Search found 503 matches

by fitzgreyve
Tue Jul 28, 2020 3:38 am
Forum: Music Tech DIY
Topic: DIY Stereo mixer for Euro?
Replies: 9
Views: 256

Re: DIY Stereo mixer for Euro?

I have one PCB (and several panels) left for my 100m inspired 4-input mixer. Can't find the original thread, but details halfway down page here : 100m-ish modules
by fitzgreyve
Fri Jul 03, 2020 4:33 am
Forum: Music Tech DIY
Topic: Postage times for DIY with international delays
Replies: 101
Views: 2249

Re: Postage times for DIY with international delays

Fedex from Mass, USA to UK: despatched 22 June, delivered 25 June (shipping was USD 20)
(software upgrade eprom for recently acquired DrumKat dk-10)
by fitzgreyve
Wed Jul 01, 2020 3:03 am
Forum: Music Tech DIY
Topic: 16 pin female-female box-power-header
Replies: 7
Views: 169

Re: 16 pin female-female box-power-header

I’m wanting to convert a 16 pin power cable to a 10 pin power cable. This is for testing purposes when plugging in a module being tested is either 16 or 10 pinned. I have one made from scratch that goes 16-pin, 16 pin, (cable then cut down to 10 way), 10 pin. If you want to modify an existing cable...
by fitzgreyve
Wed Jun 24, 2020 3:51 am
Forum: Music Tech DIY
Topic: DIY synth cartridge
Replies: 6
Views: 305

Re: DIY synth cartridge

Assuming this is read only (in the synth), you just need to connect each of the higher address lines (A13 onwards) to 0V via a switch with a pull up to Vcc (say 1K to 4k7 ?) A higher capacity (later designed) eprom should be able to cope with the same timings as the 2764 Obviously need to avoid chan...
by fitzgreyve
Thu Jun 18, 2020 5:07 am
Forum: Music Tech DIY
Topic: Multifunction Thing: ADC based Multiplier/Panner/Envelope Gen./Sample and Hold
Replies: 20
Views: 547

Re: Multifunction Thing: ADC based Multiplier/Panner/Envelope Gen./Sample and Hold

Does anyone have experience using these ADCs in free running mode and have a suggestion for an auto power up reset circuit? Done this, a very long time ago, and couldn't find the exact circui I used. You've already got the ~INTR output feeding the ~WR input, it's just a case of "injecting" that ini...
by fitzgreyve
Fri Jun 12, 2020 3:46 am
Forum: Music Tech DIY
Topic: How can I double a schematic when making my own module?
Replies: 5
Views: 343

Re: How can I double a schematic when making my own module?

There are two things to consider here: 1. Will it work? - For something like this (no heavy power consumption, no high speed digital signals) there should not be a problem. There is minimal difference between duplicating the circuit on one pcb, and connecting together several PCBs each containing a ...
by fitzgreyve
Thu Jun 11, 2020 4:27 am
Forum: Music Tech DIY
Topic: Eurorack prototyping PCBs
Replies: 9
Views: 577

Re: Eurorack prototyping PCBs

Looking at the space on the PCB, with minor re-routing of the +12 and -12 tracks you could add a set of wider spaced set of pads for diodes outside the current set for ferrites, allowing either to be fitted.
by fitzgreyve
Wed Jun 10, 2020 2:02 pm
Forum: Music Tech DIY
Topic: DG411 control weirdness - fixed - S&H schematic attached
Replies: 11
Views: 247

Re: DG411 control weirdness

couple of random thoughts: - What is the value of your hold capacitor, and what is the source resistance feeding it via the switch (the switch itself has a typical "on" resistance of 45 ohms?). your sample pulse is very narrow (100pF and 10k +100k) gives < 70uS ? It could be that your pulse (without...
by fitzgreyve
Mon Jun 08, 2020 6:49 am
Forum: Artist Discussion
Topic: Terry Riley: In C
Replies: 14
Views: 489

Re: Terry Riley: In C

A piece so special that it deserves it's own dedicated squencer:
Fitzgreyve IN-C.JPG
by fitzgreyve
Mon Jun 08, 2020 4:32 am
Forum: Music Tech DIY
Topic: Eurorack prototyping PCBs
Replies: 9
Views: 577

Re: Eurorack prototyping PCBs

Would the front panel be more generally usable without the J/D etc designations (i.e. no text at all, just the scribble strips)?

The panel looks to be left/right symmetrical, so you could have one side with the text, one side with just the scribble strips ?
by fitzgreyve
Wed Jun 03, 2020 3:02 am
Forum: Music Tech DIY
Topic: Clb300 led lens caps
Replies: 4
Views: 138

Re: Clb300 led lens caps

I have always used the same coloured LED.

I recently put some white LEDs behind coloured bezels (not these specific caps), the result is distinctly "odd", probably because (most?) white LEDs don't produce a continuous light spectrum, but mix fairly pure RG and B frequencies.
by fitzgreyve
Wed Jun 03, 2020 2:56 am
Forum: Eurorack Modules
Topic: Best BBD modules? / MF-104m users?
Replies: 52
Views: 1679

Re: Best BBD modules? / MF-104m users?

If you are into DIY, I still have some PCBs and panels left for my copy of the Roland 100m BBD Delay: https://www.muffwiggler.com/forum/viewtopic.php?f=17&t=210583&p=2964276&hilit=100m+ish#p2964276 with some extra info here: https://www.muffwiggler.com/forum/viewtopic.php?f=17&t=223748&p=3147640&hil...
by fitzgreyve
Tue May 26, 2020 3:34 am
Forum: Music Tech DIY
Topic: Postage times for DIY with international delays
Replies: 101
Views: 2249

Re: Postage times for DIY with international delays

PCBs from China to UK (e-packet, so will be slow in normal circumstances):
manufactured: 7th April
Shipped by manufacturer: 11th April
"shipped to air transport": 8th May
depart china by air: 20th May
EDIT arrived - 1st June

so, pretty slow within china.
DHL next time!
by fitzgreyve
Sun May 24, 2020 5:44 am
Forum: Music Tech DIY
Topic: Select Bus
Replies: 40
Views: 2003

Re: Select Bus

I don't normally comment on this type of discussion , but I have to side with Mr Hinton on this one "Introducing an unscreened digital communication .... weaving around an unscreened analogue system" also doesn't strike me as a wise move? Eurorack has enough "design issues" already ? While I am more...
by fitzgreyve
Sun May 24, 2020 5:28 am
Forum: Expert Sleepers
Topic: A question about Disting MIDI breakout
Replies: 4
Views: 169

Re: A question about Disting MIDI breakout

It looks like you are using the correct inputs on the disting EX 4 pin midi connector: - pin 3 - midi in DIN socket pin 5 (your yellow wire) - midi current loop source - pin 4 - midi in DIN socket pin 4 (your red wire) - midi current loop sink You are correct that there is no connection to a midi in...
by fitzgreyve
Thu May 07, 2020 2:36 am
Forum: Music Tech DIY
Topic: Fonitronik clock divider revisited for Eurorack
Replies: 20
Views: 795

Re: Fonitronik clock divider revisited for Eurorack

Can anyone explain why there are two separate transistor input circuits The two IC inputs are of opposite polarity - the clock input on the IC increments the counter on the negetive edge of clock pulses, a high level on the IC reset clears the counters. So the single transistor input circuits inver...
by fitzgreyve
Thu Apr 30, 2020 2:57 am
Forum: Music Tech DIY
Topic: AS3340 giveaway [CLOSED]
Replies: 22
Views: 521

Re: AS3340 giveaway

Very generous of you - I'd be interested in 2 or 3 if available (UK).
Many regards.
by fitzgreyve
Thu Apr 30, 2020 2:53 am
Forum: Music Tech DIY
Topic: FCUK XVCO calibration issues (newbie problems)
Replies: 3
Views: 161

Re: FCUK XVCO calibration issues (newbie problems)

Mr. Aloud wrote:
Wed Apr 29, 2020 8:43 pm
I´ve calibrated both OSCs succesfully
No problem, glad to be of help.
by fitzgreyve
Wed Apr 29, 2020 6:26 am
Forum: Music Tech DIY
Topic: FCUK XVCO calibration issues (newbie problems)
Replies: 3
Views: 161

Re: FCUK XVCO calibration issues (newbie problems)

Assume you are building the FC XVCO 2 ? the following is based on the original XVCO with add-on heater and octave switch (both of which I designed, but I'm not part of FC), but looking at the FC XVCO2 build doc it still looks to apply. Lots to cover here: first, "for calibration it .......but it doe...
by fitzgreyve
Fri Apr 24, 2020 4:32 am
Forum: Music Tech DIY
Topic: Doepfer MTC64 in a polymoog
Replies: 3
Views: 156

Re: Doepfer MTC64 in a polymoog

Reading his description, he mentions it does both MIDI in and out. I'm assuming he does a straight (digital) read of the SPST keyswitches to get the keyboard state for midi out (this is what mine does, but it's MIDI out only - any velocity sensitive MIDI KB adaptor could/should do this ?). For the M...
by fitzgreyve
Fri Apr 24, 2020 3:47 am
Forum: Music Tech DIY
Topic: Doepfer MTC64 in a polymoog
Replies: 3
Views: 156

Re: Doepfer MTC64 in a polymoog

MTC64 has simple ttl (i.e. logic on or logic off) outputs corresponding to each note. Each Polymoog key has two sets of key contacts: 1. SPST for just the external synth CV output and the internal filter keyboard tracking (upper contact in picture below) 2. SPDT (i.e. "two way switch") for the main ...
by fitzgreyve
Mon Apr 20, 2020 5:10 am
Forum: Music Tech DIY
Topic: The 2020 Show Us Your DIY Builds Thread!
Replies: 339
Views: 26171

Re: The 2020 Show Us Your DIY Builds Thread!

Woodwork rather than electronics - 126HP skiff/case:
P1070901.JPG
by fitzgreyve
Sun Apr 19, 2020 5:05 am
Forum: Music Tech DIY
Topic: Moog Prodigy CV mods - questions...
Replies: 2
Views: 153

Re: Moog Prodigy CV mods - questions...

If you have the "keyboard in/out" mod, the external CV (e.g. sequencer) replaces the keyboard CV - i.e. no transpose. If you have the "oscillator input" mod from the official Moog document, it adds the external CV to the keyboard CV - i.e. transpose. My Prodigy S/N 2400X has the kb in/out mod, so it...
by fitzgreyve
Thu Apr 09, 2020 3:31 am
Forum: Music Tech DIY
Topic: dry/wet cv control
Replies: 7
Views: 439

Re: dry/wet cv control

ChartreKhan wrote:
Wed Apr 08, 2020 8:47 am
you can do it with one VCA...
See also electric druid for a single vca cross fade circuit (I haven't tried this, yet):
https://electricdruid.net/single-vca-crossfader/

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