Now I managed to get the circuit diagram for this, which made modifications easy, as a fresh graduate Electronics Engineer, but on a limited Hi-Fi budget (Thorens TD160, Mission 774 (not the LC), AT OC9/Goldring MC4000, Denon Stepup transformers, Quad FM3, Castle Warwick speakers on Target Stands with Audioquest Indigo cables, Chord Company custom DIN cables).
So that Ribbon cable between the input & power board, replaced by silver wiring. Phono stage rebuild with lower noise matched transistors & opamps, better Caps and even Vishay ceramic resistors.
Better wiring from the Power board to output with Michell speaker posts. Better caps throughout, Alps volume control, bypass caps on the reservoir caps, then a bigger transformer which had to be housed in a separate case.
All good fun - I got power levels up to 50W, THD down and the phono stage much quieter. Served well for a good number of years.
Thank you, Neil.
So the serial number 0420 makes it an 80’s unit, right? Or is it, as Richard pointed out, an early 70’s example which perhaps had been serviced by Naim somewhere in the 80’s? I know it was paired with an early 70s NAC12 which had its DIN phono input changed to RCA during its lifetime.
You can see where you more has gone with N Dac. And how a bigger external PSU was part of the design.
Bit like an ndx2. Yes, naim will provide a starter psu, but you really ought to buy a xps or 555. Where as with the nd555, they told you straight away to buy a 555.