Refurbished digisound modular plus

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terjewinther
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Refurbished digisound modular plus

Post by terjewinther » Thu Nov 12, 2015 11:25 am

Between other work I have restored this modular:

Image

It is mostly a digisound modular, with some other modules added. It came from various sources, and most of the modules was in dire need of service, even missing lots of CEM ICs, and other parts broken as well.
The interesting part is that it is a mixture of original digisound front panels, and some DIY front panels with a curious format (not standard at all), and with texts in Norwegian ("Ny-norsk" for the Norwegians out there). Clearly homemade, as the drilling of the wholes for the jacks are not all lined up.

Cabinet and some of the original digisound modules I won in a Vemia auction from Mark Glinsky. The cabinet has seen some refurbishing, and all the original power wires and connectors have been swapped out. Power supply is updated, and I am now using Oakley dizzy power distribution board, but still original digisound connectors on the original modules.

Here is a list of the modules, from top left:
- 80-3 LFO, modified with a high/low switch (that should really be "low"/"super-low")
- 80-2 VCO
- 80-5 Processor
- 80-7 VCF (state variable filter, not the version with SSM IC but CEM-IC)
- 80-16 D.R.F. (Dual reasonant filter)
- 80-18 Dual envelope (but with a 80-8 front panel)
- 80-18 Dual envelope
- 80-4 Voltage controlled mixer

The narrow middle section, from left:
- PAiA 8785 Linear digital to analog converter (inputs)
- a dual multiple
- output jack converter, with on/off switch at the bottom of the cabinet

The bottom section, from left:
- 80-2 VCO (original digisound PCB behind the panel)
- unknown VCF, labelled "ARTS 85" on the PCB. It is a state variable filter, using a quad op-amp as the filter core, and (strangely enough) a CEM VCA IC as the controlling element. There was nothing to find on the web for this, so I had to reverse-engineer this to make it work
- PAiA 8781 QuASH (Quad Addressable Sample & Hold) outputs
- Thomas Henry "Snare+" module. It is an old version with noise, oscillator, simple envelope and modulation, based on the SN76477 IC. This one has text on the front panel, but the PCB is DIY
- Thomas Henry "Snare+" module. No text on the front panel (and different type of switches), but the PCB is original
- Tau VCO - see info here: https://www.muffwiggler.com/forum/viewt ... p?t=149568
- 80-18 dual envelope (original digisound PCB behind the panel)
- 80-9 Dual VCA (original digisound PCB behind the panel)
- 80-9 Dual VCA (original digisound PCB behind the panel)

Original digisound 80-1 power supply at the bottom (upgraded).

https://soundcloud.com/terjewinther/dig ... dular-test

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bennelong.bicyclist
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Post by bennelong.bicyclist » Thu Nov 12, 2015 2:37 pm

Nice! And welcome to the very small club of Digisound-80 owners. You might be interested in this thread, if you haven't seen it already: https://www.muffwiggler.com/forum/viewt ... torder=asc

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terjewinther
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Joined: Wed Sep 02, 2009 1:51 am
Location: Norway

Post by terjewinther » Thu Nov 12, 2015 3:26 pm

Yes, thanks. I have seen that thread. These modules had some of the same problems, like the trimmer crystals etc.

I also have another digisound modular (plus 2-3 Aries modules), housed in a wooden case similar to the moog modular studio cases. Build that many years ago. Nice instruments.

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bennelong.bicyclist
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Location: Sydney, Australia

Post by bennelong.bicyclist » Thu Nov 12, 2015 9:01 pm

We should have a little lapel badge made, so that members of the club can easily recognise each other at social gatherings...

The Aries modules are interesting. There is someone here in Oz who is resurrecting some of the designs for eurorack - looking forward to those.

micromusic
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Post by micromusic » Sun Mar 20, 2016 5:56 pm

Nice Digisound modules
Mine is a mix of Digisound and Yusynth I have lots more CEMS to make more

Any chance of a photo of your 80-7a module(PCB and component side), have built one but as yet not working you seem to be one of the few people who have the Curtis version

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batchas
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Post by batchas » Mon Mar 21, 2016 5:27 pm

Nice indeed.
I remember seing this post and wished I had 80-7 VCF + 80-16 D.R.F.

Here is mine that I have since decades, but no 80-2 VCOs anymore...
Will put in FS section when I have time... or maybe mount a couple in my Serge...

https://www.flickr.com/photos/batchas/a ... 9494917116

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