Search found 591 matches

by Bodo1967
Thu Jun 10, 2021 2:42 pm
Forum: Music Tech DIY
Topic: Drifting voltage on PSU could burn module ?
Replies: 3
Views: 107

Re: Drifting voltage on PSU could burn module ?

rafyc wrote:
Thu Jun 10, 2021 2:22 pm
I've checked my PSU volt and it's offsed by +/- 0.2 volt
Could it be this ?
A one word answer ;): No.
by Bodo1967
Wed Jun 09, 2021 8:12 am
Forum: Music Tech DIY
Topic: History of Synth DIY: Opinions requested
Replies: 114
Views: 2313

Re: History of Synth DIY: Opinions requested

and Ray Wilson (MFOS). He was mentioned on the first page of the thread by revtor ;). I was sure I had seen Ray Wilson/MFOS being mentioned in the thread a few hours ago. I would have added him myself otherwise :D. Elektor Formant modular synth book English version . :tu: Didn't know it existed in ...
by Bodo1967
Wed Jun 09, 2021 1:31 am
Forum: Music Tech DIY
Topic: History of Synth DIY: Opinions requested
Replies: 114
Views: 2313

Re: History of Synth DIY: Opinions requested

Accompanying information is mostly in German, but imho the "Formant" modular synth as presented by the "Elektor" magazine in 1977 is worth mentioning. Here's a lot to read, including schematics and original PCB layouts - however, it's in German and I doubt there's an English version: http://www.flor...
by Bodo1967
Sat Jun 05, 2021 7:08 am
Forum: Music Tech DIY
Topic: How to Calibrate a 3340 VCO?
Replies: 15
Views: 288

Re: How to Calibrate a 3340 VCO?

I have a couple of Guitar tuners, in fact the Korg one will be perfect because it has a `Through` so I can monitor the sound as well. :tu: That's how I do it as well (my guitar tuner is also a Korg :mrgreen: ). Works better for me than the frequency counter on my DMM or my (analog, it's a ~ 25 year...
by Bodo1967
Sat Jun 05, 2021 4:43 am
Forum: Music Tech DIY
Topic: How to Calibrate a 3340 VCO?
Replies: 15
Views: 288

Re: How to Calibrate a 3340 VCO?

You don't need to test all the notes, but simply octaves - but basically yes. I tend to use 2 octave spans (like C2 <-> C4) for calibrating. I find it easier to trim out very slight deviations that way.
by Bodo1967
Sat Jun 05, 2021 4:18 am
Forum: Music Tech DIY
Topic: How to Calibrate a 3340 VCO?
Replies: 15
Views: 288

Re: How to Calibrate a 3340 VCO?

Use the the 'scale'' trimmer to make sure an octave is really an octave. In the high frequency range (some kHz) it may be necessary to adjust the high freq tune as well, and in a similar way. This may help as wells: http://www.alfarzpp.lv/eng/sc/AS3340.pdf https://cabintechglobal.com/tune3340 https:...
by Bodo1967
Wed Jun 02, 2021 3:56 am
Forum: Music Tech DIY
Topic: Idiots Guide to Flashing Firmware?
Replies: 27
Views: 2787

Re: Idiots Guide to Flashing Firmware?

I already installed the "Atmel Studio 7" which is apparently included in "Microchip Studio", and which also required installing "Microsoft Visual Studio". That was an awful lot to install for just one module. Well, I'll try the process described in the following link: Well, it turned out impossible...
by Bodo1967
Fri May 28, 2021 3:31 pm
Forum: 5U Format Modules
Topic: Berlin School links
Replies: 179
Views: 31656

Re: Berlin School links

HowDoIKnow wrote:
Sat Sep 05, 2020 4:57 am
Just get it.
Thanks for that link! Just bought the album, downloading right now :D.
by Bodo1967
Fri May 28, 2021 2:36 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

Concerning the audio input path, start at the input jack and see whether you have a credible signal there. If yes (provided you have a line signal), make sure the input selector witch is set to line, and check pin 4 of U3-A, and so on until the formerly present signal becomes awol. This is to isolat...
by Bodo1967
Wed May 26, 2021 8:34 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

RoddSolid wrote:
Tue May 25, 2021 11:53 am
I have one of those 12 dollar DIY scopes.
That should do, as long as you can see the input, square wave oscillator and LFO signals. Just choose a frequency easy to monitor.
by Bodo1967
Tue May 25, 2021 2:35 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

Do you have an oscilloscope to track the signal?
Following the signal path (and the internal oscillators - square wave and LFO) might step by step shed some light on where the problem is.
by Bodo1967
Fri May 21, 2021 7:58 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

RoddSolid wrote:
Fri May 21, 2021 7:52 am
I built the 9v noisebox version. One pcb with only one 78L05.
Ah yes, you wrote that in your first question. Anyway, are the supply voltages (every single one of them!) OK?
by Bodo1967
Fri May 21, 2021 1:48 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

RoddSolid wrote:
Thu May 20, 2021 4:40 pm
My mistake, I've got one 78L05
Afaik you need two 78L05 and one 79L05 in total for the Eurorack version. The 79L05 and one of the 78L05 goes into the PSU part of the module, the second 78L05 (marked 'U2') is near the PT2399 on the main PCB.

Do you have proper supply voltages on all ICs?
by Bodo1967
Thu May 20, 2021 4:16 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

Just a thought, since I made that mistake myself in another project a few years ago: Did you use TO-92 voltage regulators (e.g. 78 L 05), or did you use 780X (without the L in the middle) in a TO-220 package?. Iirc the Echo Rockit PCB asks for TO-92. You could actually use the TO-220 version (albeit...
by Bodo1967
Wed May 19, 2021 2:36 am
Forum: Music From Outer Space
Topic: [BUILD] MFOS Echo Rockit eurorack
Replies: 53
Views: 10502

Re: [BUILD] MFOS Echo Rockit eurorack

could it be a problem that I mounted it in a plastic enclosure? Could it be that I'm not using an aluminum faceplate? No to both. Did you go through all the basic troubleshooting procedures, such as checking for bad solder joints, making sure all components have the right values and (wherever appli...
by Bodo1967
Tue May 11, 2021 4:40 am
Forum: Artist Discussion
Topic: McCartney II
Replies: 23
Views: 711

Re: McCartney II

Loved it when I first heard it in Summer 1980 during a visit to France (I was 13 then, and the album was brand new). Still love it today. It's awesome, period :D :tu:.
by Bodo1967
Sun May 09, 2021 4:39 am
Forum: Music Tech DIY
Topic: DIY VCO Monster Demo Project 2021 synthCube
Replies: 9
Views: 556

Re: DIY VCO Monster Demo Project 2021 synthCube

Apparently you haven't yet seen Sam Battle's aka LMNC Kilodrone? Look it up. It's epic. Haha :lol: . I just wanted to post that very thing (even went to YT to get the link) when I saw you beat me to it. I'll add the link anyway: https://www.youtube.com/watch?v=c3wk9WWTfNs&list=RDc3wk9WWTfNs&start_r...
by Bodo1967
Thu May 06, 2021 8:17 am
Forum: Music From Outer Space
Topic: Some notes on building the MFOS Eurorack modules
Replies: 13
Views: 1152

Re: Some notes on building the MFOS Eurorack modules

Bachelard wrote:
Thu May 06, 2021 7:59 am
It's not the pins, it's the barrel of the switch that has to go through the front panel. The hole for the barrel is too small.
Argh, my bad :doh: . Yep, you wrote "panel", not "PCB".
by Bodo1967
Thu May 06, 2021 2:35 am
Forum: Music From Outer Space
Topic: Some notes on building the MFOS Eurorack modules
Replies: 13
Views: 1152

Re: Some notes on building the MFOS Eurorack modules

ADSR: The panel hole for the sub-mini switch seems too small for the switch I got (it's a standard sub-mini toggle), so I'll probably need to use a reamer and make it bigger. If possible I'd go the other way round and make the pins of the switch a bit smaller with a file or such (been there, done t...
by Bodo1967
Tue Apr 20, 2021 12:33 pm
Forum: Music Tech DIY
Topic: OPERA ROTAS, a DIY mutant drum machine BUILD THREAD
Replies: 224
Views: 13889

Re: OPERA ROTAS, a DIY mutant drum machine BUILD THREAD

Since REV 0.9 of the Opera Rotas is hardware ready. If you have a previous PCB you need a "midi chiclet" mini PCB that Im testing right now. Mine is 0.85, so I'll just wait for the chiclet PCB and a bug and jitter free firmware version. I do have the ST-Link v2, and the utility software is also ins...
by Bodo1967
Tue Apr 20, 2021 7:54 am
Forum: Music Tech DIY
Topic: OPERA ROTAS, a DIY mutant drum machine BUILD THREAD
Replies: 224
Views: 13889

Re: OPERA ROTAS, a DIY mutant drum machine BUILD THREAD

I have just upload the latest firmware 1.3 to github. It does synch to MIDI clock That is awesome news :banana: ! but it still buggy. In how far will this affect general performance? A little jitter or system crash, etc.? And is a hardware patch (such as replacing the opto coupler) required? Im wri...
by Bodo1967
Fri Apr 16, 2021 5:17 am
Forum: Music Tech DIY
Topic: CGS 57 BI N TIC issue
Replies: 11
Views: 432

Re: CGS 57 BI N TIC issue

Nisse_D wrote:
Fri Apr 16, 2021 4:56 am
Forgot to ask, was your build running on 15 or 12v?
15 V

But afaict from the description, the difference is only in one reistor (20 k / 14 k near the LM311) anyway.
by Bodo1967
Thu Apr 15, 2021 1:52 pm
Forum: Music Tech DIY
Topic: CGS 57 BI N TIC issue
Replies: 11
Views: 432

Re: CGS 57 BI N TIC issue

Perhaps this and this may help a bit - fingers crossed (or thumbs pressed, as we do in Germany).
by Bodo1967
Wed Apr 14, 2021 1:41 am
Forum: Music Tech DIY
Topic: Post-magic-smoke troubleshooting
Replies: 5
Views: 237

Re: Post-magic-smoke troubleshooting

While you wait on the mail you could try checking whether the voltage input pins on the chips are receiving the proper voltage. If they are, you can check the op amp inputs to see if they're getting anything. :tu: It is a good idea to always power on a new build without the chips in their sockets, ...
by Bodo1967
Tue Apr 13, 2021 8:53 am
Forum: Music Tech DIY
Topic: Post-magic-smoke troubleshooting
Replies: 5
Views: 237

Re: Post-magic-smoke troubleshooting

Definitely sensible. Powering the chips with inverted voltages can destroy them (been there, done that ;)). LM13700 are not very expensive, and TL072 cost next to nothing.

Go to advanced search