2. amps-preamps
  3. 1031724377

Tubes Do It -- Transistors Don't.

I never thought transistor amps could hold a candle to tube amps. They just never seem to get the "wholeness of the sound of an instrument" quite right. SS doesn't allow an instrument (brass, especially) to "bloom" out in the air, forming a real body of an instrument. Rather, it sounds like a facsimile; a somewhat truncated, stripped version of the real thing. Kind of like taking 3D down to 2-1/2D.

I also hear differences in the actual space the instruments are playing in. With tubes, the space appears continuous, with each instrument occupying a believable part in that space. With SS, the space seems segmented, darker, and less continuous, with instruments somewhat disconnected from each other, almost as if they were panned in with a mixer. I won't claim this to be an accurate description, but I find it hard to describe these phenomena.

There is also the issue of interest -- SS doesn't excite me or maintain my interest. It sounds boring. Something is missing.

Yet, a tube friend of mine recently heard a Pass X-350 amp and thought it sounded great, and better in many ways than his Mac MC-2000 on his Nautilus 800 Signatures. I was shocked to hear this from him. I wasn't present for this comparison, and the Pass is now back at the dealer.

Tubes vs. SS is an endless debate, as has been seen in these forums. I haven't had any of the top solid state choices in my system, so I can't say how they fare compared to tubes. The best SS amp I had was a McCormack DNA-1 Rev. A, but it still didn't sound like my tube amps, VT-100 Mk II & Cary V-12.

Have any of you have tried SS amps that provided these qualities I describe in tubes? Or, did you also find that you couldn't get these qualities from a SS amp?
kevziek
sugarbrie
3,854 posts
 
I actually like pairing a tube preamp with a solid state amplifier. I find this combination gives me the best of both worlds; without the shortcommings of either format individually. This is especially true in more mid-priced systems.

There are also some hybrid tube/solid state amplifiers out there that solve many of the same issues. Blue Circle just came out with two new hybrid amps. You may also want to consider the Sim Moon W5 and Blue Circle BC26 fully solid state amps.

twl
3,251 posts
 
Hey you guys! How come I seem to be the only one who gets told that I must like the "euphonic" distortion of tube amps.

I read an extremely interesting article the other day on the web. The premise was, that single-ended triode amps sound as good as they do, because of system synergy with single driver speakers(primarily). It seems this guy did some distortion analysis of SETs, and speakers. The SET generated primarily second order harmonic distortion, which was the bulk of the total harmonic distortion measured, very little other. The speakers measured primarily second order harmonic distortion also, with very little other. These distortion characteristics mainly differed in phase relationship.

His hypothesis was that if, by way of chance, the 2nd order distortion of each item appeared at 180 degree phase angles apart, the distortion would be cancelled out, creating the "straight wire with gain" ideal. If they appeared at 0 phase angle(together), they would add, and distortion would double. Since either case was unlikely, his solution was to determine which side of the 90 degree phase angle the intersection was, and phase the speaker wiring to place the phase intersection of distortion closest to the 180 degree mark that you could. This way if it was at 30 degrees and adding, by reversing phase, you could put it at 210 by reversing phase and achieve a high level of distortion cancellation. If you leave it at a phase angle close to 0, then the distortion adds - bad. Since the majority of this occurs in the 2nd order on both items, once a certain percentage of this 2nd order cancellation occurs, the THD is dramatically lowered for both items as a package.

This is his reasoning for why SETs have the remarkable clarity they do, while measuring in distortion %, the way they do.

His finding was that by switching phase connections on your speakers, you could find out which way sounds better(reduces distortion) on your system. You don't have to use measuring equipment, just your ears. The goal is to have the amp distortion cancel the speaker distortion as much as possible with your equipment.

This is not possible with push-pull or SS amps, as their distortion characteristics are comprised of many orders of harmonic distortion, and are not coincident with the distortion characteristics of speakers.

The effect is somewhat lost on multi-driver speakers because of the phase changes induced between drivers by the crossover network.

So, while I cannot personally attest to the veracity of his findings, it sounds like a very interesting explanation for the apparent dichotomy of SETs measuring poorly and sounding great. The amp is not used to drive a measurement meter. It is used to drive a speaker, and as such may exhibit different behaviors when doing so, than some lab freak with a meter may even realize.

Maybe there is no "euphonic" distortion in SET amps, when you connect them to a speaker and listen to music. What a novel concept. I never really liked the sound of a meter anyway.
clueless
763 posts
 
Twl, might as well give them the article. Eduardo de Lima ?

Why Single Ended Tube Amplifiers

I remain,
bear
141 posts
 
There is no doubt that tubes come in various flavors and colors, some of which are quite nice. Some are really awful, I'll leave it to you to discern. Imho, for little money you can get a really *nice* sounding amplifier using tubes, one that gives the impression of "musicality" and "smoothness." So, that is all good.

To get a similar result from solid state, imho (again), you need to go an "extra mile" or so to get certain things right, or else you end up with a sound that personally I do not like at all. Unfortunately, a *great number* of manufacturers seem to either have or like that sound...

What I think is needed can be seen on my site in either the SE Mosfet amp design, or better still in the full out Symphony No.1 design.

Having said that, I admit that I *prefer* the sound of a very high quality, high power triode amp on my ESLs over the arguably more accurate and cleaner Mosfet monster(s). However on other systems, there is no horse race at all. And for bass, tubes are definitely on the short end of the stick.

So, the answer is: use the right devices for the right applications. (often that means bi-tri-quad amp'd set ups)

:- )
beemer
444 posts
 
Each to their own taste! I use 33H on the mid/tweeter panels of Infinity IRS Beta. These panels voiceds with ARC tube products when the speaker was designed. With a good source, I find the 33H and Bat VK50SE preamp combo right on the money, though I have het to try any of the higher-end tube amps on my system, a friend has a similar setup with a Mac 2000 and it sounds good as well.
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