n00b trying to hack power-supply into 181 keyboard

Repair or Modifications of the Roland System 100M
agitprop
Posts: 2
Joined: Thu Jan 29, 2015 7:05 am

n00b trying to hack power-supply into 181 keyboard

Postby agitprop » Thu Jan 29, 2015 7:23 am

I just joined this forum, to beg your wisdom with a related DIY project. Please forgive the long exegesis. . .

I don't have a 100M, but I have a 181 controller, and I was hoping to use it with my Eurorack setup. So, to provide power to the 181, I just built a Frequency Central power supply, with 7815 and 7915 voltage regulators to achieve the desired voltages. The FC board tests correctly, delivering +/-15V.

I then looked at an old System 100M manual, to get the pin assignments for +15V, -15V, and ground. I thought I understood the perspective given in the manual for the DIN pins, but after wiring my ersatz power supply to a new DIN plug, connecting it to the 181, and testing CV Out, I saw a baseline 10 volts and no response from anything other than the bender, which went to 14V.

So, I am wondering if I mistakenly reversed (mirrored?) the pin assignments, by misunderstanding the perspective of the graphic in the manual. Looking at the DIN plug I made, from the front (not at the jack):

Ground is the bottom right pin
-15V is on the bottom left pin
+15V on the middle left pin, just above -15V

Any ideas? Am I potentially missing something more fundamental?

Thanks so much for considering!

ryk
Posts: 117
Joined: Wed Sep 26, 2007 2:14 pm
Location: London
Contact:

Re: n00b trying to hack power-supply into 181 keyboard

Postby ryk » Thu Jan 29, 2015 9:47 pm

Hello

Viewed from inside the wiring side of the plug ( where you solder )
with the orientation "ridge" at the bottom centre.

Centre pin - CV

Bottom right pin - Ground

Bottom left pin - -15V

Next one up on left - +15V

If you have a 191 cabinet and a multimeter you can
Check with the kybd socket on the front of the rack.

-ryk

agitprop
Posts: 2
Joined: Thu Jan 29, 2015 7:05 am

Re: n00b trying to hack power-supply into 181 keyboard

Postby agitprop » Thu Jan 29, 2015 10:31 pm

Thanks, ryk—I am a huge fan of your work and its progeny! I have a Metropolis and think it's awesome :-)

I re-soldered the DIN pins to match your orientation, and now I see what look like the right voltages out of Gate and Bender. Unfortunately, however, I am not seeing anything out of the CV sockets. (Trigger voltages is also looking odd, but I don't need it.)

I'm about to take a look at the wiring in and out of the board, but if you have any ideas, I would welcome them!



ryk wrote:Hello

Viewed from inside the wiring side of the plug ( where you solder )
with the orientation "ridge" at the bottom centre.

Centre pin - CV

Bottom right pin - Ground

Bottom left pin - -15V

Next one up on left - +15V

If you have a 191 cabinet and a multimeter you can
Check with the kybd socket on the front of the rack.

-ryk

yusynth
Posts: 10
Joined: Sat Aug 02, 2014 4:24 pm

Re: n00b trying to hack power-supply into 181 keyboard

Postby yusynth » Fri Jan 30, 2015 11:49 am

First you should check the PSU voltages when your 181 is connected. If their differ significantly form +/-15V then you may have destroyed some ICs when you did your first attempt.


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