis response in that range, which my experience tells me I will likely find objectionable.
 
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tmallin

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I purchased a pair of DVA M750 monos a couple weeks ago. Should be here this weekend. I am looking forward to hearing how they sound, especially since I’ve been following your journey with the M225’s and now the M750s.

Thank you for the updates! I’ll post with impressions as soon as possible. Replacing a modded Jolida JD502B with some way too expensive NOS tubes!
I deleted my post about the DVA M750 monos. These have been returned. A few days after I wrote that post, both amps developed hum through the speakers which got progressively more audible/louder until it was clearly audible from the listening position. My efforts to cure the hum problem were totally ineffective. Odd, because the M225 monos were totally hum and noise free for the five months I used them and the M750s were drop-in replacements for the M225s. Nothing else changed in my system or its set up.
 
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jonstine

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I deleted my post about the DVA M750 monos. These are being returned. A few days after I wrote that post, both amps developed hum through the speakers which got progressively more audible/louder until it was clearly audible from the listening position. My efforts to cure the hum problem were totally ineffective. Odd, because the M225 monos were totally hum and noise free for the five months I used them and the M750s were drop-in replacements for the M225s. Nothing else changed in my system or its set up. I will return to the M225s, at least for now.
Interesting… I had a very slight hum from one of the DVA 750s as well. It actually came from the amp chassis, but didn’t present in the speaker it was connected to. I was using the original, provided AC power cord (a new Cardas was on order but hadn’t arrived yet). Once I swapped to a higher end, much more insulated AC cable all hum disappeared completely.

Sorry you had that issue. Not sure if it could have been resolved with different AC cords or not, but my pair are hum free now and sound FANTASTIC at about the 100hr mark. Very pleased with them!
 

tmallin

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I'm glad you were able to solve your hum problem. The transformers in my pair of 750s also hummed some, sometimes more, sometimes less. But my main problem was hum audible through the speakers. My efforts to solve the problem included a different power cord (admittedly nothing fancy, just the stock cord in place of my usual after-market cord) and attempting to interrupt any ground loop by plugging everything into a single outlet/dedicated circuit. None of my efforts appreciably affected the hum level through the speakers. Even with the input balanced cables disconnected from the amps, with all the other equipment turned off, the amps hummed the same way and same amount.
 
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tmallin

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Back to Benchmark AHB2 Amps

For the first time in the history of my audio hobby, I have purchased an amplifier for the second time. A few years ago, in my current listening room, I used a pair of Benchmark AHB2 solid state amps, bridged for mono operation with first my Harbeth M40.2 speakers and then my Gradient 1.4 speakers.

I sold that pair of Benchmark AHB2 amplifiers when I moved to active speakers, the Dutch & Dutch 8c, and later did not need separate amps with my Sanders 10e speakers since the speakers came with one Sanders Magtech amp and I logically purchased another to fill out the biamplified amplification needs of the 10e speakers. I sold both the Sanders amps as part of the sale of the Sanders speakers.

My recent experience with the 750-watt-per-monoblock Audio by Van Alstine AVM M750 amps showed me that I'm a power snob. While the smaller Van Alstine AVM M225 (225 watts per monoblock) sounded great in isolation with my Graham LS8/1 Signature Edition speakers, having heard the more powerful M750 made audible for the first time with these speakers the sense of unlimited power reserves which comes with yet more power on tap. However, while these amps sounded yet better than their smaller siblings, in my system they made way too much noise through the speakers--mostly hum--to be tolerated long term. Thus, I returned the M750s for a refund. As jonstine's comments above and elsewhere on WBF suggest, this noise problem with the M750s may be just a peculiarity of my set up.

Very few amps are truly silent in terms of quiescent hum and noise, in my experience. Usually, with no music playing, if I put my ear an inch or two from the drivers I can hear some noise. I forgive such noise as long as it is inaudible from the listening position, which, in my case is some 55 inches from the drivers.

Thus, my goal in replacing the Van Alstine DVA 750 amps was to acquire amps which provided a similar "endless power" sensation, while still being silent, both in terms of audible chassis hum and audible hum, hiss, or other noise through the speakers.

I know that the powerful Sanders Magtech amps usually are not silent enough. When I once used them with my Harbeth M40.1 speakers in another room of my house, I could hear hiss from several feet in front of the speakers. However, they work in a noise-free manner as part of the Sanders 10e system where they are combined with the dbx VENU360 Loudspeaker Management System. That unit can very effectively act as an input gain control for the power amps, providing, as it does, analog domain controls for both input gain and output voltage. Thus, the dbx can easily lower the effective gain of the Sanders amps so that hiss normally audible through the speakers is silenced. Part of proper gain structuring of a professional audio system is using high gain sources, together with a gain control/volume pot or pad at the amplifier input to allow the gain of the amps to be turned down to just a few dB. This lowers the noise and increases the signal to distortion and noise audio throughput of the system. The Sanders system is unusual among consumer audio systems in allowing for this sort of gain structuring.

The Benchmark Media company, having a foot in both the pro audio and consumer audio camps, provides a gain control switch on its AHB2 amps. In its lowest gain position the AHB2 amps have the truly low gain which ensures compatibility with the high source voltages used in pro-audio system. At this setting the amps require 9.8 volts input for rated output power. While my Lumin X1's rated output is only 6 volts, I know from my prior experience with this combination that the low gain setting goes loud enough with all source material in my room, as well as sounding best and providing the absolute least quiescent noise from the speakers. See my comments on this arrangement here. The Benchmark amps are extraordinarily quiet with any setting of the input gain switch. I hear no transformer hum from the amp chasses with my ear closer than inch from each chassis. And in their low gain setting, I hear absolutely no hum, hiss, or other noise from any of the speaker drivers even with my ear on axis with any of the speaker drivers and within an inch of the speaker grill cloths. This applies for any setting of the Lumin X1's Leedh-processed digital volume control.

My sonic evaluation of the Benchmark AHB2 amps is unchanged since I last used them. If anything, system improvements in the interim have only further revealed their level of sonic refinement in terms of perceived lack of background noise, clarity, lack of distortion, immense sense of power reserves, lack of coloration, three-dimensionality, envelopment, etc. See my 2018 discussion of the AHB2 sonics here.

In the years since its introduction, some, while acknowledging its matchless specs in terms of low noise and distortion combined with remarkable power output given its small and light form factor, have criticized the Benchmark AHB2's sonics by saying it is lacking in macro dynamic swings. I hear this, but I hear it differently and hear it as a plus for the Benchmark. The Benchmarks lack the overblown-sounding midbass of some other amps which can provide a sense of greater dynamic power. It also lacks the ultimate degree of "splash" on large transients which some interpret as a dynamic limitation. I think this "splash" is actually caused by a blast of slightly distorted sound in the higher frequencies. The Benchmark is ever precise, controlled, and clean, clean, clean, which amounts to "beautiful" sound in my book. Likewise, the Benchmark midbass is fully ample and certainly not lean in any way, just more controlled and defined/less distorted. This "uncovers" the Benchmark's lower bass, revealing more detail, definition, and power in the bottom two octaves.

In terms of size and weight, as well as cool running, the Benchmark AHB2 is roughly equivalent to the Audio by Van Alstine DVA M225. The form factor is a bit different, that's all. The AVA is narrow and deep. The Benchmark is wider and less deep. They are both easy to carry and fit well within my "downsized" system form factor goals. However, the Benchmark AHB2s, used in bridged mono, give that "limitless" power impression, whereas the AVA does not. And while the AVA is quiet enough running, the Benchmarks have noticeably more silent backgrounds. The AHB2 are, for all practical purpose, absolutely silent runners, totally concealing the vast power on tap.
 
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jonstine

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Back to Benchmark AHB2 Amps

For the first time in the history of my audio hobby, I have purchased an amplifier for the second time…

I
Back to Benchmark AHB2 Amps

For the first time in the history of my audio hobby, I have purchased an amplifier for the second time. A few years ago, in my current listening room, I used a pair of Benchmark AHB2 solid state amps, bridged for mono operation with first my Harbeth M40.2 speakers and then my Gradient 1.4 speakers.

I sold that pair of Benchmark AHB2 amplifiers when I moved to active speakers, the Dutch & Dutch 8c, and later did not need separate amps with my Sanders 10e speakers since the speakers came with one Sanders Magtech amp and I logically purchased another to fill out the biamplified amplification needs of the 10e speakers. I sold both the Sanders amps as part of the sale of the Sanders speakers.

My recent experience with the 750-watt-per-monoblock Audio by Van Alstine AVM M750 amps showed me that I'm a power snob. While the smaller Van Alstine AVM M225 (225 watts per monoblock) sounded great in isolation with my Graham LS8/1 Signature Edition speakers, having heard the more powerful M750 made audible for the first time with these speakers the sense of unlimited power reserves which comes with yet more power on tap. However, while these amps sounded yet better than their smaller siblings, in my system they made way too much noise through the speakers--mostly hum--to be tolerated long term. Thus, I returned the M750s for a refund. As jonstine's comments above and elsewhere on WBF suggest, this noise problem with the M750s may be just a peculiarity of my set up.

Very few amps are truly silent in terms of quiescent hum and noise, in my experience. Usually, with no music playing, if I put my ear an inch or two from the drivers I can hear some noise. I forgive such noise as long as it is inaudible from the listening position, which, in my case is some 55 inches from the drivers.

Thus, my goal in replacing the Van Alstine DVA 750 amps was to acquire amps which provided a similar "endless power" sensation, while still being silent, both in terms of audible chassis hum and audible hum, hiss, or other noise through the speakers.

I know that the powerful Sanders Magtech amps usually are not silent enough. When I once used them with my Harbeth M40.1 speakers in another room of my house, I could hear hiss from several feet in front of the speakers. However, they work in a noise-free manner as part of the Sanders 10e system where they are combined with the dbx VENU360 Loudspeaker Management System. That unit can very effectively act as an input gain control for the power amps, providing, as it does, analog domain controls for both input gain and output voltage. Thus, the dbx can easily lower the effective gain of the Sanders amps so that hiss normally audible through the speakers is silenced. Part of proper gain structuring of a professional audio system is using high gain sources, together with a gain control/volume pot or pad at the amplifier input to allow the gain of the amps to be turned down to just a few dB. This lowers the noise and increases the signal to distortion and noise audio throughput of the system. The Sanders system is unusual among consumer audio systems in allowing for this sort of gain structuring.

The Benchmark Media company, having a foot in both the pro audio and consumer audio camps, provides a gain control switch on its AHB2 amps. In its lowest gain position the AHB2 amps have the truly low gain which ensures compatibility with the high source voltages used in pro-audio system. At this setting the amps require 9.8 volts input for rated output power. While my Lumin X1's rated output is only 6 volts, I know from my prior experience with this combination that the low gain setting goes loud enough with all source material in my room, as well as sounding best and providing the absolute least quiescent noise from the speakers. See my comments on this arrangement here. The Benchmark amps are extraordinarily quiet with any setting of the input gain switch. I hear no transformer hum from the amp chasses with my ear closer than inch from each chassis. And in their low gain setting, I hear absolutely no hum, hiss, or other noise from any of the speaker drivers even with my ear on axis with any of the speaker drivers and within an inch of the speaker grill cloths. This applies for any setting of the Lumin X1's Leedh-processed digital volume control.

My sonic evaluation of the Benchmark AHB2 amps is unchanged since I last used them. If anything, system improvements in the interim have only further revealed their level of sonic refinement in terms of perceived lack of background noise, clarity, lack of distortion, immense sense of power reserves, lack of coloration, three-dimensionality, envelopment, etc. See my 2018 discussion of the AHB2 sonics here.

In the years since its introduction, some, while acknowledging its matchless specs in terms of low noise and distortion combined with remarkable power output given its small and light form factor, have criticized the Benchmark AHB2's sonics by saying it is lacking in macro dynamic swings. I hear this, but I hear it differently and hear it as a plus for the Benchmark. The Benchmarks lack the overblown-sounding midbass of some other amps which can provide a sense of greater dynamic power. It also lacks the ultimate degree of "splash" on large transients which some interpret as a dynamic limitation. I think this "splash" is actually caused by a blast of slightly distorted sound in the higher frequencies. The Benchmark is ever precise, controlled, and clean, clean, clean, which amounts to "beautiful" sound in my book. Likewise, the Benchmark midbass is fully ample and certainly not lean in any way, just more controlled and defined/less distorted. This "uncovers" the Benchmark's lower bass, revealing more detail, definition, and power in the bottom two octaves.

In terms of size and weight, as well as cool running, the Benchmark AHB2 is roughly equivalent to the Audio by Van Alstine DVA M225. The form factor is a bit different, that's all. The AVA is narrow and deep. The Benchmark is wider and less deep. They are both easy to carry and fit well within my "downsized" system form factor goals. However, the Benchmark AHB2s, used in bridged mono, give that "limitless" power impression, whereas the AVA does not. And while the AVA is quiet enough running, the Benchmarks have noticeably more silent backgrounds. The AHB2 are, for all practical purpose, absolutely silent runners, totally concealing the vast power on tap.
@tmallin, congratulations on finding the right sound for your system! I’m sure the Benchmarks sound exceptional based on your description above.

I wanted to return to this thread with an update on my AVA DVA M750 amps. I won’t post anymore on this thread after this unless it is relevant to the conversation, as my intent is not to hijack it with my thoughts on my system. I merely wanted to give an update on the amps after approx. 200 hrs of use…

Two things occurred recently that are noteworthy. Around the 150hr mark, I felt that the sound from the M750s was slightly thin. Highs were great, everything was clean, powerful, and dynamic, but they sounded more “solid state” and clinical than they did previously to me. So I ordered 2 SR Purple fuses (12.5A fast blow large), and inserted them. I listened to them for a few days, and felt like nothing really changed.

I flipped their orientation a couple days ago, and turned them back on. What an immediate change! There was a new warmth and thickness to the presentation that had been lacking prior to reversing them. My wife, who has a great ear for changes and who regularly listens to music with me, commented immediately that the music sounded more silky and warm. I know many folks fall in the camp of “that’s ridiculous”, but she had no idea I put in SR Purple fuses, or that I had reversed them, and noticed the difference immediately.

The 2nd thing that occurred was the addition of Rockwell XLR -10db attenuators. My Lampi TRP 3 DAC (with preamp/volume control) puts out a high enough voltage that anything above -35db on the Lampi volume (-63db to 0db range) was really loud through the M750s. My speakers are 87db efficient and even at -35db most music was crazy loud in my extra large room.

With my previous 70w/ch tube amp, the Lampi could be pushed to -25db easily, and depending on music type (DSD Jazz for example) as high as -10db. Dialing up the Lampi that high previously I noticed several changes in sound quality. Essentially, the Lampi seemed to wake up at around -30db, again at -24db, and slightly more around -12 to -10db. Based on those higher voltage outputs being in the Lampi’s sweet spot, I ordered the Rockwell XLR -10db attenuators and inserted them yesterday.

Another significant change! I can now turn up the Lampi to -30db comfortably, going as high as -10db through the M750s. That clearly is closer to unity gain for the Lampi, and the overall presentation now has more dynamic range, the soundstage is wider and taller, and the highs really shimmer. Case in point are several songs on Brad Dutz’s Random Excitement album (CD transfer to 24/96 FLAC) where the cymbal hits are crystal clear, startling high pitched, and you can almost see them vibrating in the space in front of you after the strike. The strikes on the toms are textured and much more complex. I’d never experienced either of those before the attenuators.
 

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