McIntosh schematic capacitor symbols and orientation...

lowredmoon

Active Member
I'm looking over my MAC1900 service manual and see that nonpolar capacitors are indicated with a capacitor symbol that is not direction-neutral (see attached photo). However, the voltage differences and even (as I can read it) low and high impedance sides do not correspond to the directions of the symbols. Going on the assumption that McIntosh does things will intent, I'm still looking for a reason for this orientation before defaulting to the idea that they were merely using stock symbols and the orientation doesn't mean anything unless accompanied by +/- symbols.
PLEASE help me out her if you have a well researched answer for this.
Best regards!
 
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The schematics from the 60s and 70 s were drawn up expecting the local technician to have understanding of the circuits and were not drawn up as a user serviceable roadmap.

When Joe started drawing up the schematics about the time of the MR 80 for an example, he included more information, detail and we even started getting commercial part numbers shown.
 
The schematics from the 60s and 70 s were drawn up expecting the local technician to have understanding of the circuits and were not drawn up as a user serviceable roadmap.
While the MAC1900 is toward the bottom of the McIntosh hierarchy, I'm doing my best to treat the unit with respect. Part of this is pulling parts from a previous owner's fanciful modification attempts and replacing them with parts that are as close to original as I can source. I started tinkering years ago by building tube amplifiers, and one if my habits is to orient the outer "foil" of film capacitors to the lower impedance faced by the capacitor. I'm putting time in to understand as much as I can before I replace anything.
 
C302 and C360 are film caps. Both, like the other nonpolar caps in the schematic, are marked with what I understand to be polar symbols. Fine. But what is throwing me off is that the curved part of C302, for example, is neither facing a low voltage or low impedance side. So what I am left wondering is whether the orientation of these symbols has any practical meaning in this drawing aside from the obvious - as when used with polar capacitors.
 
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