[
Date Prev][
Date Next] [
Thread Prev][
Thread Next]
[
Date Index][
Thread Index][
Author Index]
RE: Tubes in Pre-amps: your expertise and honest opinion.
I'm so tired of seeing this "warmer" expression trotted out lazily every
time someone is trying to market something with a bottle in it.
what exactly is it supposed to mean? is it to do with noise-floor,
frequency response, distortion, what?
those of us that have had the lids off some of this kit will know that,
traditionally anyway, the glass gets warmer than it's silicon equivalent.
but that is irrelevant to the end-user.
I've seen quite a few examples of equipment fitted with an
ecc83/12AU7/whatever, where the heater wasn't glowing bright enough for
the box's designers & so they fitted a yellow/orange LED underneath it to
fake the glow.
a lot of these modern valve devices run with very low HT, either for
regulatory reasons (e.g. the EH stompboxes) or because the makers just
couldn't be bothered with the nuisance of having to generate 400V DC
accurately & reliably. sure, the valves last longer, but they are working
so far down their conductance curve that they're not doing any real work
(& so the output needs buffering/boosting with a 5532 or the like) & of
course, they're operating miles away from the only musically useful part
of their character.....
which is-
here's the only major sonic difference that matters in 99% of normal
everyday contexts:
if, & only if, it's driven into non-linearity (& by this time we're in
fuzz-box territory, not super-clean mic pre-amplifier), the valve/tube
tends to produce slightly more by way of even harmonic distortion, while
the silicon or germanium tends to produce odd-order harmonic distortion.
I say again, these are distortion products, & are not supposed to be there
anyway.
some feel that the even harmonics are more musically useful; this
certainly seems to be the case in the context of (typically overdriven)
instrument amplification.
there are other (sometimes very involved) arguments for & against the
continued use of thermionic valves in "high-end" audio equipment- mic
pres, compressors & the like. class-A operation is slightly more stable,
perhaps. phase distortion.......
well.
all I can suggest is that a blind listening test be performed before the
emperor leaves the tailor's shop.
I play my bass through an orange OR120 because I like the way it sounds
when I turn it up loud. but I record it straight into a korg digital
multitrack with an sm57.
your mileage, as always, will vary.
oh- & an all-tube circuit is more likely to carry on working when exposed
to a massive electromagnetic pulse, such as caused by a nuclear explosion.
this may or may not be a selling point. :-)
duncan.