Again with the NTE404's. It's like I've finally got a reason for why I ordered so many of these low gain PNP germanium gizmo's. Sounds great. All three of them are around 55Hfe with NTE leakage and this pedal sounds like a tank being operated by a swarm of bees. Thank you!
I beöieve the part numbers wasn't specified in the schematic. This is basically Tonebender Mk3 without the Tone control so try low gain w. low leakage for Q1 and Q2. Higher gain with more leakage for Q3.
Did some digging and found that the transistor part numbers were OC75, OC71 abd CV7004. An odd one had 3x AC125. So yeah, it is rare and pricey stuff in there. My personal opinion on this would be ignore the stamps on the can and test easier to source transistors for the recommended TB3 Hfe and leakage. I've got hunderds and hunderds of soviet NPN transistors so I almost always stick with MP38 for Q1 and Q2. GT404 for Q3. It is not vintage correct but it sounds awesome.
Yeah I seen one of them with the 3x AC125s. I'll see what's available and if they're there then I'll get them. If not ill just do what you said as model doesn't really matter. What would you class as low and higher hFe for Q1, 2, and 3? Like the range for each roughly. Honestly you have been such a great help. I really appreciate the support so thank you.
I usually shoot for hfe 50 for Q1 and hfe 60 for Q2. Both with minimal leakage. The magic happens at Q3...90 up to 120 works fine, leakage around 300uA.
Hey man, this is my first pedal and I was wondering if I could get some help with the offboard wiring for it. I've got the circuit board all assembled and the wires soldered to the pot lugs. I'm using a battery clip with no dc jack. I don't really use power supplies but if I need the dc jack to be in the wiring I can get one. So I have the circuit, input and output, 3PDT switch, 2 pots, and an led. Thanks
Yup, but you can use stereo jacks as well - you just don't connect anything to ring. In the schematic the black wire is to sleeve and then the others go to tip.
Again with the NTE404's. It's like I've finally got a reason for why I ordered so many of these low gain PNP germanium gizmo's. Sounds great. All three of them are around 55Hfe with NTE leakage and this pedal sounds like a tank being operated by a swarm of bees. Thank you!
ReplyDeleteHi, what hFe values are the Ge transistors? Thanks
ReplyDeleteI beöieve the part numbers wasn't specified in the schematic. This is basically Tonebender Mk3 without the Tone control so try low gain w. low leakage for Q1 and Q2. Higher gain with more leakage for Q3.
DeleteCheers mate. Any transistor models you reccomend? Or should I just get what I can get model wise as they're a bit difficult to source in the UK
DeleteDid some digging and found that the transistor part numbers were OC75, OC71 abd CV7004. An odd one had 3x AC125. So yeah, it is rare and pricey stuff in there.
DeleteMy personal opinion on this would be ignore the stamps on the can and test easier to source transistors for the recommended TB3 Hfe and leakage. I've got hunderds and hunderds of soviet NPN transistors so I almost always stick with MP38 for Q1 and Q2. GT404 for Q3. It is not vintage correct but it sounds awesome.
Yeah I seen one of them with the 3x AC125s. I'll see what's available and if they're there then I'll get them. If not ill just do what you said as model doesn't really matter. What would you class as low and higher hFe for Q1, 2, and 3? Like the range for each roughly. Honestly you have been such a great help. I really appreciate the support so thank you.
DeleteI usually shoot for hfe 50 for Q1 and hfe 60 for Q2. Both with minimal leakage. The magic happens at Q3...90 up to 120 works fine, leakage around 300uA.
DeleteI've built other TBMK3's here and took Fuzzhead's advice to use MP38/GT404 and they all work really great.
DeleteFuzzhead,"hundreds and hundreds"?!
Hey man, this is my first pedal and I was wondering if I could get some help with the offboard wiring for it. I've got the circuit board all assembled and the wires soldered to the pot lugs. I'm using a battery clip with no dc jack. I don't really use power supplies but if I need the dc jack to be in the wiring I can get one. So I have the circuit, input and output, 3PDT switch, 2 pots, and an led. Thanks
ReplyDeleteAlso I was supposed to start this ages ago but been busy with school and such
DeleteJust replace the DC jack with a 9v battery clip - here's how to do your offboard and stomp switch wiring
Deletehttp://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html?m=1
Just remember the red wire will go to ground+ and the black wire to -9v, since this is a positive ground circuit
DeleteAre both of the jacks mono on that schematic?
DeleteYup, but you can use stereo jacks as well - you just don't connect anything to ring. In the schematic the black wire is to sleeve and then the others go to tip.
Delete