Since I acquired a Coco Orchestra 90 unit awhile back, and I am trying
to find the source of some humming in my system when the Orch 90 unit is
operational, I looked at the schematic:
http://www.colorcomputerarchive.com/coco/Documents/Manuals/Hardware/Orchestra-90%20CC%20Stereo%20Music%20Synthesizer%20(Tandy).pdf
(page 109 of the PDF)
I understand the ROM, the resistor ladders, and the latches, but analog
is not my strong suit. I made my way through the op-amp design, but I
am stumped on one component (actually three)?
C7,C9, and C10
They look like electrolytic polarized caps, but are NP (non polarized),
with no '+' on the schematic.
Can someone shed light on what these are and where you would find them
(or if they can safely be replaced with another kind of capacitor)? I
will admit I've never seen mention of these before now.
Are they "bipolar"?
http://www.digikey.com/product-detail/en/nichicon/UVP1H010MDD/UVP1H010MDD-ND/242804
Or, are they called something else now?
Jim
--
Jim Brain
br...@jbrain.com
www.jbrain.com
