I've owned this integrated amp since new (28 years). It has never been touched and almost never used (in dry storage for ~15 years). A few folks have mentioned to me that the power supply caps (a pair of GE 9300 uF/50V) should be replaced with Black Gate FK 10000 uF /80V units (from a size perspective, an exact replacement).
I would be willing to try a range of capacitors. Other than the BGs, can anyone else recommend alternatives. The GE caps are 2" in diameter and 3" tall with screw lug connections.
TIA,
John
I would be willing to try a range of capacitors. Other than the BGs, can anyone else recommend alternatives. The GE caps are 2" in diameter and 3" tall with screw lug connections.
TIA,
John
Cornell Dubelier (ungood spelling) makes very nice
caps, some of which will drop in without complaint.
Not as exotic as Black Gates but not as expensive,
either, and with a good performance record.
caps, some of which will drop in without complaint.
Not as exotic as Black Gates but not as expensive,
either, and with a good performance record.
Hornboy said:
Panasonic TSHA might fill the bill too, except they are not screw lug types. On the other side a 15000/50v type, 105 degrees, is 35mm thick and 50mm high. Cost certainly more reasonable than BGs.
In fact it's strange how few people use these supply caps and so many like FCs for preamp supplies or local bypass.
Designing a pcb holding Schottky or Fred diodes using these caps should make an excellent supply.
Carlos
Be careful with aged rectifier diodes.
Also the transformer could suffer from excess surge current during start up if you increase the capacitance that much.
Eventually replace the rectifiers, but consider that very often "modern" diodes are much more efficient, thus the resulting DC voltage can exceed the design parameter.
Measure the DC "as is" and then turn on the amp with news diodes using a variac while monitoring the DC across the caps.
When I changed old diodes in my Mc tube Tuner (MR 71) I had to increase the first R in the CRC filter to compensate the extra voltage.
Also the transformer could suffer from excess surge current during start up if you increase the capacitance that much.
Eventually replace the rectifiers, but consider that very often "modern" diodes are much more efficient, thus the resulting DC voltage can exceed the design parameter.
Measure the DC "as is" and then turn on the amp with news diodes using a variac while monitoring the DC across the caps.
When I changed old diodes in my Mc tube Tuner (MR 71) I had to increase the first R in the CRC filter to compensate the extra voltage.
Does anyone have a MA6100 functionspecification including details such as input sensitivity and power output?
Thanks,
Thanks,
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