Fever Pitch A wobbly delay

[Kipper4]

Fancy something different with a delay.
Well here it is.

[Kipper4]

[bluebunny]

"This thing's mad."

I mean this in a genuinely warm, loving way - Rich, you's totally bonkers, fella!!   

Keep on keeping on...

[Kipper4]

Without the dry signal it's bewildering.

It does lots of good sounds inc delay only.
Ring mod type of thing when the delay time is turned to short times.
Because of the tap tempo you can closely match the delay times to the modulation.
I could play with it for weeks and still be discovering new stuff.
If it wasn't for the 6 knobs and 2 switches the pcb would fit in a 1590a by my reckoning.

Thanks Marc.

[ElectricDruid]

"This thing's mad."

Never has a truer word been spoken...

Definitely one for people who find the constraints of typical tunings too constricting and who want to throw off the shackles of old-fashioned concepts like "Pitch". There are no "notes", only pure sound!!

[Bishop Vogue]

This ... is ... fantastic!   Thanks so much for sharing. I might be missing the obvious, but can you tell me what ICs you are using?

[Mark Hammer]

It's Eugene Chadbourne in a box!

[Kipper4]

No problem.

Regulator=78L05
Q1 is a regular NPN jellybean I used a 2N5088
Stompflo  is a new lfo from Electric Druid. Go look.
IC2 is the PT2399 used in most diy delays. Rebote etc.


The trick is to find the wobbled sound that goes well with the delay. Then dial it out until it is more subtle and just fattens the sound in a very different way to some of the other devices used like chorus or a flanger.
The depth control is a god send when it gets even too bonkers for me.
I should have shown a more subtle effect in the video but got carried away with just the mad stuff.

The circuit is so simple it's daft.
An input bjt amp split into two signals
One goes to the delay chip and out of there to the output.
Tother goes to the output

The lfo wobbles the delay time.
The delay pot sets the delay time.

I tried a pot to attenuate the wet signal but it was a pain so I used the Lfo's onboard depth instead.
I tried a feedback mod but it was a bit too much even for me.

Rich

[patrick398]

Love that sound at 0.23 And at 0.32 too! I've been trying to get huge and stable pitch sweeps from a pt2399 for ages, definitely going to breadboard this, looks super fun!

[patrick398]

Just bought a couple of the stomplfo's, planning some phaser based madness as well

[bluebunny]

Just bought a couple of the stomplfo's, planning some phaser based madness as well

Look what you've started, Tom!   

[ElectricDruid]

Just bought a couple of the stomplfo's, planning some phaser based madness as well

Look what you've started, Tom!   

Lol, that's the general idea! The easier I can make it to add a multi-waveshape LFO to anything that stands still long enough, the sooner I don't have to listen to things that just go "WoooWoooWoooWooo" over and over again!! Anyway, I think you might be under-estimating your own role in this whole debacle...you're the one who's scattering StompLFO circuits around like Smarties at a kid's party!

Would you mind doing a sound sample using the two random waveforms, btw? I'm curious to hear how those sound with such wild pitch bending.

T.

[Kipper4]

As requested.

A couple of things worth mentioning.
Making R5 in the couple of k range makes it more responsive.

I tried it without the delay pot (just a fixed 1k to gnd) and It just misbehaved. No pitch bending.
I attempted to use a 10k delay pot and wasnt happy with it either.
If you want you can make the delay pot bigger. 1ook is as far as i went.
Oddly enough I didnt notice any obvious degrade in the delay, but then it's hard to tell with the pich bending in the background.



It also works well when the BJT amp Q1 collector is run off of +5v and not +9v. So I guess it could be made to run entirely off a usb power supply.
Rich

[ElectricDruid]

Fabulous! I loved the wet-only bits you did with the short delay setting! Total mangling for your notes! And the "Random Levels" AKA "Sample-and-hold" waveform is utterly loopy with that thing too. Great stuff, Rich. I think you should get a knighthood for services to atonality. In fact, I might put you up for one myself!

Tom

[Danich_ivanov]

Pretty interesting! Reminds of some stuff by Earthquaker Devices/Alexander pedals.

[Kipper4]

To be honest I nearly didn't publish this.
But then I thought. Well zvex made some pretty crazy stuff and people love them and are willing to pay stupid money for them. Especially since some rock stars sanctioned them.
So what the heck. There it is in all its glory.

When I made the fuzz factory I thought i'd made several gaffs, turns out it was just meant to be like that......

Thanks guys.

Rich

[samhay]

Interesting.

RE the schematic: How are you wobbling the PT2399?
Are you sinking current into the PIC or are one of those resistors actually a LDR?

[Kipper4]

No ldrs involved Samhay.
I neglected to mention I put a 1uf np between the filter and the 100k R5
So it can be a current sink. Can it.

I wish I could do a version without any delay and just the pitch bend, but I hasn't happened yet.

[samhay]

Not a current sink if the LFO is AC coupled.
Can I confirm the LFO is connected to pin 6 of the PT2399 and not pin 2?

[Kipper4]

I can confirm the lfo output path is
Lfo out> series 10k/47nf (to gnd) (to filter out the highs. Because of the high freqauncy signal from the lfo) > series 1uf np cap > series 2k2/1k to gnd (this voltage divider ensures also that pin 6 always sees at least 1k to gnd)> 50k delay pot. Wired as a variable resistor.> pin6


I've got a 10uf cap to gnd on pin2

Here's the lfo data sheet

https://electricdruid.net/datasheets/STOMPLFODatasheet.pdf

I was going to go the vactrol across the delay pot route. But struggled to quickly establish a good value // resistor value.
So I just tried this.
And the craziness started. I should also add I did it without the 1uf and it worked too.
In fact the first demo is missing the AC coupling.

What is happening here I'm not quite sure.
I'll update the schematic if people want.

Rich