Trotsky Drive Help and Mod Ideas

[ppatchmods]

sorry for the vague reference! i used the pcb layout but the values are: r4=680(i use 620) & r3=1m

[Kearns892]

Alright, I'll draw up an exact layout of the breadboard tonight, and I think the 1 meg resistor you are referring to is the one discussed in another thread I reviewed when searching for Trotsky debugs, and it isnt part of the original schematic and is only used to prevent popping. Correct me if I am wrong though. 

[ppatchmods]

it is the pull down resistor so you may not have it on your board.

[WhenBoredomPeaks]

I have made some measurements of a working Trotsky.

Input V: 9V
Gain pot: 50K at max settting.
Q1: 2N3904

c 2,35v
b 0,7v
e 0,08v

[jmwreck]

my trotsky build, with a GE and SI clipping switch and a bright switch

[Kearns892]

Alright,  instead of a picture I used the wonderful DIY layout creator to make a representation of the breadboard layout I am using. Hopefully this will be the easiest way for me to get help.

And Jmwreck, I'm jealous.

[jmwreck]

Alright,  instead of a picture I used the wonderful DIY layout creator to make a representation of the breadboard layout I am using. Hopefully this will be the easiest way for me to get help.

And Jmwreck, I'm jealous.

what's the difference between 5088, 3904, and 2222?
i haven't tried putting 5088 and 2222, i stick with the 3904, but if there's any good outcome to those transistors, maybe i'll try it..
thanks! build it right now. sound is pretty amazing 

[ppatchmods]

i might see it wrong, but is .047 connected to 330+330 before it hits the tranny?

[jacobyjd]

i might see it wrong, but is .047 connected to 330+330 before it hits the tranny?

Nope
_____________

Kearns...is your transistor backward?

[Kearns892]

sorry that is really small. No the .047 cap does not hit the 660s ohm resistor at all goes straight to base and and the 660 ohm to the emitter.

[ppatchmods]

the grounded end of the 660 combo should go into the open end of the .047. As Jacobyjd said, your trasistor is backwards also. that will probably do it.

[jacobyjd]

the grounded end of the 660 combo should go into the open end of the .047.

Um, I don't think so...looking @ the schem, the 660R should come straight off the emitter, so that should be ok on the layout.

[ppatchmods]

you are right about the schematic and i should have gone by that in building mine. i'm going by the pcb and it has the emitter to 660(680) to ground and to 1m(optional) to .047 to base. if you omit the 1m that takes the 660(680) from emitter to ground & .047 & input. i must warn you that i have had some trouble with the pcb, but connecting the 660 to input/.047 has solved it both times.

http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album17/distortionpcb/trotsky+pcb.gif.html

try it with out connecting the 2 first. when i had the trouble, i wasn't getting any sound until i connected the 2.

[jacobyjd]

you are right about the schematic and i should have gone by that in building mine. i'm going by the pcb and it has the emitter to 660(680) to ground and to 1m(optional) to .047 to base. if you omit the 1m that takes the 660(680) from emitter to ground & .047 & input. i must warn you that i have had some trouble with the pcb, but connecting the 660 to input/.047 has solved it both times.

http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album17/distortionpcb/trotsky+pcb.gif.html

try it with out connecting the 2 first. when i had the trouble, i wasn't getting any sound until i connected the 2.

Ah, that makes sense...in your case, the 1M pulldown resistor was tied to ground in the same location as the 680R resistor. Really, it just needs to be grounded, and should not be connected to the input without that 1M in between.

[Kearns892]

sorry, should have been more clear with the transistor. What I was trying to say with the little note on the bottom was I've been trying different transistors and the orientation of the part on the layout didnt actually represent the orientation of the part since each one has a different pin out/ shape. Right now I have the 2N2222 in there and both orientations I get a clean sound, just one way there is a grounding issue.

[ppatchmods]

try rotating your diodes around. might work. if not, try new diodes.

[jacobyjd]

sorry, should have been more clear with the transistor. What I was trying to say with the little note on the bottom was I've been trying different transistors and the orientation of the part on the layout didnt actually represent the orientation of the part since each one has a different pin out/ shape. Right now I have the 2N2222 in there and both orientations I get a clean sound, just one way there is a grounding issue.

Ok then--as far as I can tell, you have an issue that we can't figure out by the layout alone. AFAIK, your voltages aren't correct--you should have something at least >0 at the base.

If you can, a picture would help. Otherwise, try reflowing your solder joints and re-check every connection. Also, look for solder bridges or other shorts.

[Kearns892]

I rotated both diodes and nothing happened, switched the diodes, nothing happened. I think the problem is with the collector and gain knob, the gain knob doesnt seem to be doing anything.

And now I dropped my transistor... This will be fun...

[ppatchmods]

the schematic says to run the gain knob like you have it, but the pcb has the gain lugs 2&3 going straight to the collector without hitting the 2.2m and .1uf first

[Kearns892]

the schematic says to run the gain knob like you have it, but the pcb has the gain lugs 2&3 going straight to the collector without hitting the 2.2m and .1uf first

I dont think I follow, do i not have lugs 2+3 going straight to the collector as well as the .1uf cap and 2.2m res?