Wah Transistors?

[ZiggY!!]

Hey people, great place this is!

I was looking through the wah info here http://www.geofex.com/Article_Folders/wahpedl/wahped.htm and was trying to find a "5117" transistor, though im having no luck. I dont spose you guys know of a suitable replacement for this application?

Cheers!

[smallbearelec]

Many general-purpose NPN devices, even types as common as the 2N3904, have been used and will work. One choice I offer that has pleased many of my customers is a work-alike of the European BC109.

Steve Daniels
smallbearelec.com

[Paul Marossy]

I like the BC109 a lot. Like Steve says, common NPN types will work fine, too. I have tried various common ones in one of my wahs, and to my ears, there is not a huge difference in the noise levels between most of them.

[petemoore]

   Note...
  I socketted the V847's transistors, glad I did...definitely alters the way the wah sounds...one of them has BCxxx tranny's another has 'something' other than the MPSA18's...
  The BC's seem to have their own characteristic sound, other Si's should be chosen for tone in a wah, mainly [if I allude correctly] gain being the deciding factor of judgements for 'better / worse" opinions.
  Socket 'em I sezz...

[Paul Marossy]

Yeah, I think the BC109s do have their character, in a wah circuit anyways.

[toneless]

Bc109's sounds best for me, too. In general I prefer using low gain transistors for this kind of stuff.

[formerMember1]

i tired bc109b current production and didn't like them.  I tried NOS bc108C's and like them alot.  THey are around 400hfe and the bc109b were around 325hfe or lower

I have bc109b NOS on the way.

I tired many transistors in the wah, the 2n5172's are great too. THey are more thicker and bass then the bc108cs, and it isn't becuase of hfe difference, cuz they are close to bc108c's as far as hfe.

mouser sells  the 2n5172, make sure you buy like at least 10, to make sure you could try different hfe,..

[ZiggY!!]

Thank you very much gentlemen!   

[Paul Marossy]

Yeah, I guess I should have mentioned that mine are NOS...

[Ed G.]

The "5117" is a Thomas Organ part number. It won't cross-reference to anything, but it is actually a 2N2925.
I don't like the metal can bc109b's, they sound bassy but dull. The 5117s in my old Thomas Organ wah have a nice sparkle, brightness that I like. Some might call it harsh, but I don't. I have a 2n4401 right now in my wah. It pays to play around with different wah transistors. I think people take the transistors for granted, but they have a pretty big impact on the sound, they even sound differently in the different positions.

[Paul Marossy]

I think people take the transistors for granted, but they have a pretty big impact on the sound, they even sound differently in the different positions.

Thanks for that info Ed! I was wondering what the heck that 5117 was. I like the sound of the 5117s as well. Yeah, I too have found that there is a difference in sound between different transistors.

[formerMember1]

the Q1 hfe should be higher than Q2, the Q1 affects the tone, and Q2 affects the sweep in my opinon,

the 2n5172 have a totally different sweep than the bc108C, i think do to hfe in the Q2,....just replace Q2 witha  300hfe than with a 400hfe and hear the sweep change,,....don't know why but it does,...

matched gains are clear/focused, mismatched gains are more wild and quacky

[Ed G.]

the Q1 hfe should be higher than Q2, the Q1 affects the tone, and Q2 affects the sweep in my opinon

That's exactly true. I said they sound different in the different positions, but that's what I meant, it's been a while since I fooled with my wah.