Getting started with analog modular

Dogue · Joined: May 09, 2009 Posts: 24 Location: New York

I have a lot of experience with software synthesis (Max/MSP, Reaktor, etc.) and some with hardware (physical controllers, effects pedals, Lunettas), but I am now interested in putting together an analog modular system and looking for advice.

I have several design goals:

1) Small and portable.
2) Modular and able to interface with computer, Lunettas, mic/instrument inputs, physical controllers (touchplates, etc).
3) Inexpensive.
4) DIY modules not overly complex or time-consuming to build.
5) Start with basics and expand as I go.

Obviously, some balances will need to be struck. For instance, while going the DIY route will often help keep costs down, I am willing to purchase manufactured modules if doing otherwise would be too difficult or time-consuming. While I have a decent amount of experience soldering and building from schematics, I am no expert.

So, do you have advice for how I should get started?

Are there particular modules I should begin with, whether DIY or manufactured? I've been looking at Ken Stone's, Ray Wilson's, and PAiA's offerings, for instance; any recommendations?

How should I design it such that I'll be able to interface with computer, Lunettas, etc.?

Thanks a lot!

Dougster · Joined: Sep 20, 2005 Posts: 272 Location: Tucson, AZ, USA

Dogue · Joined: May 09, 2009 Posts: 24 Location: New York

Thanks for the reply and the advice. You are probably correct -- this would not be the first time I've been accused of being an optimist. Smile

What, in your experience, has in general caused DIY modules to be more expensive? From my experience with effects pedals and small noisemakers, the enclosures and hardware often ended up costing much more than the parts.

How about the cost of modules available in kit form, say Elby's CGS modules? It seems that they are relatively economical.

There are certainly some unique things I'd like to build that are not commercially available, or not commercially available within my budget, but I likely can find many modules available.

At the least, I suppose I should first decide on a mounting system and a power supply.

Also, I was interested in using banana plugs so that I could have multiple sources going to a single destination, although many of the more economical units use 1/8" or 1/4" jacks. How easily could these be modified to accept banana plugs instead?

Thanks again.

kkissinger · Posted: Fri May 04, 2012 7:13 am Post subject:

The biggest expense in DIY are the control panels: the panels themselves, pots, knobs, and jacks. If you want to design your own panels and have them commercially etched, plan to spend big bucks.

However, if you can learn to build and label your own panels, this saves a good deal of money. There are numerous techniques for creating panels from aluminum, plexiglass, and other materials.

Of the companies you mentioned, I would suggest to start with MFOS (Ray Wilson) simply because the supporting documentation is excellent. Having said that, I really like Ken Stone's modules however they may not be as easy for a beginner. Also, consider Yusynth, too -- the designs and docs are excellent -- and don't shy away from etching your own PCBs. It is not difficult and it is a lot of fun to etch and drill your own.

elmegil · Posted: Fri May 04, 2012 7:41 am Post subject:

Two things have kept me leery of etching PCBs...(not to hijack the thread)

1) disposal of nasty chemicals (even though I've heard that it can be "cleaned" and reused, eventually that cycle will end). Everyone says "proper disposal" and nobody says what that disposal actually looks like.
2) experience with PCB layout software.

#2 has an obvious resolution (just do it and learn! Smile

), but #1 concerns me.

Anyone have any suggestions? I'll be happy to open a separate thread if the thought is that the answers will be long and involved. But searching here and in google have not really turned up anything I can say leaves me really cozy feeling.

kkissinger · Posted: Fri May 04, 2012 10:12 am Post subject:

Dougster · Joined: Sep 20, 2005 Posts: 272 Location: Tucson, AZ, USA

Dougster · Joined: Sep 20, 2005 Posts: 272 Location: Tucson, AZ, USA

elmegil · Posted: Sun May 06, 2012 10:49 am Post subject:

Actually I do have the TH DVD, I hadn't gotten to that part... I sat and watched through most of it in one night and my wife kept rolling her eyes at me Very Happy

.

Thanks for the reminder, I'll try to watch it tonight. Maybe I can convince her that it's better, at least I'll be out of my cave Smile

Tim Servo

Dogue · Joined: May 09, 2009 Posts: 24 Location: New York

I thought my reply to this posted, but it looks like it didn't!

Anyways, thanks for all the replies.

I've been recently reconceptualizing my approach to instruments/sounds-makers, and I am now conceiving of everything to be in some way modular, so that I can interface basically everything I do -- piano, analog modules, Max/MSP patches, Lunetta-type circuits, controllers, etc. -- together. So while I'm getting some "basics" in analog modules, many of the things I'm planning on starting with are the Buchla/Serge-type rather than Moog-type, and I'm trying not to overlap too much with what is easy to do in Max/MSP.
I did find the muffwigglers forum -- thanks!

For the time being I've decided to go with Eurorack, and I've ordered a bunch of CGS and Elby kits and also panels for them.

I have not yet procured a case or power supply. I'm thinking of going for something inexpensive and DIY for now with the case, and perhaps keeping it small enough so that eventually I can put it in a Pelican carry-on case if I get to the point that I am touring with the rig. I'm also considering going with a Tiptop uZeus or similar small power supply.

One thing I do want to do is adapt some of the Nic Collins/Lunetta-type circuits to work in an analog modular setup. So, it seems I should use a comparator circuit at the input of these, as suggested here:

http://electro-music.com/forum/post-211004.html#211004

Any more advice on this?

Thanks again.

mrmrshoes · Posted: Thu May 10, 2012 5:58 am Post subject:

A midi note 2 trigger/gate convertor might interest you seen that you are using Max. I've built one with an arduino. It's a pretty simple circuit.
I believe someone has posted a similar circuit (with Layout and Code) to the forum. Can't remember where. If i find it i'll post it.

elmegil · Posted: Thu May 10, 2012 8:46 am Post subject:

That would be me Smile

http://electro-music.com/forum/topic-52722.html

More code than circuits, but I adapted the Thomas Henry MTS-100 circuit as described in that thread.

The original TH article from Nuts & Volts is:

http://www.nutsvolts.com/uploads/magazine_downloads/11/December%201997%20Thomas%20Henry%20-%20Build%20Your%20Own%20MIDI-to-Synthesizer%20Interface.pdf

In retrospect, I wish I had thought to provide a velocity output of some sort instead of the pitch bend, and/or gone ahead and found a way to implement the pitch bend so I could use it for example with a computer-based midi controller. Once I have a fully noise-making setup, I will probably go back and adjust. A lot of commentary I've seen online about MIDI->CV btw suggests using a higher resolution DAC if you want to do pitch bending....

bubzy · Posted: Fri May 11, 2012 7:57 am Post subject:

dont be afraid of etching your own... its easy after a few goes. i etch practically all of my own pcbs although i do use perf for one offs. the etchant wont kill you (unless you drink or inject it, and maybe not even then) but it can make your clothes/hands/worktop/dog yellow for sometime, ive had it on my hands and it washes off after a couple of days, havent got it on any clothes that i care about.
if you do decide to follow that route a couple of tips:
1: make sure the copper clad is CLEAN, no fingerprints allowed.
2: make sure the copper clad is VERY HOT, BEFORE you put the toner sheet anywhere near it.
3: apply even pressure all the way across the board and keep moving the iron, do this for a couple of minutes (best to use an old iron that your wife doesnt want to use for clothes again)
4: dont rub the paper off quickly, let it soak for a few minutes and then gently rub it off
5: warm the etchant (bain marie etc) i have used the microwave before but decided that i'd be better off not doing that.
6: keep the board moving inside the etchant, i "dip" it in the solution, this allows the old oxidised copper to wash off and the ferric chloride to start oxidising underneath.

after that just give it a rinse.

sorry to "hijack" this thread but i would like to dispel the fears about home etching. its actually not hard (seriously, I can do it....)

elmegil · Posted: Fri May 11, 2012 8:55 am Post subject:

I appreciate it buzby...I think my biggest challenge is going to find a way to get a toner-based print, as I only have inkjets, and not really any convenient way to print to a laser printer...

Dougster · Joined: Sep 20, 2005 Posts: 272 Location: Tucson, AZ, USA

Well, to continue the hijack Wink

at what point do you guys decide that perf board isn't good enough and that you have to etch a board? Seems like a pain to have to drill all the holes after etching. At the same time, I would tend to think that if you were doing surface mount, it would be a good thing...

Regards,
Doug (I like having soldermask and silkscreen myself...)

bubzy · Posted: Fri May 11, 2012 10:06 am Post subject:

doug : i dont do a tremendous amount of etching at the moment, although we "decide to etch" when someone else has done all the hard work of designing a board for us Smile

then drilling a few holes doesnt seem so bad.
i do like to share my designs too for other people to benefit, additionally if im going to make multiples of one circuit i find that designing and etching a board can save a bit of time in the end. Smile

elmegil : yeah its gonna be a bummer without a laser printer (possibly a photocopier at a library or such would do it....if you can get the to let you feed glossy magazine paper through their coper Very Happy

)

Dogue · Joined: May 09, 2009 Posts: 24 Location: New York

Nice work, mrmrshoes!

For the time being I am planning on building a case out of this tool case:

http://www.harborfreight.com/hand-tools/tool-boxes/18-inch-x-12-3-4-quarter-inch-x-6-inch-aluminum-case-39196.html

I will probably just put in wood for rails for now. I'm planning using a uZeus power supply. The tool case should be small enough that I can eventually put it inside a Pelican case for travel.

mrmrshoes · Posted: Sat May 12, 2012 4:32 am Post subject:

mrmrshoes · Posted: Sat May 12, 2012 4:48 am Post subject:

elmegil Great thread and arduino build by the way.
I was thinking of a different post, but yours is Really helpful. Thanks alot.
I need to study your design coz i just used midi Note messages to turn On/Off digital pins as make shift triggers and gates. I was using the MIDI Lib aswell, very useful but the documentaion is pretty bad. I had a couple of very frustrating days trying to do basic stuff. I haven't used it in a while so i'll be back to square one when i start working with the arduino again. Rolling Eyes

elmegil · Posted: Sat May 12, 2012 6:45 am Post subject:

Thanks

Dogue · Joined: May 09, 2009 Posts: 24 Location: New York

Thanks for posting that link. It seems that's basically what Ken Stone does in his CGS CMOS designs. For instance in this schematic:

http://www.cgs.synth.net/modules/cgs39_quad_gate.html

So, buffering the inputs and outputs like that seems to be a good way of interfacing Lunettas with the analog modular.