pitch pirate schematic

rousejeremy · January 04, 2013, 12:29:52 PM

Quote from: timd on January 02, 2013, 11:13:47 PM
This might be one of those pedals that you want to buy instead of make...unless you're up to it!

I perfed one, never again. I can't believe Doug perfs all these things.

maiko · July 27, 2016, 09:33:26 PM

Sorry for bringing this up again.

but i gotta ask is the led next to r10 and ground to anything or for aesthetics only.

PRR · July 28, 2016, 03:18:30 PM

It blinks with the LFO, which lets you set trem rate without listening. Good when you pre-set for a song of different wobble speed.

If you can't spare the space or the 13 cents, you could omit it, and set by ear.

maiko · July 31, 2016, 09:30:32 PM

Thanks PRR for the reply

But i had problems actually with the 2nd led on there. Eventually the LFO would stop and the led just stays lit. After about 3-5 mins playing. I tried various adjustments to cap values and res. but eventually removing the 2nd led just solved it. I guess the two leds must have identical tolerances and also the resistors to be matched for 2 leds in parrallel to stop messing with circuit.

Any way very happy with it.

anotherjim · August 01, 2016, 06:15:11 AM

The LED resistors should do a good job of stopping the indicator LED interacting in any way with the LDR LED.

What did you do with the point on the schematic marked "SW"? That I think should be switched to ground when you want the LFO to act on the delay time - however, I don't think that can work properly like that, the LDR still ends up connected to the PT2399 pin 6 via the LDR resistance in series if "SW" is not grounded, and can still wobble the delay time.

Anyway, the stripboard layout on page 2 here ignores the "SW" switch and hard-wires "SW" to ground, so if you followed that, you shouldn't have a problem with the extra indicator LED.

maiko · August 01, 2016, 09:50:01 PM

the pads marked sw i used a toggle switch to ground. when its on the circuit will wobble and wave. hahaha when off the led towards the ldr is off so it only functions as a delay and a subtle chorus. it does not wobble at all if sw is not connected to ground.

anotherjim · August 02, 2016, 11:23:12 AM

Yeh, I just noticed "SW" also supplies 0v for the LFO op-amp, so it should cease to wobble with the switch open.
The intention there is for the LDR and associated LED to be enclosed together as in a Vactrol (note the dotted lines enclosing them) while the extra indicator LED is up in the panel. The extra LED must never, ever, shine on the LDR.

maiko · August 03, 2016, 09:25:01 PM

i use a led and ldr i wrap in aluminum tape then shrink tube lenght wise and cross wise. works quite well i see 1 meg ++ with out the led on and drop s to 0 the moment i put a 3v cr2032 batt on the led

rutabaga bob · August 06, 2016, 10:51:08 AM

To clarify this for a clod like me: does the switch just interrupt the connection of the led to ground? This is what eliminates the warble? Thanks!

anotherjim · August 06, 2016, 11:38:49 AM

Yes Bob, that would appear to be the intention.

You know, I wouldn't want to say for sure without probing the circuit.

Pin 6 of the PT2399 has about 2.5v on it. There is a path when the switch is off (0v disconnected) via the LDR to that 2.5v. Switch at off also removes the negative supply to IC2 of the LFO. With that the positive supply remains connected, so I would expect all the LFO connections could drift up to +9v. That means there's some chance for the LDR to leak enough current for the LED's to be partially lit. It probably depends on the dark resistance of the particular LDR. But if low enough to let the LED's light, the LDR resistance falls, increasing the leakage to turn on the LEDs more!
If the LDR resistance fell enough, then IC2 gets 2.5v on it's 0v pin - and could run!

Anybody else see that - or am I fooling myself?

rutabaga bob · August 06, 2016, 01:53:28 PM

Looking at the schematic, I'm still confused.

Is the switch supposed to break the connection to ground of both the Vactrol led and the display led?

anotherjim · August 07, 2016, 09:18:02 AM

Yes it is.
Actually, I now think the switch is the 3rd pole of the 3PDT stomp switch. The LFO rate indicator LED doubles as effect active indicator.
There may have been trouble with audible ticking from the LFO when bypassed, which is why the switch also stops the oscillator.

rutabaga bob · August 07, 2016, 11:07:48 AM

Thanks, Jim! I've been working up a perf layout...almost ready to post.

maiko · August 07, 2016, 09:31:53 PM

Ive built 3 already hehehehe i think using a dpdt to toogle the switch to ground would be usefull. This thing has awesome delay powers heeheh.

rutabaga bob · August 07, 2016, 09:47:34 PM

A footswitch would definitely be the way to go.
Here's a layout for Jeremy...

rousejeremy · October 29, 2016, 03:38:28 PM

Quote from: rutabaga bob on August 07, 2016, 09:47:34 PM
A footswitch would definitely be the way to go.
Here's a layout for Jeremy...

Where were you three years ago?

rutabaga bob · October 30, 2016, 02:41:36 PM

Didn't know about it then...built a Clari(not).

doug deeper · November 06, 2016, 07:53:20 PM

Yeah, the switch pad on the LFO ground goes to the 3pdt, turns the LFO off when the pedals off.
The current version of this circuit doesn't REQUIRE this, but I still do it just to be safe.

velouriafx · November 29, 2016, 10:46:20 AM

Hi. I built the vero version and its poping when i engage. Isnt R1 1M? Thanks.

rutabaga bob · November 29, 2016, 12:53:56 PM

R1 is 100k, I believe...in series with the input, not a resistor-to-ground (pull-down).

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pitch pirate schematic