Valve Digital hybrid: feasible???

Feanor · « **on:** 27 Nov 2005, 01:00 pm »

Of course, Frank Val Alstine is leading hybrid proponent and his tube/FET hybrids are greatly admired. But we note the surging popularity of switching amps base on Tripath, ICEpower, NuForce, UcD, and other technologies. While many models have gotten high praise from reviewers, there is some consensus that they lack the "je ne sais quoi" of the best tube units

. Which leads me to wonder whether a tube/digital hybid is feasible.

I know that digital designs do use feedback. And recently Frank made this comment, "Our take on it is that vacuum tubes have a significantly higher overload immunity in summing the input with the feedback (maybe 200V or so) while a solid state design might have half a volt or so at best. Thus feedback related transient corrections can be handled way better with vacuum tubes. ...". Would it be possible to insinuate a tube circuit in that feedback loop?

I wonder! In many cases modular OEM components offered by ICEpower, et al. would perhaps make circuit modification difficult, but who knows?

I'd love to hear some comments or speculation -- especially (but not exclusively!) from Frank.

JoshK · « **Reply #1 on:** 27 Nov 2005, 07:00 pm »

FYI:

je ne sais quoi

French expression literally meaning "I know not what"; je I , ne...pas not , sais know , quoi what . In Oxford English Dictonary since 1656. It is a way to express a quality that is hard to describe; a certain something.

*I had no idea what you were talking about, I never took french.

avahifi · « **Reply #2 on:** 29 Nov 2005, 01:25 am »

I guess I would wonder why in the world anyone would want to screw up the musicality possible with a great vacuum tube amplifier with digital solid state switching circuits? Vacuum tubes are not going to be a cure for that sterile little switching amp.

To me the sound of any class D amp I have heard is like the flavor of prime rib reheated in a microwave oven.

The object is the music.

Frank Van Alstine

jswallac · « **Reply #3 on:** 29 Nov 2005, 03:00 am »

One man's ceiling ... Pretty harsh, don't you think. I just received my Red Wine Audio Clari-T. It has replaced several different valve amps, although I still use a valve pre. This amp is anything but reheated prime rib. Many, many people believe it is sonically superior to tube amps if mated with the right system. And for a lot of those, the right system includes a valve preamp. Far from messing up a good sound, these little digital amps, if done correctly, make things better. I take it that you think otherwise, which is certainly your right. I guess my ceiling is your floor. Fair enough, after all this is all completely subjective. There is no universal best piece of equipment or technology, it is simply what sounds best to each of our sets of ears.

Parnelli777 · « **Reply #4 on:** 29 Nov 2005, 03:02 am »

Quote

I guess I would wonder why in the world anyone would want to screw up the musicality possible with a great vacuum tube amplifier with digital solid state switching circuits? Vacuum tubes are not going to be a cure for that sterile little switching amp.

To me the sound of any class D amp I have heard is like the flavor of prime rib reheated in a microwave oven.

That would be my thought exactly. Well said.

I see all this enthusiasm for these digital amps, and I 'spose I just don't get it. "Detailed", "dynamic", etc., "just like vacuum tubes", but "not exactly", etc., etc. Really.

Feanor · « **Reply #5 on:** 29 Nov 2005, 11:17 am »

Quote from: avahifi

I guess I would wonder why in the world anyone would want to screw up the musicality possible with a great vacuum tube amplifier with digital solid state switching circuits? Vacuum tubes are not going to be a cure for that sterile little switching amp.

To me the sound of any class D amp I have heard is like the flavor of prime rib reheated in a microwave oven.
...

Frank Van Alstine

Well, Frank, I do feel rebuffed. But it does cause me to wonder when and to which switching amp you last listened to. Maybe time to try again. For someone on the record as believe that it is best to use the right technology for the job, you are all of a sudden coming a cross as a bit closed minded.

I guess that I am less so. I have limited experience with tube gear but am willing to give it a try despite some skepticism. Whereas I love my Bel Canto eVo -- which is far from sterile, or small for that matter -- I would like to try front-ending it with a tube or tube hybrid preamp just to see if I do get some of that elusive tube quality. And (despite your straight-arm response), your Ultra or Transendence 8 are high on my wish list.

Finally if you don't know the technical answer to my question perhaps you ought to admit that. Which is fine. I don't expect you to research the matter on my account.

TheChairGuy · « **Reply #6 on:** 29 Nov 2005, 05:39 pm »

Feanor and jswallac.....this is the Van Alstine Circle. Frank, the proprietor here, is allowed to espouse any opinion he has on audio. He's been doing so in print, ably, for four decades.

I don't agree with his opinions on some of the new digi amps either, but don't take him to task on HIS Circle. Do it in Two Channel, Audio Central, etc. Frank van Alstine hasn't heard any digi amp that makes him squeel and giggle with delight....that's his experience and he designs his current amps to other architecture.

I just wanted to remind you that that is how Audio Circle has been set up...circles for manufacturers to freely divulge their opinions and those for audio enthusiasts elsewhere to talk about ours.

In other words, if you're gonna' crap on the guy's opinions...don't do it in HIS store. This circle is truly an extension of his store and an important part of his livelihood.

Sorry for the spanking...I just thought it fair to Frank to re-establish the ground rules so he doesn't have to

Feanor · « **Reply #7 on:** 29 Nov 2005, 06:18 pm »

Quote from: TheChairGuy

Feanor and jswallac.....this is the Van Alstine Circle. Frank, the proprietor here, is allowed to espouse any opinion he has on audio. ...

I just wanted to remind you that that is how Audio Circle has been set up...circles for manufacturers to freely divulge their opinions and those for audio enthusiasts elsewhere to talk about ours.

Sorry for the spanking...I just thought it fair to Frank to re-establish the ground rules so he doesn't have to.

Well sorry but I'm not particulary contrite. I'm glad to his opinion on digital apps, however I asked question which he didn't bother to answer -- I'll take him to takes on that, which is fair I think. ("I don't know" would have been fine.)

I remain impressed with the AVA products concepts which I deem very well-conceived.

jswallac · « **Reply #8 on:** 29 Nov 2005, 07:29 pm »

TheChairGuy,

I apologize if I offended any readers of this particular circle, but I have to disagree with you regarding my "spanking." If you carefully read my comments, in no way did I disrespect Frank, although I wanted to. I simply pointed out that I differed in my take on digital amps. I feel that the question asked by Feanor was a legitimate one, one that deserved a legitimate answer. While this may be Frank's Circle, it is a public forum. There was no need for him to give what amounted to a very rude, snobbish, and arguably ignorant response. As Feanor has pointed out, a simple "I am not informed enough on the topic" would have been a much better answer. Rude behavior, in any forum, is inappropriate and no way to further one's agenda.

avahifi · « **Reply #9 on:** 29 Nov 2005, 07:33 pm »

If you guys could just hear an Ultra DAC driving an Ultra SL preamp driving an Ultra Phase Inverter driving a pair of Ultimate 70 tube amplifiers, the debate you raise would be over, no contest. We will make your digital amplifiers sound just icky.

And it is so nice in keeping the sound room warm on a cold winter day.

Frank Van Alstine

skrivis · « **Reply #10 on:** 29 Nov 2005, 09:35 pm »

Quote from: avahifi

If you guys could just hear an Ultra DAC driving an Ultra SL preamp driving an Ultra Phase Inverter driving a pair of Ultimate 70 tube amplifiers, the debate you raise would be over, no contest. We will make your digital amplifiers sound just icky.

And it is so nice in keeping the sound room warm on a cold winter day.

Frank Van Alstine

I got a good listen to an ARC Class D amp, a brief listen to a bel canto eVo-something, and I've also listened to a Teac and Sonic Impact amp (both modded). I feel my all-OmegaStar signal chain makes the Class D stuff sound icky.

I just didn't hear anything worth praising about the Class D stuff, except that it's vastly improved from the Class D amps in the '80s. They all sounded mostly ho-hum, with maybe some brittleness in the high end. The Teac and SI were definitely clipping on normal program content, so maybe some people like the sound of that?

skrivis · « **Reply #11 on:** 29 Nov 2005, 09:43 pm »

Quote from: jswallac

Fair enough, after all this is all completely subjective.

I just have to say that I don't think it's _completely_ subjective. In fact, from a design point of view, I'd say it's not very subjective at all.

If it's completely subjective, then the guy with his car "stereo" thumping and distorting is just as right as the most critical audiophile. I simply can't wrap my brain around _that_ concept.

Tweaker · « **Reply #12 on:** 29 Nov 2005, 09:49 pm »

My experience with class D amps is limited but what I have heard has not made me want to sell my Van alstines amps...yet. Plus, I have speakers that need a bit more juice to really sing!
I think it is a technology with great potential, however. When some reasonably priced high watt models hit the market I will for sure be checking them out.

skrivis · « **Reply #13 on:** 29 Nov 2005, 09:55 pm »

Quote from: Feanor

Well, Frank, I do feel rebuffed. But it does cause me to wonder when and to which switching amp you last listened to. Maybe time to try again. For someone on the record as believe that it is best to use the right technology for the job, you are all of a sudden coming a cross as a bit closed minded.

I guess that I am less so. I have limited experience with tube gear but am willing to give it a try despite some skepticism. Whereas I love my Bel Canto eVo -- which is far from sterile, or small for that ...

I think Frank's response was right on the money. If Class D amps worked better from an engineering standpoint, don't you think he'd be selling them?

He offered his opinions. One was that Class D circuits don't do things better than what he's already got. The other was that, to him, the Class D stuff he's heard is lacking in various ways.

Personally, what I get out of Class D is that it lets you build cheap, light, and small amps. I'm not at all sure that I'm convinced that it lets you build _better_ amps. Maybe they're as good, maybe not. What I've heard wasn't...

An AVA preamp could be a very good choice for you, but I'm not sure that it would add any "tube" sound. My old F-V amp probably sounds more "tubey" than the current gear, and it doesn't really sound "tubey" to me. (Old Mac gear, C-J and ARC stuff sound "tubey" to me.)

WEEZ · « **Reply #14 on:** 30 Nov 2005, 12:45 am »

I just had to chime in here...

icky...

Hey, I've never heard a class D amp, so I will not get into the frey over whether they sound "icky", or not. I think Charles uses an Ultra with the CI D-200 amps, so maybe he will add his comments....

icky.. damn, that just struck me as funny..sorry

Usually, I'm a fan of Cardas wires (sorry, Frank..) and when I asked Bobby Palkovic about the super expensive Neutral Reference speaker cable his reply was, " they are 'skinny' sounding with my speakers".

I laughed at that one, too.

Just some free advice- learn to listen for icky and skinny. If that's the way it sounds good to you- have at it! I'll settle for rich and full, instead.

WEEZ!

Feanor · « **Reply #15 on:** 30 Nov 2005, 01:24 am »

Quote from: skrivis

I think Frank's response was right on the money. If Class D amps worked better from an engineering standpoint, don't you think he'd be selling them?

...

I didn't know that's why I asked. It was Frank's success with hybrid designs that made me think if it. For all I knew he already had a valve/switching prototype on the bench. Seems not; well OK.

The likes of ARC, Jeff Rowland, Cary, and Kharma didn't have to be bothered with digital if they thought there was nothing to it.

skrivis · « **Reply #16 on:** 1 Dec 2005, 08:57 pm »

Quote from: Feanor

Quote from: skrivis
I think Frank's response was right on the money. If Class D amps worked better from an engineering standpoint, don't you think he'd be selling them?

...

I didn't know that's why I asked. It was Frank's success with hybrid designs that made me think if it. For all I knew he already had a valve/switching prototype on the bench. Seems not; well OK.

The likes of ARC, Jeff Rowland, Cary, and Kharma didn't have to be bothered with digital if they thought there was nothing to it.

I didn't say there was nothing to it. It's a great way of reducing cost.

I don't know anything about Kharma, but ARC, Rowland, and Cary don't impress me much. Well, I lied. I'm impressed with how much money they get for their stuff. hehe

skrivis · « **Reply #17 on:** 1 Dec 2005, 09:03 pm »

Quote from: WEEZ

I just had to chime in here...

icky...

Hey, I've never heard a class D amp, so I will not get into the frey over whether they sound "icky", or not. I think Charles uses an Ultra with the CI D-200 amps, so maybe he will add his comments....

icky.. damn, that just struck me as funny..sorry

Usually, I'm a fan of Cardas wires (sorry, Frank..) and when I asked Bobby Palkovic about the super expensive Neutral Reference speaker cable his reply was, " they are 'skinny' sounding with my spe ...

You might want to check out some of the articles at: http://www.audioholics.com/techtips/audioprinciples/cables.htm

Cardas is blowing smoke up your...

Speaking of fancy cables, I just ran across the silliest thing I've seen yet.
http://www.stealthaudiocables.com/products/dream9.htm

Do people actually buy this stuff?

Red Dragon Audio · « **Reply #18 on:** 1 Dec 2005, 11:39 pm »

That's nothing! Transparent has been making these speaker cables for many years - they sell for around $37,000 per pair!
But you can get 'em used on A'gon for around $20,000.

WEEZ · « **Reply #19 on:** 2 Dec 2005, 12:30 am »

skrivis,

nobody blows smoke up my...

(I still think icky is funny

)

WEEZ