RNG (random number generator) mods?

[mattpocket]

Hi,

My parts arrived yesterday and I am in the process of breadboarding...

I read back through the weird pedals thread that I started a while back, here: http://www.diystompboxes.com/smfforum/index.php?topic=55603.0

I cant seem to find any reference to any mods, nor can I figure out where the "second" pot of the original schem went, as the bad schem was pulled for the new one...

Could I just switch a load of the resistors for pots? I am having a hard time getting this to work on the breadboard and I dont want to switch parts out right away without any idea what I am aiming to do...

Here is the schem:


Matt

[choklitlove]

i made a layout for this, including the original second pot.  it should be up soon.  seems like a very cool build.  anyway, the second pot can be seen on this:

[mattpocket]

Oh cool! Thanks!

I thought that it was there?

Would that be known as a feedback resistor?

Matt

[calculating_infinity]

ok here is an updated schematicwith the second pot.

Doug posted his modified schem with the pot and I referenced the pot location within the thread as well.     If you are breadboarding and have enough pots try replacing all the resistors and have at it.   

[mattpocket]

The only schem I could find was the one at the top, and I am fairly new to electronics (only being doing anything since january) and couldnt decide which resistor to swap out...

Thanks though!

Matt

[ambulancevoice]

i really think the random number genorator is a good candidate for mods

i say just poke around, experiment with different compontents and mould it into something to your liking

[mattpocket]

at the minute I cant get it to work...

I built it on breadboard but I couldnt be bothered to do the offboard wiring yet, so i just put the tip of a mono jack to the input cap and the sleeve to ground (emitters of the transistors) and got another mono jack and put the tip to the .01 cap at the end and the sleeve to ground (again, emitters of the transistors) and then hooked the red line of the battery to the power rail (with all the resistors on, at the top on the schem) and then hooked the black line to the ground, where my jacks and emitter-ground contacts are... that should work right?

If I take the tip of the output jack and disconnect from the breadboard and hook it to the left hand side of the input cap (left of the schem) I get clean guitar noise (basically because this is like connecting the two jacks directly together, right?) but if I put it on the right hand leg of the input cap I get nothing... I changed the cap and still no luck...

Any ideas?

[ambulancevoice]

are the caps and ground's soldered to the sockets??
and did you check that everything is orientated properly?

[ambulancevoice]

completly go over how everything is connected, and compare it with the schem

[mattpocket]

I am rebuilding the whole thing as we speak!

[mattpocket]

Haha, nothing again! It must be something to do with the way I've wired it up off board I think...

The circuit is exact to the schematic...

I thought id got it working for a moment when I moved a ground wire round, but it was UB40 singing "red red wine" thorugh my amp! haha I think I turned it into a radio reciever! haha

I'm vexed now... but no Z! haha

Matt

[oldrocker]

I breadboarded this thing a couple of days ago and didn't know for sure if I would commit to building it.  After some thought I decided it was cool enough to keep.  I put it in a Altoids mint tin.  (Always wanted to try that.)  I didn't add the feedback pot mod and used a 100K trim for the volume pot. (I open the lid to adjust it.)  No bypass or LEDS just a bare bones rng circuit.
Make sure you connect all the cross points between the trannies since they don't show the dots on the connections.  Only where the hump is, are cross over points, on the emitters of the two 3904's going to ground.  Everything else is actually connected. 
It's cool to just throw it in your pocket and throw it in the pedal board for some wacky effects.

http://www.logmonster.com/images/full/?pic=rng5_1177544066-422-15024.jpg
http://www.logmonster.com/images/full/?pic=rng4_1177490169-422-15023.jpg
http://www.logmonster.com/images/full/?pic=rng3_1177544314-422-15022.jpg
http://www.logmonster.com/images/full/?pic=rng1_1177563984-422-15021.jpg

[mattpocket]

Yeah, I am definately having problems with my "simple" wiring off board... I did a HP yesterday and get nothing from that either... Looks like I am gonig to have to wire up all the switch and jacks and led and everything else! Oh well... worth a try...

Matt