MU: Super Mini Modular synth project construction journal.

[Rex Coil 7]

NEW (THIRD) CONFIGURATION OF THE RING MODULATOR CREATES A SCREAMING SCREECHING BEAST!!!

For many years I goofed around with different configurations of guitar overdrives. Y'know, your basic opamp driven signal amplifier with a set of diodes shorted to ground to create that diode clipping distortion that so many guitar players dig the livin' shit out of. In that pursuit, I discovered that one of the main differences between different diodes used, was a difference in gain before the diodes actually clipped. (There's an entire shit-ton of reasons why that is such an important thing when an opamp/diode clipping overdrive units are used with guitars, this thread is not about that).

Anyhow, taking that experience into the studio this morning, I removed the diodes in the ring mod, and replaced them with a totally random selection of square-red LEDs. Besides, I wouldn't have the first clue of how to match LEDs as diodes anyhow.

It worked FAMOUSLY!!!! It created a ring mod that does precisely what I want one to do in the role it plays in my synthesizer. It created a fekking SCREAMING SCREECHING BEAST of a sound! And (just as I mentioned above regarding voltage-levels-before-clipping aspects of different diodes) the overall output level of the ring mod was increased dramatically.

Ok .. alright alright .... I'l shut up .... here's pics already ....






I also went ahead and added a proper VCF, as well as a signal mixer. So now this patch is ~pretty much~ the same setup as I have planned for my Super Mini Mod. I installed the Q150 ladder filter (LP 24db), and the STG Soundlabs "Mixer" (geez, I wonder how long it took Suit and Tie Guy to come up with that name? Work on it all month, did ya?). For anyone unaware, the STG "Mixer" is a modern copy of the R.A. Moog modular CP3 signal mixer. It's about one fat bastard! (the module, that is).

So this patch emulates precisely how a basic patch on the SMM synth (Super Mini Mod) is set up without a single patch cable. Oh man, bla bla bla already about how fekking GLORIOUS my synth is. Back to the ring mod ....

So the red LEDs worked out SUPER well. Much more output, ~holy shit~ amounts of top end freq-response now, too. And in a patch I can emulate with my SMM without any patch cables.

This test did 2 things .... it proved an idea about which diodes to use in the basic 2-transformer/4-diode passive ring modulator ...... and ..... it also proved out the topography of the way I want to configure my synth (normalizing routings).

The way I patched up in the first RM tests I used a different routing, using the feedback setup in my Q113 mixer to distort and drive the inputs to the RM (which my synth can do, but it would require patch cables).

This way that it's patched today, the VCO outs go directly into the RM's ins. You see, with either silicon or germanium diodes the signal is so eaten up by the restrictions the diodes place on it that I needed a serious signal boost going in AND coming out of the RM. Changing the diodes to LEDs really (really!) upped the output gain of the RM, so no extra signal boost was needed going in to the RM. So I didn't need to use the modded Q113 mixer to boost the living shit out of the VCO output to properly drive the RM anymore.

I still need a boost on the output though, but that's already baked in to the signal routing design that I have going on. I've placed another Dot Com mixer (a modded one, of course) on the Center Strip, providing boosted signal levels on the outputs of both Ring Mods (the right one for Voice 1, and the left one for Voice 2). RE; the picture below. the black knob is the RM's output level, and the red knob sets the drive level of the modded Dot Com mixer used for the RM's output. I'm using ONE Dot Com mixer PCB for both RMs, one bus per RM. The PCB itself will be stacked on top of the main mixer's PCB in the upper row (I had to have SOME place to put it, that was as good a place as any other!). This picture is of only half of the Center Strip ... which is home for the Ring Mod that services Voice 1.



Well, this patch pictured here in this post is an exact emulation of one of the SMM's voices, plus one of the VCFs in the lower row or modules, including the STG "Mixer" (geez .... "Mixer" ... really?) and one of the two VCFs I have going into the SMM.

I'm super excited! The sound is precisely what I'd hoped for. Think of what guitar players call "pinch harmonics" ... that's what I was going for, and that's what using LEDs in these particular passive transformer style ring modulators provide.

RC7 out.

EDITS:

1.) I may not even use the standard built ring modulators (the ones with the germamium diodes).

2.) That said, the two little ~blue~ toggle switches on the Center Strip will become *ON-OFF* instead of an *A/B* toggles for each Voice-RM.

3.) I'm not really sure just ~what~ I'll do with those 2 completed ring mods that have germanium diodes. Perhaps make a guitar pedal or something? Perhaps sell them? Dunno.

[Rex Coil 7]

SORRY - NO MODULE PICTURES THIS POST - JUST SOME SUMMARY VENTING PRIOR TO MOVING FULL BLAST INTO COMPLETION OF THE CONSTRUCTION OF THE MAIN CAB:

I've spent the better part of the last 3 or 4 days trying to convince myself I needed a new (read ~better~) VCO/VCF/VCA/MXR (any or all of the above) ... but to be completely honest, I can't find anything that really offers anything better than what I already have.

I'm speaking of core circuits. Now, when it comes to features, yea, sure, there's a lot of other modules out there that have little features that may offer some advantages. But a lot of those features are attempts to increase functional density of a given module. Such as added CV depth controls, or the added toggle switch here or there, or some additional subcircuit added to a given module (such as a state mixer on a state variable filter).

But, going down to the core circuit level, I cannot seem to locate any modules that would be worth the time and trouble to replace the VCO/VCF/VCA ensemble that I have collected. As far as added features, or increased density ... that is what my Euro wedge is tasked with. The MU cab has a specific role, that is creating and processing audio, the end.

So, with all of that having been said, I feel pretty comfortable with moving forward at full speed with finalizing fabrication and getting it on!

I'm just working out the final details of precisely what I'll do with the controller modules I'll be putting into place.

** 2 VCO Controllers (I think I'll label them "Q106B Controllers") that will be tasked with the fiddly bits of controlling the two 2-VCO voices.

** The VCF Controller panel, a 2 space panel that does pretty much the same thing for the filters that the VCO Controllers do for the VCOs. Mixing of the state outputs for the Q107, switches for this and that, bringing in various CV signals and routing those CV signals to their proper destinations. Tie in the VCFs to the lower row's Normalizing Rail. And so on.

** The Pre-VCF mixer/distributor signal routing panel. There's 2 Ring Mod signals, 4 VCO/2Voice signals, some send/return jacks, some routing toggle switches, 3 mixers, 1 distributor, 1 Instrument Interface ... all of that stuff needs to be tied together before sending it all to the VCFs.

** The Output Stage ... pretty much same as the Pre-VCF stage ... mixers, reverb, the output VCA, some sends/returns to interface with the Euro wedge. On and on.

In this quest, I may partake in the services offered by Front Panel Express. The last 24 hours I've been getting acquainted with Front Panel Designer (the free program that's used to create your panel construction files that Front Panel Express uses to fabricate your panels with). This option offers some things that are otherwise a pain in my ass. Such as an eloquent manner to create a pair of matching 3 space panels that I'll use to make the two Q106B control panels with. Call me lazy as all hell, but I'm totally NOT looking forward to drilling over FOURTY holes .... twice (40+ per panel).

I have enough holes to drill, the bus bars alone are tasking me with over 280 holes to drill!

I'm also looking at using Front Panel Express for the VCF control panel, as well.

So there ... I've got all of that off my chest. Just a load of bla bla bla. No oddball-assed pictures of more of my hill billy technology this time around.

Well, one picture .... it's of daddy's little helper ... CooCoo ... my little 4 year old cat. She was erroneously brought home one night when we thought we had found our lost cat (Daisy May). She's been "daddy's little girl" ever since.





EDIT: By the way, I just recently learned that AJH had named their small synth ensemble "MiniMod", the copyright date of that webpage is 2014. I started this project in 2013 I believe. Just to get it said, their efforts and their synth have nothing to do with what I'm doing. This is, and always will be THE one, THE only, SuperMiniMod. A minature modular synthesizer (relatively speaking), normalized to create a super live performance 4 VCO/2VCF synth.

[Rex Coil 7]

The RC7 Q419 - Dual VCF Module:

HA! Boy, am I full of myself here or what!? "RC7 module" ... really then!

Anyhow, ego matters aside. I've been working with Front Panel Designer for a few days, and I've fairly well go the hang of using it. It's very much like the PCB construction program I used to make my own circuit boards a few years back.

Here's my first whack at it. I've combined three modules here (5 spaces wide), the Q107 State Variable VCF, the Q162 State Output Mixer, and the Q150 Transistor Ladder Low Pass filter. Combined, they produce the Q419 Dual Filter. (107 + 150 + 162 = 419 .... ain't I clever?)

$72.19 delivered as shown, (3mm thick panel, rounded corners, anodized black finish, machined graphics). Compare that price to buying two 2 space blanks, and the "Q107AK" panel kit from Dot Com to produce this same thing, which I would still need to do a ton of hole layout on to drill them myself, as well as figure out a means of applying lettering ... at a cost of $70.00 ($36 for the Q107AK kit panel, and 2x$17 for two 2 space blanks).

Here's a screen grab ...



LEGEND:
** F R F R mean Freq Resonance Freq Resonance for each of the two filters.

** "- F +" means it's a CV control which uses an attenuverter.

** F + 5 means it's a filter cutoff CV that is not an attenuveter, it only provides 5 volts from off to max.

(SWITCHES)
--- "RESO" is the Q107's resonance volume level jumper.
--- "SRS-PRL" puts the Q107 either in SERIES or PARALLEL with the Q150.
--- "BND-WTH" changes the Q107's operation from Constant Bandwidth to stock.
--- "LVL-LVL" is the Q150's resonance vs signal level jumper
--- "12-24" changes the Q150's slope from 12db per octave to 24db per octave.

The small pots on the left of the panel are the Q162's state mixer knobs
--- "N" = Notch.
--- "B" = Band Pass.
--- "H" = High Pass.
--- "L" = Low Pass.

The two unmarked pots beneath the mixer controls are FEED BACK levels for each output bus. Same feed back modification I've done to the VCO Mixer.

The large rectangular cutout in the lower center of the panel ... well ... that's a Top Secret mystery! It's actually a panel cutout where a thinner aluminum subpanel will reside where all of the I/O jacks will be mounted. It's 100% replaceable so if I change my mind about certain I/O jacks that I am using for certain CV applications, I can simply drill out a new sub panel and attach it to the main panel via the 8 mounting screws. It's essentially a simple replaceable subpanel with "window".

I've enlarged the component holes to represent the largest part of any given component. For instance, the flat washers that I use on some of the pots are actually larger than the knobs themselves, so on those particular pots I've used the flat washers to represent that pot. Sometimes the knobs are the largest thing, so I'll use the knob's outer diameter to represent those particular controls.

I do this to help me position various components, so as not to have them overlapping PCB mounting screws, and it also helps me to better position any lettering that may be associated with a given control.

I then save that file to a different name, which I reduce the size of the holes to the proper drill hole sizes for the components at hand.

It's just the way I've decided to use Front Panel Designer. So what you're seeing above shows the knobs (BIG holes), and the flat washers (smaller pot holes) because those are the largest parts of those pots.

The entire idea springs from simple layouts that I do on a piece of paper that I trim to the same size as the actual finished panel, and begin to place various knobs and switches and jacks on to suit my needs. Then I shoot a photo of that, and add lettering to the photo. This simple mushed together image creates the basic inspiration for the actual panel design.



I then spend hours getting the panel designed with all of the mounting holes in their exact positions, and everything made ~just so~. I go over my work several times to make certain hole placement and hole size is absolutely spot on. I had to measure the spread between mounting holes for the PCBs, and then use those measurements to place the drill holes in the panel designer. Roger Arrick used some interesting design standards in his PCB designs, and they made total sense to me.

So there's my first attempt at using Front Panel Designer. I'm not sending it to them for a new panel though. That's because I'm adding 2 or 3 more panel widths to it so I may add two more circuits to the ensemble.

All I'm willing to say right now is that the new 7 or 8 space/5 circuit rendition will be named the Q679.

[bwhittington]

Brian, I'm just bedazzled by the amount of thought and effort you are throwing into each aspect of this beast. It will be a wonder to behold when the project is finished. I'm sure I'm not the only one who would enjoy seeing it in action one day.

[Dr Gris]

Agreed!!

//M

[neandrewthal]

You're putting 1/2" knobs on a 5U synth?

Who does that!?!?!?

[Rex Coil 7]

Brian, I'm just bedazzled by the amount of thought and effort you are throwing into each aspect of this beast. It will be a wonder to behold when the project is finished. I'm sure I'm not the only one who would enjoy seeing it in action one day.

Agreed!!

//M

wow .... uh .... thank you both! (I am horribly awkward at receiving compliments, sorry if I seem ungrateful, I'm really bad at gracious acceptance). But thank you both, very much. I sincerely mean that. Your encouragement only drives me harder.

You're putting 1/2" knobs on a 5U synth?

Who does that!?!?!?

Me. The same guy that throws every other convention out the window to bring my own ideas to life. I also put 3.5mm jacks on 5U! (I swear I just heard the collective anii of every 5U purist suck the seat cushion up their asses after reading that!).

NO! ..... not 3.5mm jacks ... AND half inch knobs too?!? ~gasp~ .... the horror ..... the horror .....

This might happen .... (might = will) ...

This mockup is done in 1:1 scale:



It only makes sense. Well, to me.



Now I just need to spend the next day or so getting the FPD file done. It will be good experience and practice before doing the two 6 space voice panels.

























HALF INCH KNOBS!!

HA!!! Gotchya!









(half inch knobs!)

[Rex Coil 7]

MADE THE LEAP - COLOR CHOICES:

Ok, so I finally put on my big boy pants and made a decision on the Center Strip ... and COATED THAT SUCKER IN PICKUP TRUCK BEDLINER!

I did it yesterday afternoon, around 1400hrs. From my experience with the stuff, it will set up to the touch after about 12 hours, give or take. But, for it to truly cure, it actually takes about a full seven day week. That stuff isn't an evaporative curing chemical, that is to say that it doesn't cure by having the solvent in it simply evaporate (such as lacquer based paints, the lacquer thinner in the paint just evaporates from the paint, which is how it cures).

This bedliner stuff is more like an epoxy enamel, which doesn't cure by evaporating the solvent, it uses a molecular curing process (again, like epoxy enamels do). So it has to be handled and dealt with differently than evaporating solvent finishes. To add subsequent coats to solvent based finishes you can add as many coats as you like, whenever you like. This is because when you add more coats, the liquid solvent in the fresh paint softens the already applied layer(s), and allows the new coat(s) to really adhere and bond with the old coats.

Molecular curing finishes are more picky than all of that. You either have to add subsequent coats inside of 24 hours (sometimes 12), hitting it before it cures too far ... OR ... you must wait a full week for the molecular curing process to complete it's cure, then you have to do some surface prep (sanding, etc..) to that coat before you may add a subsequent coat.

Just some finish trivia that I've learned, mainly from rebuilding old motorcycles over my life. My other passion ... two wheels and an engine.

A.n.y.h.o.w. .... the Center Strip will have to sit without being bothered for another 6 days or so before I can assemble it and wire up the Ring Modulators. Essentially, the Center Strip is the synth panel for the four Ring Modulators.

I'm super happy with it!






(below) As you can see, all of the holes will require reaming to dimension since the bedliner has such wonderful "flow out" properties. So much so that it tends to flow into predrilled holes a bit. I'll wait another 3 or 4 days before I ream the holes back out to size, the bedliner will still be just soft enough to allow easy reaming. There's nearly this slight sortof rainbow effect off of reflected light from the textured surface.






Brightwork (nickel plated and stainless steel hardware), as well as those black and red ... (wait for it..) .... HALF INCH KNOBS! .... look just great against the backdrop of textured black finish.







Ok, so I'm glad I made the leap of faith and did it. It's not a decision I took lightly, since once that bedliner stuff is applied, YOU OWN IT! It cannot be removed (at least very well) once it'a applied, it's not like paint. It's quite literally liquid plastic, and once cured, that stuff is ~forever~.


COLORS:

My venture into Front Panel Designer has been something that has changed the way I see the outcome of this synth project. By consolidating circuits into single large panels, normalizing becomes a shit ton simpler! FPD has also provided me with options otherwise unavailable to me. That said, I am faced with another set of decisions.

(oh bloody hell .... he has to decide on something again? .... well there goes another month!)



I see that red anodized and blue anodized finishes are available, and quite frankly, fairly cost effective options! So, I've been thinking of going past just a simple natural aluminum color, or black anodized finish. I have a few of those little aluminum flashlights that are red and blue anodized, so I've thrown together a couple of pictures to see how things look, with stainless and plastic knobs tossed in to check contrast with those parts.


Black knobs really ~JUMP~ against red ano, so does stainless. Then again, stainless and red knobs look good against blue ano.

Friggin Decisions!!!! (and again, pretty permanent ones!)







So, I'm wondering what to do with this new 8 space panel. 8 spaces is a LOT OF RED! But that panel will sit dead center of the lower row. Since the Center Strip is now black, and the 6 surrounding modules (3 on each side) of the proposed red (or maybe blue) filter stage will be .... well .... not red or blue ... going with a large chunk of ~color~ on the lower row, dead centered, might actually look fantastic!

Also consider that there will be two 6 space panels in the upper row, evenly spaced apart by a two space mixer, which will also serve to offset and contrast the large colored panel in the lower row.

May have to mock something up before I click ~SEND~ on the FPE order once I complete the file.


~strrrrrreeeeetch~ ..... (damn that felt good!) ...... alrighty then, back to Front Panel Designer ..... I've work to do! There's an 8 space panel I have to get done!



EDIT: Damn .... I just clicked "preview" to make sure I didn't need to correct and grammar or splleling problems, and man, that blue looks good ... but so does the red .... SHIT!

[Eric the Red]

Stick with the black. With the other different color knobs in you System, this thing will end up looking like a clown with bad acne with all different color panels throughout.

Edit. Here is an image of a clown with acne for reference.

[Rex Coil 7]

Stick with the black. With the other different color knobs in you System, this thing will end up looking like a clown with bad acne with all different color panels throughout.

Edit. Here is an image of a clown with acne for reference.

Yea, you may be right ... the examples I've seen of anodized panels aren't encouraging.

In that other thread I started about panel color, even though some offerings look nice, there's a disconnect between them and what I'm doing here.

Good advice! Thanks Eric.

[Rex Coil 7]

Meh .... I'm over it. It doesn't look like what I picture anyhow.

Back to black, stainless, and aluminum.

[Rex Coil 7]

Q678 ... THE FIRST ATTEMPT AT DESIGNING MY OWN MODULE PANEL:

1 Q147 Distributor.
1 Q107 State Variable VCF.
1 Q162 State Mixer.
1 Q150 Transistor ladder filter.
1 Q112 Mixer.

Add toggle switches to take advantage of the various jumper link options.

And design a panel to house all of that stuff.

Out comes the Q678 Multi-Circuit Dual VCF.

Here's how I got started with mine.

Anytime I'm designing a new electronic toy, I begin with just doing a simple controls layout, usually on a piece of paper the same size as the enclosure or panel that I'm going to use to house the entire thing.

I cut out a piece of construction paper to 16.99" x 7.95", which is the same size as an 8 space Dot Com synth module, sans the cabinet mounting flanges at the top and bottom of the panel (the entire panel is actually 8.75" tall, but the mounting flanges are 0.400" each, so 0.800" from 8.75" is 7.95").

I then layout all of the knobs and washers that fit the controls, and begin to arrange them to suit my needs.




I then cut out pieces of construction paper to represent the PCBs and other items that will present obstacles to mounting any of the pots and switches. This helps greatly in obtaining some idea of where to place what.






After taking pictures of both the knobs and washers layout, and the paper cutout layout, I then take to growing a root out of my ass into the seat in front of my computer. It takes me about 12 solid hours to get from start to finalized when designing a large panel like the Q678. Here's the early stages:


A first rendition. This has the desired lettering, as well as what I think I can get away with as far as component placement goes.....




I also did a back-panel to make sure that the Jack Field subpanels are not interfering with anything in back once they are installed.






After many hours of tedious work and moving/moving/moving various components, as well as completely covering sheets of note paper, eventually slathered with various notes (lots of notes, lots and lots of notes, plus tons of basic math problems to figure out the center of this part and the edge of that part) the panel begins to take shape. Making sure that the graphics and lettering do not hit various screws or open holes, as well. Hours upon hours go by.

And then, I'm ready to sign off on a finalized panel design....




So there it is! The Q678 dual filter panel. Note how much more sparse the lettering is? Yea, I learned about watching for tool changes (a line item on the invoice!), and how the price can go WAY up just because you selected a certain type face. Watching out for not getting too wrapped up in pretty details as well. This panel maxxed out at $179+ bucks at once point!

After all is said and done, it landed at $98.16. Black infilled lettering, no anodizing (raw aluminum finish for me, thanks!), and no fancy type faces.

I'll hand wet sand the panel once it arrives, then clear coat it with rattlecan clear coat.

Not too bad for a friggin noob. I'll most likely send this off to Front Panel Express tomorrow. One more go around to make absolutely certain all the holes are round, and all of the mounting holes for the PCBs and case mounting holes are in their exact locations. Then, I'll take a deep breath and fire that muthuh off!

[Pav]

Thought I'd return the compliments...enjoying reading your journal
Sounds like you have all the skills and patience to make sig savings on a midiDac from Oakley.

[Rex Coil 7]

Thought I'd return the compliments...enjoying reading your journal
Sounds like you have all the skills and patience to make sig savings on a midiDac from Oakley.

Thanks much, Pav. This project is one of those ~love it or hate it~ types. Many folks don't like what I'm doing to my synth, then again others really enjoy the way I'm going about it.

I suppose that's true with just about anything, isn't it?

Thanks for the encouragement ... it's not much like the super clean stuff that you do, that's for sure!

Onward ....

[Rex Coil 7]

OPTION PANELS COMPLETED:

Ok, I finished designing the Option Panels for the Q678. It took a lot longer than I figured it would! Getting everything aligned was tougher than it first seems. Hopefully, I'll be able to use the same panels in the dual VCO voice panels, and maybe even the Main VCO mixer as well. I did what I could to make the dimensions ~just so~, that way these panels will fit in 2sp synth module panels, if stood up on end.

I came up with the idea to handle a problem that came up while kicking the Q678 around in my head. The use of a 3mm thick panel was paramount, I mean, that was just gonna happen! I really like the look of the thick aluminum panel, and as it turns out, it's the very same thickness as the Center Strip panel that the Ring Modulators are housed in, so the look is consistent.

The problem was that the 3.5mm jacks I am using won't fit a 3mm panel when flat washers are used with the jacks. That is, with the flat washers that I use, anyhow! So I came up with the notion of a removable panel that is only 1.5mm thick, permitting the use of the 3.5mm jacks with the thicker stainless steel flat washers that I prefer. Suddenly a lot of advantages came into play with the use of the Option Panels. The fact that they are inexpensive, and very easily changed out in the event some new modification comes into view are just a couple of things they provide.

Peace of mind is another feature. In the event that I have forgotten some pot, or some switch or whatever when I designed the main panels, I may always add things like that while preserving the symmetry of the design of the main panel. It's easy to see how I came up with the name "Option Panel" for it.

So here it is. In this rendition there are provisions for 15 components, which will all be jacks. The left Option Panel will carry nothing but "SEND" jacks, and the right Option Panel will have nothing but "RETURN" or "INBOUND" jacks (such as CV inputs).

I'll have to make a cheat sheet to keep track of which jacks do what, but like many things I'm sure I'll end up memorizing the jack patterns.



One more pre-flight check of the hole placement of the PCB and mounting screw holes, and I'm sending the whole works in for order.

The Option Panels turned out costing $25.33 each (2x = $50.66) and the main panel will cost $98.26 for a grand total of $148.92 for all three. The main panel will be raw aluminum with black infilled lettering, and I'm still bantering what the option panels will be finished in ... black maybe? Probably end up just being raw aluminum, hand wet sanded and clear coated. I don't want to stray away from the DIY look and feel of this synth.

All things considered, that's really not bad. Especially considering what I can get away with due to the accuracy of the use of CNC milling equipment to drill and cut the panels.

I'm happy with it. Next set of panels will be the 2-VCO voice panels, and the VCO mixer that sits in between the 2 voices.

Next up is finishing construction of the Ring Mod PCBs (red LEDs and all!), as well as finishing up the wood work and installing the wooden cross blocks used to mount the bus bars.

Good thing that I like doing this stuff, there's lots to do!

[Rex Coil 7]

IMPROVED ON THE FINALIZED FPE PANEL - LESS COST, BETTER LOOK, MORE READABLE:

I learned how to further manipulate Front Panel Designer. I was able to find the right point size that allows using a larger engraving tool, which creates more clarity and larger characters without raising costs. In fact, I was able to reduce the cost by finding that ~just righty~ combination of tool, font, point size, and finish.

So this panel went from $98.26 down to $93.88 (saving $4.38), while simultaneously increasing the size of the characters, and adding a lot more characters as well. Adding more characters means that instead of having these cryptic markings over certain knobs, I can actually spell out their functions.

For instance, the CV control for the Q107 Cutoff Frequency previously was "- F +" meaning that the control was for the cutoff frequency ("F"), and the plus and minus was a secret code that meant the control was bipolar.

Now, that same knob's markings say "CUTOFF BIPOLAR".

I was also able to add props to Roger Arrick's circuits down on the bottom of the panel with "ARRICK ROBOTICS" emblazoned across the span.

All that, and less money too!

Here's the two panels, so they may be easily compared:

FIRST RENDITION ($98.26):




LATEST RENDITION ($93.88):





For anyone wanting specifics, here ya go:

*** Font type = STENCIL, 1 STROKE.
*** Font size = 18 point.
*** Tool Used = CUTTER 0.6mm.
*** FINISH = Raw Aluminum.
*** INFILL = Only mill engraved.

Note the tool, this way I only had one single tool change. FPE uses a 3mm cutting tool for all of the hole drilling, panel shaping, hole cut outs. Once that machine has to stop cutting aluminum to change tools (in other words once it stops making money ... if the mill isn't cutting, it isn't making money) you, the customer, pay for the "down time" even though changing tools only takes literally a few seconds since the process of changing tools is 100% fully automated. So, any time your design requires a tool change, you're going to get smacked with a ~roughly~ $10.00 to $14.00 line item on the invoice ("line item" is a slick way to say you're getting charged for something).

So I learned my way around within the production and billing process of Front Panel Express, and the time it took me to do so has certainly paid off! I still have 2 voice panels and a mixer panel to do, so what I have learned will help keep costs down quite a bit!

OH! Nearly forgot. I have also designed a small "testin' panel" that will allow me to try my own method of in-filling and applying a finish to these FPE panels. Looky here, a screen grab of the FPD program ... the little panel's dimensions are on the left margin of the screenshot, and I added the font details in blue:



This little panel only costs $21.80. Since it uses precisely the same raw aluminum, unfilled graphics, font size, cutter size, and so on, it will permit me to do some infill testing of my own, as well as wet sanding and clear coating tests. For (kinda) cheep! If nothing else, it will be a learning experience that I can apply to designing panels using FPE, without messing up an expensive synth module panel in the process.

Ok .... that's it for this installment of the Super MiniMod project photo journal.

L8R SK8RS!!!

[Rex Coil 7]

This placard is only 2 inches x 4 inches x 3mm thick ....

..... I shall find a place to mount it on the synth.

..... I will do it.

..... This is going to happen.

..... Some stuff are just that cool.

[Rex Coil 7]

Q816 2 VCO VOICE PANELS MOCKED UP - Q113FB MAIN VCO MIXER PANEL COMPLETED - WARNING PLACARD COMPLETED - OPTION PANELS COMPLETED:

I got the main VCO mixer panel done. I found (more like ~made~) a place to mount that cool little "placard" panel I cooked up, it ended up on the mixer panel. It lands right dead center of the top row, and uses nice large-headed button head allen screws to hold it to the panel. Those are the same screws I use for Technical Earth terminations, as well as bolting the heavy aluminum ~lugs~ that the heavy welding cable terminates in to the bus bars. All four corners of the placard have the same radii as the bolts' heads, so the bolts will have phenomenal fit-up on the placard.

The mixer panel turned out great, I was even able to mount 4 of those large toggle switches to it for turning the VCOs on and off (like on a Minimoog).

I also finished up the Option Panels, so they are all ready to order now.

And the filter panel is done, too. So far, the filter panel, 2 option panels, the mixer panel, and the warning placard all come to $207.00 plus shipping. I was able to actually pull the VCF panel even lower, finally got it down to $91.51 ... not bad for an 8 space panel!

And lastly, I got started on the VCO panels, dubbed the Q816. Those are going to be a challenge! But I'm confident they will work out. I decided not to use the Option Panels on the VCOs, instead I'm using all 1/4" jacks on the two voice panels. I only need the Option Panels if I am using 3.5mm jacks, and on the VCOs there's no need for them since they're already normalized together, as well as normalized to the CV control interface that connects to the Euro Wedge via a modified 5-pin DIN connector set up (2 of those, actually).

So here's some pics ......






And here's the layout mockup for the Q816 VCO panels. Two of these will be used in my synth. As I said, these suckers will be a challenge. Each VCO has a Q161 Waveform Mixer, a Q141 Ocsillator Aid module, and fully normalized CV inputs. Nothing has been sacrificed, every single 1/4" CV input jack as well as every single 1/4" output jack has been preserved. Like the VCF panels, I used those giant "Ravenhead" knobs for the frequency controls ("fine tuning knob"). There's also small chickenheads on the rotary switches, both the octave rotary selector and the Q141 waveform selectors use the small chickenheads. This helps reduce panel clutter, since they are obvious in appearance they require no labels to describe their functions.

The little washers designate SPDT mini toggles which will be used for A/B-ing the CV signals to all five CV control inputs on each VCO. Said another way, each CV input on each VCO has an "A" signal, and a "B" signal that is normalized to each given CV function. This actually can provide up to FOUR individual 1v/Oct signals that may be instantly selected for each VCO. This feature will come in handy after I add a Kenton Pro 2000 MIDI-CV converter to my rig. That unit has the capability of doing 4-voice polyphony and this switching array will handle working with that Kenton just fine!

The small knobs on each VCO control the Q161 Waveform Mixer wave levels. I've added a FeedBack modification to the Q161 which will allow me to boost the gain on any of the four waveforms. The Sine and Triangle waves are assigned to one bus, and the sawtooth and pulse waves are assigned to the second bus. The small washer in the very lowest corners of the panel are a toggle switch that selects either the Q141 output or the Q161 output to be sent to the input of each VCO's channel in the main VCO mixer panel (the one with the placard).

The large toggles in the center select either "HARD" or "SOFT" sync, the middle position of that same toggle switch is an "OFF" position to be able to turn a preset sync level on in an instant. There's also a sync signal level knob, so I can preset the soft sync level to something I want, then instantly kick it in with the large toggle.



The mockup layout is 100% 1:1 scale, so what I see there gives me an accurate idea of how much space things will require. This method saves me time, at least for the way I've learned how to use Front Panel Designer. The sheet of paper is sized so that all that is there is only the usable space on a 5U/MU panel, the module mounting flanges are not on the paper, so there's no chance that I've decided to put some component in an area of the panel that will be hitting the wooden cabinet. It's also exactly to the Dot Com specification (module space x number of modules less 0.010" off of the overall width to produce a 0.010" gap between modules). So even though six module spaces add up to 12.75", this sheet of paper is 12.65" wide. Same with the Y-axis, even though modules are 8.75" tall, there's 0.400" devoted to the wooden cabinet's mounting flanges. So I've made the Y-axis of this paper 7.95" on the Y-axis. Doing things this way helps to keep me from making mistakes on the layout. I can use all of the space on the paper without worry of using space that is dedicated to something other than components.

Ok, I am tired! Totally rambling on here. Time to crashola...

Gotta Jet!

[Rex Coil 7]

Q816 PANEL JUST NEEDS LETTERING:

It only took six hours to get the dual VCO panel worked out. So far the cost is less than $74.00, but that will go up after the lettering is done!

Looks like all 7 panels will run right in around $400 bucks. I can live with that.

So six hours ...... from here .......





To here .......




After it gets lettered, I'll go over all 7 of them just once more to be sure I didn't miss anything, and then send them in for doing their wonderful work, and shortly thereafter, I hope to have panels!

Just a short post this time.

[Huba-Swift]

^ those cutout holes look way too big. Am I missing something? or are there smaller panels going behind each set of controls with the correct cutout diameter?

[Rex Coil 7]

^ those cutout holes look way too big. Am I missing something? or are there smaller panels going behind each set of controls with the correct cutout diameter?

That's actually a good question.

It's a little trick that I use (and I suspect it's a technique many others use as well) where I make the holes whatever size the ~largest~ part of whatever component it is that the holes represent.

For example, if a toggle switch uses a flat washer that is larger in diameter than the switch's own dimensions, I will use the diameter of the flat washer to represent that component. Or, if a knob is larger than the pot, I depict the knob's diameter on the image instead of the pot.

This is done to make certain that nothing is hitting a screw head, or bumping in to something else when the panel is actually assembled and put into use.

Those huge holes represent the super sized chicken head knobs that you see in the mockup layout. I use the knob's largest diameter to represent the ~spot~ it's in so that I know that when the knob is turned, the ~nose~ of the chickenhead knob will not hit any of the PCB screw heads, or interfere with any of the other controls.

In the program "Front Panel Designer" it is very simple to resize the holes to the actual drill hole size required to fit a given component. That said, I make two files, one that has the actual drilled component hole, and one that has the larger representations of the knobs and washers that the parts will use that actually take up the most space.

Another example is the jacks. Even though the jacks themselves are 0.625" x 0.625" dimensionally, the lock washers are actually 0.680" in diameter. If I only used 0.625" as a component dimension for the 1/4" jacks, when I went to assemble the panel they would not fit, because the lock washers would overlap and prevent aseembly. So I use 0.680" to represent the 1/4" jacks when designing the panel, to make certain I've spaced them far enough apart to make room for the lock washers.

When I'm all done creating the panel you see above (which I name with the panel name plus "parts and washers" in the file name), I simply save that file to another name, and then go in and resize all of the holes to their proper drilling dimensions. I've created a database which has all of the required drill hole sizes for any given part I use, so I just refer back to that "WORD" file with all of the correct mounting hole sizes, and resize all of the oversized holes to their correct dimensions.

This process does take longer, yes. But it is the only way I can be absolutely certain that when I put the module together, none of the knobs will hit any of the PCB screw heads, and all of the flat washers and/or lock washers won't prevent the panel from being assembled.

Here's that same screen shot of the file showing the oversized holes. This is the file that I use while I am placing all of the graphics, with the holes being the size of the knobs and washers, I will know precisely where to place lettering so that it isn't hidden by a knob.



Here's a screen shot of the same file, with the holes all resized to the dimensions that Front Panel Express will actually cut into the panel.



Here's a short list of the hole sizes that I use for given parts, they are based on actual observed dimensions of the parts that I've measured with a dial caliper. I don't just copy the hole sizes used by other panel makers, such as Dot Com, unless otherwise designated.

** Pot holes diameter = 0.2850"
** Large toggle switch drill holes = 0.4800"
** Mini toggle switch holes = 0.240"
** Case screw holes = 0.1700" (Dot Com dimension)
** PCB screw holes = 0.1250"
** Sub panel border screw holes = 0.1250"
** 1/4" x 28tpi Button Head screw holes = 0.2500"
** 3.5mm Jack holes = 0.2400"
** 1/4" Jack holes = 0.3800"

The file with the oversized holes full name is "Q816 - 6sp Dual VCO - parts and washers - 1E" ... the "E" is a designator I have as part of a file naming standard I created just for using Front Panel Designer.

The file with the proper drill hole's full name is (Q816 - 6sp Dual VCO - 1F" ... the "F" designating that the panel has the proper hole sizes, and no lettering.

The file naming standard looks like so:

"A" = nothing but the module's mounting screws for the module case are represented. These files are useful for creating new panels that are the same number of MU spaces, in the event I want to make another one. Think of it as a basic template.

"B" = Case Mounting holes and PCB holes.

"C" = "Parts and washers, rear view" in the event I need to see the back of the panel. I've only used this one once so far.

"D" = "Parts and washers - no graphics" - the oversized holes and no lettering.

"E" = "parts and washers - with graphics".

"F" = Component holes - no graphics"

"G" = Component holes- with graphics" It's basically ready to order, but I haven't "certified" it yet by going over it once more to verify that everything is in it's proper location, and all of the holes are their proper sizes.

"FINAL" = fully checked over, finalized panel, ready for ordering.

"TESTER" = some panel that I'm testing various ideas with.

"1" (or "2" or "3" and so on) indicate various versions of a given panel. The letters (A, F, etc) indicate a level of development while the numbers indicate a version of the design. "2E" means it's a 2nd version with some sort of differences to version 1, and that it is in the "E" stage of development, meaning it shows the oversized holes, and the graphics.

I had to come up with this to have multiple representations of each panel so as to be able to create accurate designs. This way it's easy for me to load a panel into the program that has been created to a certain level of completion, usually for working out some variation of a given design idea.

I've only been using FPD since Nov 12th of this year (one week ago), so I have only about a week of use so far. But in that time I have created seven panels and came up with some standards as well as a pretty complete database of dimensions, all of which are kept in one "WORD" file for quick reference. These methods may evolve into simpler ways of doing things once I put in more time with the system.

[JohnLRice]

Rex Coil 7 You are like a tornado that has lots of arms and makes modular synths! Impressive amount of thought, time and effort there, good sir!

[JohnLRice]

^ those cutout holes look way too big. Am I missing something? or are there smaller panels going behind each set of controls with the correct cutout diameter?

That's actually a good question.

It's a little trick that I use (and I suspect it's a technique many others use as well) where I make the holes whatever size the ~largest~ part of whatever component it is that the holes represent.

In the program "Front Panel Designer" it is very simple to resize the holes to the actual drill hole size required to fit a given component. That said, I make two files, one that has the actual drilled component hole, and one that has the larger representations of the knobs and washers that the parts will use that actually take up the most space.

Hey, there is a cool feature in the program you might like in case you weren't aware of it.

Objects have a property titled "Do not produce" and if set to Yes it wont be produced when you order your panels. And there are easy options to toggle on and off viewing the non produced elements as well as only viewing them.

So, you could have both your drill hole object AND your knob/control area object in your file at the same time and not have to maintain two separate files.

[Rex Coil 7]

^ those cutout holes look way too big. Am I missing something? or are there smaller panels going behind each set of controls with the correct cutout diameter?

That's actually a good question.

It's a little trick that I use (and I suspect it's a technique many others use as well) where I make the holes whatever size the ~largest~ part of whatever component it is that the holes represent.

In the program "Front Panel Designer" it is very simple to resize the holes to the actual drill hole size required to fit a given component. That said, I make two files, one that has the actual drilled component hole, and one that has the larger representations of the knobs and washers that the parts will use that actually take up the most space.

Hey, there is a cool feature in the program you might like in case you weren't aware of it.

Objects have a property titled "Do not produce" and if set to Yes it wont be produced when you order your panels. And there are easy options to toggle on and off viewing the non produced elements as well as only viewing them.

So, you could have both your drill hole object AND your knob/control area object in your file at the same time and not have to maintain two separate files.

I found that feature just the other day, John .... however, if I need to move a control/knob then I have to move the non-produced element as well. I know I can use the "shift-click" function to move several elements together, but using the multiple file system seems to work better, less fiddly.

On the other hand, using the "non produced element" feature is VERY helpful for setting up the actual working dimension of the panel. The panels are 8.75" on the Y axis, however (as you know, John) there's only 7.95" of working space on the panel due to the mounting flange's dimensions using up 0.800" (0.4" on each end). So I use the non-produced element feature to draw a line on each end of the panel that make sure to not place anything where there's gonna be wood!

I learned a shatload of tricks from YOUR panels, John. Just those two little templates that you posted, I learned a lot about the non-produced element feature from those, as well as actually learning that I was dead wrong about the Dot Com panel dims, holes, and hole placement. Ego became involved .... I measured a 1sp Dot Com panel and found that my own observations of hole placement, panel width (that thing about the panel being 0.010" smaller overall than the sum of 2.125" intervals), and mounting hole sizes were WRONG.

See, I saw that my own measurements were different than the ones you used, so in my efforts to prove how bitchin I am and make a "corrected" ~ahem~ version, I went straight to the CAD drawing posted on the Dot Com site. After careful study of that drawing, I learned that .. in fact .. YOU were correct and the almighty ~me~ was full of shit. Truly, one of those " DAYUM! " moments.

Had I not set about on that quest, I may have spent serious money on several panels that didn't fit my case.

So ... here's to the ego, here's to this forum, here's to John L. Rice and his well intended and accurate postings!

Thank you, John. I appreciate all you do for us, for me, and for the forum.

And thanks for the encouraging posting, just there, beneath the (typical of me) 10k War And Peace tome I wrote to member *Huba_Swift. Hearing praise from members such as yourself and members *Eric The Red and *Bwhittington (and many others) goes a long way towards keeping the tornado stormin' on at force ten.

Brian .....

[Rex Coil 7]

GOT IT! .... Q816 READY FOR ORDERING:

Amazing, the more I use FPD the more I learn about how efficiently a person can create panels with it. Very well worked out program, no doubt about it.

I got the voice panels done! Lettering and all! Due to some constraints I had to make some compromises, but life is all about compromises. Most of the jacks had to be labeled in lower case, and I had to get a little creative on some of the jack names.

.x. means Exponential CV input #1.
..x.. means Exponential CV input #2.
x... (or ...x depending on which side of the panel you're looking at) means Exponential #3, which is the adjustable FM exponential CV input.

And the "HARD" "SOFT" switch (which is the selector switch to choose between hard sync or soft sync) sortof shares a label with the input level knobs for soft sync, when the toggle is DOWN the VCO is in soft sync mode, and being ~down~ it's sortof pointing at the knob beneath it, which is the soft sync amount knob.

The pwm CV input jacks have to share one label, so I used underscores to show that the label applies to both jacks.

The huge circles are the FINE TUNE controls for the VCO frequency tuning, and the other large circle next to it (that's not as large, but still larger than the rest of the knobs) is the chickenhead knob that is used for OCTAVE and LFO select. Both of those two knobs are so distinctive that neither requires a label.

Same with the other large-ish knob lower down, that is another chickenhead knob that is for the Q141 waveform rotary switch. It too is so obvious in it's presence that it also requires no label.

Also, the 1" knobs will be color coded, so that will help a lot for memory-burn to memorize what each one's function is.

Had to use lower case lettering on the jacks. And had to scoot a few jack labels over one way or the other to make room for screw heads.








I just need to give these one more good looking over, sign off on them, and they're ready to order!

But first, I'm ordering that little warning placard, I need to test out how the bare aluminum and unfilled lettering will work out.