Search found 158 matches

by ringroad1
Mon Feb 15, 2021 9:28 am
Forum: Music Tech DIY
Topic: In Development: New DIY Monosynth MSW-810
Replies: 17
Views: 597

Re: In Development: New DIY Monosynth MSW-810

Looks nice, I'm tempted.

Did you ever find a service manual for the CMU-810? Interested to know what the differences are between it and the 101/202
by ringroad1
Thu Jan 07, 2021 7:25 am
Forum: Music Tech DIY
Topic: Sources for LM301 - do you trust Ebay?
Replies: 41
Views: 1072

Re: Sources for LM301 - do you trust Ebay?

The simplest circuit I'm dealing with is an clock osc for a Roland System 700 S&H clone. The problem another user duplicated is it doesn't oscillate under 10 or so HZ when the circuit goes down to to 0.3HZ as expected with a reliable chip. In other words if I dial in say 0.3 or even 5hz no clock go...
by ringroad1
Fri Jul 10, 2020 1:18 pm
Forum: General Gear
Topic: Roland MPU-101 has parasite impulse at CV outputs ???
Replies: 5
Views: 639

Re: Roland MPU-101 has parasite impulse at CV outputs ???

Can confirm the behaviour outlined by the OP - for me the pulse lasts about 594 microseconds, max of about 7.5V at velocity 127, -2.9V at velocity 1. mpu-blip.jpg Not convinced my oscilloscope is particularly well calibrated so take those numbers as ballpark. Suggests the timing of switching the mux...
by ringroad1
Fri May 22, 2020 6:03 pm
Forum: Music Tech DIY
Topic: Ryk M185 Sequencer - per step repeat and gate mode
Replies: 319
Views: 26005

Re: Ryk M185 Sequencer - per step repeat and gate mode

No way! A thousand thanks Ryk!

I was just over a half-a-centimetre out on the height. My version of the VCA arrived yesterday, my estimate based off photos and the internet generally was 99mm x 192mm - I'll tweak it for the remaining boards.
by ringroad1
Fri May 22, 2020 11:43 am
Forum: Music Tech DIY
Topic: Ryk M185 Sequencer - per step repeat and gate mode
Replies: 319
Views: 26005

Re: Ryk M185 Sequencer - per step repeat and gate mode

Hey ryk - sorry this is a bit OT but I've been trying to work out the size of the 100M PCBs for a personal project cloning the original boards - your 185 front panel board there looks like it's 19.7cm tall: is that exactly the same size as the originals?
by ringroad1
Tue Apr 07, 2020 10:49 am
Forum: Music Tech DIY
Topic: a legend is back...System-700 in eurorack
Replies: 172
Views: 20764

Re: a legend is back...System-700 in eurorack

As I understand it if you sync the System 700 sequencer from an external clock source the step time pots don’t vary the timing. (source for this: http://search.retrosynth.com/ah/search/lookit.cgi?-v0410.1455 and again: http://search.retrosynth.com/ah/search/lookit.cgi?-v0807.593) I was going to make...
by ringroad1
Mon Mar 30, 2020 6:28 am
Forum: Music Tech DIY
Topic: Silly Crazy (Im)Possible Juno-60 DIY Idea
Replies: 1
Views: 207

Re: Silly Crazy (Im)Possible Juno-60 DIY Idea

Someone tried this a while back:

https://www.matrixsynth.com/2014/07/dua ... d-kit.html

No mod kit ever surfaced as far as I'm aware.
by ringroad1
Thu Sep 12, 2019 4:42 pm
Forum: Music Tech DIY
Topic: Kobol Expander I Calibration Procedure?
Replies: 32
Views: 3309

aieeee, SSM2050 :waah:
by ringroad1
Tue Sep 10, 2019 11:14 am
Forum: Music Tech DIY
Topic: a legend is back...System-700 in eurorack
Replies: 172
Views: 20764

In a brief test I did a while back LM13700 worked fine in the 24db VCF, although I had to do some convoluted wiring up to check 'cos the pinout is very different. Not a UK/EU supplier but Tayda say they have loads of LM301. I've bought some from them in the past, I don't remember having any trouble ...
by ringroad1
Sun Sep 01, 2019 2:14 pm
Forum: General Gear
Topic: Boss BX-8 European Users what Adapter do you use?
Replies: 3
Views: 743

I bought a cheap BX-16 a while back - there were PSUs available at the time on eBay but they were much more expensive than the mixer, so I ended up making my own. As far as I can remember I based it on the pictures in this: http://djjondent.blogspot.com/2014/11/roland-mixer-power-supply-replacement....
by ringroad1
Mon Aug 19, 2019 3:30 am
Forum: Music Tech DIY
Topic: a legend is back...System-700 in eurorack
Replies: 172
Views: 20764

Yeah sorry, I should've realised the numbering would be different given that this version of the 711 doesn't include the spring reverb or the tuning oscillator. I went through a few µPC324C's and it came alive. Seems these chips are hit and miss, shame these are not available from any of the major o...
by ringroad1
Sun Aug 18, 2019 5:25 am
Forum: Music Tech DIY
Topic: a legend is back...System-700 in eurorack
Replies: 172
Views: 20764

Just in terms of narrowing down the problem or ruling things out, and presuming the numbering is the same as the original, then on the phaser it might be worth checking that you’ve got some audio input at R55/IC9C input. If there’s something there, but nothing at output of IC9B then there’s somethin...
by ringroad1
Thu Jul 11, 2019 8:19 am
Forum: Music Tech DIY
Topic: a legend is back...System-700 in eurorack
Replies: 172
Views: 20764

backfromearth wrote:What would be great after the system 700, is all modules from the SH-05 !
you really want the slow, low output AR envelope?

not much point, you could get a more flexible SH-5-style synth with the System 100 clone PCBs, the SH-5 VCF clone and the Ken Stone CGS30 bandpass.
by ringroad1
Sat May 25, 2019 2:16 am
Forum: Music Tech DIY
Topic: Roland SH5 bandpass filter
Replies: 50
Views: 5275

Re: 12v?

guitargodmiles wrote:Will this work on eurorack 12v as is?
I've got a couple running in my +/-12V box, don't think I made any changes, works fine
by ringroad1
Fri Feb 08, 2019 5:50 am
Forum: Music Tech DIY
Topic: Where to find Roland/Korg style toggle switches
Replies: 11
Views: 911

Have a look for Alco CST-023n - I've used a bunch of these on a project behind a 2mm panel, the toggle could be a bit longer but they feel great.
by ringroad1
Fri Jan 04, 2019 7:55 am
Forum: Music Tech DIY
Topic: System-100 Model-101 & 102 in eurorack
Replies: 173
Views: 18921

Is it ok to replace the sc945-q with 2n3904? Or does anybody know where i can buy sc945 transistors? also i don't see the high-pass-filter potentiometer on the bom. Am i right, that it is a 1megaohm pot? Presuming it's included on this version, for the HPF you'd be best off with a 1M reverse audio ...
by ringroad1
Tue Sep 18, 2018 4:00 pm
Forum: Music Tech DIY
Topic: Roland CSQ-600 Battery Replacement?
Replies: 5
Views: 350

Soz if this is obvious but presuming the original was a rechargeable battery, you might want to stop it from trying to recharge the CR2032.

If the battery is the blob thing to the right of the RAM in the service note schematic (labelled GB50-3?), wonder if snipping D123 would do the trick.
by ringroad1
Mon Apr 16, 2018 3:33 pm
Forum: General Gear
Topic: Akai!!!
Replies: 72
Views: 10425

I've got an S1000 with a creaky old hard disk that has some random East 17 samples and a bunch of empty programs, get the impression it might have been from a tour.
by ringroad1
Mon Apr 09, 2018 1:04 pm
Forum: Music Tech DIY
Topic: Roland SH5 bandpass filter
Replies: 50
Views: 5275

Just looked again at your wiring and the photo looks correct, but I'd just say that the frequency pot is specified as a dual 100K linear. It should do some filtering stuff with two separate 100Ks, just not quite as expected. I'm guessing you've got the 800R-ish resistor on that switch? Are you sure ...
by ringroad1
Sun Apr 08, 2018 9:20 am
Forum: Music Tech DIY
Topic: Roland SH5 bandpass filter
Replies: 50
Views: 5275

shhhhhhh-5 bpf

Yeah, sorry - this was probably the first layout I ever did so it's a little wonkier than I'd do it now (although it should work) Looking at again all these years later I realise the placement of C1 and C2 is a bit confusing, this (attached) slightly revised version might help. If you've got that ri...
by ringroad1
Wed Mar 28, 2018 3:15 am
Forum: Music Tech DIY
Topic: Still seeking a slider for a Roland 100M model 150
Replies: 3
Views: 396

I realise it's not the same value or taper but this is closest I've seen, might have to fashion an adaptor board to get it to fit.

http://en.uraltone.com/slide-potentiome ... lider.html
by ringroad1
Thu Mar 22, 2018 5:36 pm
Forum: General Gear
Topic: Opinion : Roland System 100 vs 100m
Replies: 43
Views: 4137

sh-5 envelopes

Tempting to do a replacement envelope board for the SH-5 subbing in the 100M envelope and a sharper/beefier AR. Although it'd probably be simpler just to sub a smaller timing cap (SH-5 envs spec'd twice as long as System 100) and add a little stripboard to boost the output - if it's the same as the ...
by ringroad1
Mon Mar 05, 2018 1:55 pm
Forum: General Gear
Topic: Roland MC-4 restarting at random
Replies: 19
Views: 776

I love my MC-4, and this makes me shudder. I don't know what it could be, but something something CPU reset pin? Looking at the datasheet for the uPD780, reset is active low (so 0V = let's reset). It also suggests that it'll take between 2V and the supply voltage as high but it might be worth having...
by ringroad1
Thu Jan 25, 2018 5:23 pm
Forum: Music Tech DIY
Topic: ua726 analysis
Replies: 4
Views: 747

good stuff.

just ooi were your test subjects original Fairchilds? I had some more recent Korean versions a while back, they seemed to work ok, but I didn't do any temperature testing.
by ringroad1
Sat Dec 30, 2017 9:09 am
Forum: Modular Synth General Discussion
Topic: [RETURNED!!!]- STOLEN MOTM Stroh Mirror Core VCO
Replies: 14
Views: 2214

It might be worth asking this lot if this is within their remit, as a starter for ten at least

https://www.actionfraud.police.uk/

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