freestompboxes.org

I've always liked the tone benders, and thought that it would be fun to build a few with differing component choices and various transistors. Over the last few months, I've made about twenty of the things - all slightly different. I've extensively played through them, and have chosen the two or three that sound best (to my ears). The very best is shown here - it's a smoothed silicon bender, and just sounds great! All the other prototypes were put into diecast boxes and given to musician friends as presents. None of them sounded bad - it's just that some versions just had the edge over some of the others.

Anyway - enough chat and here's the layout - a Vero version and a PCB:
More:
Have fun!

no schematic?

Ya

Schems! I've dug some silicon Tone Bender's I've made. They're underrated. I think the top end edge you get with the silicon helps the texture of the fuzz. With all the gain going on in a bender its easy for things to get too mushy. Especially when using too high gain of germaniums.

--Brad

How about some sound samples? that would be killer.

Thanks

RnFR wrote:No schematic?

Of course there is: Adjustment: set the 1k "Abuse" pot halfway. Play though it, and adjust 5k preset until "gating" just stops. That's it!

You'll find that it has plenty of output, that the "Abuse" control gives a good range of colour, the "Sparkle" control has a very wide range and the sound is remarkably reminiscent of early Jeff Beck (certainly not a bad thing!).

Possible mods:

Put small value capacitors from base to collector of the middle two transistors - start with 47pF. This "smooths out" the sound a lot, but reduces the treble available.

If you have radio interference, put 100pF from base of the first transistor to ground.

Experiment with the capacitor values in the tone control - the 8n2 could go as low as 3n3, which would give a ridiculous range of treble control!

Increase the value of the 47k feedback / bias resistor - try as high as 470k. The gain will rise, the touch sensitivity will disappear, and it will become a high gain screaming monster!

Enjoy!

Nice job on the Vero layout! It's quite a lot tidier than mine. However, I prefer the PCB version.

ibodog2 wrote:http://formantfive.net/stb.mp3

That's an unboxed build of the original vero layout with BC109C.

not bad! sounds good dog!

ibodog2 wrote:http://formantfive.net/stb.mp3

That's an unboxed build of the original vero layout with BC109C.

Sounds good

I like it , very nice.

I like the sound!
Thanks!

Wait a minute...
Isn't this the "Hot Silicon"?
http://www.aronnelson.com/gallery/main. ... ewsIndex=1

John Lyons wrote:Wait a minute...
Isn't this the "Hot Silicon"?
http://www.aronnelson.com/gallery/main. ... ewsIndex=1

...and isn't tonebender supposed to have 3 transistors?

John Lyons wrote:Wait a minute...
Isn't this the "Hot Silicon"?
http://www.aronnelson.com/gallery/main. ... ewsIndex=1

That's what I was thinking when I started reading it. I just built Doug's 'Hot Silicon'.

quarara wrote:

John Lyons wrote:Wait a minute...
Isn't this the "Hot Silicon"?
http://www.aronnelson.com/gallery/main. ... ewsIndex=1

...and isn't tonebender supposed to have 3 transistors?

Yes, but the tone control isn't a typical tone bender type
although it's closer to the MKIII circuit. The 4th transistor is a
buffer so the tone section won't load down the circuit.
Not that this is that close to a Ge tone bender in the first place
circuit wise.

quarara wrote:

John Lyons wrote:Wait a minute...
Isn't this the "Hot Silicon"?
http://www.aronnelson.com/gallery/main. ... ewsIndex=1

...and isn't tonebender supposed to have 3 transistors?

Looking at the "Hot Silicon" circuit, it's not far away. The circuit actually came from a Colorsound "Tone Bender" that didn't work very well. It produced a nasty, gated spluttery racket. A couple of resistor changes and the addition of the preset cured all the problems. The last transistor is just to buffer the tone control, and has little effect on the sound of the thing. My latest version has a fifth transistor, to provide an output buffer!

Wow. You don't give credit to where the circuit came from? That distortion section looks to be the one that has been posted at Aron's for years. The Hot Si input section gain was designed for about a gain of 10 and the input resistance for loading of the pickup.

gus wrote:Wow. You don't give credit to where the circuit came from? That distortion section looks to be the one that has been posted at Aron's for years. The Hot Si input section gain was designed for about a gain of 10 and the input resistance for loading of the pickup.

The circuit came out of tracing a faulty Colorsound Tonebender which sounded horrible when it was working! A few resistor changes (to the values in the layout), a new tone control, and it sounded great.

I built about a dozen Tonebenders - three with germanium transistors, and the rest with silicon. The silicon versions were more consistent (mostly consistently bad), and the germaniums mostly had low output levels. I gave up on the germanium ones, and recovered the transistors for a few fuzz-face builds.

I messed around with the values of the silicon ones until I got to something that worked with every guitar I plugged in. Single coil and humbuckers give similar results, though the onset of distortion is much earlier with the humbuckers. Since my original building session, I've modified the silicon bender a bit more - I've changed some of the values in the tone control circuit, added a unity gain buffer after the tone control, and made the input amplifier have a higher input impedance, with lower noise and a bit more gain!

If anyone's interested, I'll put the changed layout up here.

I am interested.

Chugs wrote:I am interested.

Good! Here's the high-gain version. This sustains for weeks!

Your input resistance might not be as high as you think it is and how stable is the input bias (base current vs bias current vs temp).
You have a cap bypassed emitter resistor. hfe x emitter leg resistance in || with both of the bias resistors.

What Colorsound has a 100 ohm emitter resistor with a 10K collector and a 5K bias pot and 47K feedback/bias resistor?