Colorsound 3-knob Tone Bender

[karter2000]

Hi all,

I've just finished a Tone Bender, using a PCB from General Guitar Gadgets, and a matched Ge transistor set from Small Bear.  As far as I can tell, it appears to be working as it sounds good to me.  However, I'm not sure as I don't have much experience with the Tone Bender.  Could someone more or less confirm what I'm supposed to be hearing?

Also, as I want to use it with bass, is there a way to improve the bass response?  Could I up the input cap value (0.1uF to 1uF) without affecting the circuit too much?

Thanks,

Lyle

[Steben]

You could do that, but remember the simple tone stack of the 3-knobber dials in form "normal" to "over-the-top-treble".
"Spiky the Bendy is" Yoda would say.

[mac]

There is a 10k going from the tone pot to gnd. When I played with it, I increased that resistor and used 472 instead of the 222 cap. NOt only the final volume was higher but there was no such a extreme treble response.
The input cap to 105... try it, but the fuzz control is a little muddy with the std cap. Breadboard a copy and test before mod what's built.

mac

[karter2000]

Thank you!  I'll try that out.

Lyle

[BBQLS1]

Thank you!  I'll try that out.

Lyle

Let me know how you like it, I'm building one as soon as the parts get here!

[karter2000]

What bugs me about this project, is that the reissue available from Macaris in the UK sounds like it has much better bass response (judging from the clips I've heard).

http://www.macaris.co.uk/product_full.asp?productID=176&typeID=27&catID=5

I'm not sure what's so different from their version to the one I built, except that their version uses silicone transistors as opposed to my germanium transistors.

Shame though, as my version really has a beautiful fuzz to it.

Lyle

[mac]

Si versions need the addition of a pot at Q3 between base and collector, if not Si won't bias. Ge bias because of the leakage. But I've found that if the leakage is higher than 50 - 100uA then the 18k - 10k -10k network put vc3 near ground. If this happens tweak the 10k to gnd from the junction of the 18k and the other 10k.
The 3-knob needs low leakage Ge, under 50uA or less

BTW, there are some schematics that uses the pot I told above even in the Ge versions. Although not necessary, it worth the try.  Sometimes it gives more focus, sometimes not.

mac

[mac]

I forgot to say that Si versions also need to reduce the 220k in the darlington pair to around 100k to 150k to set vc2 at 3.9v to 4.3v which IMO make it sounds better.

mac

[stobiepole]

I just built one myself. I used a pair of about 120hFE Ge for Q1 and Q2, and a 170hFE for Q3, and it sounds great. Leakage is about 100 for Q1 and Q2, Q3 leaks about 200. I haven't tried it yet, but I plan to see if I get the same tone with Si in Q1 and Q2, Easy Face style. I think that'd be the easiest solution for those who don't have buckets of germanium trannies lying around...

Chris

PS I do have buckets of Ge trannies. Ebay is your friend.