All true, but design and implementation play a large part in it too.m6tt said:Old guitar amps were commodity items, whereas old hifi amps were expensive. Thus, more time was spent in the old hifi amps to quiet them. Another factor is that most hifi poweramps have at most two gainstages before the power tube (excluding a phono preamp/RIAA)...many guitar amps have more gainstages, and also higher-gain gainstages. this tends to amplify a lot of hum unless careful precautions are taken.
All true, but almost all designs used are based upon 'classic' ccts which had little filtering and often poor design and layout. There are often 'better', 'alternate' ways of doing it, but then you lose a big part of the market; those for whom classic is god.1400WATTSRMS+ said:Well, for starters when you boost your signal to overdrive it so it can be clipped and generate distortion, you're also boosting the noise that's present in the input signal. Hi-Fi amps would in fact do the same thing only you'd never be boosting the signal into clipping like we do for instruments.
However, the more you refine your "distorting" set up, the less noise you'll have aside from the pesky grounding buzz which is really determined by the quality of your power system's ground.
Have a load across the secondary at all times whilst it's on for safety's sake (OPT protection).Marcelinho said:detaching the speakers is a good idea.
What about changing heater supply from ac to dc for the three 12ax7's
+1 Geek.Geek said:Hmmm, I've never designed a noisy guitar amp and also never needed DC filaments. All of them have headphone outputs and are quieter than any SS guitar amp I've tried.
Just decent layouts, proper tube selection (keep 12AX7's out of the V1 position) and bias the heaters +40V or so above ground and instant quiet
Marcelinho said:It's a ac30cc2
22uF with 10nF in front and after 15mH Choke.