Above Motthird>>If any of the tubes were microphonic, would I have audible problems throughout the range or could it be frequency-specific?
I've never seen anything tying M to F.
above Gs>>Tube microphonics, generally, degrade soundstage imaging and detail.
agreed. Why do you agree with Sugarbrie that it is good thing? Or, is your position that it (microphony) is it simply unavoidable in normal audio usage, in which case, I basically disagree.
>>As to an "identifying" sound, tubes do not have a sonic character - the sound is a product of its environment (circuitry).
Agree and disagree. A tube cannot do work without a circuit. You need a load. No one has ever heard a tube alone. However, tubes do have individual characteristics and this leads to a certain results given a particular circuit. Look at a tube's plate curves and constants. It does not come close to telling you all you need to know but it tells you something. The curves and loadlines will of course change with the circuit.
>>As to the "tube sound" (warmth, LF bloat, etc), it's attributed mostly to distortion that's inherent in its construction and function as a gain device, especially at the clipping point.
basically Agree. And distortion at the clipping point has little to do with microphonics. Some distortions, like microphony, can be controlled in the audio range and in normal audio uses (which does not include tapping).
>> I also think that the microphonic characteristics of tubes contribute to the effect
To a very limited degree in most circumstances. All tubes are microphonic. You can't use a tube that isn't. Tap one (yes it's not a good idea) and they all respond. But this is not the normal use in audio so who cares.
Usually when someone says they have a microphonic tube it means they have one where the internal structure of the tube is weakened and lose. It acts similar to a microphone diaphragm as picks of vibrations (either music or tapping) and amplifies it. The technology has come far enough that this can be avoided for most audio uses.
Guitar players love this effect sometime and exploit it. Listen to Jimi Hendrix's use of feedback (or many others) which is, in part, caused by this.
Some folks like the effect in audio too. Kevin Deals statement is as follows:
True microphony will rear it's ugly head and make itself known with the most obnoxious distortion you can imagine. A smidge of microphony can (at least in the hi-fi world) add a sense of "air". That's why some guys buy tube dampers and find it sounds better without them. Sometimes.
True microphony is ugly. Generally it can and is to be avoided.
When you (Sugarbrie) imply it is the reason NOS tubes sound the way they do, you imply microphonics are a dominant reason for sound in NOS tubes (and therefore all old tubes). I think you are going way overboard and making it sound like it is generally a good thing and at the heart of tube sound. This is just wrong. I do agree above that the tube sound is a tube/circuits distortion characteristics. Microphony play a very minor role in most audio because it is a distortion that tube manufacturers have learned to control although QC is an issue. (again, all tubes are microphonic, but if they are used as intended they will perform with out it.)
Deal says a smidge and sometimes. If you had said sometimes a little M can be a good thing and qualified that in a meaningful way I would agree. You did the opposite, IMHO. Deal is is not saying that it is the secret reason behind NOS tube sound or that it is a way to increase "highs", or that "a tube with absolutely zero microphonics will *very likely* sound kind of dull in many systems" all of which I think are far-fetched and misleading.
There are better ways to get air into your system simply because microphonics are by their nature untunable. As Karls said above, unpredictable. Better to remove them ( it ptretty much can be done) and then tweak with something more subject to control if you ask me. You are more likely to get the sound you are looking for.
Cheers
I remain
