Polyphase

[Fab66]

Hello to all, this is my first post

I am interested to build a polyphase with a wider board than those compacted to fit in smaller pedal enclosure

I need this type of circuit for using components without space limits for placement

I have seen an old post with a bigger board but I don't know how it works

Someone can help me?

Thank you in advance

Fab

[StephenGiles]

That's a very good idea for this complicated circuit, I allowed myself a full sized veroboard when I built this in the 1980s, ie roughly 17" by 5", then broke off the used section. Luckily I had some CLM 8200 optos back then.

[Marcos - Munky]

There's a layout made by Paul Nelson which is pretty big, it fits a 10cm x 10cm board. I etched myself a board, but didn't got to build it. It would be something nice to do on this isolation time, but I don't have all the pots for it

[Fab66]

I have found an old post of Morocotopo in which he published a "big" pcb with the layout, but I don't know if it has been tested

[Marcos - Munky]

Yeah, is this exact one. Sadly, that page was gone, it had some great layouts for pedals you don't usually see people doing layouts for, for example the eh bad stone phaser.

I can't say that layout is verified, and I can't verify it for you because I'm lacking parts and the stores down here are all closed. But what I can say is it will probably sounds different because of the optocoupler.

[Fab66]

The optocoupler I see in the schematic is CLM 8200/2
Is it not the same used in the original polyphase?

[Marcos - Munky]

It is probably the same one used in the original polyphase.

The big issue is they're so long obsolete. If you find one, it will be very expensive and there's a chance on being counterfeit. And you don't need one, but three, to build the polyphase.

That said, there are other optos that will work, and even an homemade opto will work (that's the route I'm going for). But each opto have different response, the same goes for ldrs in homemade optos. And this difference in response may make it sounds different from the original. It may be a big and noticeable difference, or a small but noticeable difference, or maybe a small and mostly unnoticeable difference. I never selected ldrs when I used them, and I'll just do the same and see how it turns out.

Btw, I found an old thread here that says the layout is verified. Great news.

Your thread got me interested on building this one again. Yesterday I picked my board, drilled it and soldered what I had in stock. This is where I stopped, because I'm missing a few caps and resistors and a 2N3904 (didn't even bother checking for pots because my stock is so low I'm sure I'm missing some values):

[Fab66]

Great!
At the moment I can't realize the board because here the electronic stores are closed, so I have to wait

[newperson]

clm8200/2 clairex eBay has some posted. Is this what you need?

[Marcos - Munky]

There's this pack: https://www.ebay.com/itm/5-Stuck-CLM8200-2-Clairex-Optokoppler-mit-Photowiderstand-Photoresistor-5pcs/323436151039?hash=item4b4e4c00ff:g:uRcAAOSwv9hW6m91

But since they're so long obsolete, there's a good chance on being counterfeits. Who's buying them have to keep that in mind.

It's something similar to the MN3007 situation. You find loads of them on ebay and aliexpress. But are they legit and do they work? Once I bit the bait and got a pack of 10 or 20, can't remember right now. All of them ended up at the trash bin.

[Fab66]

I have bought a set of these clm8200/2
As soon as I receive them I will let you know

[Fab66]

Hello, the clm8200/2 are arrived. They seem genuine, but I can't verify until I will complete the circuit as soon as I will find some other components

[Marcos - Munky]

Yesterday I got the parts I was missing. So far, didn't had time to solder them. If everything goes alright, I'll do this weekend. Can't go out of the house, but have lots of things to do.

[Fab66]

Great. Let me know 
Have a nice weekend

[StephenGiles]

Good luck, do you have that strange part - jp something, I don't have the circuit to hand, I got one from EH UK 40 years ago!!

[Scruffie]

Good luck, do you have that strange part - jp something, I don't have the circuit to hand, I got one from EH UK 40 years ago!!

The thermistor, it's not strictly necessary, I think it was there to compensate for the transformer heat.

[Marcos - Munky]

Small update. Soldered almost all the parts to the board, then I noticed I don't have any 10K trim. I'll try to buy one tomorrow.

I also have to think a little on how I'll make the optocouplers. I have something in mind, but still have to try and see how it goes.

[Fab66]

  Thank you, let us know Marcos 

[Marcos - Munky]

I finally got time to finish it and test it. It works. Well, the lfo and a few other things aren't working, I'll try to debug them later. But the envelope phaser is working. And it sounds awesome!

Just a info: if you're thinking on using a voltage doubler using a ICL7660 to power it, forget about it. The 7660 can supply only 20mA, while this circuit needs 80mA to work.

[StephenGiles]

I invested in a couple of motorbike batteries back in the 80s to power a 50 watt amp I used when playing for Northwood Morris. Depending on how loud the amp was, those batteries gave about 3 hours use when fully charged, but lasted weeks when used as initial power supply for effects, even hungry ones like the Polyphase.