Any cool mods for Soul Vendor? Bias pot? More useful tone pot?

[Had2Much2Think]

Whoa! Just built the Soul Vendor (my first Tonebender style build) and I am shocked how dang good this thing sounds right out the gate. Sustain for days!

Gnarlier than any fuzzface style circuit I’ve built but still very tight and well defined with rich harmonics. It’s nasty but not overly gated, sputtery, or muddy and actually seems like it would cut through a mix well which I can’t say for all my fuzzfaces (although I think the fuzzface is more versatile and “musical” sounding with it’s ability to clean up which the Soul Vendor doesn’t really excel at)

For transistors I used two Soviet MP41A with gains of around 60-70 for Q1 and 2 and one of the more “modern” production AC128’s with a gain around 125. Can’t remember what the leakage was for Q3 but it seemed sufficiently high, especially compared to the Soviet trannies which don’t leak much.

I didn’t have any 1N270 diodes so I used a 1N34a which seems to be working just fine. I’m not sure what effect it has on the tone, if anyone can tell me I’d love to know.

So it sounds great so why would I want to mod it? Well the tone control doesn’t do much for me, I seem to prefer it all the way down (which is somewhat counter intuitively the brightest setting) and it seems like everything past noon is way too dark to be useable- maybe a different cap somewhere could give me a more useable sweep?

I also feel like a bias control of some sort could be fun for this circuit. I thought I might have to mess with some resistor values in order to make it sound right as I’m used to having a trimpot to set the bias (like you might do with a fuzzface) but it seemed to sound great without any tweaking- almost too great maybe…..,It might be fun to have the option of making it sound nastier and shittier on the fly if I felt like it.

I know how to set up an external bias pot on a fuzzface style circuit (like a sunface- probably my favorite fuzz I’ve built so far) but am not sure how this would work with this circuit. Which resistor(s) would I replace and with what value pot? Or do I want to use a lower resistor value before the pot like the sunface does to reign in the range of the bias pot and keep it useable?

I could be way off base as to how this might work, I’m still learning about how these circuits actually function. Any ideas are welcome- I have nearly everything socketed so it should be easy enough to try something out.

So yeah- fun pedal! I plugged into my AC10 at bedroom levels and got some very satisfying Mick Ronson/Jimmy Page tones- it really does the Sabbathy/Tony Iommi tones very well too (although I don’t think he used a Tonebender or for that matter a fuzz pedal at all). Even my roommate/bandmates 8 year old daughter was impressed with the sound- I heard her ask her Dad “is that really Matt playing guitar in there??!”.

Thanks in advance for any help and thanks to pedalpcb for putting in the hard work it takes to reverse engineer these circuits and design these boards so elegantly.

 

[andare]

Didn't Mick Ronson use an MKI? You mention a diode so this is the MKIII.

I haven't been able to do any mods to the bias, just the usual mods to get more output (remove the last resistor) and play around with that input cap and volume pot for more or less bass.
I haven't built mine yet because I can't get it loud enough.

With the tone all the way down it's ridiculously harsh and bright. The fact that you like that tone is weird. Do you have an unusually dark rig? Tone suck?

 

[Had2Much2Think]

Didn't Mick Ronson use an MKI? You mention a diode so this is the MKIII.

I haven't been able to do any mods to the bias, just the usual mods to get more output (remove the last resistor) and play around with that input cap and volume pot for more or less bass.
I haven't built mine yet because I can't get it loud enough.

With the tone all the way down it's ridiculously harsh and bright. The fact that you like that tone is weird. Do you have an unusually dark rig? Tone suck?

Yeah Mick Ronson used the MK1.5 with a cocked wah I believe. The Soul Vendor is based on the MK3 for sure. I’m not saying it was a dead ringer for his tone per se but the massive amount of sustain reminded me of his playing.

I certainly don’t have a dark rig, my guitar is a Reverened Eastsider S which is a tele style guitar with 3 pick ups and a Strat style bridge/wiggle stick. It’s all tele in the bridge position (bright and clear but not an ice pick like a Strat) and all Strat in the other 4 positions. My amp is a Vox AC10 and I keep the bass around 8 or 9 and the treble around 11 or 12 o clock. I run the gain pretty low, like 9 or 10.

If anything my tone is pretty damn bright, I’m the lead player in the bands I play with so I like to be able to cut through the mix but try not to make people’s ears bleed .

As far as tone suck, I was running the pedal right into the amp with a patch cable. I was using a fairly long cable but I don’t think it would make that big a difference.

Could be just a matter of preference but the tone all the way down didn’t sound bad to me at all, it was bright but not in an unpleasant way- kind of like a rangemaster/Ge treble boost.

Also I had no issue with volume loss- it was plenty loud. With the volume all the way up I could barely get the volume on the amp up past 7 without feeling like I was gonna drive the neighbors crazy.

It’s weird, it seems like it’s almost behaving differently than other tonebenders but I don’t mind it at all. The only major difference (aside from the obvious variations in transistors) is I used an 1n34a diode.

 

[andare]

It's not weird, the MKI, MKII and MKIII are all completely different circuits.