Refurbishing my old Monarch SA-600 that is currently not working. Previously was working fine but has now kicked the can. It's been a while since it was last working so can't give a great description of the symptoms other than constant noise over both channels, from memory.
Being quite comfortable with digital circuitry (robotics background) but not at all with analog I've needed guidance to get me on track. I have been using this guide. I'm planning on recapping all electrolytics with identically rated caps, other than the eight 25V 1uF because I can't find any. Using 25V 3.3uF instead. Schematic found here.
The guide also recommends updating the power supply section as it's no longer up to standard. Not sure what needs doing here other than up-specing the diodes to 400V 3A ones? Any help here appreciated.
It also recommends to replace some of the transistors due to noise, specifically the 2SC900's on the tone amp board and the 2SC945's on the power amp board. Can anyone recommend suitable replacements for these?
Was planning on getting contact cleaner going on all the sliders.
Any other input from people much more in the know?
Any help appreciated!
Being quite comfortable with digital circuitry (robotics background) but not at all with analog I've needed guidance to get me on track. I have been using this guide. I'm planning on recapping all electrolytics with identically rated caps, other than the eight 25V 1uF because I can't find any. Using 25V 3.3uF instead. Schematic found here.
The guide also recommends updating the power supply section as it's no longer up to standard. Not sure what needs doing here other than up-specing the diodes to 400V 3A ones? Any help here appreciated.
It also recommends to replace some of the transistors due to noise, specifically the 2SC900's on the tone amp board and the 2SC945's on the power amp board. Can anyone recommend suitable replacements for these?
Was planning on getting contact cleaner going on all the sliders.
Any other input from people much more in the know?
Any help appreciated!
Hi fhamersley,
How did you go with the refurb? I've just started refurbing the same unit and am curious to see how you went.
Cheers,
How did you go with the refurb? I've just started refurbing the same unit and am curious to see how you went.
Cheers,