Tubes... what do they do?...

Eddie, you really don't comprehend english well at all ...

Some strange comments here.

Vacuum tubes are amplification devices, and tubes like the 243 or 300B are the most linear open loop amplification devices known to man. The proof of this is that you actually get vacuum tube power amplifiers that do not make use of any form of negative feedback, and those that do, use very little NFB.

Transistors have very high open loop distortion levels, which need be addressed by using negative feedback loops. The use of negative feedback (in both vacuum tube and transistor) in amplifier lowers distortion levels.

Opinions differ pertaining to the use of negative feedback, as it does introduce non-harmonic (i.e. phase) distortion, which many folks find disturbing. Distortions associated with vacuum tube amplifiers (with little to no negative feedback) are mostly a diminishing amounts of first, second and third harmonic distortions which many find pleasing to the ear.

Harmonics occur naturally with all sound waves i.e. strum a single guitar string and the other vibrate in harmony; so an amplifier with a high level of harmonic distortion can still sound extremely lifelike and real (because it is). Phase and inter-modulation distortion do not occur naturally, so even very small amounts can give the music a cold or hard edge and sound very unnatural.

Good amplifiers (and bad amplifiers) can be had using either vacuum tube or transistors. Anybody that simply dismisses one topology as being bad or distorted is simply demonstrating ignorance.

Regards
Paul

11-16-06: Cdwallace “what testing results or guidelines do you use or suggest one should use to determine the difference between a good tube amp and bad tube amp?”

Use the most complex and most accurate audio evaluation devices known to man - your ears.

As a bit of an education, have a look at http://www.high-endaudio.com/. Arthur is somewhat opinionated, but has a wealth of knowledge and experience and you may just end up learning something.

CD Wallace – apologies for my tone in prior post, it was uncalled for.

The article you posted pertaining to the CAD300SEI is spot on. I always cringe when folks want to show me test results to prove how good their sound is … my ears have rarely been able to match their test results.

The hobby wouldn’t be much fun if there wasn’t things to learn.

Slightly off topic. I spoke to a gent name Peter Ledermann of Soundsmith (http://www.sound-smith.com/cartridges/sg.html) . He has just developed a brand new type of electro mechanical cart that does not make use of coils or magnets. If what he says is true, it will be a paradigm shift for analogue folks … Yep, there a lot to learn and a lot of new things audio.

Regards
Paul

CDWallace – Not sure what you consider “progress”, but I doubt I was leaning towards what you consider progress. After 30 years in this hobby I do still learn a lot, but most certainly not from just anybody.

What I have learned though is that facetiousness and irony is lost on some, and in a big way. Anybody following the thread would know my statement “my ears have rarely been able to match their test results.” is obviously tongue-in-cheek … well almost anybody.

I recall many years back watching a flamenco guitarist tune his guitar with an electronic tuner. I recall thinking that he probably wouldn’t be much of a musician if he couldn’t tune by ear. I was right; he was pathetic.

Same holds for an audiophile. An audiophile who cannot trust his ears is not worth listening to.

Regards
Paul