Hi Ben, Glad to hear you like the Filtrex and you're getting good use out of them. is there any benefit in connecting the ground to the grounds added to the PSUs for connecting the modular cases ? There is a benefit but whether it is audible is another thing. Ideally, all 0V points should be connect...

Actually, just noticed this other thread which could be the same thing:

viewtopic.php?f=78&t=225723

My new Unipulse Mk3 doesn't always respond when triggers are sent in quick succession. This is perhaps related to active sensing. On controllers that use active sensing the Unipulse only responds to triggering every second or so. Without active sensing, eg. my computer's midi interface, the unit app...

Can I ask, is it expected that audio in -> audio out when the unit is powered off? Ive not tried it but I would expect a small amount of signal to get through (called 'bleed') but not much. I would also expect the amount of bleed to be worse without the power lead in place. If the signal is the sam...

My first thoughts are that this is a wiring problem between the main board and the sockets. It'll be worth double checking there is no issue there first. Also, if you are using the five way Synthesizers.com power header on any Oakley 5U module then you need to fit the MU power header into the PWR lo...

Graham Hinton wrote: ↑

Wed Feb 19, 2020 7:24 am

The contacts are also available with solder buckets so the only tool you might need is the extractor at about £15 from Farnell. Use tin contacts for power rather than gold. There are cheaper shells than the Ringlock too, if you don't need gigability.

Good to know. Thanks Graham.

Personally, I'd have a power supply in each box. This simplifies the distribution and usually reduces any problems with unwanted return currents travelling down the screens of the patch cables.

I use ITT-Trident connectors for small peripheral devices, with several contacts and wires in parallel and usually with one end captive to eliminate the resistance and cost of another contact pair... Beautiful work as always Graham. And those multiway Trident connectors look excellent. The price of...

you should do a roland filtrex! I think the time for any such thing has passed now. The Oakley Sound Filtrex in its various guises has been around for over twenty years now. Sales were pretty slow in the later part of the production run. I don't think even an exciting new variant of the same thing ...

Paradigm X wrote: ↑

Mon Feb 17, 2020 6:16 am

all fixed, thank you. i had pin 3 and 1 mixed up on the output. it now works fine on an insert.

Excellent news.

I like story with a happy ending.

C1 was 1nF instead of 100nF. :tu: It doesn't explain the gliding or scaling problem you had initially with the KCV1 output though. C1 only really affects the speed of the LFO. You probably sorted those things out by the various other bits of work you did on the module. But welcome to the sometimes ...

This is a mains connector and should not be used for any other purpose. It may be used to connect switched mains though. Understood. I didn't even know they were limiting their official use to that. Definitely makes sense though, wouldn't want to mix low voltage DC with high voltage AC. Aside from ...

You want the biggest and most rugged connector that will fit. Avoid using small signal audio connectors. You need to keep the resistance of all connections as small as possible and that means big chunky wires. If you don't, you'll have unwanted interactions between modules. https://www.neutrik.com/e...

Pins 5, 6 and 7 should be connected together when nothing is plugged into the CV IN socket. All three pins should be carrying a sine wave from the LFO. When you plug something into CV IN then the LFO sine wave is disconnected from pin 6, and whatever you've plugged in to the CV IN should now be seen...

Does the second CV channel work, or does it do the same as CV1?

Does everything work with the VCO Controller module powered up but not used?

Built in LFO runs from about 10Hz to 6kHz instead of very slow to about 50Hz R18 could be the wrong value. It should be 100K. Can't trim scale of CV1, pitch seems to glide upwards on its own, weirdly. That sounds like a poor solder joint somewhere. Possibly pin 3 on U2, or maybe the pins on R10. Oc...

... my Hill audio mixer is +4dB line out... will a DI be needed so I don’t murder the input, or just some very low input gain. Also in either case would the instrument be the better choice as it is in between mic and line level? You should connect the aux out from your desk direct to the instrument...

Metal panels and cases which are grounded either directly or via the audio connecting leads offer more protection against unwanted interference from other equipment. Putting a module in a non conductive case or panel will never be quieter in terms of noise and interference. However, the amount of in...

Can anybody recommend what jack plugs and "wonderfully rubbery cable" to use. After a lot of looking for ready made patch cables I think the best way is to build myself. The plugs I use are by Neutrik - although they are from the old Rean range: https://www.rapidonline.com/neutrik-ag-nys201-6-35mm-...

Pav wrote: ↑

Tue Feb 11, 2020 2:24 pm

do not see +12V power at the multicomp connectors of the main board. Its there on the power header.

Check the soldering on R29. And that R29 is 22R.

I see this is another schematic where I have left +/-15V. I think I'll have to update that one along with the sequencer.

Tony

Just a small correction if I may. The JP-8 (and JP-4, SH-101, Juno-6, SH-1, SH-2, SH-09, 100M, JX-3p and others) filter is a cascaded OTA filter. Four identical OTA low pass sections cascaded together to create a one 24db/octave low pass filter. Resonance is applied from the final output back to the...

I assume either a TL074CDR or TL074CDRG4 is ok to use? I think they're the same part. It's probably just the packaging that they come in is different. It may also be due to differences between National Semiconductor and Texas Instruments parts. They're now the same company, TI, but some legacy nami...

Is it correct it only works with soft clip on? It only gets a brief mention in setup. Maybe build guide should say a little more about Asymmetry as it is not a feature of 5U COTA... Yes, the asymmetry control only works with soft clip engaged. It has no effect in the clean mode. Normally this sort ...

Yeah I looked at that one, it’s a wima 680. Probably OK then. What does the VCO 1 to VCA triangle wave sound like? This bypasses the filter entirely and goes direct from the VCO to the VCA circuitry. Turn down all the other waveforms going into the filter and listen only to the triangle wave. Do yo...

Awesome, thanks. Sorry didnt mean to second guess you just making sure i explained the problem as best i could. The CV does seem to produce a smooth crackle free 'morph' from saw to tri and PWM on the square. No need to apologise. It's not easy to fault find via the medium of forum posts or e-mails...