Tonebender 3 knob mod suggestions?

[axg20202]

OK. I've built an all-germanium 3-knobber and have kind of settled on a build based on a combination of features of the Tone Burner and Boutique Bender, both at GGG. Basically, my circuit has the same component values as the Tone Burner, but with the following features:

1) Same pot values as Tone Burner – I have omitted the 'String' and 'Treble' controls.

1) Instead of adding the 'tightness' switch from the Tone Burner, I've just added a single 10uf cap coming from the Emitter of Q2 going to ground – this basically adds about 3 more pairs of balls to the circuit, giving the 'Mud' (Fuzz) control the range to go into brain haemorrhage territory.  

2) I've included the 500k trimmer and 10k stop resistor coming off Q3, as per the Boutique Bender layout, although I've actually used a proper 500k pot for this (so it's a 4-knobber!). I guess it's a kind of Q3 feedback control, which seems to work interactively with all three of the main controls. It allows you to back off the throttle of the pedal while making up the gain loss using the Volume control – more subtle, overdriven sounds can be had if the fuzz ('Mud') level is backed off too.  Anyone else used this? Opinions?  

3) I've gone from volume pot wiper directly to pedal output.


Before I box it up, can anyone recommend anything else I could tinker with to improve the circuit?

Is there something in my mods above that could be done differently or better? 

[Dragonfly]

Add a switch that bypasses the first stage, thus giving you essentially a TB and a Fuzz Face.

[axg20202]

...ooh, yes, not a bad idea....although I already have a Fuzz Face, this could be worth looking at. I'm planning on theming the enclosure design by calling it a 'Purple B*stard'...the switch could be a 'Bitch/B*stard' selector 


...any other suggestions for mods anyone?   

For example, the demo clip on GGG of the Tone Burner gives the impression of some crunchy, octavey stuff going on - mine doesn't really do that......how come?

[Dragonfly]

...ooh, yes, not a bad idea....although I already have a Fuzz Face, this could be worth looking at. I'm planning on theming the enclosure design by calling it a 'Purple B*stard'...the switch could be a 'Bitch/B*stard' selector 

Just make it on a footswitch so you can change it during a song...use the FF for rhythms, and click the switch and go to Tonebender for leads. Ive made a few of these for friends, and they all love them.

[axg20202]

I'll give it a try. At what point in the circuit do i tap it off?

[Dragonfly]

I'll give it a try. At what point in the circuit do i tap it off?

disregard

[Dragonfly]

I'll give it a try. At what point in the circuit do i tap it off?

wait...are you building off the MK2 schemo ?

[axg20202]

I thought that was the case but wasn't sure....the mkII is a FF with a stage shoved on the front...but the 3-knob is a different beast, so it can't be done...ah well, like I said, I have a FF already...

Thanks though.

Any more?

[Dragonfly]

yep...thats what i was remembering...i was thinking you had built a MK2....

i'll go look at the schemo though, as im SURE there are some good mods available

[caress]

i just made one of these last night and it sounds ok, but i'm confused about some things...  i changed the input cap to a 1uf and added an output cap of 1uf as well, used pulldown resistors, ommited the resistor to volume pot and subbed the Q3 feedback control pot with a 100k and 10k stop resistor.

my issues are:
1.  it doesn't really get too nasty...i think i need higher gain transistors, though.  the ones i'm using right now are all realllly low...like 30-50hfe.
2.  the fuzz, tone and Q3 feedback pot all turn the volume down a good amount.  so much so that if all are turned fully CCW and the volume is at full, there is a little volume drop...  ??

mostly it's number 2 that's bugging me...does this happen to any one else?

[caress]

some interesting changes i made whie messing around...

1.  i couldn't exactly get the right sound i wanted from the original tone control...it basically attenuates the lows on the HP side but really just brings them back in on the LP side...i wanted a little high attenuation on that end so i added .02uf to ground from the LP side of the tone pot.  it drops the gain a very small amount, but the tone control gain was very uneven to begin with...
2.  a really great mod imo is to add a switchable 1M, 500k or 100k pot (or for really simple operation, just a switch with no resistor) from the output to the collector of Q1.  it is a feedback loop and seems to work in a very strange way.  at minimum resistance, it sounds HUGE!  really LOUD!  so be careful...   ...but none of the controls really work except for the volume, and even that is very limited...   if you turn down the volume a bit on the pedal and your instrument you can get a nice bit of control out of the feedback pot, but none of the other pots!  it really does sound gnarly, though, especially over-saturated and gated and compressed if you throw a boost or something before it...   if you use the pot, though, you need the switch...


edit:  from my earlier post, i found out why my fuzz pot was working strangely...i had soldered the .22uf to the base of Q1!  wah wah...it was kind of overdrive-y before, but now it's nice and fuzzy.

[axg20202]

1) Instead of adding the 'tightness' switch from the Tone Burner, I've just added a single 10uf cap coming from the Emitter of Q2 going to ground – this basically adds about 3 more pairs of balls to the circuit, giving the 'Mud' (Fuzz) control the range to go into brain haemorrhage territory.  

Did you add this 10k 'tightness' cap to yours? It makes a huge difference and is probably more sympathetic to the controls than your Q1 resistor mod. I'm still debating whether or not to have this swichable but I might keep this as standard and omit the switch because it sounds so good.

[caress]

Did you add this 10k 'tightness' cap to yours? It makes a huge difference and is probably more sympathetic to the controls than your Q1 resistor mod. I'm still debating whether or not to have this swichable but I might keep this as standard and omit the switch because it sounds so good.

if you mean the 10uf coming from the emitter of Q2, then yes.  it's in the original schematic, which is mostly what i went by.  it still wasn't that huge imo, though i might try using a 22uf there instead.  try the other feedback switch i was telling you about...it's like adding one more pair of balls that are the size of grapefruits.

[axg20202]

Did you add this 10k 'tightness' cap to yours? It makes a huge difference and is probably more sympathetic to the controls than your Q1 resistor mod. I'm still debating whether or not to have this swichable but I might keep this as standard and omit the switch because it sounds so good.

if you mean the 10uf coming from the emitter of Q2, then yes.  it's in the original schematic, which is mostly what i went by.  it still wasn't that huge imo, though i might try using a 22uf there instead.  try the other feedback switch i was telling you about...it's like adding one more pair of balls that are the size of grapefruits.

So it is - I did't notice it down there on the layout. I'll give your mod a go. Thanks.

[caress]

one question i forgot to ask...will subbing the 2N270 ge diode for a 1N34A make a differrence?  i'm checking the datasheet for the two and they seem quite different...

http://www.datasheetarchive.com/search.php?q=2N404A&sType=part     (it's the second datasheet from the top)

[axg20202]

Hmmm, not sure. I just used the germanium diode supplied with the transistor set I got from Small Bear.