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I have a thing that I'm building for my dad that's still in progress: a battery powered practice amp. I got a cheap SS amp from Monoprice just for the cabinet. I replaced the speaker with a Jensen C8R and replaced the black grill cloth with some Oxblood stuff that was on sale at Mojotone.  The circuit is the Runoffgroove Professor Tweed, going into a little 2.5W class D amp as a power section. I designed and 3d printed a bit to hold 6x AAs for power.  What's mostly left here is to make a new metal enclosure to hold all the electronics.  I'm still struggling with figuring out how to cleanly cut my aluminum sheet to size. Then it goes into the cheapy Harbor Freight metal brake to bend it into a box.

I need to get myself an Aion board to build...

Those new 125b projects look amazing. Easily the best documentation for effect PCBs that I've seen around.

I'm pretty sure I got them from Smallbear, but I don't know how likely a dead or counterfeit chip is from them. Unfortunately, I didn't order any spares, so I can't check with another one yet.

If its from Smallbear its a legit chip. There is a small chance it may have been damaged on installation, but that is a bottom of the list sort of error in figuring out the problem. Definitely recheck all the solder joints, and look carefully to make sure there aren't any hair-fine bridges anywhere.

Also, is smallbear where you got the diffuse blue LED? I've wanted a few of those in the past but my usual suppliers don't carry them (that I know of, anyway)

I think I got the diffuse LEDs from Mouser.


I reflowed a handful of the solder joints on the board, and got wet signal to come through! At first I was worried, because the wet signal still didn't have any effect. So fun fact: you don't get any effect when a trim pot that controls the effect level is turned down all the way 

Thanks for all the help, I'm glad to finally have this thing working!

Hey mate, check the build doc. There is a resistor linking pins on an IC, that you might need.

R9? I don't have that in yet because I'm planning on doing the Vibe switch mod.

Its fairly unlikely with the coolaudio chips, but are you 100% sure your BBD is legitimate? I've gotten burned by ebay 3007's in the past. (Even if they were real chips they shipped them on styrofoam, poor things were toast)

I'm pretty sure I got them from Smallbear, but I don't know how likely a dead or counterfeit chip is from them. Unfortunately, I didn't order any spares, so I can't check with another one yet.

You might need to redo some of your solder joints. Notably the transistor and diode in the top right in the first photo. And some of the resistor a below the v3207.

A good solder joint should look like this
http://diy.koenigs.dk/wp-content/uploads//2014/02/f07cf7b0d360dfc9184fac3b5c59254a92f8f56b.png

Might wanna socket your transistors in the future. It's possible to get a bad one or fake. Or that you fry it while soldering.

And build yourself an audio probe.

Thanks for the tips! I'll redo some of the poor solder joints and see what happens. I can make an audio probe and see where the effect signal starts to die.

I've gone through and checked all my resistor values and component orientation, still getting no effect, and some wonky voltage readings.  I haven't wired up R9 yet (planning on putting in a vibe switch) but if I place the resistor in the holes, I still get dry signal with the effect engaged. The rate LED lights up and changes with the Rate knob.

Here are my IC voltage readings:

IC1	IC2	IC3	IC4
2.17	0	8.64	oscillates
2.18	4.18	4.16	4.5
2.17	1.57	0	oscillates
0	8.08	4.18	0
2.17	8.64	275mv, osciilates	4.58
2.18	4.16	8.3	4.62
2.18	4.59	2.75, oscillates	oscillates
8.85	4.6	8.08	8.68

Transistor voltages:

	Q1	Q2	Q3	Q4	Q5
C	8.81	8.81	8.81	8.62	7.4
B	1.92	2.09	1.98	oscillates	350 mv
E	1.42	1.54	1.46	oscillates	0

V+ measured at the board is 9.08 (coming from a wall wart)




Any help would be greatly appreciated!