shruthi 1 as dco in modular.

[reve]

Hey all y'all.

Has anyone thought about adapting the shruthi 1 as a dco module in a modular synth setup? I'd much prefer that to building one straight, having to bypass the analog section and push it through a preamp...

Having done this kinda thing with the 4bit and 1bit synth projects, I thought I'd give it a whack... but after looking at their codebase I realized its way over my head.

Anyone with more smarts working on this?

[Sebo]

Hi:
I think that the Shruti is MIDI only, so the interaction with a modular system will be limited.
If you want a wavetable module I recommend you the Papareil Synth Labs Quantix-8, is only the wavetable part (not an oscillator, you have to plug it to a VCO) plus a quantizer, an 8bit sample playback, a sequencer, etc.
I have one, and is amazing.
Also I´m looking for another module called Tabula-Rasa, is a simpler one, but includes the oscillator (a digital one).

[reve]

Yeah I put money into the tabula rasa kickstarter project, but man those shruthi guys sure thought stuff through in terms of waveshaping options... I always use MIDI for cv/gate so MIDI isn't a dealbreaker for me, personally.

[certain2]

This interests me too. I've got a Shruthi-1 on order.

You could always get round the midi issue with one of these:-
http://tomscarff.110mb.com/cv2midi/cv2midi.htm

In fact, cv2midi would make a useful module for a lot of applications

[Tim Servo]

Yeah, I'm working at stuffing one into my modular. It will have an additional board to condition the outputs to standard synth levels, and to limit the inputs to Shruthi levels. I'll post more info as the project progresses.

You can order just the digital board for the Shruthi if you're going to use an external VCF and VCA.

Tim (let's get digital!) Servo

[reve]

[Tim Servo]

Just a quick mockup - still much work to do.

Tim (and miles to go before I sleep) Servo

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Shruthi Module Mock Up.jpg
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Shruthi Module Panel R03.jpg
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[Dan Lavin]

Tim,

Looks good. I decided to work with the Shruthi myself and as a result, I abandoned my planned OB two-Voice for a Shruthi two-voice. The 2 units mix together with a simple mixer/panner circuit that was found on a MFOS tech page. The CV1 and CV2 jacks arent currently hooked up yet. Id like to make a little buffer board for them.

System-wise, I have the units hooked up as a two voice polysynth. Although it is primarily for lead lines, I like to plop down a second note every now and then for harmony. The units can be configured as two separate mono voices if I want too. I really like how the Shruthi system is organized.

I have the stock 24dB low pass filter. I decided not to use the 12dB option on the filter. With all the filter options, Iḿ surprised no one has done a transistor ladder yet.

I went with Front Panel designer for the panel because of the square holes. Iḿ not good enough on the mill machine to do this kind of work, yet. Bill/State Machine inspired me to use the gold finish instead of my usual black.

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DSCN3249.JPG
Description:	My Shruthi 2-Voice temporarily resting in my percussion rack#2 with my quad Bass++ and my yet-to-be released Monkey Cymbals (still needs 1-2 tweaks)
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Description:	Close-up of one voice. The panel was made with Front Panel Designer.
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DSCN3247.JPG
Description:	Hereś the patch panel/mixer-panner section.
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[jordroid]

OooooOOOOooo, nice! I've been thinking of building one as well, and possibly building several for use as a poly synth, if i burn the chips myself and build my own boards it shouldn't be crazily expensive to do a small bank of them.

It's nice to see you guys setting them up to interface with modular gear, something i will be wanting to do if i ever get around to actually building one/them.

The filter choice is something to ponder as well, i'd be tempted to do a state variable filter, just because they are versatile and i tend to like the way they sound, lots of ways to go here...

I look forward to seeing more of what you guys go with these

cheers

jordan

[Dan Lavin]

Jordan,
One of the next planned Shruthi filters is a dual SVF, so you might want to just get that filter board. Personally, I will probably replace the stock LPF with the dual SVF when those come out. Nothing against the LPF, it's a fine filter, but I really like having two filters and especially bandpass mode which I used a lot with the old SEM.

[XCenter]

Dan, that panel looks great. I´m toying around with similar ideas and seeing your finished panel is a great motivation.
BTW are you willing to share the FPD file to the public? Would things make easier for others, planning to do one.

[Dan Lavin]

Yes, I can post the file. However it may be a few days due to the holidays. A couple words of warning, however. There are a couple errors in the file. I was hoping for more detailed mechanical specs from the Shruthi website, but they were a little lacking. I had to fill in a lot of details by measuring my pcbs with a caliper and inputting the data into FPD. On the LCD, the measurements are exactly the size of the LCD so it is a very tight fit with no room for adjustment. My intent was to enter the data, then go back and add 1mm to each dimension but I forgot to do that. On the encoder, my center hole dimensions are off by ~1mm to the right and ~1mm too high, so I could not use the normal knob. You can see in the picture I put a knob with a smaller OD so it would fit in the hole.

The rest of the dimensions work just fine as is. I am using small light pipes on the LEDs, which may not be apparent from the photos.

[XCenter]

[Dan Lavin]

Almost forgot about the request. Attached is the front panel designer file. Please see my notes above on needed corrections. I did not make any with this file since it is a one-off.

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sTRUTHI1.fpd
Description:	2 voice shruthi panel 3u height	Download (listen)
Filename:	sTRUTHI1.fpd
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[XCenter]

No prob at all. Checking the correct measures isn´t that much of a deal. Having the design almost done with all elements in it will save a lot of time. Thanks a lot for the file.