Marantz MA500 mod

[kst]

Hi all,

Just get hold of a pair of Marantz MA500...
Thinking of doing a simple mod by changing the output transistor and some cap along the signal path....

Original output transistors used is 2SC3280/2SA1301.
Thinking of changing them with 2SC5200/2SA1943 higher power compared to original parts used.

BUt the 2SC5200/2SA1943 hfe classification is "O" type, the original part has hfe of "R" type.

Not sure if this modification still worth it.....
And not sure if the different hfe classification will create problem...

Any advice ? Any other mod that I can try ??

Many thanks in advance.

[jaycee]

There is no point in doing much with this amp except perhaps replacing the 4.7uF 50V input capacitor with a polyester type.

Don't bother replacing the output transistors unless they are damaged. The original 2SC3280/2SA1301 are quite capable, they are the "baby brothers" of the wellknown 2SC3281/2SA1302 devices.

The heart of this amp is the UPC1342V. If that dies, the amp is history - you will have a lot of difficulty getting another one.

[sakis]

agree to that ....

the sound of these original pairs is unbetable .... see if you have any caps to be replaced ....