Monday, August 14, 2017
Tortenmann TA-100
Came across the schematic for this and thought it would be a good addition. It's a unique germanium overdrive using PNP AC128s, though the effect is a negative ground effect (so it can be daisy chained with other pedals). The TA-100 has been used by Ryan Adams and sounds great through a Princeton Reverb. Schematic here on FSB.
Layout is good y'all.... The only thing is the gain pot goes from just breaking up to all out crazyness in the last 5%. The gain switch kicks things up a notch for sure. Turn your guitars volume pot down and you can get some great tones out of this. You should build this. I built mine with NOS 2n408s and bat41's cause I ran out of 1n34s. Have some on order so will report back once I receive them. Another great layout brotha!!!
ReplyDeleteCool. Thanks for verifying! You might want to try a C50k (rev log) pot for the gain to even out the sweep.
DeleteWorks great, thanks a lot !
DeleteSame remark for gain pot.
Does this require AC128's of a certain gain/hfe? Thanks for the layout!
ReplyDeleteNothing was posted about the transistors being a certain hfe. You'll probably have to experiment with that. But it should work with other PNP germanium transistors as well.
DeleteHI
ReplyDeleteIve built this and I am getting no affected sound. Using GT 313B trannies. Only part sub was 220nf cap.
Voltages at trannies are:E-B-C
Q1 9.1 8.3 0.0
Q2 6.8 6.6 6.8
Q3 9.2 8.6 0.0
Also, FWIW, I am getting continuity between the input and ground. That does not seem right?
Thanks!
P.S. Using 9volt battery reading 9.5V to power
ReplyDeleteI have a short question: Would it be possible to use a SPDT Switch for this layout and then just change Pin 1 to 3?
ReplyDeleteA SPDT is fine. You don't need to change the pins tho. Just use pins 1-2, and ignore pin 3.
Deletei think there is mistake with Q1. It has to be npn, just look on resistors on collector& emiter! I used Q1 npn mp38a, tried bias, working great from slight over to fuzz teritory. Second thing - gain pot should be 2or 5 kom max!! Just do it, people! look at my changed scheme here: https://imgur.com/TU07btD
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DeleteMade a couple of these with Texas Instrument R591 transistors and a C50K gain pot. Excellent stuff - raw and lots of fun.
ReplyDelete