I've narrowed it down...


So my first venture into tube equipment will be an integrated amp based on the recommendations of this fine group of enthusiasts. I have narrowed the field to the Rogue Audio Tempest III, Rogue Audio Cronus Magnum, the Cayin H-80 and Cary SLI-80.

All of this is based on what I have read and what fits in my budget. The Cary is a little over but for something I think I'll have for a lifetime I'm willing to go a little over...

I will be driving B&W 602S3's until more $$$ are available for something else.

My intent is to listen to vinyl then maybe venture into CD's or digital music. Any feedback or suggestions are appreciated.

Going somewhere to listen to any of these is not an option for me, and room size is undetermined as I am in the process of moving.

Thanks.
botit

Showing 5 responses by atmasphere

what is it that makes one speaker sound better on ss and another on tubes? Is this an experience item or are there specs I can look at?

Maybe you should look here first:

http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

In a nutshell tubes drive speakers differently than transistors tend to, although you can make them do it if you add enough feedback. The problem is that when you do this, you will also rob them of the music. IOW, its not so much a transistor/tubes debate as it is whether or not making an amplifier into a Voltage Source is a good thing or not.

To this end I don't agree with Unsound, as the research that has been done in the last 45 years points to the fact that the human ear is very sensitive to the use of feedback in an amplifier, and also that it hears harmonic distortion as tonality. Another way to putting this is that you will have a very difficult time to get the equipment to sound like music and run feedback at the same time.

The B&Ws require that the amplifier be a constant voltage source which is why they don't work so well with tubes.

So if you want tubes, you *have* to find a speaker that works with them. If you go with the speaker first, you may be forced into using a transistor amp. Since most transistor amps use a fair amount of feedback, its nearly impossible to get such a combination to sound like real music- at best it will sound like a good hifi. Its that last nuanced difference that brings home the bacon!

Now you could try using transistor amps that have no feedback; there are a few around like the Pass Labs and Ayre. The problem is that transistors have non-linear capacitive aspects in the junctions of the device itself. This contributes to odd-ordered harmonics- the very thing that the ear uses to sort out sound pressure (volume of a sound).

Another way to put this is that the more the equipment obeys human perceptual/hearing rules, the more it will sound like real music. In a nutshell its easier to do that with tubes than with transistors- I am not saying that its impossible with transistors, just that its several orders of magnitude more difficult.
Unsound, I have also outlined how anyone with modest test equipment can prove what I have said for themselves. There are even 'goners that have set up the test themselves and come up with the same conclusion. Check the archives; your statement to the contrary, I've not seen 'numerous requests'; please refrain from misleading statements.

How do you debate with equally renowned SS builders i.e. Pass,Gryphon,Vitus,Boulder.Soulution etc. who would I`m sure insist their products produce music as'real' as any tube component and possibly better?

Nelson and I are often on the same page. I often refer people to the distortion article on his website:
https://passlabs.com/articles/audio-distortion-and-feedback

In it we see that adding negative feedback does enhance odd-ordered harmonics, which *maybe* you could sort out by having even more feedback, although you would need to add more gain to do that, likely requiring even more feedback...

The fact that feedback does have this effect of increasing odd orders was also documented by Norman Crowhurst 50-some years ago. You can find his articles on http://www.tubebooks.org (vol. 3 of Basic Audio).

I totally concede I have a bias towards tubes, although if you were to check the archives I have often mentioned that I think we can get to the same performance with transistors, but they often fall short on account of its a lot easier to build a linear circuit with no feedback using tubes than it is with transistors. With regards to the other manufacturers, the debate has not actually occurred as most of the ones you mention are not active on this or other forums that I frequent. However I would likely point to past work at the links I dropped above for starters.

As far as the human hearing rules, the fact that we use the odd orders to determine how loud a sound is is easily proven with modest test equipment. I'm happy to provide the test procedure if you like; Unsound that goes for you too.
Unsound, you used the phrase
numerous requests

Your request for links which I provided does not constitute the above and my response also satisfied your lone request.

So your statement above is clearly misleading.

With regards to Norman Crowhurst, he does imply that negative feedback is beneficial. I pointed to him because he supports my claim about odd orders being distorted in a small degree by the presence of negative feedback. IOW he does not make a value judgment- that is made elsewhere, for example by Nelson Pass.

However in Crowhurst's text if one is familiar with Chaos Theory http://en.wikipedia.org/wiki/Chaos_theory we see that Crowhurst shows the formula for feedback; compared with that of a classic chaotic system that the two are nearly identical. He also mapped the Strange Attractor that is characteristic of the resulting Chaotic system that an amplifier is when using feedback. These things are not coincidental; the presence of bifurcation (distortion) is predicted by Chaos Theory and Crowhurst, despite Crowhurst's writings preceding the formation of the branch of science we call Chaos Theory.

Now the fact that Chaos Theory predicts negative feedback to be a destabilizing factor in amplifier design is something that should not be ignored (BTW, many designers will mistakenly claim that negative feedback is a stabilizing factor). However no value judgment is made, simply the expression of what is.

It is other studies including the rather simple and repeatable test (to which I have already referred) that make the value judgment. That judgment is not entirely mine, BTW, but a fairly large consensus in the audio community which agrees that odd orders are unpleasant to the human ear (and is the reason that over 50 years after the introduction of transistors, tubes have failed to become a footnote in audio history). All I have done is outline what is.
Unsound, The 3rd harmonic is one of the lower orders and is the only one considered musical with relation to the fundamental by the human ear. So Nelson's comment is spot-on.

When Crowhurst was writing, it was not generally understood at the time that the odd orders (above the 3rd) were the distortions that the ear finds unpleasant, although you will see Crowhurst refer to 'listener fatigue' with respect to the use of feedback. IOW he knew something was up, but some of the aspects of the human ear simply were not understood at the time.

Charles1dad, the DHTs are far more linear than tetrodes or pentodes. In fact all triode tubes (whether directly-heated or not) are quite linear, enough so that is is fairly easy to build an amplifier with them that does not need feedback. Triodes in general will generate distortion that favors the lower orders while the tetrodes and pentodes generate more distortion and also more of the higher orders and so tend to sound harsher, thus the need for feedback with them.

If you speak to almost any SET designer, they will likely tell you that the lower orders that their amps tend to make are not objectionable to the human ear, which is true. They do color the sound though- the ear hears distortion as tonality- so the lower orders contribute to the 'rich' or 'lush' sound of SETs.
Every bit of audio equipment ever made has warmup times at least that long. Not that you can't enjoy it long before that. Many years ago when I still ran transistors, I had to leave them on 24/7 so they would sound their best. It took them a week to warm up.