Thanks for your response Malte, and
everyone else (including those off-list). I'll be having another
look at the unit tonight and will try out the excellent
suggestions received.
Malte, the -15' and +15' lines (with the ' prime or dash symbol) are only used to drive the op-amps on the power supply board, not to supply the rest of the synth. If you have a look at the schematic it should be clearer - pretty cool technique, I think. If you want more info I can post the PCB layout as well, which shows the very well-labelled test points (which are basically protruding pins connected to the supply rails that power the rest of the synth).
Cheers,
A.
On 20/07/13 5:20 PM, Malte Rogacki wrote:
Malte, the -15' and +15' lines (with the ' prime or dash symbol) are only used to drive the op-amps on the power supply board, not to supply the rest of the synth. If you have a look at the schematic it should be clearer - pretty cool technique, I think. If you want more info I can post the PCB layout as well, which shows the very well-labelled test points (which are basically protruding pins connected to the supply rails that power the rest of the synth).
Cheers,
A.
On 20/07/13 5:20 PM, Malte Rogacki wrote:
I somehow don't quite understand:
You're getting both +15V and -15V at the opamps, but you assume that
something is wrong with the power supply because the test point in the
supply itself doesn't give you -15V?
I would guess it's probably the wrong test point then.