Trotsky Drive Help and Mod Ideas

[ppatchmods]

you have it the way the schem says to connect it, but the pcb has 2&3 connected straight to the collector without hitting the resistor+cap:
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album17/distortionpcb/trotsky+pcb.gif.html


i'm not saying your wrong or i'm right, just something to try.

[jmwreck]

ive noticed that there really is a great volume difference regarding the 1n34a and 1n4148.. 

[ppatchmods]

that's true. the ge's clip harder. i used 914's in several of mine with great results...IMHO

[jmwreck]

that's true. the ge's clip harder. i used 914's in several of mine with great results...IMHO

clip harder in a sense that it has more dirt sound than the 4148, right?

[Kearns892]

The PCB has lugs 2+3 connecting to the end of C3 and meeting the collector which is also connected to the end of R2, is this different from having the ends of R2 C3 and lugs 2 and 3 connect to the collector at the same time?

[ppatchmods]

yeah...it's more of a fuzzy sound to me. i'm sure it depends on the circuit too. i'm no expert

[jacobyjd]

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

you have it the way the schem says to connect it, but the pcb has 2&3 connected straight to the collector without hitting the resistor+cap:
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album17/distortionpcb/trotsky+pcb.gif.html


They are connected in parallel--meaning nothing is 'first'. They're all connected equally in this case.

i'm not saying your wrong or i'm right, just something to try.

The PCB has lugs 2+3 connecting to the end of C3 and meeting the collector which is also connected to the end of R2, is this different from having the ends of R2 C3 and lugs 2 and 3 connect to the collector at the same time?

One way is the same as the other--this is correct.


Just in case your pot is bad, try jumpering the lugs on the pot--that basically shorts it at maximum gain. If that doesn't work, you still have a problem elsewhere that isn't showing on the layout you posted.

[ppatchmods]

the pcb has c3+r2 connected to the collector...then it goes to lugs 2&3 of the drive pot. i'm not saying either is right, but i would give it a try and see what happens. i've had stuff happen with this circuit that didn't always make sense. if it works it works!
yeah, it shouldn't matter either way. i just try to eliminate all possibilities.

[Kearns892]

I tried replacing the pot with a 33k resistor to see if the pot was bad and it had no effect. I've been looking at this all morning and if you guys dont see the problem I doubt I will. Later I will give it another once over and if that doesnt work I will probably take it apart swap all components and try to set it up again.

[jacobyjd]

the pcb has c3+r2 connected to the collector...then it goes to lugs 2&3 of the drive pot. i'm not saying either is right, but i would give it a try and see what happens. i've had stuff happen with this circuit that didn't always make sense. if it works it works!
yeah, it shouldn't matter either way. i just try to eliminate all possibilities.

Yeah...both ways are correct. They just all have to connect together.

I tried replacing the pot with a 33k resistor to see if the pot was bad and it had no effect. I've been looking at this all morning and if you guys dont see the problem I doubt I will. Later I will give it another once over and if that doesnt work I will probably take it apart swap all components and try to set it up again.

Do you have any way to take pictures? That would let me see what you've got going on.

[Kearns892]

I tried taking a picture with my camera and even borrowed a slightly better camera, but in each picture (even after fiddling with the settings) the leads were pretty much invisible. I could post one of these pictures if you think it would help, but I doubt you would be able to see anything.

I think now I'm going to give this one more try starting from scratch and see what happens.

[jacobyjd]

Eh, that's too bad the pics won't work out. At least it's a low parts count. Give it another go, and good luck!

[Kearns892]

just rebuilt it with the same results, my 2n2222 transistor measures 32 hFE which is really low is this a problem with the transistor?

[Kearns892]

Checked voltages -.07 at emitter  0.00v at base 2.65 v at collector w/ gain max 2.61 v at collector with gain minimum battery measures 8.47 v

I might just skip straight to perf using a confirmed layout if I dont get this working soon. I wont be able to tweak it to where I want it, but I'm getting tired of looking at this breadboard.

[jacobyjd]

just rebuilt it with the same results, my 2n2222 transistor measures 32 hFE which is really low is this a problem with the transistor?

a 5088 or 3904 will be your best bet that's a bit low.

[Kearns892]

Swapped for a 162 hFE 3904, gain control doesnt do anything, and only varies voltage by .04. Ive replaced the pot with a fixed resistor, checked the 3.3k resistor with a multimeter, what else could the problem potentially be?

[jacobyjd]

Something else has got to be wrong then. Don't hold me to it, but I'm pretty sure it will never work right as long as the base voltage is 0.

[Kearns892]

I finally got this thing working, thanks so much for your help.

Only thing I would like to change, lows are a bit too rumbly and muffled. How could I change that?

[ayayay!]

Honestly?  Throw a buffered pedal or compressor in.  Changes the whole dynamic of that pedal.   

Or maybe a .001 cap across the input & wiper of the volume pot.   

[WGTP]

Some ideas for mods.  Check out the threads on using Darlingtons with low gain GE's and high gain SI's.  

Or, use 2 of the recommended transistors in Darlington configuration...

2N3053 at Radio Shack, if they still have them, have a GE look, but sound good in Fuzz's at least...

2N5089 has more gain than 2N5088 and MPSA18 a little more than that...  

Try a 1K trim between the diodes and ground for clipping/output control.

Try 1 LED and 1 GE for clipping...

Try 2 in series...