This was a request. here is a change to try out your low gain and low leakage soviet transistors in a Tonebender Mk. II. There is a trimpot for each transistor and an onboard voltage converter for daisy chaining. The schematic specifies MP40 for all transistors but I bet other should work and sound good as well like MP41, MP42, MP20, MP21, GT308, GT402 etc, etc, etc. Just mind the pinout for the GT series transistors. Vero - Point2Point Layouts has a spreadsheet for for most NOS russian transitors HERE.
You can also build a Marshall Supa Fuzz by upping the 5uF (....or4,7uF) capacitors to 10uF or a Vox Tonebender Mk. II by upping both 10nF caps to 15nF.
Verified... Q3 Collector trimmer should be 10k though
ReplyDeleteThanks! Tagged.
Deletecould you post voltages of each C pls :-)?
Deletewow the world would sure be a boring place without DIRTBOX LAYOUTS, everyone really appreciates what you're doing !!!!!
ReplyDeletehaha, thank you!:-D
DeleteThis is awesome. Thank you! I have a bunch of transistors sitting around that didn't quite make the cut for other stomp boxes. Will be happy to try this out.
ReplyDeleteHey...great site...thnx so much! I want to put the trim pots externally. Would I use linear pots? What would be the best way to do this? Thnx again!
ReplyDeleteI suspect that the only trimpot that would be usable as an external control would be the 10k one. The 50k's might have a very limited range and/or just sound bad.
DeleteFor the 10k trimpot as an external control; solder a wire from K16 to lug 3, L16 to lug 1 and 2. Not sure about the taper, I think you need to try it yourself.
I would also increase the 470ohm resistor to 1k or so for more output and for some voltage protection for Q3.
Ya the 50k trimmers are to help with oscillation... the 10k is the bias, mostly helps with sustain, and it changes the flavor of the fuzz.
DeleteI was wondering why visits to the Russian pinout chart was so high. Thanks Anders.
ReplyDeleteI can't find this schematic in the usual places, is it unshared (completely understand) or am I just sucking at searching?
ReplyDeletehere is the thes schematic:
Deletehttps://drive.google.com/file/d/1vdNnWEvjsoRdWDLnF98S7eMQZciKS_X-/edit
As you can see, it is pretty much a standard TB Mk2 with three bias trimmers and a voltage inverter.
fuzzhead... I can post the DIY Pedal discord link here if you'd like. That is where Miguel(pointreyes) shared the schematic for the pedal.
DeleteSure! Bring it on!
Deletehttps://discord.gg/kMaGjdzKjd
DeleteTried building this and the fuzz sounds great however I am getting a constant high pitched whine. Tried a few transistor sets and it is constant regardless of transistors. Any ideas? A cap maybe?
ReplyDeleteWhich charge pump do you have and where did you buy it? These can cause oscillation if it the wrong type and there is still fakes out there....
DeleteI can't believe I didn't think of that. I have some 7660's from Tayda and they've been unreliable in the past. Do you have a reccomendation?
DeleteI buy them at a local shop so I don't have that much experience when it comes to buying charge pumps online but I've read that you should avoid ebay and Tayda...
DeleteIf you're in the US I guess you're safe if you order from Smallbear or any of the big electronic chains like Mouser...
For the EU, Musikding, Banzai and few others is pretty safe.
Canada but I order regularly from SmallBear. You can trust them for Fets and transistors so I don't mind paying a little extra. Thanks for the help and thank you for your absolutely excellent website!
DeleteJust thought I should chime back in. I bought some better charge pumps and voila. Problem solved. This is a great sounding fuzz!
DeletePerfect! Glad everyting turned out good!
Delete