How to make my wah a bit louder?

[yeeshkul]

I made brand new guts for my wah, using the standard wox schematics with whipple inductor and black bear pot. It sounds better than before but also a bit more quiet. I used KC109 trannies (local BCs) for Q1 and Q2, where Q1 is about 350 hfe and Q2 about 250. Emitter resistor for Q1 is 470. Is there any way to kick the loudness up a bit? Maybe a smaller emitter res?
Also i used a 100k trimpot instead the so called "Q" 33k resistor. I noticed that it doesn't have that much influence on the sound...

[yeeshkul]

the voltages are:

Q1
C: 4.32V
B: 0.67V
E: 0.09V

Q2 - emitter follower
C: 8.49V
B: 2.7V
E: 3.2V *
* emitter seems to be higher than base here. I red that in "Technology of.." but can't figure out why

[andrew_k]

Have you tried adjusting the series input resistor? Check this page under the heading 'Volume' - http://homepage.ntlworld.com/s.castledine/greenfuz/wah.html

[yeeshkul]

thanks andrew, i'm gonna check it right now.

Could please anyone explain to me why is the voltage on Q2 emitter above the base? That would help me sleep 

[petemoore]

  there's gotta be wah transistors 'noted' voltages around somewhere...I never noted them...just tried the transistors and figure if it's wah-ing good it's a good wah with transistors biased ok for it...
  Might not explain it, but might help you sleep !!!
 

[Exactopposite]

this happens with a true bypass wah setup. You get some volume loss without the buffer. Replacing the 68k input resistor with a 47k should do the trick.

i'm also a big fan of the whipple inductor.

[ayayay!]

While that's completely true, it only goes up to a certain point before it just sounds more "gainy" than increasing volume.  I've got one now that I've set all the way down to 33k and it still doesn't hit unity gain for volume.  I had to find some nice "beefy" transistors (that I cannibalized from another wah) to get it to be loud enough.      Sorry, I don't have the type or measurements in front of me.  I'm at work.

[petemoore]

Q2 - emitter follower
C: 8.49V
B: 2.7V
E: 3.2V *
* emitter seems to be higher than base here. I red that in "Technology of.." but can't figure out why 
  Me too, and it seems 'contrary' enough I think I would have remembered having seen it before if it's 'normal'...*
  Maybe make that the title of the next thread... 'E of wahs Q2 be higher than base..?'
 
 

[Exactopposite]

While that's completely true, it only goes up to a certain point before it just sounds more "gainy" than increasing volume.  I've got one now that I've set all the way down to 33k and it still doesn't hit unity gain for volume.  I had to find some nice "beefy" transistors (that I cannibalized from another wah) to get it to be loud enough.      Sorry, I don't have the type or measurements in front of me.  I'm at work.

I would think those must have been some pretty low gain transistors (maybe you should try them in a fuzz). With bc108b transistors my wahs are at unity gain with  47k. you can also lower the 470 ohm resistor to increase gain but it also adds bass so u can only go so far with that before it getrs too bassy.

[ayayay!]

Actually I remember what happened now:  I put BC109s in the wah and HATED them.  That's what was putting them below unity gain, even using 33k on the input resistor.  So I put the cannibalized ones back in (I broke the originals) and it was fine again.

Yeah, I also put a trimpot in all mine for the 470 (actually 390) ohm Q1 bias resistor and it still wasn't enough.  I had to put those trannies back in.  Anyone know what the stock trannies are in a GCB-95?  That's what I like.

Still want to try a Whipple inductor. 

[ayayay!]

Ahh, I now see there are variants of 109s.     I guess I shouldn't write them off just yet...

http://www.diystompboxes.com/smfforum/index.php?topic=57313.20

[Exactopposite]

Ahh, I now see there are variants of 109s.     I guess I shouldn't write them off just yet...

http://www.diystompboxes.com/smfforum/index.php?topic=57313.20

yeah, i think the bc109b is a good choice for a wah. A has the lowest gain and C the highest. The ones with no letter after them could fall anywhere within the range of gain if i remember right.

to answer your other question, the stock crybaby transistors are mpsa18. At least the last ones i took out of a pretty new crybaby were. The BC types give the wah a a different sound.

[yeeshkul]

i used 47k instead of the 68k and reached the perfectly balanced laudness. thanks guys.

[ayayay!]

yeah, i think the bc109b is a good choice for a wah. A has the lowest gain and C the highest. The ones with no letter after them could fall anywhere within the range of gain if i remember right.

to answer your other question, the stock crybaby transistors are mpsa18. At least the last ones i took out of a pretty new crybaby were. The BC types give the wah a a different sound.

Thanks Exactopposite.  You are correct, they definitely give you a different sound.  I'll check those trannies when I get home.  Thanks on the stock part number too!