JackieJoe
New Member
Hi everyone,
While working on my Sansui AU-317, I noticed that C07 and C08 are missing from the F-2751 phono equalizer board.
The service manual lists both capacitors as 100 pF, 50 V, P.C. (polystyrene). They are shown on the PCB layout and included in the parts list, but I cannot find them on the circuit schematic.
From the PCB layout, they appear to connect each phono input to ground, in parallel with R03/R04, so I assume they contribute to the input capacitance seen by the cartridge.
I’m trying to establish whether their absence is original or the result of a previous modification:
Has anyone found C07/C08 unpopulated on an apparently untouched AU-317?
Is removing these particular capacitors a known modification to reduce phono input capacitance?
Does anyone have clear photos of an original F-2751 showing these two positions?
The amplifier previously had a phono noise issue, which I resolved by repairing solder joints and connections. I would now like to understand the intended configuration before deciding whether to reinstall these capacitors.
Any help with this board would be much appreciated.
While working on my Sansui AU-317, I noticed that C07 and C08 are missing from the F-2751 phono equalizer board.
The service manual lists both capacitors as 100 pF, 50 V, P.C. (polystyrene). They are shown on the PCB layout and included in the parts list, but I cannot find them on the circuit schematic.
From the PCB layout, they appear to connect each phono input to ground, in parallel with R03/R04, so I assume they contribute to the input capacitance seen by the cartridge.
I’m trying to establish whether their absence is original or the result of a previous modification:
Has anyone found C07/C08 unpopulated on an apparently untouched AU-317?
Is removing these particular capacitors a known modification to reduce phono input capacitance?
Does anyone have clear photos of an original F-2751 showing these two positions?
The amplifier previously had a phono noise issue, which I resolved by repairing solder joints and connections. I would now like to understand the intended configuration before deciding whether to reinstall these capacitors.
Any help with this board would be much appreciated.
