ASM-2

[Uncle Krunkus]

I'm just posting here the block diagram and a front panel idea for the ASM-2 which I think is the project I'm gonna finish next. I've had the PCB for 2 years now, mostly populated, and I have all the pots and switches, (which I got while I was at Jaycar at "staff" prices. Still cost well over AU$200 just for them) so I think I should get this beauty up and running first before I go starting anything else. (sorry Daniel, the DS806 monster drum units will have to wait a few weeks! (okay maybe months!))
Pehr, Laurie has been doing heaps of work updating his site and documenting everthing needed in the way of patched out and unpatched out options. It's still gonna be a big job though.

---

asm2-genie-block.pdf
Description:		Download
Filename:	asm2-genie-block.pdf
Filesize:	36.15 KB
Downloaded:	1523 Time(s)

---

---

asm2-wizard.pdf
Description:		Download
Filename:	asm2-wizard.pdf
Filesize:	114.98 KB
Downloaded:	1352 Time(s)

---

[Mr Swirling Vortex Man]

Please keep us posted on your progress Uncle. My Soundlab kit came from Laurie/ Elby Designs and I'm pretty happy with it. I may one day purchase an ASM-2 from him. I was quite amazed/pleased to find someone selling synth kits in Australia! I thought that kind of electronics DIY was mostly dead over here.

[Uncle Krunkus]

Yeah I was surprised too, at the time. I think Laurie actually took over the job of looking after and developing the ASM(1/2/Genie/etc) from another guy in America who developed the original Electronotes articles into a DIY project. I'm pretty sure Laurie was already doing DIY electronic music design before that.
I'll have to point him in the direction of electro-music.com. I'm sure, if he has any spare time, he would have heaps of interesting stuff to contribute. I get the feeling he's pretty busy though.
Meanwhile, I've got to use my new found photoshop skills to whip that front panel into a 19" wide rack layout!

[Mr Swirling Vortex Man]

Have you worked out the panel height that you'll need? Just intereseted as I have a few 2RU and 3RU panels at home that will no doubt one day be populated with various esoteric knobs and switches for electronic sound manipulations. I'm in the deep thought phase... You could call it planning for the future! ...Or day dreaming!!

[Uncle Krunkus]

The front panel which I posted up the top of this thread is for the Wizard. It's the completely patched out ultra deluxe version. I've tried re-distributing it in photoshop for a 43cm wide rack version, but it looks like it would turn out to be at least 65cm tall (and that's with removing the polydac and scaling the whole thing down slightly!)
That's not beyond possibility, but I'm now looking at this other front panel layout. It's called the Genie. It's basically not patched out at all. I'm not really big on patching stuff, mainly 'cos I like the immediacy of just flicking switches and turning knobs. Heaps of actual setups I'm likely to use will fit with a pre-patched version. I don't like the idea of having heaps of sockets and plugs (which can all potentially go faulty) and heaps of leads lying around, just for that 1 in 100 time when you want to re-route for a strange idea. Maybe I'm not a real "modular" kind of person. Maybe I just need to play around with a real modular to fall in love with it. But I've also heard Stein and Mosc saying that modulars can be a real pain. (finding ways around interface limitations, reliability issues etc.) So I'm thinking if I want to ever get back to actually composing again, I need to make it more user friendly than adaptable. In keeping with the idea of not burning bridges though, I'd like to leave room for a simple patchbay at the bottom. So it will work as a complete, pre-patched, midi controlled analogue synth, but I'll have room for about 12 or so patch points when I decide what I want.
Does anyone out there have any advice about this major lifestyle choice?

---

asm2-genie-frontpanel.pdf
Description:		Download
Filename:	asm2-genie-frontpanel.pdf
Filesize:	71.99 KB
Downloaded:	1238 Time(s)

---

[dnny]

[zipzap]

I can see the advantages of both concepts. Maybe it´s not such an question of lifestyle after all. Both is useful, and someday you´ll have both. And being able to instantly play is a big advantage.
For the more exotic modules, you never know where to put them... So no way to do it non modular.
In my synth i´m trying to get a good inbetween of the two worlds. It´s also not always easy, since i want those jacks in case i want to use them, on the other hand want prefixed connections in many places. Since i´m using bananas there are no normalized jacks, so i have to add switches to break internal connections.
Often it´s worth it. I added a adsr directly to the vcf via env pot. still it´s got it´s own out. There is a filter out jack. next to it is the vca. That is connected to the vcf-out, or it´s own jack, depending on a switch.
I´m still thinking about a bussystem. That could get rid of many cables. All my filters and vco´s have a Keyfollow swith that connects them to the cv-bus. Then there will be a bus-control module with a little mixer-matrix-whatever-idon´tknowyet thing to route the midicv, the sequencer 1 or 2, maybe an external cv (like theremin or so).
Maybe put in a quantizer also. Maybe have a second cv (and maybe two way switches on the modules)
Bout the same thing with trigger/gate and clock. Could even imagine white noise on the bus, so every module that can obviously use white noise has a pot to dial it in (and maybe a switch to dial in something else alternately).
Of course vco´s can have individual outs and still be routed to the mixer via round switches.
Many wires can be omitted, but it always costs another switch. I still like it, because it makes things clearer and there are still enough cables hanging around when it comes to modulation-madeness and soundshaping. (and those are the things where i believe a ready fixed system get´s boring the fastest.

[Uncle Krunkus]

Thanks Zipzap,
I think I'm gonna go about it in kind of the same way. I'll leave room for 6.5mm normalised jacks at the bottom (don't like leads infront of the controls, unlike the G2 you can't make them invisible with a mouse click)
Not as many as are on the Wizard, (80-100?) I'll probably just leave room for 15 or 20. And I'll work out what I want when the pre-routing gets boring!

[Mr Swirling Vortex Man]

I quite like the idea of having a synth that is pre-routed, but with key modulation inputs on certain modules and maybe also the possibility of intercepting the audio and control signals at a number of key points so that they can be used outside of the synth's regular signal path. I agree that there are many purposes for which a basic preconfigured synth is perfectly useful/gratifying, especially if you need to use it regularly in that configuration.

I'm considering building a number of modules that will have the controls mounted on standard rack panels and all of the jack sockets located on patchfileds on the left-hand side of each panel so that all interconnection points will be close to each other and away from my twiddlin' hand -as I'm right handed. I figure that if all the sockets are on the left, if I end up stacking rack panels on top of each other the points will still be relatively close together.

[zipzap]

I´ve seen pictures of modular synths using a big matrix patchfield. All outs going top to bottom, all ins going left to right. Guess the attenuators will then be on each module, but instead of a jack they own a row an the matrix. Needs a lot of planing, and a big matrix i guess. A growing modular can have many ins and outs...
Also if you add another vco and want to have it next to the other vcos on the matrix you would have to do a lot of soldering. And what if ONE connection-point somewhere gets broken..? Maybe there are modular matrix systems, where individual rows can be joined.
Some company has something like that, think only 8*8 connections, but it´s programmable. If you build something like that, maybe 20*20, add 380 vcas you could have a fully programmed patch-system. I imagine like this: 20 buttons left to right, 20 buttons top to bottom. Push 2 buttons for the routing between two points, have one pot for the amount.
Modules could still have attenuators on their ins, so that you have something to touch.
Now this sounds like NASA. Think i´ll start building one right now

[Uncle Krunkus]

No, I don't think it's rocket science. But it might take a fair bit of R&D. The right circuitry could even be controlled from a plug-in on your computer. So that whatever piece of music you load into the sequencer, the correct patching of your modular system is setup at the same time. But by the time you did all that, you may as well build digital models of the modules and a way to interconnect them with virtual patch cables. Hmmm,.... I think someone's already done that haven't they?

These decisions about useability, tactility, ease of performance, aesthetics, DIY potential, reliability etc. are very important ones, and it's important for anyone getting into electronic music to think about these things before they commit to a particular path, design, or budget.

[zipzap]

[Uncle Krunkus]

Oh, for sure!
And the other thing that I think will be great will be when some little fingers come along and change the setup for me behind my back! It'll be like the synth is doing it's own thing. I'm all for the nutty professor, mad scientist effect!

[sneakthief]

the ASM-2 is a great sounding modular. i think it really shines in the full modular-format (instead of the genie).

i made a little ASM-2 page which includes construction photos and descriptions:

http://sneak-thief.com/modular


...and here's my ASM-2 sandwiched between a Blacet and a rack of Midibox CV & CGS modules:



cheers,
michel

[zipzap]

Good Work! Nice Site.
How was your experience with Futurlec? How do you like those Pots? Better than the cheap plastic from Reichelt i guess.
Schöner Gruss

[Uncle Krunkus]

Great job, well done. You've managed to fit a completely patched out version into about the same space I was planning on putting a completely pre-wired version. So you've made me re-think what is possible in the space that I've allowed myself. I must admit that I'd like mine to be a bit more spacious, but I'm sure now that I can squeeze a bit more patchability in there.

[sneakthief]

Re. pots: as I mentioned on my page, Alpha pots feel great BUT have a wide variety of resistances, eg. a 100k pot could be anywhere between 80K and 105K, but mostly between 92-99k.

apparently Wiard uses Alpha pots so they can't be that bad


Re. knobs: due to the knobs that I used, my layout feels cramped compared to my Blacet, so I'm considering replacing all my knobs with Blacet-style Re-An Soft-touch knobs from Rapid Electronics - they costs 0.09 GBP each in quantities of 100. that's cheap!

Zipzap - Futurlec is cheap but slowwww. i waited 1 month for my order, but I wasn't in a hurry. anyhow, i would definitely order from them because I got exactly what i wanted at a very nice price.

Liebe Gruesse!

michel

[amos_joseph]

[bigtex]

Hey sneakthief, good to see you around here. Your site was one of the many that helped me make the decision to buy the Blacet kits when I was trying to decide which modular format to go with. I'm glad I did. Thanks for putting your experiences and information online.

Also, that's a really nice job on the ASM-2. It looks great and sounds great. Makes me want to build one. I know what you mean when you say you have modularitis!

[sneakthief]

bigtex - i'm happy to hear that i had a small part in your Blacet choice

i think modularitis is incurable ...it just goes into remission on occasion!

speaking of DIY, i'm in the midst of planning 3 (!) more racks right now and have most of the parts for them lying around; cgs, oakley, tellun, blacet, wiard, etc. i should really be saving this for the winter when the weather is crummy.

cheers,
michel

[bigtex]

[Uncle Krunkus]

Opinions wanted please! Critique away. All recommendations considered.

Here is the front panel layout at the moment. I haven't re-done the text yet, but I plan to. I hope you can read what all the controls do, 'cos I'd love some feedback on whether I've included everything crucial in a pre-patched synth of this size. If I've put in stuff I won't really need then let me know that too! The space at the bottom will have 6.5mm patch sockets for about 20 key points. What would they be? Mostly inputs? Mostly outputs? 60/40? 70/30?
This image is only 1024 across, the working version is over 3500 across and looks heaps sharper.
Thanks heaps to anyone who can be bothered to scrutinize my plans!

---

asm2-frontpanel.jpg
Description:
Filesize:	212.21 KB
Viewed:	1058 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

---

[Scott Stites]

Hey Uncle K,

Very sweet indeed.

My take on it, just food for thought. You'll have to forgive me, it's a subject I'm quite passionate about.

One word: Modulation, Modulation, Modulation. IMO, this is what makes the difference between a great synth and an outstanding mind and ear gobbling monster. You can have a jillion doodads and jewjaws that perform all kinds of awesome functions, but if you can't route and control them, they will never serve more than a limited function.

So, here goes

External VCO outputs
External VCO Modulation inputs

You may find, for FM, pulse wave modulation can be nice, but tires the ear much more quickly than sine or tri modulation (speaking in reference to VCO2). Crossmodulating VCO 1 and 2 is an interesting patch, particularly dynamically controlled through a VCA or two under control of a non-related function. Self modulation of a VCO produces unusual waveforms.

External VCF modulation input

Audio rate modulation of the VCF is a powerful tool. Just one example: processing VCO 1 sawtooth while modulating the cutoff with a variable pulse width VCO (VCO2) will produce formant tones, adjustable by the PW of VCO2.

External VCA Signal Input, CV input and Output

IMO, the VCA is one of the most underrated modules in a system. Being able to pipe audio/subaudio (if the VCA is DC coupled) into the VCA and routing that signal for modulation can produce wonderful dynamic effects (dynamic depth FM of VCO or filter, for example).

External LFO CV input, external LFO outputs

If you want to modulate the frequency of the LFO with the second LFO through the VCA controlled by the EG output, well there you go.

If the LFO can clock the S&H, pipe a bit of the output of the S&H output back into the LFO CV input. Subotnick.

External EG outputs, External EG Gate Inputs. I notice the EG's can be set for repeating, so I imagine a signal occurs when the EG ends it's cycle. Pipe that out of a connector. An EG just became a gate or trigger delay. Put it on both and alternate between EG's on each cycle.

Noise output. How else are you going to modulate your filter with it?

External S&H input
Noise is the choice most often seen as the input of an S&H. I rarely use noise myself, it wears thin pretty quickly for me. I'm more interested in the effects obtained from varying the frequency relationship between the clock and an LFO input. Or, gently frequency modulate a triangle LFO set for around 50 Hz with pink or red noise and sample that. You'll be glad you did. Or that may just be me (and Don Buchla, too, I suppose).

A mult or two wouldn't hurt, but cover the important things first, you can always build or make Y cables, or build an external mult box. Us non-banana jackers are at a distinct disadvantage here, but switching jacks are much more than enough payback for that, IMO. I'd die without my switching jacks.

Asking too much, I know, but IMO, another sadly underrated module in a synth is the DC coupled mixer. You'll understand what I mean once you start patching this puppy. An ideal DC mixer would have a number of attenuverters feeding the input, with inverted and non-inverted outputs. If you really wanted to get jiggy with it, each attenuverter could have a separate external ouput. That arrangement serves not only to have an inverter (as you already have), but a number of inverters plus inverted and non-inverted composites of the signals as they're processed. But, that's knobbage that would take up room needed for the other catalog of stuff mentioned above, and space is limited. There is always Krunkus Sorcerer II, the plans for which will begin forming in your mind as soon as the soldering iron cools......

Did I mention modulation?

Cheerios,
Scott

[Uncle Krunkus]

Thanks Scott,
That's exactly the kind of in-depth response I was hoping for. It might take me a little while to incorporate all those ideas, but I'm getting a lot better idea of which patch points to include.

[bigtex]

Scott's routing comments were great. Flexibility is very important. One thing I'd change (aside from adding more routing flexibility) is the layout structure. For example, you have two VCFs next to each other, but the common modulator inputs are not in the same order between them. Why not put the ADSR pots side by side rather than on the bottom for VCF1 and in the middle for VCF2. For me, this would make more sense and my hand would just know where to find the knobs, without thinking. I'd know that for anything that gets modulated by the ADSR, it's always the second knob down, or the bottom knob, or whatever you like. Consistancy, though, throughout the panel. That's what I like.

Now, so far I've only made designs, I have yet to actually fabricate anything... so take what I say with a grain of salt. In the designs I have made so far, though, I always try to repeat a pattern, and lay things out in a set order rather than just cramming knobs where they will fit. It might take up more panel space, but it will be worth it in the long run to have a very logical and orderly layout. In fact, I find that it often ends up taking the same ammount of panels space, but it just takes longer to find the right layout style.

Just think: if you build this yourself, you'll want to keep it for a very long time. I've been adjusting and remaking my panel designs for the Ray Wilson PCBs I bought (some modules and a Sound Lab) since April. I'm just now getting the layout refined to the point where I'm really happy with it. Of course, I only work on it for an hour or so every so often, but coming back to something after some time I see things that I dislike that I wouldn't have noticed before. But, then, I guess I can't delay this for ever... one of these days I'm going to have to actually build these things

Anyway, I'm kind of rambling here... but just think about your own ergonimics and the way that you personally like to have things organized. Approach the layout from that perspective and you should settle on something that you like for years to come.