Eagle Files - VCO, Filters, Touch, and SeqSw

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AlanP
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Eagle Files - VCO, Filters, Touch, and SeqSw

Post by AlanP » Sat Oct 17, 2020 10:31 pm

No commercial use! Don't PM or email me for help (you can ask in this thread, but don't expect miracles.)

'Arpad Touch' is a PCB layout (including panel) for the Synapse touch controller schematic.

'korg34 ms10' has two PCBs -- one is a small board to replace the KORG35 module (thank you to Crazy Patroche for this), and a V/Hz based MS10 VCF to run it on. The audio input needs work done on it, seriously loud and touchy.

buchla291 is a layout for the Buchla 291 Bandpass VCF, with mods from Scott Stite to include LP and HP as well. One of the few filters to include a 'Bandwidth' control... it does need four VTL5C3 vactrols, however.

buchla 258 is a layout for the Buchla 258 Dual Oscillator. Version 0.1 uses the THAT340 transistor array, while Version 0.2 uses BCM857 and BCM847 (the dual-transistor type, not the single transistor type.) 0.2 is harder to solder, but 0.1 uses spendier parts. Be VERY careful when selecting the FET for the waveshaper part of this circuit.

seqsw962 is a three stage sequential switch, modelled after the Moog 962, except that this one is bi-directional and can handle bigger signals.
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HighLordFixer
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by HighLordFixer » Sat Oct 17, 2020 11:00 pm

Thank you so much for posting these Eagle files!

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vladosh
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by vladosh » Sun Oct 18, 2020 3:48 pm

Thanks for sharing these Alan :)

Ayab
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Ayab » Mon Oct 19, 2020 1:34 am

AlanP - Thank you your designs are beautifully laid out.

Haven't heard of the synapse touch controller but sounds interesting,

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by julios » Mon Oct 19, 2020 8:52 am

Nice work!
About the vco, is it running até +/-12?

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AlanP
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by AlanP » Mon Oct 19, 2020 9:00 am

Yep, +/- 12V for all the modules.

On the 258, for 0.1 you need a through-hole jfet (selected for sine shaping), for 0.2 you can use either a through hole, or try your luck with a MMBFJ201 or MMBF5457. (Don't use both SMD *and* TH on the same side, the two footprints are electrically paralleled.)

The absolute worst one to actually solder is the KORG35 module -- it is a small PCB, and some of the parts on it are tiniest damn things I've ever soldered in my life. I strongly suggest anchoring the board you're working on to something solid, like a spare metal enclosure, and hitting it with a hot air rework station when done.

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by julios » Mon Oct 19, 2020 9:08 am

Thanks!
One more thing, how many usefull octaves with the BCM857/4? Should i go straight for the That3340 for a more acurate tuning?

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Bamboombaps
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Bamboombaps » Mon Oct 19, 2020 11:46 am

thank you, im looking to put together a euro buchla like system, this will help loads

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AlanP
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by AlanP » Mon Oct 19, 2020 6:06 pm

I'm not sure on the octaves thing, I still have to do some (read: any) measurements on their accuracy. (If I want accuracy, I use Braids.) But the BCM transistors are a pig to solder, compared to the THAT, and the THAT is placed so that you can solder the tempco resistor on top, if you want.

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Bamboombaps » Tue Oct 20, 2020 11:46 am

can i just check that the 258 main pcb 01 is compatible with the controls pcb 02?

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AlanP
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by AlanP » Tue Oct 20, 2020 5:53 pm

It is, only difference for the control was that v0.1 of the control PCB had no power lines going to the TL072.

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Ayab » Wed Oct 21, 2020 8:00 am

Re: Touch -

A couple of questions:

- Can you please confirm the type of jack socket your footprint is for. If easier just post a picture.

- Does the panel need piezo discs soldered on?

Thank you again so much AlanP you rock!

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AlanP
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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by AlanP » Wed Oct 21, 2020 8:33 am

PJ301BM -- what I think of as 'Erthenvar Jacks'. The ones with metal wrapped around three sides. https://www.thonk.co.uk/shop/3-5mm-jacks/

You could possibly redesign it for thonkiconns. I have lots of both lying around.

No, no piezo discs -- the copper layer on the front of the panel acts as a capacitive pad, and the two 3 pin headers connect the capacitive touch pads to the rest of the circuit. (The touch panel MUST be made using normal FR4 PCB material, you cannot use aluminium when ordering!)

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Ayab » Wed Oct 21, 2020 12:35 pm

Thank you for the reply Alan P

Erthenvar jacks is fine - I can get some.

I suspected that it was just the capacitative touch pads. That is so amazingly excellent.

:hail: :hail: :yay: :sb:

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Re: Eagle Files - VCO, Filters, Touch, and SeqSw

Post by Ayab » Thu Oct 22, 2020 4:46 am

For anyone interested this is the original touch controller article by Arpad Benares (see AlanP's panel) from Synapse Magazine.
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