Search found 1532 matches

by cygmu
Thu Sep 17, 2020 9:39 am
Forum: Buchla, EMS & Serge
Topic: A "new" Buchla 265 (functional) clone!
Replies: 27
Views: 829

Re: A "new" Buchla 265!

@Minimoog56 Nobody's throwing stones at anybody. electromusic site is directly connected to current Buchla IP owners. I suppose you are referring to electricmusicstore.com; is that right? I was not aware of a connection to Buchla though I will confess I have not been following along with all the be...
by cygmu
Wed Sep 16, 2020 5:16 am
Forum: Music Tech DIY
Topic: Ken stone quad universal slope generator debugging
Replies: 3
Views: 103

Re: Ken stone quad universal slope generator debugging

Since the LED is working ok, this tells me that the main output must be correct on the board, so I suspect something has gone wrong in the wiring of the DCO and Bipolar Outs to the panel. The bipolar output is inverted (and offset) from the main output so it could be that you have accidentally wired...
by cygmu
Sun Sep 13, 2020 8:22 am
Forum: Buchla, EMS & Serge
Topic: MARF 248r source code available
Replies: 206
Views: 14131

Re: MARF 248r source code available

With these new features does that mean the rev1 is essentially not being supported by further developments? I believe it is the case that none of the people who have been contributing to this project have access to v1 hardware. The v1 is different from the v2 internally -- it's not just that one is...
by cygmu
Sat Sep 12, 2020 4:04 am
Forum: Music Tech DIY
Topic: Precision Adder
Replies: 17
Views: 361

Re: Precision Adder

Thanks for sharing this! Have need for such a module but not gotten one yet. Do you have experience if it will keep its precision with other opamps like e. g. TL074 too? Or is the type of OpAmp critical? I would guess, that precision comes mainly from using buffered inputs and selecting matched res...
by cygmu
Fri Sep 11, 2020 4:26 pm
Forum: Buchla, EMS & Serge
Topic: MARF 248r source code available
Replies: 206
Views: 14131

Re: MARF 248r source code available

Noticed an odd behavior and wanted to see if it was a known issue in software. On Right Programmer(Correct behavior?) 1. strobe/cont up to continuous -> yellow light goes on 2. start -> no affect 3. strobe/cont back to center position -> red light goes on 4. start -> starts On Left Programmer (Bug)...
by cygmu
Fri Sep 11, 2020 1:59 am
Forum: Buchla, EMS & Serge
Topic: Serge PCO/NTO - stronger sync mod?
Replies: 14
Views: 1693

Re: Re:

I would try increasing the value of R15 -- the 2k2 that goes from the comparator pin 3 to the reference voltage -- so that the sync signal is attenuated less. I did this today (4K7, 10K, 20K for fun) and it glitches the waveforms Oh dear. It must be that the capacitor takes too long to recharge to ...
by cygmu
Wed Sep 09, 2020 11:01 am
Forum: Music Tech DIY
Topic: Buffered Multiple
Replies: 2
Views: 134

Re: Buffered Multiple

Beautifully neat and tidy and carefully documented as always.

I am intrigued by the compensation capacitor. At 5.6pF it is absolutely tiny so presumably only has an impact at pretty high frequencies, and the LT1013/4 does not have much bandwidth anyway. Is there a reason for this choice of cap?
by cygmu
Tue Sep 08, 2020 6:15 pm
Forum: Music Tech DIY
Topic: DUSG Help!
Replies: 81
Views: 4620

Re: DUSG Help!

I would draw the same conclusion as you, from that image.
by cygmu
Tue Sep 08, 2020 3:04 am
Forum: Music Tech DIY
Topic: DUSG Help!
Replies: 81
Views: 4620

Re: DUSG Help!

ok i'm double checking components and it looks like I have used C557B. These are installed following the layout on the board. The pinout of these looks like it is reversed in comparison to BC557. This would mean they are backwards. Is this correct? Do you have a datasheet? I can't find anything cal...
by cygmu
Mon Sep 07, 2020 4:11 pm
Forum: Buchla, EMS & Serge
Topic: MARF 248r source code available
Replies: 206
Views: 14131

Re: MARF 248r source code available

I remember installing it on Catalina was annoying. I’m afraid I don’t recall exactly how to do it but I think this post was part of the solution that worked for me:
https://community.st.com/s/question/0D5 ... 0151-19b88
by cygmu
Wed Sep 02, 2020 1:29 am
Forum: Music Tech DIY
Topic: Frying Teensy on Orgone Accumulator DIY v1 first version: any clue?
Replies: 18
Views: 389

Re: Frying Teensy on Orgone Accumulator DIY v1 first version: any clue?

Maybe the image at the bottom of this page is the schematic you are after?
http://neutron-sound.com/noa.html
by cygmu
Sun Aug 30, 2020 2:17 pm
Forum: Buchla, EMS & Serge
Topic: coa cgs cannon engine advice needed
Replies: 4
Views: 331

Re: coa cgs cannon engine advice needed

The man Dmitri says they’re all wired to the same inputs: post here

viewtopic.php?p=1348939#p1348939

This actually explains why it’s called the Canon Engine. Finally I get it!
by cygmu
Sat Aug 29, 2020 4:19 am
Forum: Music Tech DIY
Topic: standalone benjolin powersupply
Replies: 26
Views: 357

Re: standalone benjolin powersupply

ketem13 wrote:
Sat Aug 29, 2020 3:34 am
I just looked again into the datasheet of that particular power supply and I've seen two pins marks as COM: https://imgur.com/a/jpcKgnF

is that mean a common place between +-12v aka the ground point I was looking for ?
Yes, the voltages at the other outputs are with reference to the COM pins.
by cygmu
Fri Aug 28, 2020 4:18 am
Forum: Music Tech DIY
Topic: Power Rails voltage drop
Replies: 31
Views: 501

Re: Power Rails voltage drop

Yes, I have many components: 17 Quad Op Amps and 4 VCA IC's. Aha, then 200mA starts to seem reasonable. Op amp supply current might be 1.5 - 2mA per amplifier and you have 68 of them, so 130mA draw for the analog parts of the circuit might even be on the low side of things :) The datasheet for the ...
by cygmu
Thu Aug 27, 2020 5:05 am
Forum: Music Tech DIY
Topic: Power Rails voltage drop
Replies: 31
Views: 501

Re: Power Rails voltage drop

Currently using two LM1117MPX-3.3 voltage regulators for the stm32, one the digital VDD and the other for the VDD_A. This chip wouldn’t work without having power to the ADC and have read that it is good practice to have split power for both normal 3.3 and analog 3.3. Maybe I should go for just one?...
by cygmu
Tue Aug 25, 2020 7:33 am
Forum: Music Tech DIY
Topic: DUSG Help!
Replies: 81
Views: 4620

Re: DUSG Help!

The way you have it wired, i.e. the opposite of what you described, means that turning the pot clockwise will make the rise slower. I believe this is the way Serge DUSGs were wired originally, so that the control was "time" rather than "rate" if you see what I mean. Obviously you can swap it over if...
by cygmu
Tue Aug 25, 2020 7:07 am
Forum: Music Tech DIY
Topic: Power Rails voltage drop
Replies: 31
Views: 501

Re: Power Rails voltage drop

If your modules are drawing 200mA then the 10R will drop 2V. That seems plausible to me. What are you powering from this?
by cygmu
Mon Aug 24, 2020 3:22 am
Forum: Music Tech DIY
Topic: DUSG Help!
Replies: 81
Views: 4620

Re: DUSG Help!

Everything sounds ok with those parts.

Is it still not cycling/responding to triggers? I wasn't clear from your first post whether the problems went away after you fixed the pot lug shorts.
by cygmu
Mon Aug 24, 2020 1:46 am
Forum: Music Tech DIY
Topic: Help me troubleshoot Fonitronic PS3100 LFO
Replies: 15
Views: 235

Re: Help me troubleshoot Fonitronic PS3100 LFO

Looked at the site from the top. You used the documentation for the black PCBs, not the red PCBs. What this means specifically is that for your board the J111 (or J112) should be installed aligned with the silkscreen, not backwards. The orientation of this transistor does indeed explain the behavio...
by cygmu
Sun Aug 23, 2020 11:45 am
Forum: Music Tech DIY
Topic: AS3310 problems with Different TL072 ICs (TL072IP and TL072CP)
Replies: 6
Views: 238

Re: AS3310 problems with Different TL072 ICs (TL072IP and TL072CP)

If the circuit you built was anything like Figure 1 here http://www.digisound80.co.uk/digisound/modules/80-18_files/80-18.pdf then I guess the issue is that the 358 shown there is powered from +15V and 0V. A TL072 will not like this at all. I have heard rumours that some of the ICs sold as TL072s fr...
by cygmu
Sun Aug 23, 2020 5:28 am
Forum: Music Tech DIY
Topic: ISSUE: potentiometers interacting with one each other [SOLVED]
Replies: 6
Views: 195

Re: ISSUE: potentiometers interacting with one each other

batchas wrote:
Sun Aug 23, 2020 5:02 am
Thanx a lot for the suggestion. I'll change R11 and report back.
It's R32 in the schematic. I don't see an R11 so maybe we are talking about the same resistor under different names but I thought I had better make sure.
by cygmu
Sun Aug 23, 2020 4:54 am
Forum: Music Tech DIY
Topic: ISSUE: potentiometers interacting with one each other [SOLVED]
Replies: 6
Views: 195

Re: ISSUE: potentiometers interacting with one each other

First thought is that the resistor that feeds the LM4040 its current is a bit high. Using 5k there means you only have 1mA going in to the shunt regulator and all the pots. Calculating in my head it looks like this should be just about enough but it is pretty close, so I'd suggest trying a smaller r...
by cygmu
Sat Aug 22, 2020 2:06 pm
Forum: Music Tech DIY
Topic: Help me troubleshoot Fonitronic PS3100 LFO
Replies: 15
Views: 235

Re: Help me troubleshoot Fonitronic PS3100 LFO

emmaker wrote:
Sat Aug 22, 2020 1:41 pm
Might remove the JFET and see what happens. If that gets it to oscillate then there is something wrong with the sync circuit.
This is a good idea.
by cygmu
Sat Aug 22, 2020 2:05 pm
Forum: Music Tech DIY
Topic: Help me troubleshoot Fonitronic PS3100 LFO
Replies: 15
Views: 235

Re: Help me troubleshoot Fonitronic PS3100 LFO

If my understanding of the headers is correct then one pin of P4 should be connected to pin 7 of IC4, so it should be at -10.35V, and yet it isn't. Somehow you have the negative supply voltage appearing there instead. This seems suspicious although it may not be the source of your problems. It is wo...
by cygmu
Sat Aug 22, 2020 11:44 am
Forum: Music Tech DIY
Topic: Help me troubleshoot Fonitronic PS3100 LFO
Replies: 15
Views: 235

Re: Help me troubleshoot Fonitronic PS3100 LFO

X1, X2, X3 and X4 are headers and it looks like X1 mates with X3, and X2 with X4. So when the boards are mated together, X1-8 is joined to X3-8 and so on. The voltages you've measured look sort of ok: IC4B is the comparator and that has gone full negative as it should. This should make the integrato...

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