OK I understand now. Thanks.If you search this site you will find information on the Andy Weekes super regulator
It's a diy voltage regulator (that can be adjusted for output voltage) and supplies "quiet" voltage for many purposes
Try this thread for further reading....
Help with Nac72 Regs wiring please
So I want to wire my ALWSRs in to my Naim 72 in a more permanent and neat way than I had them before (though I was happy with the previous sound improvement) I just want to run the 4 regs to the two gain and two time alignment boards (these are Ryan Sound Labs boards) Should I just remove the 4...
Naim Nac 42.5 Naim NAC 42.5 servicing?
- Thread starter John_73
- Start date
John_73
pfm Member
Have recapped the Nap42.5, resprayed the outer chassis, and am into the home stretch (...touch wood!).
I desoldered the balance pot to make it a little less fiddly to spray some Dexoit Faderlube into it. In hindsight probably OTT and could have done it in-situ, but it's done now.
I thought I'd be 'clever' and use my multimeter to aid setting the balance pot to its exact middle position, so when I install the plastic cover over it it'll all be adjusted to perfection with the centre point being perfectly true/balanced. I put the black lead onto the middle leg (the wiper?), and adjusted the pot so the readings on the other two legs, read approx. 4.8k per side. However, when measuring the 'rear' gang, the measurements where way out, whereas I assumed they'd be a near mirror image of the forward facing gang.
Obviously I'm measuring it incorrectly! Does anybody know how I can adjust this accurately in terms of what legs/pins to adjust/measure to set it up for correct left/right balance, before soldering it back in please? Could do it by ear of course but this seems like a better way to get it done accurately. Ta.
I desoldered the balance pot to make it a little less fiddly to spray some Dexoit Faderlube into it. In hindsight probably OTT and could have done it in-situ, but it's done now.
I thought I'd be 'clever' and use my multimeter to aid setting the balance pot to its exact middle position, so when I install the plastic cover over it it'll all be adjusted to perfection with the centre point being perfectly true/balanced. I put the black lead onto the middle leg (the wiper?), and adjusted the pot so the readings on the other two legs, read approx. 4.8k per side. However, when measuring the 'rear' gang, the measurements where way out, whereas I assumed they'd be a near mirror image of the forward facing gang.
Obviously I'm measuring it incorrectly! Does anybody know how I can adjust this accurately in terms of what legs/pins to adjust/measure to set it up for correct left/right balance, before soldering it back in please? Could do it by ear of course but this seems like a better way to get it done accurately. Ta.
John_73
pfm Member
OK, think I may have figured this out. Does the highly skilled technical CAD drawing below look accurate?!
I set the pot to roughly its mid point, and by sheer fluke got exactly 1K35 (ignore the incorrectly written 1.35R below!) between pins 1-2 on the forward gang, and 5-6 on the rear gang. Looking at the PCB wiring this seems to make sense.
Assume it's good to solder back in now?
I set the pot to roughly its mid point, and by sheer fluke got exactly 1K35 (ignore the incorrectly written 1.35R below!) between pins 1-2 on the forward gang, and 5-6 on the rear gang. Looking at the PCB wiring this seems to make sense.
Assume it's good to solder back in now?
John_73
pfm Member
Have had the Nac42.5 working really well for the past week. Been delighted with it running into a Class A serviced CB Nap160. Unfortunately yesterday evening I started hearing some fairly loud rumble/fluttering noises, quite low/bassy sounding, on the left channel. Checked the pots on the pre and all fine. Checked the SNAIC and interconnects and sockets, all good. All caps already replaced so all fine there too. Tried once more and the left channel was almost completely dead. Tried plugging the DAC directly into the Nap160, and fortunately that is fine. So the fault if in the Nac.
I'm assuming it's either a transistor that's gone south, or could the relay cause this too perhaps? Thinking at this point I may have to send it for a service to JJS Thatcham, but if it's relatively straight-forward to trace I'd prefer to give it a shot first. My desoldering/soldering skills are very good, but I have limited fault finding skills unless there's somebody that could walk me through it. I do have a Peak DCA55 transistor tester I can use if needed, but there's 18 of them in there...
I'm assuming it's either a transistor that's gone south, or could the relay cause this too perhaps? Thinking at this point I may have to send it for a service to JJS Thatcham, but if it's relatively straight-forward to trace I'd prefer to give it a shot first. My desoldering/soldering skills are very good, but I have limited fault finding skills unless there's somebody that could walk me through it. I do have a Peak DCA55 transistor tester I can use if needed, but there's 18 of them in there...
bob smog
Member
Watching with interest.
I too have a 42.5 that I’ve awakened from a long slumber. It too has developed an intermittent low rumble/flutter in one channel. I swapped the positions of the phono boards and it seemed to follow the boards.
EDIT: reversed the polarity on the input cap - Doh! need to quit soldering right before bed. All quiet now.
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