MU: Super Mini Modular synth project construction journal.

[Flareless]

Nice

[Rex Coil 7]

Nice

Thanks.

Ok, it's 5:26 am as I type this. I woke nearly in a startle, realizing that toggle switch number X1B is already assigned to "duophonic operation". In the Kenton 2000 Pro there lies a feature which permits duo-op. I plan on using X1A for monophonic and switching both the Kenton's program (from mono to duo) and VCOs 3 and 4 to X1B for duo. I forgot about using Exponential Switch 1 (X1) in the "B" position to switch VCOs 3 and 4 into High Note Priority feed from the Kenton.

So the entire multiple-slew scheme I posted a few hours ago has to be rethought. Toggle X1 is completely spoken for, therefor something different will need to be worked out for the slew deal.

faaaaack ....

[Rex Coil 7]

Perhaps MIDI may be helpful in this ~slew~ business. I found another couple of toys I'd forgotten about, a pair of Kenton CV-to-MIDI Pro units. That's CV-TO-MIDI .... not the other way 'round.

The Kenton MIDI-CV converter I use (Pro 2000 Mk2) has A and B outputs for 1v/Oct. Both outputs have their own dedicated portamento functions ... time or rate based ... legato, all that. So when I'm using the ~duo mode~ the low-note priority 1v/Oct signals have their own glide ... and the high-note priority 1v/Oct signals have their own glide. Now, how to control those glide times/rates in realtime? Well, like I said above I found a couple of things that may make this possible. First, there's this ....
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That would be controlled realtime using these (??) .....
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Which would be used to send the proper MIDI commands to the Pro-2000 for realtime control of both slew limiters. CV input from ~whatever~ is all those little silver Kentons to control any number of MIDI CCs.

I also have two of these to work with ....
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So maybe ..... dunno yet .... but one thing for sure this absolutely needs to be tested before I go drilling holes and soldering stuff. It's not exactly what I was aiming at with the muti-slew idea, but it may actually be more fun ... a lot more fun. Notes all slewin all over the place ... Expo-FM goin on to throw gasoline on the fire... then there's them ringy dingers (ring mods) connected across a number of VCO configurations. Duo-phonicals sliding up and down creating tonal havoc as two dual-VCOs fight it out with the press of two keys on the keyboard. Then there's that evil EHX Ring Thing sent out to an EHX Pitch Fork with the interval set at 1 whole step (creates dissonance). Ok, now we're gettin somewhere ... at least I think so.

[Rex Coil 7]

I may go with this performance control setup that fits in the BOX4 mounted on the left of the keyboard rather than using the big joystick.

[Rex Coil 7]

Pffft! ... maybe better yet. Testing it later tonight;

[Rex Coil 7]

PORTA-DANG-MENTO! I may have this problem whooped!

Oh wait! I think I may have discovered a method to get the kind of portamento I'm wanting. The Kenton Pro 2000 has it in there, but I've no ~real~ way to control things via MIDI. I'll need to control the portamento rate/time for two "channels" of 1v/Oct .. so that needs to be a pair of variable controllers (one per glide rate/time). I'll also need a way to switch between ~rate type~ glide and ~time type~ glide via MIDI.

I may have a method;

This thing for doing any ~switching of modes~;

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And this gizmo here for controlling MIDI thingies;

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That's a 16-fader module by Michigan Synth (??). Each fader may be mapped to MIDI .. and simultaneous CV out with voltage selections (0-5 .. 0-10 ... 5-0-5). So one fader can adjust "A" glide time, another for "B" glide time, and a few others to control the Kenton's onboard LFOs. Leaving enough faders to control the time of attack, decay, release and sustain levels of two Ornament and Crime modules (that would be eight envelope generators) ... and still having two faders left over.

That said (if it all pans out) the 168HP Euro main controller cabinet might look like this ..

I have a 3rd O_C module not pictured there. It will be dedicated to producing PWM ... either through envelopes ... looping envelopes ... or LFOs. It's four outputs will be connected to each of the four VCOs' PWM inputs via one of the trunk lines for the proper mod bus. In other words ... normaled. I'll set up good envelopes that work well for this purpose (looped or gated) and a set of four LFOs properly set up for the same purpose in the one O_C.

More notes taken, more diagrams done. Moving forward.

EDIT: BTW ... Only the 16 fader module would need to be purchased, I already own everything pictured other than that fader module. Same with the BOX-4 in the posting prior to this ... well, I suppose that one is short one Q147 Distributor (I only have ~one~). Anyhow, just sayin .. this isn't a bunch of pipe dreamin' that can't happen without a pile of cash. The fader module is less than $300 bucks. I even have the 168HP rails (four of them) and the end pieces. All just waiting on the boss to shit his git together and build something!

[JohnLRice]

You are the best kind of madman, sir!

[Rex Coil 7]

... oh, and 'aforn I fergit ... I tried this last night ... wow .. it's an unuseful car wreck if too much control depth is used. Get it all just right, and this variation of audio rate FM is really neat.

[Rex Coil 7]

CONTROL CABINET #1 -- LOWER ROW (controller interfaces);

There are two controller cabs. One of them is mostly Dot Com, the other are CVs (Euro). The Euro controller cabinet (aka Control Cabinet #2) is all Euro consisting of basic tools (4 stage envelopes .. simple LFOs .. a few manual controllers). Control Cab #1 is pretty much all Dot Com by choice. It's all "interface" stuff for the two ribbon controllers as well as several passive controls (foot/hand) to produce CV that's got it's own sets of controls (voltage amounts, gates, and so forth).

The silver panel in the upper edge of the picture is not part of this cabinet, it's only there on a temporary basis for some testing. That upper row will be consumed with the global LFO and it's minions.

So this lower row is wired up around back and finished. The power interface is needed to power the keyboard and the BOX-4 goodies. The main synth cabinet uses a busbar distribution system of it's own. I'm becoming familiar with the Dot Com ~Interface~ layouts and how they work. There are FIVE channels of this type of interface in the lower row picture. In the picture with the Joystick and dual Q147 Distributors there are two more of these interface channels. Makes it easier to understand what can/will happen with any of these devices ... joystick, wheel, ribbon controller, foot controller, et al. They all use the very same interface system.

I've just about got enough figured out to enable designing/engineering the actual CV busses and trunk lines for each "group" (VCOs .. VCAs .. VCFs .. Gates) going from Control Cab #1 and #2 in to the Main Synth Cabinet. Looking like around a total of thirty wires, maybe less. For example, the VCOs will require TEN CV wires (4 unattenuated Exponential FM sources and/or "1v/Oct" ... 2 attenuated Expo FM sources ... 2 attenuated Linear FM sources ... 2 attenuated PWM sources .... so there's ten wires, just for the VCOs). So this is what I've got to work through next ... designing/building the CV highway system.

Anyhow ... lower row of ContCab#1 is ready for service!!!

[Rex Coil 7]

That previous post got me to thinking .... Dot Com should offer an "interface module" similar to some of their other interfaces ... a dual interface for Velocity and Aftertouch. Feed the velocity voltage from a MIDI-to-CV converter in to one channel of the interface, and feed the aftertouch voltage from the same MIDI-to-CV converter in to the 2nd channel of the interface. Maybe?

[Rex Coil 7]

Just tried this ... ribbon position on the Ring Thing and ribbon pressure on the Pitch Fork. Worked great!

With the way some stompboxes can integrate with external passive controllers AND active control voltages makes this whole modular thing sortof mean something more than just synthesizer modules.

For example ... the following are screenshots from the manuals of the Ring Thing and the Pitch Fork;
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Envelopes, LFOs, manual controllers, on and on. Along with well made Instrument Interface and VCAs any of these types of FX can be introduced mid-patch at any point in the audio signal flow ... and controlled with active CV as well!

Shee-yit ... I could control the Ring Thing with aftertouch fer cryin' out loud (just pointing out some abstract control sources).

Oh boy ... this synth is getting more fun every day.

[Rex Coil 7]

MAIN LFO -- CONTROL CAB-1 .. CONTROL CAB-2 -- LIVE PERFORMANCE CAB -- AND DADDY'S HELPER;


MAIN LFO -- CONTROL CAB-1;
Remember this little pcb I found (dot com Q113 8ch mixer board)? Due to unavailability of components there is no indication of when the parts needed to complete the Dual VCA boards I have I'm taking a different route to arrive at the same destination (talkin' 'bout the whole VCA controlled depth of cross modulated VCOs thing). That said, the Q113 pcb will be put right back in the module it came out of .... which fortunately is an OSCILLATOR MIXER! Perfecto!!! I had forgotten about this, I found the circuit board but could not recall where it came from. Yesterday I quite by accident found the Q161 Oscillator Mixer module without it's board. So, since the dual VCA+Mixer for cross modulation is not happening, I'll use the board for something just as important .... mixing Q106 waveforms to modulate the whole gang.

Dot Com Q113 circuit board - 01.jpg (141.86 KiB) Viewed 1055 times

I got the upper row of CONTROL CAB-1 completed with the installation of the GLOBAL LFO. From left to right

Q106 VCO.
Q141 VCO Aid.
Q161 VCO Mixer (yay!).
Q111 Pan/Fade.
Q108 VCA.

So that makes up the main controller interface row (lower row) and the GLOBAL/MASTER LFO ensemble (upper row);
** The speed of the LFO may be controlled any number of ways.

** The VCO Mixer can create many different complex waveforms.

** The VCO Aid provides rather instant waveform changes with it's rotary switch.

** The Pan/Fade allows for swapping back and forth between the Q161 mixer output and the Q141 rotary switch output (the swapping/mixing controlled manually or by any of several realtime or periodic controls).

** The VCA controls the gain ("depth") of the whole circus to any of several destinations, but usually to the Exponential FM inputs of some/all of the VCOs, VCAs, and/or VCFs.
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So this pretty much "completes" Control Cabinet #1. Some work needs to be completed (knobs re-installed, a bit more normalling to the upper row is required, a few other niggles, but beyond that this one is done and ready.

LIVE PERFORMANCE CAB (Euro):

This is cut down to just the usual suspects. Four non-voltage-controlled LFOs ... four EGs (Roland type) ... a stick ... a pair of Lightstrips ... and a Dual VCA. The Dual VCA is what I'll use as the actual output VCAs for the synth itself. I got no danged money to buy a pair of VCAs at this moment, so I'm using what I have. The output of both filters of the main synth will be routed in to each of the two VCAs and controlled by one of the Dual ADSRs (there are two envelope gens in each one of those ... just right for dual VCAs!). And right there all nice 'n handy as well.
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CONTROL CAB #2 .... the flex cab;

4 rows of Euro stuff. The upper-most row is what will take over cross modulation duties. There are two tiny little Erica Pico VCOs in the upper row (3HP each). They are wavetable oscillators, no interpolation between waveforms, and two banks of 16 waves (including white noise). Perfect for use as a modulator in a "cross modulation" set up. To their left is 1v/Oct input, slew, active 1v/Oct "mults" so each of the two VCOs can track 1v/Oct (or not). Most of their waves aren't well suited for audio rate exponential frequency modulation aside from about the first half dozen or so. Their outputs go into a Quad VCA/Mixer, which are then sent to any VCOs' ExpoFM Inputs .. or all of them (snicker snicker). I find this no less effective than cross modulating two of my four VCOs with one another. With the help of those two Hendrickson modules ROMplers may even be used as the modulators in this scenario.

Most of the other stuff is for pushing voltages around (changing unipolar, bipolar, polarity, offset, mixing, and so on) or creating various voltages/signals. There's FOUR of those Quad VCA/Mixer modules, very handy. And I like those Soundmachines Lightstrips and Lightplane. The largest difference between those and any other voltage source that can record gestures is that with these Lightstrip/Plane things I can ~jump~ directly to some voltage level, or ~sweep~ to that same level. Do THAT with a knob!

This cabinet is supposed to remain ever-flexible. Hopefully it's contents will diminish over use ... that's a LOT of stuff!
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ONE OTHER PICTURE .... This is CooCoo ... she's ten. Daddy's girl.

Coo - 2023 - 01.jpg (78.12 KiB) Viewed 1055 times

[Rex Coil 7]

... I'll be out in the shop now .... holes to drill and such ... any questions, just post them here.

[Rex Coil 7]

Just a notice ... looks as though it's become more like a Minimoog ... more to come! Switches ... oy! .. the switches! There will be switches involved. Working on a weirdo tweeky dual envelope thingy as well. Lopsided asymmetrical performance control system weirdness coming as well. And LESS EURO ---- MORE 5U!


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[Rex Coil 7]

So why did this change to 3-VCOs happen? I have the money required to complete the dual filter panel ~OR~ the second Dual VCO panel. Since I already have another Q106 Ensemble (Q106, Q141, Q161) it seems the obvious choice. When I posted that picture of the "UPPER ROW" of the control cabinet, suddenly I "saw" the Minimoog 3rd VCO staring me in the face.. with a VCA even! It was that moment when the obvious solution hit me .. finish the dual filter, install the "minimoog 3rd VCO" in the Super Cab, and we're nearly there.

Routing of CV as well as routing output of VCO3 are the current tasks on this portion of this project. Lack of the munnies makes for creative use of existing equipment.

Oh, and that "Center Strip" where I had mounted a pair of ring modulators??? .... I'm making an all new one sans ring mods. Signal routing toggles and maybe even a few chunks of VCO3's Q141 may come to call the center strip home. VCO3 has some work in it's future, requires routing of it's outputs, adding the same "CV Bus Access" that the other two oscillators have (switch X1A etc .. etc ..) and modifying the 4ch wave mixer (Q161) to a 6ch waveform mixer ... after all, it has a Q113 pcb in it, may as well use it all!

Now ... sell some more Euro and obtain four Q109 EGs .. two Q108 VCAs .. gee whiz, that's only about $850 munnychecks.

[Rex Coil 7]

I've always been in a state of awe at the power of "forced creation" if you will. Where environmental changes or situational changes force one to creatively do more with less.

So lack of cash and new life situation(s) made me decide to set-back the completion of the VCO3/4 panel in favor of completing the dual filter panel. Then I was able to locate enough spare parts to wrestle together a 3rd VCO/LFO/King-BadAss-Modulator. Then the keyboard controller thingy (j-stick + distributor + slew) came together. Then last night I saw yet another opportunity ... so I mounted the two ribbon controller interfaces in the main cabinet along with another "dual" controllable voltage source (Q142).

This makes sense. When I'm done reconfiguring VCO3 and cleaning up some of the ribbon destinations there will be nearly nay a single knob or switch below the "jack line" on the upper row modules. The fact that a number of patch cables will be required (for a few hundred hours of research/use/playing to work out routings/normalings) will be very little trouble since 90% of all of the knobs/switches are above most of the jacks.

This configuration also lowers the main cab by about seven or eight inches; previously the main cabinet had to be up on risers that are roughly a foot tall so that it was high enough to rise above the Euro cabinet that would fit between the keyboard and the main cab ...like in this old picture ...

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Now that the main cabinet has been reconfigured it allows for lowering it by quite a bit. There's no more Euro controller cabinet between the main cab and the keyboard now. And with the lower row of the main cab being mostly jacks/cables it may now sit at the very same level as the kybd (hooray!!). So the upper row is now at eye level and that row also has most of any knobs/switches needed. Another hooray!!.

It will take me awhile to work out the 3rd VCO's outs and ins ... the ins won't be too difficult (the same five A-Off-B toggles the other two VCOs have) ... VCO3's outs will need some work, for example the waveform mixer is actually a Q113 (8ch);
... one bus-out will be routed to the other two VCOs and will have Tri-Sine-50%SQ (waves best suited for modulation).
... the other bus will be run into the "audio" pre-filter mixer with the other two VCOs (saw, ramp, PWM) (waves best suited for rockin bone).
... y'know, that kind of stuff.

So here it is, the latest reconfiguration;
... UPPER ROW = VCOs 1 and 2 .. the pre-filter mixer .. and the dual filter.
... LOWER ROW = VCO3 control toggles (same as the ones for VCO1 and 2) and CV bus inputs are to be in the place holder panel on the left .. VCO3 and it's ensemble .. manual voltage controller interfaces .. and (later) two output VCAs will mount on the far right of the bottom row (place holder panel there now).

All three oscillators meet up in the pre-filter mixer as well as an outboard instrument.

So it's now down to only the keyboard, the Main Cab, and the Euro "Flex Cabinet". I've eliminated the extra 5U cab that held VCO3 and both ribbon interfaces as well as the "pedal interface" that are now in the main cabinet. Smaller system, and yet more likely to force better creation. Here it is ....

I'll get the filters done, and it's pretty much ready. I'm going to drill the Q147 panel for that X-Off-Y toggle switch since I have a spare Q147 empty panel on hand ... so if for whatever reason I need to sell the Q147 in my keyboard I'll have an unmolested panel on hand for it. This is better than drilling the joystick panel.

More in a bit, I'm hungry.

[Rex Coil 7]

Came to the conclusion that I had placed the ribbon interface modules on the wrong side of the lower row.

That placement forced the keyboard waaaay too far to the right due to the short length of the ribbon interface cables. That said, VCO3 and the two ribbon interfaces have to trade sides. I really hope this is the final configuration. At least ~now~ all of the manual controller inputs and control voltage inputs are all located on the left side of the lower row.......

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I also concluded the Q141 was not needed. So it got removed. This made room to include the Q118 Instrument Interface which is something I really want in there.

Movin on ......

Here's four utility modules that really are useful.

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...buuuuuut ......

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YES! Rather easily so at that. Check the dimensions I have to work with, plenty of room.

I'll be building the passive controls (that THREE of those modules need to operate) into the 2sp panel that sits next to the Dot Com joystick in the BOX4 bolted to my keyboard. At the very least that passive control panel will include pots for controlling the two channels of the Q142 Pedal Interface as well as a passive joystick for the same two channels. Another passive pot for the Q181FJ single channel interface and a combination ON-Off-Momentary toggle switch for the GATE input of the same module (the switch will provide latched 5v gate, or momentary 5v gate, or no damned gate).

Rest certain that there shall be photographs and plenty of bla bla bla once metal begins being cutted and holes drillified and wires begin being soldereded.

This stupid little thing was what inspired the notion ... I'd just happened to set the joystick panel atop an upside down used Dot Com panel .... and the light went on! That orange knob? .... that'll be slew amount.

There we have it. As I said, I really (really! a lot!) hope this is the final configuration. I'm dun phukin wiff it ... I want to play this bitch .. and do some recording!

[Rex Coil 7]

Oh, and second entry for tonight ..... here's the audio pathway. I named the external instrument input "VCO4" however I believe that's going to actually be named "VCO5". It's output will be normaled straight into the Q113 Pre-VCF mixer into the non-attenuated channel on bus-2. That input will rely on the Instrument Interface's output level as the "mix level" for whatever line level signal I send into my synth. This will leave Channel-4 (attenuated) open for external VCOs that are still at modular levels and won't require gain boost.. perhaps Euro VCOs that I wish to run through my Dot Com Dual Filter Array .... er sumthin?

Anyhow, here's the audio pathway (it assumes four VCOs).

[Rex Coil 7]

I FINDED ME A TREASURE CHEST, I DID!

As things go, while looking for something utterly different I located one of those tubs that had about A THOUSAND BUCKS worth of parts for this project, specifically the dual filter rig. WAHOO!!!!!!!!!

The wonderous chest of goodness ...

Dual Filter - 03.jpg (48.52 KiB) Viewed 825 times

Dual Filter - 04.jpg (53.1 KiB) Viewed 825 times

Thar be CIRCUIT BOARDS in there, mates!

Dual Filter - 05.jpg (47.63 KiB) Viewed 825 times

And a right load of extra booty specifically pulled for the project, the likes of toggle switches, pots, standoffs with screws/nuts/washers.

... this entry is continued in the next post ...

[Rex Coil 7]

... continued from previous posting ....

Even plenty of two conductor and three conductor pigtails for connecting pots/switches/LEDs to the Dot Com pc boards.

Dual Filter - 06.jpg (52.01 KiB) Viewed 820 times

Now I may finally get the danged QX675 Dual Filter put together and tested!

Oh wait! I found something else as well! I'll post it next entry .. in about one hour.

[Rex Coil 7]

.... six-foot-long ribbon controller extension cables ... now I can put the keyboard controller across the damned street if I wish to. They were in that same tub along with the filter parts.

With that, the third VCO and those ribbon interface modules went back into their earlier locations (vco on the left, interfaces on the right). With that tub of filter guts showing up I can get that empty dual filter panel done .... poor sad little empty filter panel.

I really like this. I'm not only left handed but it's easier for me to use my left arm (old neck injury) and I'm able to play a little better with my right hand. This configuration puts most of the controller activity clustered within the radius of my left arm/shoulder and more or less in one area. Since I am finally happy with this 3VCO configuration I can now get to work on the what I'm going to do with the BOX4 stuck on the left of the keyboard. The joystick is fine so all is well there. I'll be working out things like slew and passive controls for several built-in modules that expect passive control. All in the BOX4.

Later.

[Rex Coil 7]

I went through this entire thread last night. Gotta say I'm ashamed, ten years of bullshit, no synth to show for it. There are usually a few hundred views anytime I add an entry, but nearly zero replies. I understand why now. There's nothing to see or hear, no progress, no sounds. Even less conversation. I need to think about ~why~ I post this journal.

[JohnLRice]

I think this thread is cool so I hope you keep posting, if it's something you enjoy doing?! Sometimes I just skim through the posts, especially if they are long, and more often than not I don't really have a comment or something intelligent to add. I wish ModWiggler had a quick and simple "approval/thumbs up" thingy to click because it would be faster than making an entire post just to send you thumbs up or other emoticons, plus if everyone did that for every post this thread would become 10 times longer, but I know a lot of people hate the thumbs up/down rating system and I think there was discussion a few years ago and a vote/poll for it and it didn't get approved.

Anyways, keep on doing you I say!

[Flareless]

Anyways, keep on doing you I say!

[dedwards]

Just want to say that I enjoy reading the journal. I'm a musician and have no electronic expertise and poor soldering skills but have modded a couple modules based on your ideas (normaling mixer feedback with switches on the q113!) I've learned a lot from your journey and hope you will keep sharing if it's something you enjoy. Thanks for documenting the project. I'm sure it takes a lot of time!