Worht The Effort
Hello
It has been some weeks since I got this amplifier, I connected it up to my system and was some what surprised how sweet and spacious it sounded.
I got a service manual and set about replacing all the "fusable resistors" as these had drifted in value, I used 1% tolerance resistors, I replaced the Bias pre-set pots with multi turn pots to set the bias voltage.
Then I replaced the 4 big power supply capacitors, 4700uf 63v + 4700 35v I used Nichicon audio grade ones. The other capacitors in the power supply I replaced with Panasonic FG types.
I replaced the coupling caps with polypropylene ones of the same value and any others with Nichicon audio grade.
I then totally re-wired the amplifiers power supplies and speakers with 1mm solid core copper cable, I replaced the 4 amp fuses in the output stage with the same 1mm cable.
I also removed a 10k inline and a 100k to earth resistor in the output of the pre-amplifier, so as to increase the output of the pre-amp slightly but also to open out the bass end a little.
In between doing these jobs I have been listening for changes/improvements in sound from the amplifier which I have achieved now with it in its present state.
It is a smooth warm and spacious sounding amplifier which is very good to listen to, my next job will be to build in a Moving coil cartridge pre-amp on phono 2 input.
I am pleased I bought this.
Gary
Hello
It has been some weeks since I got this amplifier, I connected it up to my system and was some what surprised how sweet and spacious it sounded.
I got a service manual and set about replacing all the "fusable resistors" as these had drifted in value, I used 1% tolerance resistors, I replaced the Bias pre-set pots with multi turn pots to set the bias voltage.
Then I replaced the 4 big power supply capacitors, 4700uf 63v + 4700 35v I used Nichicon audio grade ones. The other capacitors in the power supply I replaced with Panasonic FG types.
I replaced the coupling caps with polypropylene ones of the same value and any others with Nichicon audio grade.
I then totally re-wired the amplifiers power supplies and speakers with 1mm solid core copper cable, I replaced the 4 amp fuses in the output stage with the same 1mm cable.
I also removed a 10k inline and a 100k to earth resistor in the output of the pre-amplifier, so as to increase the output of the pre-amp slightly but also to open out the bass end a little.
In between doing these jobs I have been listening for changes/improvements in sound from the amplifier which I have achieved now with it in its present state.
It is a smooth warm and spacious sounding amplifier which is very good to listen to, my next job will be to build in a Moving coil cartridge pre-amp on phono 2 input.
I am pleased I bought this.
Gary
Last edited:
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