Blackfire low gain Mod?

[crawler486]

Hi guys,

        I'd like to tame my Blackfire a bit. Anyone knows a good link to a low gain mod?
        I tried the search. Nothing good turned out.

Thanks!!

[petemoore]

I'd like to tame my Blackfire a bit. Anyone knows a good link to a low gain mod?
        I tried the search. Nothing good turned out.
  Gain altering techniques...
  Gain control between stages.
  Eliminate a stage [or two, they're inverting]
  Diddle with the bias resistors, IIRC there may be emitter bypass caps which could be lifted.
  Series resistance in the circuit.

[John Lyons]

In general series resistors (the 10Ks and 470K) can raised and will make the gain lower
and all resistors to ground  can be made smaller and this will lower gain.

I would do this:

The 1 meg gain pot could be switched out to a 500k Audio.

The 1 meg at the base of the 3rd transistor can be lowered to  470K .

Try this and see how you like it.

If you need less gain:
Make the first 10k bettween the first two transistors larger. Try 50K or 100K...
Make the 10K after the 3rd transistor 50K or higher.

This should do it.
Do each one and test it out, stop there if you like it
Let us know how it works.

John

[crawler486]

Thanks for the suggestion guys!

I'll try those, maybe after the xmas parties!!!

[WGTP]

Another method I didn't see, is to disconnect the by-pass cap in the second stage.  Easily switchable.