Pitch/Detune Warble Pedal

[patrick398]

Here's the latest schematic for reference

[eeliyx]

Thanks for the schematic. I ordered the parts now and will attempt a vero build.
Gonna report back when I inevitably run into trouble with my build.
I'm however still interested in a PCB whenever yours arrive.

[patrick398]

Thanks for the schematic. I ordered the parts now and will attempt a vero build.
Gonna report back when I inevitably run into trouble with my build.
I'm however still interested in a PCB whenever yours arrive.

I have a feeling the vero layout is going to have to be pretty big, good luck! PCBs should be here in a couple of weeks, i'll drop you a line if they function

[patrick398]

PCBs have arrived!

[snk]

Wow, the faceplates look very good !

[eeliyx]

Hi again, I'm trying to understand the circuit and have some more questions.
It's my first time diving deeper into PT2399 and I'm learning so much.
How did you go about choosing a suitable value for R16?
Does it depend on the hFE values of the transistors and the desired range of delay times?

[ElectricDruid]

Hi Patrick,

Did you use a make-before-break or a break-before-make rotary switch for this? I had an email from someone recently asking about it, and I'd not really considered it before. They were having trouble, and thought it might be because they'd got the wrong type of switch. I'd like to know what your experience has been, please.

Thanks!
Tom

[patrick398]

Hi Tom, i'm using Lorlin CK1049 rotary switches and apparently they are break before make:
https://uk.rs-online.com/web/p/rotary-switches/0665180/?relevancy-data=636F3D3126696E3D4931384E53656172636847656E65726963266C753D656E266D6D3D6D61746368616C6C7061727469616C26706D3D5E5B5C707B4C7D5C707B4E647D2D2C2F255C2E5D2B2426706F3D31333326736E3D592673723D2673743D4B4559574F52445F53494E474C455F414C5048415F4E554D455249432673633D592677633D4E4F4E45267573743D434B31303439267374613D434B3130343926&searchHistory=%7B"enabled"%3Atrue%7D

What problem are they having specifically? Might be worth asking which pin numbers they're referring to, it took me a while to realise that the numbers on the top were for the 'stop' and the numbers on the bottom were the actual pin numbers

HTH

Patrick

[ElectricDruid]

Thanks. They were seeing it sometimes not getting the correct waveform, and wondered if it might be because the input floats briefly while switching. I've never heard of such a problem before, so I think it's unlikely, but PICs do hate having floating inputs, so it's possible - once you've eliminated other more likely causes, of course.

[patrick398]

Thanks. They were seeing it sometimes not getting the correct waveform, and wondered if it might be because the input floats briefly while switching. I've never heard of such a problem before, so I think it's unlikely, but PICs do hate having floating inputs, so it's possible - once you've eliminated other more likely causes, of course.

The first times i tried using a rotary i had a similar problem. The very first time i think i was using the wrong switch, one i had lying around, could have been 3p4t or something. Second time i used the correct switch and had the same issue, could have been overheating the pin(s) on the switch. They overheat and break fairly easily i think. Also if you're using a 1p12t switch without a stop then you have 4 positions where the pic is floating. That confused me at first, i lost where i was on the rotation and then all the waveforms seemed to be all over the place

[ElectricDruid]

Thanks. They were seeing it sometimes not getting the correct waveform, and wondered if it might be because the input floats briefly while switching. I've never heard of such a problem before, so I think it's unlikely, but PICs do hate having floating inputs, so it's possible - once you've eliminated other more likely causes, of course.

The first times i tried using a rotary i had a similar problem. The very first time i think i was using the wrong switch, one i had lying around, could have been 3p4t or something. Second time i used the correct switch and had the same issue, could have been overheating the pin(s) on the switch. They overheat and break fairly easily i think. Also if you're using a 1p12t switch without a stop then you have 4 positions where the pic is floating. That confused me at first, i lost where i was on the rotation and then all the waveforms seemed to be all over the place

That's very interesting, thanks. It's certainly true that floating inputs makes weird stuff happen, and not just with whatever feature happens to be associated with the floating pin - it seems to spin the chip right out and all sorts of unrelated odd stuff can occur.
I suggested to them that they should try a make-before-break, so I guess we'll see if that helps. A make-before-break will essentially short out one resistor in the chain as the contacts move, so it might briefly (glitchily) select a different waveform as it switches, but it shouldn't ever have a floating input, so hopefully the chip will be happier.

[patrick398]

That's very interesting, thanks. It's certainly true that floating inputs makes weird stuff happen, and not just with whatever feature happens to be associated with the floating pin - it seems to spin the chip right out and all sorts of unrelated odd stuff can occur.
I suggested to them that they should try a make-before-break, so I guess we'll see if that helps. A make-before-break will essentially short out one resistor in the chain as the contacts move, so it might briefly (glitchily) select a different waveform as it switches, but it shouldn't ever have a floating input, so hopefully the chip will be happier.

Worth a shot! Given that mine seems to work flawlessly with BBM contacts i'm tempted to think it's some other error that's being made. You obviously know infinitely more than me about the effects of floating pins etc, but my set up doesn't seem to mind. My guess would be wrong type of switch or pin number mistakes

[patrick398]

Finally got round to making a demo for this if anybody is interested.

[bluebunny]

I may never sleep with the lights off again.   

[patrick398]

I may never sleep with the lights off again.   

Beware the blue hands that twiddle so deftly in the night 

EDIT: That sounds dirtier than i meant it to haha

[deadastronaut]

mental.....but cool.. nice work man. 

[bluebunny]

Beware the blue hands that twiddle so deftly in the night 

Indeed.  I was probably finding the gloved hands more disturbing than the audio wobbling.  Chaps of a certain age, don't y'know...

[ElectricDruid]

Finally got round to making a demo for this if anybody is interested.

I love it. That's fantastically disturbed! The surgical gloves and scapel just add to the general air of menace, like someone is about to perform some kind of unauthorised experiment on you (clue: they are).
The killer is when you get to the part that says "Sine wave: more traditional chorus like sounds"...just trying to lull them into a false sense of security before you bash them in the head with another sonic assault of deranged lunacy. Excellent work.

T.

[patrick398]

Ah thanks Tom that means a lot! Though I think really you deserve all the credit, all the interesting stuff is coming from the Stomplfo. Next pedal out is going to be a very strange robot state variable filter using the stomplfo, which will be followed by a bi-phase using 2 stomplfos which also gets pretty weird haha

[bluebunny]

No wonder the "Intensive Care" moniker.   

Great work, Patrick.