I've already mentioned many times that I get a lot of satisfaction from the Conrad Johnson tube amps powering my speakers. To me they do have some classic "tube attributes" when I compare them directly to solid state amps (e.g. the Bryston 4B3 I had for a couple months) and I love what the tube amps bring to the sound.
Could it be pure subjective bias based on "tubes are supposed to sound this way?" Sure (though that wouldn't directly explain why I have rejected other tube amps that don't sound 'tubey' to me). Could it be that I'm actually hearing sonic differences? Plenty of people with knowledge of electronics say this is entirely plausible, that tube amps can depart from neutrality. That is one of the reasons "strict objectivist engineers" like Arny Kruger and the like decried the perseverance of tube amplification among audiophiles when truly neutral solid state was available. "Why color the sound?"
Could my impressions be due to a mix of hearing real differences AND bias? Sure.
All this is why I don't come on a board like this to make some objective claim that my tube amps Absolutely Do Sound Different than solid state.
But rather, I only present reasons why I continue to use them (which also includes that I think tube amps are charming and cool looking and I like seeing the music signal visibly passing through tubes).
I have both and while tube amps are fun they are lower power and generate a lot of heat and the tubes wear out. I went to a lot of trouble to set up a double blind ABX level matched test between a Dynaco ST 70 and a Neurochrome Mod 86 amp and could not tell them apart ... I would highly recomend you try this yourself as it will really open your eyes and set you free from a lot of BS surrounding the hobby.
Hi levimax,
I thoroughly enjoyed and appreciated your report of blind testing those amps.
Depending exactly on what you mean by your last sentence, I am of two minds about that.
If you mean that doing blind tests can really open one's eyes to the power of our bias, and help us take a position as to what claims are likely b.s. or not, I certainly agree. As I've mentioned I've done numerous blind tests with those results.
But if you mean that an individual doing a blind test of a tube amp at home will open his eyes to the B.S. idea that tube amps can sound different in a system, that would seem to be overreach (I'm betting you agree).
That would be evidence that the individual's tube amp in question doesn't sound different from the SS amp he has on hand. But it certainly doesn't establish that no tube amps alter the sound of any speaker system. So you wouldn't have established from that test "Tube Amps Sound Identical To Solid State." There are tons of different tube amp designs and speaker pairings, that make that inference problematic.
As to my own attitude towards the tube amp "sound:" As a "layman" in terms of not being an electrical engineer or amp designer, the best I can do is try to triangulate my own experience with observing what knowledgeable people have to say on the matter. While some will say that audible differences between tube amps and SS are simply a myth that seems to be a minority opinion. From what I've seen, most electronically knowledgeable folks acknowledge there are entirely technically feasible reasons for why tube amps can alter the sound of a system. They CAN be built to sound indistinguishable from solid state, but generally speaking "tube amps designed to sound exactly like solid state" isn't the market most tube manufacturers are designing for.
And I've noted that there is on almost any technical subject, whether it's tube amps or "the best speaker design" or anything else, there will be differences of opinion among experienced engineers, much of it ultimately born of their own experience.
It reminds me of my blind tests. I found some expensive AC cables indistinguishable in blind tests, which went against my sighted impressions.
That gave me personal/experiential reasons in support of being suspicious of claims about AC cable differences - which I triangulate with technical reasons to be suspect as well.
On the other hand, in the 90's I was told by a bunch of experienced audio engineer folks that the differences I percieved between some cd players and DACs were due to sighted bias. They "shouldn't sound different at all" if sighted bias is removed. So I tested that myself, did more than one series of blind tests, using the very recommendations of those engineers, level matching, randomized, in which I was able to easily identify between the CDPs and DAC. So what was I to do? Call 'em as I see 'em. They sounded different. I didn't expect the other folks to accept my test as overturning their own skepticism. They weren't there, couldn't see if I made any mistakes. But we individuals are going to be strongly influenced by our personal experience. I suspect that if any of those engineers had performed the test I did and were able to identify the devices just as easily, that experience would lead them to say "Well, yeah, it looks like in this case these ones do sound different."
So I understand why your test would heavily influence your view of tube vs ss amps. From my point of view, I take it as another data point to consider, a reminder of the power of subjective bias. Though, that was something I already accepted. It doesn't establish though that my tube amps don't sound different from the solid state amp I had. I just won't say definitively my tube amps sound different, because it could be subjective bias. But it could also be...they sound different in my system. My hunch is the latter. Either way the subjective effect is so strong I can't seem to shake it, I simply enjoy listening more with the tube amps in the system, so I'm going with it.