Search found 403 matches

by mcop
Fri Oct 23, 2020 8:55 am
Forum: Music Tech DIY
Topic: New Syncussion with MIDI and Silent power - VIDEOS
Replies: 1009
Views: 92155

Re: New Syncussion with MIDI and Silent power - VIDEOS

I had a problem like this with one of my builds. It was solved by reflowing the solder on the dual transistors associated with the VCA.
by mcop
Sat Aug 31, 2019 8:15 am
Forum: Music Tech DIY
Topic: plague bearer DIY ?
Replies: 324
Views: 27872

The beveled edge on SOIC chips indicate the side with pin 1 on. This is indicated on the pcb with a line inside the body outline of the chips board marking.
by mcop
Sat Jun 01, 2019 12:07 pm
Forum: Music Tech DIY
Topic: Bozak DJ Mixer Clone - Opened up
Replies: 68
Views: 10907

I did my own pcb using the LM317HV fed by a transformer.

Image
by mcop
Fri Apr 26, 2019 11:15 am
Forum: Music Tech DIY
Topic: New Syncussion with MIDI and Silent power - VIDEOS
Replies: 1009
Views: 92155

aabbcc wrote: Nope :) (at least not to my ears)
To be fair I didn't expect it to make much difference!
Rather get on with building than wait for an order to arrive :)
by mcop
Fri Apr 26, 2019 2:40 am
Forum: Music Tech DIY
Topic: New Syncussion with MIDI and Silent power - VIDEOS
Replies: 1009
Views: 92155

I'm just getting the parts together to build a couple of these and have a quick question about resistors.
As I've been building stuff for many years now I have a good supply of metal film resistors and wondered if there was any noticable audible difference in using metal film rather than carbon?
by mcop
Fri Apr 05, 2019 3:31 am
Forum: Music Tech DIY
Topic: [PCB offer] Thomas Henry's Contr.LFO. 2nd run, check PMs
Replies: 585
Views: 59424

I'm guessing you're talking about the 555 VCO here rather than the LFO. If that's the case as Elmegil says a good C0G works for the 2200pF - it's what I've used in all of my builds. The 0.22uF is just blocking DC on the Linear FM input and can be Mylar or a box type poly. Question about the BOM C4 s...
by mcop
Thu Oct 18, 2018 12:18 pm
Forum: Music Tech DIY
Topic: [PCB offer] Thomas Henry's Contr.LFO. 2nd run, check PMs
Replies: 585
Views: 59424

Are you looking for the three way switch for the waveform select going into the control output? Here's a few from a quick search: https://www.ebay.co.uk/itm/3pcs-Guitar-Toggle-Switches-DPDT-6-Pin-ON-ON-ON-Mini-Switches-Car-Boat-Switch/261977787124 https://uk.rs-online.com/web/p/toggle-switches/71098...
by mcop
Sun Oct 14, 2018 11:08 am
Forum: Music Tech DIY
Topic: New Syncussion with MIDI and Silent power - VIDEOS
Replies: 1009
Views: 92155

RS have them: https://uk.rs-online.com/web/p/bjt-bipo ... s/7920841/
Minimum Order is 20 though.
by mcop
Tue Aug 21, 2018 5:31 pm
Forum: Music Tech DIY
Topic: The Phonic Taxidermist
Replies: 206
Views: 25601

Sorry, hadn't noticed the mistake with the layout. There's also 4x100K resistors missing on the layout as well as the diodes. The diodes protect the inputs to the comparator from signals below 0V. I made the diagram after building my own unit. On my build the 10K, 100K and Diode are on a seperate bi...
by mcop
Thu Jun 21, 2018 9:29 am
Forum: Music Tech DIY
Topic: The 2018 Show Us Your DIY Builds Thread
Replies: 840
Views: 77719

I've still got the tail end of one from my days of etching pcb's in the 80's. Not sure this is exactly the same but RS seem to still do them: https://uk.rs-online.com/web/c/pcb-prototyping/pcb-cleaning/pcb-cleaning-scrub-blocks/ I have a mildly abrasive eraser thing I've used to clean oxidation off ...
by mcop
Fri Apr 13, 2018 1:11 pm
Forum: Music Tech DIY
Topic: RYO Penta issues - help me troubleshoot?
Replies: 39
Views: 2392

Sounds like you could have a duff Transistor there. Just checked the transistors on my build with the diode test function on my multimeter and only get a reading in one direction as I'd expect to.
by mcop
Wed Apr 11, 2018 5:52 am
Forum: Music Tech DIY
Topic: RYO Penta issues - help me troubleshoot?
Replies: 39
Views: 2392

Can you post photo's? My first guess would be a short to the reset of the CD4017. This could well be on one of the board to board connectors. When looking at the back of the boards (back of switch on panel PCB/power header on PCB 2) check the top right pin. This is the connection which carries the R...
by mcop
Sat Apr 07, 2018 6:46 am
Forum: Music Tech DIY
Topic: RYO Penta issues - help me troubleshoot?
Replies: 39
Views: 2392

Looks like the LED's for those stages are also a bit dimmer which could indicate somethings pulling the voltage down on those stages. Looking at the schematic here's a few more things to check: 1. Check pins 3 and 7 of the CD4017 are soldered correctly. 2. Check all the connectors between the boards...
by mcop
Sat Apr 07, 2018 6:28 am
Forum: Music Tech DIY
Topic: RYO Penta issues - help me troubleshoot?
Replies: 39
Views: 2392

From your pictures those resistors look correct. How much lower than the other three outputs are 1 and 4?
by mcop
Sat Apr 07, 2018 6:21 am
Forum: Music Tech DIY
Topic: RYO Penta issues - help me troubleshoot?
Replies: 39
Views: 2392

First thing I'd check is that R10 and R15 are the correct values (100K).
by mcop
Sun Nov 12, 2017 7:59 am
Forum: Music Tech DIY
Topic: solder
Replies: 58
Views: 8451

Perhaps a bit more than you wanted to pay but I really like the Warton Metals Omega 63/37 Fast Flow: https://www.rapidonline.com/warton-meta ... wire-28723
by mcop
Fri Jul 28, 2017 3:43 am
Forum: Music Tech DIY
Topic: [PCB offer] Thomas Henry's Contr.LFO. 2nd run, check PMs
Replies: 585
Views: 59424

Does sound a bit weird. When calibrating did you start with the triangle offset? If I remember rightly all the waveforms are derived from the triangle so once that's correct you can move onto the others. Forget all about the controller outputs until the rest is sorted. If none of this helps I'd star...
by mcop
Tue Jul 25, 2017 5:13 pm
Forum: Music Tech DIY
Topic: [PCB offer] Thomas Henry's Contr.LFO. 2nd run, check PMs
Replies: 585
Views: 59424

Have you tried turning trimmer R33 all the way in the other direction?
by mcop
Mon Jul 10, 2017 12:41 am
Forum: Music Tech DIY
Topic: plague bearer DIY ?
Replies: 324
Views: 27872

edit - Make that 2!

I'd be up for a pcb/panel combo as I've probably already got most of the parts apart from the large cap and the switch. Depending on price I may be up for a few.
by mcop
Thu Jun 15, 2017 12:35 am
Forum: Music Tech DIY
Topic: New firmware for hexinverter MIDI2CV
Replies: 82
Views: 8338

If you could add me to the waitlist I'm interested in a chip.
by mcop
Thu Jun 08, 2017 3:50 pm
Forum: Music Tech DIY
Topic: 7Dials CV Express DIY Expression Pedal Interface
Replies: 79
Views: 9433

Glad it was an easy fix and good luck with the gig.
by mcop
Thu Jun 08, 2017 1:46 pm
Forum: Music Tech DIY
Topic: 7Dials CV Express DIY Expression Pedal Interface
Replies: 79
Views: 9433

Do you mean that the signal from the expression pedal isn't reaching the output and you're only getting 0-5v when you sweep the offset knob? If this is the case and there's a signal from the expression pedal at the other two outputs then look at SW1, P3, R26 and J14/15 which is the connection betwee...
by mcop
Tue Jun 06, 2017 12:20 am
Forum: Music Tech DIY
Topic: temps_utile / 6 x clock generator [build thread etc]
Replies: 810
Views: 62973

Here's two I've just finished. Having a lot of fun with them.
Thanks to all involved developing this.

Image
by mcop
Fri May 19, 2017 2:39 pm
Forum: Music Tech DIY
Topic: 7Dials CV Express DIY Expression Pedal Interface
Replies: 79
Views: 9433

P2,P4 and P5 are just voltage dividers so it should work. It will just increase the current draw a bit. P3 is an attenuator so again should work. P1 is the voltage divider for the Comparator and if you change it you'd need to change the value of R4 and R10 to ensure the range remained the same. edit...
by mcop
Fri May 19, 2017 2:23 pm
Forum: Music Tech DIY
Topic: Harry Bissell's Fast Response Low Ripple Envelope Follower
Replies: 246
Views: 26752

For this one I used 20mm x 2mm anodised aluminium from a local DIY store. It came in a 1 meter length. For most of my panels up to 12HP I get my aluminium in lengths on ebay and cut it down. For larger panels I just buy small sheet offcuts and cut them down. I dont have spares sorry as I cut the len...

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