Are Integrated Amps making a comeback?

[Whatmore]

That is in fact what can make that 12 W sound better than say 100W: the power supply in the former is very firm, does not deviate or flinch when pushed hard, and clips "cleanly". The supposed higher powered unit sags badly, and it's all too obvious via the speaker cones that it's stressed ...

Frank

This comes back to my earlier point. If the 100w amp sounds worse than the 12w amp because its power supply is badly designed then that is the fault of the badly designed power supply (and therefore badly designed amp). I don't think you can take much more out of it than that.

IMHO a more powerful well designed amp driving a difficult load will sound better than a less powerful well designed amp driving a difficult load

 

[Orb]

Just to clarify;
I think it is best to differentiate between clipped-compressed digital signal and an amp clipping;
The reason being a compressed signal will have different affect (both can blow speaker drivers though) and characteristic to that of an amp; an amp's square wave output.
This is further complicated by the type of compression applied to the signal.
You could fill pages discussing this and probably best as a seperate thread, especially when one also considers digital amps and how they can be made unstable.

Cheers
Orb

 

[fas42]

Yes, all things being equal the more powerful will do a better job. But when are things that equal in real life?

A fun experiment to do, I've mentioned this before, to demonstrate how the objectivists are often deluding themselves about the quality of components. Use one reasonable amp to drive a speaker fairly hard, then clip a AC coupled probe to its power supply, and connect that to the input of another amp and listen to the first amp's power supply on headphones plugged into the second amp. Would make an excellent backing track to the next rap album!!

Frank

 

[fas42]

I think it is best to differentiate between clipped-compressed digital signal and an amp clipping;

Remember, compression and clipping are two completely different things. A signal going to a speaker can be compressed, or clipped, or both of these at once. Bad amps will both compress and clip, good ones will only clip; a digital signal will be one of that 3-way split, or "clean".

It would be extremely unlikely to have something like a square wave out of an amp. A technician's test CD may have this, or a preamp grossly overloading the power amp's input could do it.

Frank

 

[Orb]

That makes the earlier posts on this then a bit vague and not sure where it is going, because compression-limiter is used in studios when it comes to clipping - hotness of tracks.
Also when saying square wave, I do not mean a "perfect square wave".
BTW Rod Elliott and also Rane have very good articles on both, with examples of effect measured or modelled that fit in with what I mention.
But we are digressing from original post, and as I mentioned it would be possible to discuss this over many pages and why maybe it is better with its own thread.

Thanks
Orb

 

[fas42]

Okay, quick explanation: from Elliot, "An amplifier is said to be clipping when the output signal attempts to exceed the supply voltage". Very simple,straightforward, a technical behaviour.

From Wikipedia: "compression reduces the volume of loud sounds or amplifies quiet sounds by narrowing or "compressing" an audio signal's dynamic range" and "Downward compression reduces loud sounds over a certain threshold while quiet sounds remain unaffected." It's the latter we worry about when amplifiers are stressed, it's an audible phenomenon easily discernible when you substitute a more capable amp. An amplifier that's compressing is actually distorting because the power supply has gone "soft", become noisy, and the amplifying circuits can't cope: the subjective impression is that the sound is compressing. Compression in a recording is different, technically there is no distortion, merely that using some rule the loud peaks are reduced in amplitude.

Frank

 

[Orb]

Okay, quick explanation: from Elliot, "An amplifier is said to be clipping when the output signal attempts to exceed the supply voltage". Very simple,straightforward, a technical behaviour.

From Wikipedia: "compression reduces the volume of loud sounds or amplifies quiet sounds by narrowing or "compressing" an audio signal's dynamic range" and "Downward compression reduces loud sounds over a certain threshold while quiet sounds remain unaffected." It's the latter we worry about when amplifiers are stressed, it's an audible phenomenon easily discernible when you substitute a more capable amp. An amplifier that's compressing is actually distorting because the power supply has gone "soft", become noisy, and the amplifying circuits can't cope: the subjective impression is that the sound is compressing. Compression in a recording is different, technically there is no distortion, merely that using some rule the loud peaks are reduced in amplitude.

Frank

Frank, if using wiki (which is not always best to IMO) then look at Dynamic range compression when discussing music and the original signal.
Elliot does a much greater detail article on two type of clipping-"power compression", which fit in with what I am saying.

However my posts was in response to the below that I just expanded upon as it needed further information, which is why I originally posted that anyone reading this thread should think of signal and power amp clipping to be different;

..... But a conventional amp has not got this extra level of engineering, the supply plummets when asked to work harder, it's no longer a nice DC signal, but a rather unpleasant looking ripply mess. Sounds like a good recipe for unpleasant clipping, compression, distortion? You bet!

So when a heavy duty Krell amp clips, it's very close in nature to a conventional amp replaying a clipped musical signal at low volume: it you look at the signal being fed to the speaker it will have the same waveform, but different amplitudes.

Frank

As you say, in your most recent response technically they are not the same especially when considering the distortion, and this is my point; clipped music in the Krell example should not exist as studios use limiters-compression, and as I mentioned this is further complicated by the implementation and functionality used in the limiter.
I felt differentiation was needed because the risk is some may assume that common pop music then will have the same effect as an amp clipping at normal sound levels, and it is more complicated than that for the summary reasons outlined - again if wanting to go into explicit detail it really needs to be another thread.
Where this can still be critical though is for digial amps as without digital signal protection in place they can become highly unstable.
Thanks Orb

 

[fas42]

We are going on a bit, but it's worth getting some closure on this area of thinking now ...

Elliot does a much greater detail article on two type of clipping-"power compression", which fit in with what I am saying.

When I read Elliot he only uses the term "power compression" to refer to speaker drivers driven so hard their internal temperature rises and their performance characteristics change. This is something totally specific to speakers, not amplifiers.

clipped music in the Krell example should not exist as studios use limiters-compression, and as I mentioned this is further complicated by the implementation and functionality used in the limiter.

Most certainly it shouldn't exist, and I was very surprised to see it, firstly in a piece of classical music recorded by a highly reputable organisation, and secondly in a jazz piece posted in the forum by Bruce. When I say clipping occurs, this is not happening frequently but rather occasionly, several times through the track.

Many current pop recordings, including some remastered under the direction of the original artists now not only suffer severe compression but high levels of clipping as well: Iggy Pop comes to mind. They probably feel comfortable with a sound that mimics the typically overdriven PA setup ...

The variation on that is the 100W Krell, with a preamp driving its input hard to get volume on an inefficient speaker. This will work very well because the Krell will most assuredly drive the the speaker correctly, except for those moments now and again when the peak input level outstrips the dynamic range of its power supplies, and it will clip for a split second, unnoticeable unless you very specifically listen for it at the precise moment, probably ...

I felt differentiation was needed because the risk is some may assume that common pop music then will have the same effect as an amp clipping at normal sound levels, and it is more complicated than that for the summary reasons outlined - again if wanting to go into explicit detail it really needs to be another thread.
Where this can still be critical though is for digial amps as without digital signal protection in place they can become highly unstable.
Thanks Orb

When you say risk, are you thinking of tweeter damage? The Krell clipping "cleanly", a lesser amp reproducing clipped as recorded music at normal volumes poses little risk; a very dangerous situation is using a conventional amp playing back recorded clipped music which the user ups the volume on, the sound subjectively compresses, loses its dynamic intensity, so the user raises the volume yet again to try and inject some energy into the playback. Now you're in real trouble: the amp's compressing AND clipping, while replaying music that in itself is clipped! The tweeter will be rapidly fried, bye, bye, little unit ...

Frank

 

[Orb]

Frank,
ask yourself how many times drivers are damaged in a studio that record/master the more dynamically compressed albums and play them loud (I hope you will not suggest studios are using sturdier speakers than audiophiles as this is not true if ignoring the non-mainstream consumer ones).
This is a simplistic way to see the real world practical effects with what you mention in the last paragraph.
I will drop the technical aspect of the discussion because I just do not want to derail this thread anymore.
Thanks
Orb

 

[JackD201]

Has anybody heard the Beyond Frontiers Tulip? It's supposed to have been made by ex- Sonic Frontiers engineers from Eastern Europe. It's a tube-Class AB hybrid that does 200wpc into 8 and 400 into 4. It also comes with an optional built in DAC. Weighs in at 100lbs, costs....gasp....$18,000. More importantly, why would anybody name a 100lb high power amp "Tulip"? Tip-toeing around these would be painful!

 

[Orb]

Would be interesting to read someone who has compared-experience with all the hybrid amps out there, including the ARC and Lamm (appreciate this is not exclusive to integrated).

Cheers
Orb

 

[JackD201]

I run four Lamm Hybrids (Bi-amp) Orb. What would you like to know?

 

[Orb]

It would be great to have some information on how the hybrid compares in terms of traits-performance-characteristics to say the good class A/AB and tube amps.
I feel the audio publications omit hybrids from their reviews, and we hardly see much forum posts on them, so for those who would not consider tubes also miss out on the hybrid concept amp and what they are capable of compared to solid state and tubes.

Thanks
Orb

 

[fas42]

This is a thought right off the top of my head, but the Vas, Voltage amplification stage in an amplifier is absolutely crucial to determining SQ, and is very vulnerable to power supply problems. If latter is badly behaved, then bad sound. So, an "easy" fix is to use valves/tubes here because the power supply for running this area of the amp is now relatively independent of the rest of the power supplies, those used for the SS area of things. This alone should help a hybrid do a better job ...

Frank

 

[JackD201]

Hi Orb,

I'm not quite sure if hybrids are being snubbed by the press. I think there just aren't very many of them out there now or ever. The Lamm, Aesthetix, Moscode, Tenor and ARC Tube-SS hybrids and the ARC and Kronzilla SS-Tube hybrids are the only power amps I can think of now. In terms of integrateds the number seems to be growing. There's LSA, Vincent, a whole slew of hybrids coming out of the far east and that Tulip I mentioned. The Lamm 1.2 in particular is probably the most awarded and reviewed amp around no doubt helped along by having an unusually long product life cycle. It's the only non-vintage amp I know of that got a Golden Ear 10 years after it's first one.

In the last audio show we participated in last year, we were neighbored with JE Labs and Harana. JE, Joseph Esmilla the violinist and amp designer, is a dyed in the wool triode guy and Harana build horns and OBs. They commented that our room sounded more like tubes than the other rooms showing high powered tube gear. I did know that our common friends who brought the said tube amps encountered delays and were using brand new units. Folks had walked into their shops and bought the units they were to bring to the show leaving them no choice but to order more. We on the other hand borrowed burned in units of both loudspeakers and amps from our client/friends, instead of using inventory, as I didn't have a place to burn in speakers and amps at the time. We also used our own personal units of pre-amplification, cables, power conditioning and sources. So, I laughed, I didn't know if that was a compliment or that they were saying we sounded better than cold gear. They assured me it was a compliment.

Actually, I'm topology agnostic. It just so happened that the amps I have been using for some time now fit both my ear and my lifestyle. Sonically, I can't say that they are the best. I can't even say I like them because they are hybrids. I say this because my favorite amplifiers are all tubed: the Lamm ML2.1. the ML3 which I can't afford, the VAC 450 Statement and the VTL Siegfried (in triode mode). I would put the 1.2 in the category of the VAC 300.1, ARC Ref 210 and like it better than any VTL except the one mentioned and perhaps the S-400 also in triode mode. The pluses of the hybrids for me anyway, is that I know longer have to deal with the white flashes of B+ fuses going off. That is a huge one for me. I want to fire and forget. I also get to tailor the sound by tube rolling just one 6dj8 a side. I've got a stash of premium, extremely quiet and strong tubes that if I sold today would almost double what I paid for them only a few years ago.

It's often said that tubes have dynamic ceilings and SS has resolution ceilings. The 1.2 has more continuity than any SS amps I've had in my system but I still feel it falls short of my favorite pure tube amps. It is a compromise that I am happy to live with for now. I just have to stay away from those amps! Technically I believe it has got a lot to do with 2 things. First is the contribution of the tubes themselves and the second is that the amp employs fast transistors. I believe bandwidth is 5Hz to 150kHz. I'm playing with a pair of 50wpc monoblocks right now that are DC to 300kHz and these too have that continuity in spades albeit it is a pure SS design. If the maker could make a version that sounds identical o this with 350wpc behind it. I am buying. Alas, he says he knows not how.

 

[Orb]

Thanks Jack,
really good info and I never realised there were so many hybrids.
Frank, along with your thoughts go ARC as a classic example is their CD8 CD player amongst its other models that utilise tube in the power supply (apprecate others do this as well), although this is offset as such circuitry seems expensive and consumes space.

Thanks
Orb

 

[mauidan]

Jack,

Another great post.

Somehow, I think if you really wanted to own ML2.1s or ML3s you'd figure out a way to make that happen.

For those without deep pockets, the AVA Fet Valve 400R and 600R amplifiers maybe a good choice:

http://www.avahifi.com/index.php?option=com_content&view=article&id=108&Itemid=210

Dan

 

[JackD201]

Thanks Dan and Orb. I wish it were that simple. Although my speakers are rated at 94dB they really like a lot of juice. Even if I could get those amps, I'd still need to change my speakers which I really, really like. Anyway, when I really feel the tube itch, I've still got my ML1.1s and my BAT VK-150s. With the way the system is doing right now, it might be a while.

I've heard lots of good things about Franks amps but have never heard them.

 

[Johnny Vinyl]

I just reread this entire thread and thanks for everyone's participation. I'd like to take the discussion into another direction if I may. I have no doubt that many of you have signifciant experience in what I'm trying to find the answer to, and I encourage you to speak out and voice them.

What is the difference in sound signature between British made IA's and U.S./Canada made IA's. I know it's a kind of open-ended question as many factors come into play, but I always got the sense that British-made amps sounded more polite and less in your face. I don't know if "veiled" is an accurate word to properly describe the difference, so your thoughts and opinions are patiently awaited.

 

[JackD201]

That's a tough one John. When UK integrateds are mentioned the first two manufacturers that come to mind are Rega and Naim. To me they sound so different from each other that it makes me wonder if there IS a british sound. Throw in Musical Fidelity and how their house sound has changed from the 90's to today and it makes me even more hesitant. Right in your own backyard there's NAD whose classic signature would out Brit the Brits and Bryston which would fit in the old US muscle car mold like Levinson, BAT and Krell while Classe to me goes the other way. I wouldn't know where to put well respected UK Creek and the Kiwi Plinius' and Primares.

If there is a trend at all, I think it's that if you're looking for a variety of choices from 25wpc to 100wpc the bulk will come from the UK. Above that look to the US and continental Europe to provide the big battleship integrateds.