Muff's Modules & More

keninverse · Posted: Thu Apr 12, 2012 6:43 am Post subject:

If you look at the ms10 and ms50 schematic the Mike posted, there are two resistors forming a voltage divider at the Hz/v input (10k and 1k). That little + sign is the positive supply. 1.36V needs to be applied to the Hz/v input. This is what I was confirming earlier. I posted a schematic of a simple divider and unity gain buffer a few pages back that should work. I'm also doing a small run of PCBs for those boards that I should have back in the next week. I should point out my boards are designed for power filtering as well as dividing voltage.

janvanvolt · Posted: Thu Apr 12, 2012 7:12 am Post subject:

Keninverse: Thanks for the info then :-) Can i have 3 PCBs from you then ?

janvanvolt · Posted: Thu Apr 12, 2012 8:33 am Post subject:

E.A.S. · Posted: Thu Apr 12, 2012 8:40 am Post subject:

keninverse · Posted: Thu Apr 12, 2012 8:42 am Post subject:

If you're okay with just fine tuning with each octave jump then I would just leave it alone. But if it bothers you then add the buffered divider. I'd like to give you a few of my boards but I unfortunately only ordered enough for what I needed. Apologies.

Isaiah · Posted: Thu Apr 12, 2012 9:54 am Post subject:

I'd like two VCF/VCA PCBs please.
Would it be possible reserve them until I pay at the end of the month please (payday)?

Are there plans to do a run of VCOs again?
I'd be interested in two VCO PCBs.

E.A.S. · Posted: Thu Apr 12, 2012 12:11 pm Post subject:

Isaiah · Posted: Thu Apr 12, 2012 2:16 pm Post subject:

E.A.S.
I'd like to update my order please:
Two VCF/VCFA PCBs
Two VCO PCBs

I can pay at the end of the month if that's okay.
I'd also like two HADSR PCBs and one LFO/S&H/Noise PCB, but I will post in the respective threads.
Perhaps sending you a PM or email regarding those PCBs would be best since they are already in stock.

Voltage buffer for Hz/V would be great, thanks.

negativspace · Posted: Thu Apr 12, 2012 3:59 pm Post subject:

If you find space, Mike, a little double-inverting opamp mixer for the PWM and Width controls would be 3 different kinds of awesome. (hides)

E.A.S. · Posted: Fri Apr 13, 2012 5:23 pm Post subject:

asterisk · Posted: Fri Apr 13, 2012 8:17 pm Post subject:

i might be interested in a VCO PCB if there are any of jason's panels left.

edit: just paid for 1 VCO PCB. looking forward to it!

spotta · Posted: Sun Apr 15, 2012 5:50 am Post subject:

Paid for one of each, cheers! Guinness ftw!

haima · Posted: Mon Apr 16, 2012 11:01 pm Post subject:

Just paid for two VCF/VCA pcbs - thanks Mike! w00t

Barcode · Posted: Thu Apr 19, 2012 9:44 am Post subject:

Payment sent for 1 x VCF/VCA! Thanks!

asterisk · Posted: Sat Apr 21, 2012 1:27 pm Post subject:

any timeline on when you expect the VCO PCBs to be ready?
excited to build mine!

greydominion · Posted: Sun Apr 22, 2012 1:22 am Post subject:

Paid for 1 VCO and 1 VCF. Thanks!

keninverse · Posted: Fri Apr 27, 2012 11:11 pm Post subject:

Finally built up a VCF/A and I'm having problems...no audio passes. I've taken all the pots off the headers with the exception of the input, output, res, switch and cutoff. When I remove the switch header off I can hear the audio at pin 1 and 6. I tried just jumpering the switch for just low pass (pin 1 and 2) and still nothing. I disconnected the VCA at R88 and probed for audio and still nothing. I placed NOS 2SC1685s on the PCB but all the transistors were checked for Hfe and measure over 350. The pinouts then should be correct. Also checked for solder faults and I don't see anything. Can anyone give me direction on this? I'll double check all the resistors tomorrow but if anyone has any ideas of where to measure what voltages where that would be really awesome. I'll also check the resistors with a meter just to make sure none of them are open.

E.A.S. · Posted: Fri Apr 27, 2012 11:26 pm Post subject:

keninverse · Posted: Sat Apr 28, 2012 12:31 am Post subject:

E.A.S. · Posted: Sat Apr 28, 2012 8:42 am Post subject:

Most importantly check the pin-out on your f.e.t. vs. the p.c.b.

I realized I was a little vague when I mentioned the silkscreen being reversed.

-Mike