Hi there
I've been playing about with the Electra and Trotsky type circuits, I've had it on the breadboard for a few days and have been playing about with some of the modds and tweeks. I've found that most of the distortion comes from the transistor rather than the diodes, I can't tell a great deal of difference with different diodes/no diodes. There is a difference but it's mainly the volume/dynamics. Is this normal?
I've also tried the emitter cap to ground to increase the distortion, I like the increase in gain but it seems to add a lot of mids.
Also is the COT50 based on this type of circuit?
Thanks in advance
Ross
Quote from: rosscocean on February 17, 2011, 09:13:35 AM
Is this normal?
Without the diodes you've got a booster and may be overdriving whatever comes after the circuit in your chain.
Quote from: rosscocean on February 17, 2011, 09:13:35 AM
I've also tried the emitter cap to ground to increase the distortion, I like the increase in gain but it seems to add a lot of mids.
What value cap are you using? Using the good old F=1/(2*pi*R*C) formula will give a roll-off frequency, with the gain boost being less effective below that. It might be that you're not boosting the full frequency range of the guitar - if that's the case then increase the cap value so that the lower frequencies get a push too.
Quote from: rosscocean on February 17, 2011, 09:13:35 AM
Also is the COT50 based on this type of circuit?
Yes.
on the trotsky, i've found the diodes have a significant impact on the amount of drive. I like and si+led series
Quote from: ppatchmods on February 17, 2011, 11:21:11 AM
on the trotsky, i've found the diodes have a significant impact on the amount of drive. I like and si+led series
I've not tried different types of diodes in series yet. I'll have to give that a go. Your Rat pedal looks cool BTW.
Quote from: anchovie on February 17, 2011, 09:55:37 AM
Without the diodes you've got a booster and may be overdriving whatever comes after the circuit in your chain.
What value cap are you using?
I've beenusing a 10uf from the emitter to ground bypassing the 680r.
I put a volume control after the circuit to check that it wasn't just pushing my amp into overdrive. At the minute I've just been using resistors instead of the gain controll on the Trotsky drive, with gain set high (47K resistor) there is alot of distortion coming from the transistor without any diodes in. I guess that's just how it is when the transistor gets less voltage?
Do you know where I could find the COT50 schematic?
Many thanks
Ross
thanks
Quote from: rosscocean on February 17, 2011, 11:59:29 AM
Do you know where I could find the COT50 schematic?
Check the Freestompboxes forum
This makes me want to get my Trotsky goin' again. I think I had to kype the 3PDT for another build and never messed with it again.
pm me if you want the schematic.
Cheers Groovemeister!