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...