its back in the 6U case and working. I checked the power lead and it appeared firmly connected at both ends. put back panel back on, and fired up...and voila. The duff joint idea makes sense. I will also double check the power consumption of the modules i have one row of 10 and one of 8. The psu pan...

Aha - Solved by reseating the main pcb with pot pcb . Phew!

But wait . Spoke too soon. It works in my mini doepfer case, but not when put back in my 6U case powered by Oakley euro PSU.

Hi Tony, its been a while -thought id get in touch, and hope you are coping well with lock downs and the like up there in Cumbria. Should have seen the beach down here on south coast nr bournemouth today. Too busy for me at 9am to get my usual post walk coffee and be comfortably "social distanced", ...

Oh and it's more common in builds I have completed at least to have a single tempco aligned lengthwise so body sits centrally on top of ic.

Well done for having a working build. A little thermal paste applied with a matchstick or similar to avoid messy application should solve the tempco issue. I managed without by bending and putting the leads in pcb first, then retracting them to get the body of tempco just to cover the ic by a couple...

With the antiphon, getting the correct orientation of sockets was my build mistake. Solder joints especially ones to the earth plane of the pcb are the main culprit of problems once built. Particularly a problem with this kit. Also because there are a lot of resistors, there's a danger of inserting ...

Thanks Whoop_ John, Good to hear from you.

KSS, EatYourGuitar, thanks for your words of wisdom. Luckily there are only a few instances of std vs min for me to think through. I have taken the Psu first to check, and there is a std res 1k for a resistor to a led where resistor is connected to +20v dc rail. The led calculator suggests 1k 0.6W. ...

Thanks emmaker. That helps me.

<t>I'm refurbing my 1979 Maplin 5600s and seeking some confirmation..Std Res resistors are occasionally stated in BOM. Is there an implicit higher power rating assumed like 0.6w?? One instance in bom explicitly asks for 2% Std Res which I read as better than min Res which would have been 5% carbon. ...

The only difference in my test patch was frequency knob at 12 o'clock . I retested with it at full ccw. At the lowest octave the voltage flatlined with just clicks audible. But moving up the octaves it never exceeds +-5 v ..maybe 5.5 ..I'm using intellijel 1u scope module. So I'm wondering if yours ...

My two m32s tested with sustain on to keep vca open and volume full clockwise both exhibit +/-5v I'm afraid. I have just upgraded to v2 firmware prior to testing for you. Could it be your scope being the diva? Or it's probe setting. I tested with square pulse .

I have built two of these successfully and for me a definite improvement on previous euro Classic vca.

Upgrade for me was very smooth and worked first time on two m32s. +1 to Moog.

Pm replied to

Thanks for the caution on pa20. I have replaced all zeners and diodes with fresh ones, replaced the tantulums with regular caps. Whilst the 2200uf caps look fresh,replaced with quality ones. Do not know if I should replace the rest. There was no specific fault on the psu ...just age, and not that ma...

This is the 5600S variant of ETI ...build guide says 1979...but I built @85 I would only use PA20 with one synth at a time...and at first on the bench with only the load of a couple of boards. The stated max expected current draw from other boards is 300ma per rail. Unlike modular, it has +/- 14 , +...

When Yamaha state the voltage rating of the PA-20 as 17.5 V ac x 2 does that assume a load of some known value ? I measured my PA-20 at 19.2V with just a meter across the pins. My reason for doing so was because i wanted to see if I could drop the 17.5 with three 400x rectifier diodes by 2.1v to 15....

Ic 10 and 11 are voice 7 acc to schematic. Ic10 pin1 is the output we want signal on. if you have swapped ic 10 and 11 , and reflowed ic Socket pins if sockets used, and reflowed feedback loop of small components ..whose values check out, hmm I'm at the limit of my knowledge I'm afraid.

Agree with Synthiq ..check the supply voltages on the ic. Then It would be useful to simply confirm there is no sine wave signal at the output pin of the ic itself, with oscilloscope. That can confirm whether it's a simpler downstream continuity issue, or a component issue preventing oscillation as ...

Hi, have you thought to see if it is just out of audio range and needs calibration trimmer adjusted? Osc 7&8 are intended for Lfo modulation, so pre calibration position of trimmer may not be as expected. Have you soldered well the slider potentiometer pins.? I found the earth plane a pain to get go...

Apologies I moved on to finishing vcas . II'll get back to that test later. I have problems with the vca...replace pot board u3 3 times trying to get linear mode and any cv to work, oh and outA ha no output,but B does. I did reverse the u3 at one point,could have done some damage. I'll open up a new...

Tony ,shorted c2 as suggested..triangle looks more sine with vpp 7.2v but pp does not change with gain control. I dont have the 5U installed and running at the moment - but will try comparing the overdrives when i can. ok i removed both diodes D1 and D2 from the circuit. Gain control works ! but the...

odrive resistance 20k, distortion resistance 30k i have measured every resistor on the board is correct value and they are. i have swapped out u1 with a tlo72 - not that. tested socket u1 for shorts - no joy. I next decided to put a filter and vca in front of the dvco triangle... in odrive mode and ...

well I pulled up the lead of D1 to run a diode test of dmm on both D1 & D2 and they passed.
As i was using a germanium diode -one of the the two suggested, i swapped back to 1n4148 ... sadly it did not solve the puzzle.

peculiar - not a lot else to check.