Oh, well thats no problem then, I still might run up a couple when you re-up the panel gerbers for use in other places in my system where negative envelopes are more useful. I was tempted to have them made in purple but went with a black finish in the end, maybe I’ll do some ‘flashy’ ones so its easy to tell them apart at a glance Now all I need is a load of resonant active LPG’s in the same form factor to replace the boring (but super useful) Quad VCA that they will be pinging.
Yeah, I have seen this design before (I think it a clone of the Meng Qi Euro dual passive LPG you can buy as a kit from Thonk), but I want something where I can dial in some resonance rather than just having the passive LPG effect, not to mention some actual amplification. What I am looking for is probably closer to a Buchla 292 Quad LPG, where the signal actually gets amplified, or a Make Noise QMMG (yes yes, tall orders, lol).
It is a super useful LPG though, and is on my list of stuff to pick up for my modular once I have met my current ‘needs’.
In kosmo, 2.5cm still gives you a lot of space to play with, pcb fabbing wise. Ditch the crystal graphics and there’s room for two more knobs.
The only circuit that even came close to getting tight on these was the dual gate to trig
I’m sure you could squeeze a circuit in the footprint just depends how many inputs/pots there are really
If you build from the pcb it will work! No guarantees on BOM hahaha
I’ll fix that after the gerbs
Yeah, I have no doubt I could fit the circuit behind the 2.5cm panel. Technically (if I just took a single channel of either of the quad devices I am lusting after) they boil down to three sockets and (up to) two knobs. Hell, I could even mount the PCB on its edge going into the case, as I build my cases at 20cm deep I would have LOOOOOOOOADS of room. The problem is getting hold of an MN schematic for their only just out of production (because they are too expensive to make) QMMG is deeply unlikely, although I think I have the old bucha circuit as a PDF somewhere and I could build it, I’d just never be able to share the finished product and I am not nearly experienced enough to design the things from scratch yet
Seriously, much respect to you and the other module designers who actually know this stuff well enough to help soldering iron jockeys like myself get functioning stuff that makes music.
You can also do a double stack if you wanna get fancy!
you give me too much credit lol I’m no designer just strip boarding in pcb form. Maybe adding some LEDs lol cause I love those bicolors.
I’ll have to check out those cause I really like the sound of the passive lpg.
Its only the perfect circuit demo reel from the recent QMMG re-issue (I think it was 2018/2019) and it is some super ‘west-coast’ style weirdness. Sadly I couldn’t afford one when they were still being made and the prices have only gone up since then. Also three knobs per channel, but still, positivly tiny in comparison to the kinds of panel space you can get in Kosmo. 4x LPG/VCF/VCA all in a single module, all interlinked with that beautiful (IMO) Make Noise art style. I love their kit.
But I digress
For the LFO I think this is the correct BOM based on the schematic:
Ref | Qty | Value |
---|---|---|
C1 | 1 | 10n |
C2 | 1 | 1u NP |
C3, C4 | 2 | 10u |
C5, C6 | 2 | 100n |
D1 | 1 | R/G LED |
J1 | 1 | 10 pin shrouded header |
J2-J7 | pin headers/sockets | |
J8A | 1 | 1/4" jack |
- | 1 | 14 pin DIP socket |
R1, R2 | 2 | 10R |
R3, R12, R13 | 3 | 470R |
R4, R6, R9 | 3 | 100k |
R5 | 1 | 47k |
R7 | 1 | 4.7k |
R8, R11 | 2 | 10k |
R10 | 1 | 2.2k |
RV1, RV2 | 2 | 100k |
U1 | 1 | TL074 |
SW1, SW2 | 2 | SPDT |
For the BOMs, I used the export feature with the “group2” something or the other I saw on YouTube and cut out the important bits and went to a combined BOM. I’m not sure how it got mixed up. My girl who works in sales had to help me the whole way with excel the first go around
Yep, I build from the PCB, mostly finished populating the boards tonight. Is there something specific that was off?
What diode does the G2T want? The BOM seems to just list a D.
It’s the 4148 for both!
@CTorp On the Glide module, I see that C6 is labeled as “unpolarized.” Does that mean it should be a ceramic capacitor?
I used this one, not sure if you can get a 2.2u ceramic very easily but it would probably work if u did
How does this look for the SubOsc diode?
https://www.mouser.com/ProductDetail/Nexperia/BZX79-C16133/?qs=me8TqzrmIYUovZaHYSLVdQ%3D%3D
Nope, that’s a Zener. You just want a regular switching diode, a 1N4148 or a 1N914 (which is really the same thing).
Tayda does have a 2.2 µF MCC:
I’ve had great luck with 1N914’s
For the Atten and attenuvert daughter boards - @CTorp mentions the headers being a long distance, so you can wire them -
I found that if you happen to have stackable headers on hand, make two 3-pin’s but cutting two 4-pins down and face them towards one another and push them together.
It’s pretty much the exact distance