BSIAB2 gain control

[swever]

Hi alls!

Ive breadboarded this http://gaussmarkov.net/layouts/bsiab2/bsiab2-schem.png bsiab yesterday. Seems to work fine, but the gain control is a bit naughty.

First of all, there is no output at all with it all the way ccw. Is it supposed to work like that?

Then, there is too much variation of output volume when the gain is tweaked. It is rather impossible to have it at light breakup and at unity compared to bypassed signal. I understand that this could be the nature of this ciruit, dynamic with no hard clipping etc. Still, maybe there is a way to improve?

And lastly, there isnt enough gain (for me) at the maximum setting. In fact, I was (and still am), planning to build the bsiab-x2, even bought the russian jfets. But im still waiting for these a1m and b50k pots to arrive.

Anyway, are there any ways to address those issues? And in case anybody had built bsiabx2 - does the gain control behave like that?

[Keeb]

Hi alls!
First of all, there is no output at all with it all the way ccw. Is it supposed to work like that?

Yes, when the gain pot is fully ccw the base of Q5 goes to ground and takes all signal with it! This can be tweaked by putting a resistor between lug 1 of the pot and ground. Maybe try a 47K or something?

[J0K3RX]

Read through this topic.
http://www.diystompboxes.com/smfforum/index.php?topic=94608.0