More Volume for BSIAB II?

[stalefish]

New to the forum so a big 'hi' to everyone here!!

I recently built the BSIAB II.. First build.. Had a couple problems at first but I managed to sort 'em out.. It works fine now except that the volume is not very high.. I can get it a little bit louder than the bypassed signal when the volume pot is maxxed out but that's it.. Is that normal? Thanks!

Oh, I've checked all the connections and the solder joints.. Besides, I'm getting some fantastic tones from it so I'm guessing my circuit should be ok??

[MartyB]

The volume boost should be big.  Sounds like your tones are ok.  Could you have damaged a JFET?  Did you socket those?  I've killed J201's before...

[Phorhas]

Sounds like something is indeed not in order inside, but anyways, if you'd still wish to boost it up - I really suggest experimenting with the last JFET's source resistor. more out put, more saturation and a more interesting sound. but it could get oscillationg and even TOO much gain, so have fun trying it out

[powerplayj]

Where is your gain setting?  When the gain is maxed, my volume hits unity at 1/4 turn.  When gain is at minimum, unity is ~ 2/3 turn on the volume. 

[stalefish]

Thanks for the replies.. To answer the first post, yes, I am using sockets.. I was also rather cautious about burning out a JFET so I decided to be safe.. Secondly, my gain setting is at about 1/2 to 3/4.. I'll experiment with the resistor and see how it goes.. Thanks for the help!!

[Headshot]

Wow.  I really love my BSAIB II, but I've had to crank the volume almost full up to get to unity.  I just thought that's maybe the way the pedal is.  I guess something is actually wrong and I need to mess with it some more!!!   Any other ideas to try?

Thanks!!

[T113]

It's early, but IIRC, unity on mine is around 25% on the volume knob.

[Headshot]

Ed, are you around?  Any ideas on why mine has low output?

Thanks!

[bluesdevil]

I'm not Ed, but thought I would report my build was also at unity gain with the volume knob maxed. I didn't think anything drastic was wrong because I'm using active pickups.... still, my other pedals seem louder. I wouldn't mind building it again on a pcb instead of the vero I used, just in case I screwed up though.
       That's a great circuit...... makes your guitar strings sound like they're begging for a shredfest even if your fingers aren't quite up for the job. 

[petemoore]

  Should be pretty hot in the output Dept.
  All the knobs affect output volume, tone knob least, but I can get mudboost out of it, N/P. 

[Headshot]

bump

[jeffy]

Mine has the same problem as well. I have to crank it almost full out to make unity. i checked over all solder joints and everything seems fine. Any ideas at all. It seems that there are a number of people who have the same problem as well.

[Headshot]

bump....   any one else?

[Ed G.]

Sorry, I've been away.
On my pedal, I have lots of extra output. I use audio taper pots and to get it a little louder than bypassed, I usually have the volume pot set at about 1 o'clock. So yes, there should be plenty of boost.
Check the voltages on the fets. The drain on the bottom fets should always be biasing at around 4.5v...about half of the power supply, give or take a little bit. If that's off, something is off.
Same goes for the final fet stage, I usually bias it by ear but it should be at around 4.5v.
Fets can be tricky sometimes and they are variable. Sometimes you get a lot of variations within the same part number. Some variations also among FET manufacturers. I can't say which work best, it's worth it to socket and try different ones out.
Anyhow, the short of it is that if you're not getting a healthy output from the pedal, I think something's wrong somewhere.
Hope this helps,
Ed

[jeffy]

Thanks ed,

I remember checking all of the voltages on the fets and I do recall them being pretty close to what the voltage sheet on the fets say. Maybe i just need to get some more fets and try that out?

[Headshot]

Thanks Ed!!

I figured out my problem.  I mistakenly put two 8.2 k's in for the 82 k's.  Plenty loud now, and a ton more gain....

Thanks for sharing such a great circuit Ed.  It's a winner.

Headshot