Muff's Modules & More

elemental

I just got a 2nd hand Model 15 Osc, and it seems to have a problem with my power supply. When plugged in (and from what I can see its all the right way round) I just get a buzzing from my power supply and it cuts the power to everything else. When I unplug it everything works fine again.
Could it be not compatible with the power supply? I have an Analogue Solutions case.

dkcg · Posted: Tue Nov 11, 2008 8:08 pm Post subject:

Sure it's plugged in right? Red goes on top in the ASys cases. Ignore the key on the cable plug, the keys are often the opposite the way the ASys cases are keyed, I end up using a sanderbit in my Dremel to grind off the keys in most my modules in the ASys case.

It could be a ground issue too, the M15s need to be grounded, in Doepfer cases, by just having the faceplate touch the rails, not sure about ASys cases, I would think they're grounded, but not positive.

If it was plugged in backwards, pray the M15 didn't blow up.

A Dingleberry Monstrosity · Posted: Tue Nov 11, 2008 8:48 pm Post subject:

yeah, I dont think its plugged in right.

GCF · Posted: Tue Nov 11, 2008 11:06 pm Post subject:

Analogue Solutions or Analogue Systems? Not sure if that changes the situation, but I thought I would point that out. Is it the Concussor case?

dkcg · Posted: Tue Nov 11, 2008 11:50 pm Post subject:

Oh, I read wrong. I thought it was Analogue Systems. No clue about the concussor cases.. d'oh!

elemental · Posted: Wed Nov 12, 2008 6:39 am Post subject:

Well the cable is def plugged in right .. the red stripe is where it says it should be on the module, and the power sockets are all keyed - and yes its the Analogue SOLUTIONS Concussor case.

I've had the buzzing power supply thing before, which I think was from a loose power connection in one module. No idea this time tho... I'll email Mr Grenader aswell.

e-grad · Posted: Wed Nov 12, 2008 7:12 am Post subject:

I assume, too, that either the power connector of the module itself is up site down or you plugged it up site down into the bus board. Or the module came with a short.

From a sheet that came along with my sole ASol module I guess there must be the word "stripe" on the bus board of your case. Since Tom pointed out that the Doepfer power sockets are up site down the ASol sockets should have +5V (first pair) and +12V (2nd pair) above and -12V at the bottom.

On the Model 15 pcb it is possibly indicated where the +12V pins is located. Thus make sure that these are connected correctly. However, once plugged in the other way round the Model 15 will have some burnt parts unless there's a protection circuit on the board.

flts · Posted: Wed Nov 12, 2008 7:26 am Post subject:

The time I had that issue was when I plugged an ASys module into a Doepfer style busboard and the adapter cable I had had one of the supply voltage lines and ground (I think) shorted together. Same thing, other modules weren't harmed but all I got was hum.

So I'd wager either the cable orientation is wrong or the cable is busted somehow. Or maybe a broken VCO if it isn't about those.

sabasan · Posted: Wed Nov 12, 2008 12:36 pm Post subject:

If it is like mine
Analog Solution case are made of plastic
so probably is just a ground problem

elemental · Posted: Wed Nov 12, 2008 12:44 pm Post subject:

Thanks, but mine is the metal 6U version.
There is still hope...!

A Dingleberry Monstrosity · Posted: Wed Nov 12, 2008 2:08 pm Post subject:

maybe the cable itself is reversed?

make sure the ribbon cable on the board is hooked up right.

elemental · Posted: Wed Nov 12, 2008 5:35 pm Post subject:

Cat-A-Tonic · Posted: Wed Nov 12, 2008 5:37 pm Post subject:

It sounds to me like one of the rails is shorting to ground.
For your sake I hope this is the case.
If so, locate the short on the M15 between the rail and ground (likely near the power connector pins) and desolder it or just cut it.
I accidentally did this to my Binary Zone when building, but everything was fine after I cut the short.
I used an exacto knife to remove the solder bridge.

The primary reason for Plan B making a protected power distribution board is for use with the Model 15 Oscillator to prevent reversing the cable from frying the module.

Chuck E. Jesus · Posted: Wed Nov 12, 2008 5:58 pm Post subject:

is there a chance you are asking too much from the PS? try taking some mods off the PS and see if the problem persists...

elemental · Posted: Wed Nov 12, 2008 6:56 pm Post subject:

Chuck E. Jesus · Posted: Wed Nov 12, 2008 6:59 pm Post subject:

elemental · Posted: Thu Nov 13, 2008 5:33 am Post subject:

Chuck E. Jesus · Posted: Thu Nov 13, 2008 7:19 am Post subject:

elemental · Posted: Thu Nov 13, 2008 11:12 am Post subject:

Got an email back from Peter Grenader... he's gonna help me fix it, hopefully!

Hope he doesn't mind me posting part of his email but thought it would be useful for anyone else with an A.Sol or older A Sys case getting an older Rev 1 M15: