Pitch Pirate volume increase

[El Heisenberg]

Built this AWESOME pedal. Sounds and works exactly like the vids on youtube, except I get a volume boost. I'm sure this is the 386. I dunno what happened. I had alot of problems getting it to work in the box because of a recycled 1k pot. So Im hesitant to go right in opening it up and poking around since the slightest touch messes up the 1k pot and I only get square wave.

I remember subbing a 33uf cap for one of the 47 uf but I dont remember which. If I did this with the cap from pin 7 of the 386 would that cause volume boost? With so few parts I dunno how I got this problem. Both the 100k resistors are there I'm sure.

When i first soldered up the board I accidently had 9v going to pin 1 of the 386. Big deal?
Bleh.

[El Heisenberg]

Oh, I forgot, I actually have real problems with this pedal.

When I power up (switch power on to entire pedal chain with one switch) the  PT2399 section doesn't work. No modulation. And when blend knob completely wet, no signal. This happens when I power up and the depth knob is at minimum. I have to have the depth knob set a bit high and then power it up to get the thing to turn on. Weird?? I dunno. I didn't put the 1n4001 diode in there...

I've had this happen once with the echo base. I might've had the echo base on a setting I don't use alot so it only happened that one time. It might happen again.


Is it the PT2399 not liking what it's being told to do right when it wakes up???

[El Heisenberg]

will lowering the 1k resistor before the depth pot gimme less depth in the lowest setting? I find even the lowest setting has a little too much vibe. Even tho the problem I'm having at start up is when the depth is set too low, i'd be willing to live with it for a lower depth setting.

[El Heisenberg]

Ugh! I cant figure out whats causing the volume increase! The 100k resistor is there at the input. The thing is so simple i cant see a mistake on the board.

[El Heisenberg]

Maybe its in the pt2399 section? I just changed the 100k resistor at the input of lm386 and theres no difference really. Still volume jump.

[Earthscum]

Seeing as how the output cap is left hanging, and 100n, why not just use a 100k volume pot?

So far with the PT's I've got, I can fire up with 820R. Any lower gets questionable chip to chip. I wonder what's up? The newer they get, the crappier they are... next datasheet will be "Nothing under 2.2k recommended". 

[El Heisenberg]

Ah cos the things already boxed up. Ill try a trimmer or fixed resistors.

This pt2399 had different markings than the ones ive gotten before. Thinner print. Indent in different place.

[doug deeper]

The power up problem happens if your led is too bright for the lrd.
Basically it happens if there is zero resistance when you power it on.
So just make sure the depth knob is up a little and you'll be fine.
if you want less modulation you can add a trim pot in line with the led to adjust it's brightness.
Not sure what the volume issue could be though, start checking for resistor values I guess!
R3 through R7 can all shoot the volume up if the values are out of whack.

[El Heisenberg]

R3 thru r7 u say???

I built mine basrd on the perf layout for rick holts clarinot. I noticed in his layout R5 and r6 were reversed. I built the pitch pirate per schem.

I dunno its hard to check the board cos its upside down.

[Dr.maligno]

it happend the same in my clon unit, put a 1M trimpot from the input to ground and check. Maybe one setup will resolve it.

[Ryder17]

Anyone got a schematic for this? The photobucket seems to have a hole in it