Re: mic preamp modification


Joerg wrote:

> Hello Rex,
>
> > Phantom power is not the problem, or at least not the main problem. I
> > connected a condenser mic, turned phantom off to disable it and cranked
> > up the volume. That's where I realized that there is more hiss from this
> > thing than I would have liked.
>
> If you really want to figure out where that hiss comes from there is a
> trick: Take a cap and ground one side with a short braid. Hold the cap
> at the inputs of the various amps in there. But turn down the speakers
> since this can cause a loud pop if there is DC on a node. Discharge the
> cap everytime before probing a new spot or you could fry things.

I think he already said it used SMT ! Maybe use a pin as a probe ?


Graham

.

Relevant Pages

  • Re: What makes noise/hiss; redux?
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  • Re: Turns out the Hum on my 2204...
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  • Re: What makes noise/hiss; redux?
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    (alt.guitar.amps)
  • Re: Turns out the Hum on my 2204...
    ... that the same leg is Cap coupled to the V1a input as well. ... becoming HISS But I can handle that for now. ... Old carbon comp plate load resistors can be very noisy in any amp. ... If it doesn't need correcting then all the rest do but I will ...
    (alt.guitar.amps)
  • Re: Turns out the Hum on my 2204...
    ... that the same leg is Cap coupled to the V1a input as well. ... caps give you hiss but I haven't read that, ... Old carbon comp plate load resistors can be very noisy in any amp. ... If it doesn't need correcting then all the rest do but I will ...
    (alt.guitar.amps)