Skip further down if you're not interested in the back-story.
About 10 years ago, as a poor student, listening to my uncle's nac 82 + nap 250 amp set up got me scouring ebay to get myself some naim amps as cheaply as possible.
I ended up with the remenants of somebody else's projects picked up pretty cheaply:
- A NAC42 without the sleeve or volume pot and with a dodgy source selector
- The insides of a NAP140:
I got a case built to original specs off ebay and fixed up the NAC42 enough for it to be functional if ugly (and it still is).
I soldered some connectors onto the NAP140 guts and it played music through some rubbish test speakers. Then I got a job, got busy, bought a nap 160 and got on with listening to music.
I'm trying to finish off half done projects at the moment and the NAP 140's guts have been in a box nagging me to do something with them for ages. I have the sled half of a case from the NAC42 rebuild which will get me going but I'll need to try to procure a sleeve or a suitable alternative at some point. I've drilled most of the required holes with a terrible quality corded drill and press. I'm in the middle of replacing the bulk caps.
The boards have some damaged traces where the previous owner replaced some capacitors and made what looks like some minor modifications.
Here's where I could use a little help:
(I tried embedding or linking to images on imjur but my post was rejected due to inappropriate or spammy content!)
I'm having some doubts about whether the boards are originally from the same amp and have some questions on ground wiring.
The power supply board is a NAPS140/3 and the amp boards are NAPA5/7. From browsing google images, it looks like some NAPA boards used in the NAP140 have three connections on the "front" end while some earlier boards only have two. It looks like the two connections are always used for the signal and its shield and the additional third connector is wired to the supply board where it is connected to ground through a cap on the boards which have it.
My supply board has the traces and pads for these extra ground wires but the amp boards don't have the third connectors.
What is the purpose of the third connection? Do I need it if the amp boards are lacking the connector?
Where should the signal shield be connected to? One of the DIN connector pins? The case?
The previous owner has moved the ground wires to remove the caps from the circuit. Why do this?
Is there anything else I should be worried about with these boards given they have a questionable history?
Any components I should definitely change or tests I should perform?
Thanks for reading if you made it this far!
About 10 years ago, as a poor student, listening to my uncle's nac 82 + nap 250 amp set up got me scouring ebay to get myself some naim amps as cheaply as possible.
I ended up with the remenants of somebody else's projects picked up pretty cheaply:
- A NAC42 without the sleeve or volume pot and with a dodgy source selector
- The insides of a NAP140:
I got a case built to original specs off ebay and fixed up the NAC42 enough for it to be functional if ugly (and it still is).
I soldered some connectors onto the NAP140 guts and it played music through some rubbish test speakers. Then I got a job, got busy, bought a nap 160 and got on with listening to music.
I'm trying to finish off half done projects at the moment and the NAP 140's guts have been in a box nagging me to do something with them for ages. I have the sled half of a case from the NAC42 rebuild which will get me going but I'll need to try to procure a sleeve or a suitable alternative at some point. I've drilled most of the required holes with a terrible quality corded drill and press. I'm in the middle of replacing the bulk caps.
The boards have some damaged traces where the previous owner replaced some capacitors and made what looks like some minor modifications.
Here's where I could use a little help:
(I tried embedding or linking to images on imjur but my post was rejected due to inappropriate or spammy content!)
I'm having some doubts about whether the boards are originally from the same amp and have some questions on ground wiring.
The power supply board is a NAPS140/3 and the amp boards are NAPA5/7. From browsing google images, it looks like some NAPA boards used in the NAP140 have three connections on the "front" end while some earlier boards only have two. It looks like the two connections are always used for the signal and its shield and the additional third connector is wired to the supply board where it is connected to ground through a cap on the boards which have it.
My supply board has the traces and pads for these extra ground wires but the amp boards don't have the third connectors.
What is the purpose of the third connection? Do I need it if the amp boards are lacking the connector?
Where should the signal shield be connected to? One of the DIN connector pins? The case?
The previous owner has moved the ground wires to remove the caps from the circuit. Why do this?
Is there anything else I should be worried about with these boards given they have a questionable history?
Any components I should definitely change or tests I should perform?
Thanks for reading if you made it this far!