KeithR's "Dream Speaker" Search

[microstrip]

I was scanning the thread to see if the very simple and dispositive issue about the low sensitivity of the ARC 160M input stage had yet been mentioned.

The subjective discussion about the sonic inadequacy of the ARC 160M is obviated by focusing on this objective specification. With double the number of tubes per channel compared to Keith's REF75SE, according to ARC specifications, the gain of the 160M exceeds the gain of the REF75SE by only .5dB. So with essentially the same gain, and with half the input sensitivity, it is predictable that the 160M will not sound as good on the YGs as even Keith's REF75SE.

The 160M's low input sensitivity (and where is what should be almost a 3dB increase in gain hiding?) should have made the 160M a nonstarter for Keith's application.

People are misunderstanding gain and sensitivity effects in Keith system. As far as I see it the main difference in his new system is the speaker sensitivity and impedance - the gain of both ARC amplifiers referred is very similar.

We could probably predict that the REF75 could not drive the YG's, but apparently no technical aspect on his system precludes the use of his TVC preamplifier with the ARC REF160. However, due to the lower speaker sensitivity the preamplfier is probably being operated at higher gain, something that increases significantly the load on the source component - it is one of the drawbacks of some passives, their are not a constant load as active ones. This is just my guess, probably Keith will tell us what steps he is using in the TVC.

Speaker sensitivity affects the whole chain, not just the amplifier.

 

[moby2004]

As an YG owner myself ( Sonja 2.2 and had Sonja 2.3 during 4 months) , I can jump in . I tried five different stereo power amps ( Luxman m900,CH M1.1,Accuphase A70,Dart 108,Soulution 711) with their respective (active) preamps and did some mix and match. My Dac output is flexible: 2V or 6V ( depending on the pre I was using 2 or 6)
In terms of drive and dynamics (Putting aside other sound aspects such as voicing, timbre etc.. ) the Dart was the only one really struggling ( was a bit better with non dart preamp) . The other ones were fine ( Accuphase was suffering a bit as well then maybe a bit Luxman but it was with very specific music at very loud level so in 99% of the situation not an issue) so yes YG needs juice but I don’t think that driving them properly requires “Godzilla power”.

 

[chuck]

As an YG owner myself ( Sonja 2.2 and had Sonja 2.3 during 4 months) , I can jump in . I tried five different stereo power amps ( Luxman m900,CH M1.1,Accuphase A70,Dart 108,Soulution 711) with their respective (active) preamps and did some mix and match. My Dac output is flexible: 2V or 6V ( depending on the pre I was using 2 or 6)
In terms of drive and dynamics (Putting aside other sound aspects such as voicing, timbre etc.. ) the Dart was the only one really struggling ( was a bit better with non dart preamp) . The other ones were fine ( Accuphase was suffering a bit as well then maybe a bit Luxman but it was with very specific music at very loud level so in 99% of the situation not an issue) so yes YG needs juice but I don’t think that driving them properly requires “Godzilla power”.

Does not require but they sure do like it.

 

[bonzo75]

As an YG owner myself ( Sonja 2.2 and had Sonja 2.3 during 4 months) , I can jump in . I tried five different stereo power amps ( Luxman m900,CH M1.1,Accuphase A70,Dart 108,Soulution 711) with their respective (active) preamps and did some mix and match. My Dac output is flexible: 2V or 6V ( depending on the pre I was using 2 or 6)
In terms of drive and dynamics (Putting aside other sound aspects such as voicing, timbre etc.. ) the Dart was the only one really struggling ( was a bit better with non dart preamp) . The other ones were fine ( Accuphase was suffering a bit as well then maybe a bit Luxman but it was with very specific music at very loud level so in 99% of the situation not an issue) so yes YG needs juice but I don’t think that driving them properly requires “Godzilla power”.

I have tried Luxman m900u on the YG Hailey with the Nagra pre, also compared to Viola symphony, and I have tried Nagra power amp compared to burmester 909 on the Hailey too. Inn another room I compared boulder 2160 to burmester 911 mk3 and plinius the top model with burmester 77 pre.

The Luxman and the boulder were the best of those. Nagra was the only one that under drove. I can relate why you found Dartzeel not driving it properly as it is not good on tough to drive speakers, something we realized while comparing it to constellation on Wilson Alexia.

I can see dagostino working very well though expensive, my personal value voice would be symphonic line Kraft.

I have separately compared m900u to gryphon mephisto on TAD bookshelves. Gryphon had much more bass and jump and speed and detail, but to me a bit artificial, like when I compared colosseum to burmester 911 mk3 and a Norwegian amp on Kef blades and gryphon pantheon.

The m800a biamped easily out did Ypsilon aelius hybrids on the vivid g1 with the coincident 101d preamp.

The one place I did not like the m900u and was quite surprised at that was with the Martin Logan Renaissance, where the Chord did better, with the Luxman preamp

 

[Folsom]

@Folsom Here is my phono - believe it's set for 68db gain right now.

http://www.octave.de/en/htdocs/verstaerker/phono_eq_2.php

What gain setting do you run it at? It can put out over 2v. But that doesn't mean it provides enough current to drive amplifiers with lower input impedances. The fact that yours was so high helped a lot.

 

[Folsom]

A TVC does not make it more difficult for an amp to drive a given speaker! That is a function of the amp/speaker interface. A TVC may-can-might make it more difficult for a given source to drive a given amplifier. Both of Keith's sources work via TVC with a wide variety of amps.

Phil

Actually it can. Whenever you go past 0db into the positive you are turning current into voltage instead of the reverse.

The fact that the same chain works fine with 20Kohm amps tells me we should move on the from TVC topic. I seriously want to understand what makes YG so difficult to drive.

That's not true for various reasons. An amplifiers input impedance isn't a brickwall. Different amps respond more and less to what's up the chain from them. For some it's almost like there is no front end unless it has a source. There's also some things like capacitance. I won't go on about it.

I couldn't hear the YG to know, but it's not entirely unprobable that it wasn't about whether it was being driven right or wrong, but rather if it sounded homogenized. Sometimes speakers and amps do thing much better but not in all respects so it sounds off - and it would have made more sense to the listener not to have any of the improvements.

 

[Folsom]

A couple comments.

1. TVC are probably the best volume device ever. If you think everything else is as transparent well, unlikely. Resistors have some self noise, potentiometers just sad... There really is nothing on the level of a TVC. I'm not saying it's necessary for good sound, but I cannot see any reason why it wouldn't be fine to run a TVC with a buffer. A buffer can be as transparent, where the signal doesn't pass through anything but a pair of transistors.

2. If you want more umph from a Luxman just use no capacitance signal cables.

 

[bonzo75]

Such theory is not sufficient. Tang has a high sensitivity system. The EMT phono has a 60 db gain and a 72 db gain. Putting his higher output carts including the vdh strad in the 60 db input kills the drive. The 72 db input brings it to life. It is whatever EMT is doing to achieve that 12 db difference that is causing the issue. If someone simply comes away without trying, there will be pages and pages of debate on how another input in the same phono could have driven a system where the other input had failed.

 

[213Cobra]

Actually it can. Whenever you go past 0db into the positive you are turning current into voltage instead of the reverse.



That's not true for various reasons. An amplifiers input impedance isn't a brickwall. Different amps respond more and less to what's up the chain from them. For some it's almost like there is no front end unless it has a source. There's also some things like capacitance. I won't go on about it.

I couldn't gear the YG to know, but it's not entirely unprobable that it wasn't about whether it was being driven right or wrong, but rather if it sounded homogenized. Sometimes speakers and amps do thing much better but not in all respects so it sounds off - and it would have made more sense to the listener not to have any of the improvements.

Keith was not using the +6db switch on his TVC. The TVC attenuator switch never got as high as 0db. It's a TVC, not an active circuit. -Phil

 

[Folsom]

Keith was not using the +6db switch on his TVC. The TVC attenuator switch never got as high as 0db. It's a TVC, not an active circuit. -Phil

 

[bonzo75]

Dallasjustice on WBF owned the m900u and YG Hailey with the m900u and then JBL waveguides.

From him at that time.

“I haven’t tried toobs. But I’ve tried the following so far:
Dartzeel 108
Mola Kaluga
Audionet Max
Luxman 700u

My favorite so far is the Luxman. I will soon have the Luxman 900u.”

He was quite a bass and measurements junkie and had two subs with the YG

 

[213Cobra]

People are misunderstanding gain and sensitivity effects in Keith system. As far as I see it the main difference in his new system is the speaker sensitivity and impedance - the gain of both ARC amplifiers referred is very similar.

We could probably predict that the REF75 could not drive the YG's, but apparently no technical aspect on his system precludes the use of his TVC preamplifier with the ARC REF160. However, due to the lower speaker sensitivity the preamplfier is probably being operated at higher gain, something that increases significantly the load on the source component - it is one of the drawbacks of some passives, their are not a constant load as active ones. This is just my guess, probably Keith will tell us what steps he is using in the TVC.

Speaker sensitivity affects the whole chain, not just the amplifier.

It's a TVC, not a passive resistor attenuator. In the TVC, current is maintained as voltage is reduced for attenuation. The "preamp" -- a transformer volume control -- is not operated at "higher gain" due to lower speaker sensitivity. As an attenuating device, the TVC is operating below unity gain with the source, at any volume setting below 0db. At no time during Keith's listening tests was his TVC operated at 0db. It was always negative <something> or -Xdb. The load on the source component is easier with a TVC than with many active preamps, and easier than with a passive resistive volume control. Now, Keith's Music First TVC is equipped with a +6db coil, but that was not switched in at any time. In any position below 0db, the TVC is attenuating but not wasting voltage as heat.

None of us was surprised that the REF75SE was inadequate for the YG. What was surprising was that the 160m played somewhat louder but sounded worse, though they both sounded unsuitable in similar ways. Of all the amps tried, it was the 20kOhm input impedance amp that handled the speakers most competently. The TVC was not the issue here. The amp-speaker interface is where optimization has to happen, but the cure can't be found in available electronic specifications alone. Amps driving complex passive crossovers have to cope with deleterious effects that they do not all handle equally well, and the reasons are not explained in the incomplete electrical specifications manufacturers supply for either speakers or amplifiers.

Phil

 

[Folsom]

Dynamics are a funny thing. If you get them as big and bad as you could ever want, you start realizing how limiting it is to normal listening habits. I mean, it's hard to do anything else with some music playing and you're not always in the mood. Sometimes you want something easy going to listen to... just saying, I wouldn't toss the idea of Luxman out just because something else is more dynamic. Judge based on what you'll listen to, not what is "better" because that's not always best.

 

[Folsom]

***

It should be noted that TVC's impedance isn't flat across the board. It changes a lot based on the input impedance of load. Think about it like this, were there no impedance of any kind it would look like a dead short, and nothing would be able to power it. General rules of thumb work decently but a buffer is best.

 

[213Cobra]

Dynamics are a funny thing. If you get them as big and bad as you could ever want, you start realizing how limiting it is to normal listening habits. I mean, it's hard to do anything else with some music playing and you're not always in the mood. Sometimes you want something easy going to listen to... just saying, I wouldn't toss the idea of Luxman out just because something else is more dynamic. Judge based on what you'll listen to, not what is "better" because that's not always best.

Dynamics via Luxman were disappointing, especially to someone who has or has had 101db/w/m (and in his case also 92db/w/m) speakers driven by less power. But I suppose I can imagine someone thinking that the Luxman driving the YG delivers good enough dynamics. It didn't take anyone but Keith himself to say, "...this amp has no balls..." There were other traits I didn't like about the Luxman, especially relative to its cost, but they were not objections Keith had so are immaterial. The two things equally disappointing -- or possibly more so to him -- were that deep bass was AWOL, and spatial projection was tepid. The soundstage just didn't scale in any dimension. The Luxman would probably be fine on his old Devore Gibbon X with its simpler crossover and 5db greater efficiency.

Phil

 

[bonzo75]

The soundstage on the with the Luxman and the YG was gigantic in a much larger room. Yes I did feel at that time it needed subs, and I felt the same with burmester and boulder

 

[KeithR]

Keith was not using the +6db switch on his TVC. The TVC attenuator switch never got as high as 0db. It's a TVC, not an active circuit. -Phil

Actually, I am. Still comfortably between 12 and 2 though. With the 160s, it was a bit higher, especially on phono which worried me. One vinyl cut was only 4 clicks from full bore.

The Luxman was even less tHan my ARC 75 SE. Ie. More capable.

To all: I’m really tired of people telling me what I should have heard or that others ears are better. Or that I need $20k preamp’s or $120k amps for these to sound good.

I have more experience with YG than most and *in my room* - and prefer very high power. I even remarked before at a show that dual sets of Audionet monos was the first time I heard Sonjas sound dynamic. I did not feel that way last year in a large room with Luxman on Haileys. Alex liked the Luxman in my room- I didn’t. Who cares?

So I’m done with this, period.

 

[spiritofmusic]

Why are you throwing yr toys out of the pram? Then again, I did wonder why you hadn't contributed much, and yr response here is the reason.

If you don't want people to contribute to yr spkrs thread, then don't start a spkrs thread. If you want people to just agree w you, then maybe Whats Best Soviet Forum c.1984 would be a better place to post.

 

[bazelio]

That's not true for various reasons. An amplifiers input impedance isn't a brickwall. Different amps respond more and less to what's up the chain from them. For some it's almost like there is no front end unless it has a source. There's also some things like capacitance. I won't go on about it.

LOL. If the amp is providing a complex load to the source, it's the design of the amp that is problematic. Best to avoid such amps lest you get drawn in to the "need" to buy it's preamp counterpart. On the balanced inputs, I'd expect a balun transformer at most.before a high impedance input stage.

Resistor internal noise - LOL. It's negligible in $0.12 low noise resistors available at mouser. I'm talking about removing an entire power supply from the signal chain. You're worried about negligible resistor noise. Buffering a TVC ... To each his own. Enjoy.

 

[morricab]

I thought YG more than any other spkr were measurements driven. Listening tests less crucial than the theory. If so, how can there be this 3dB discrepancy?

Good question! The advance wishful thinking department might have gotten involved...same for the whole time correctness...Thiel was and Vandersteen is...YG is not.