Complete overhaul, all electrolytics replaced, including the ‘big four’ which originally contain two capacitors each, so in each I put two new Kemet/Rifa 15000 uF 63 Volt. Of course all the notorious ‘black-flag’ capacitors are replaced, as well as the triple diodes in the power amp and the MD phono preamp. This replacing of the triple diodes is not stricktly necessary but I replaced them with LED’s which just looks nice…
Only recently I compared the AU20000 with the AU919 and although both sound stunningly good, I found the 919 to be slightly more refined and having a better stereo imaging, I suppose this is largely due to the far superior power supply of the 919, but also the presence of the DD/DC circuit.
It is worth noting that the silk screening of F2844 on C07 and C08 indicates the polarity incorrect! The actual voltage across these two capacitors is only between 5 and 10 Volts, but it is reversed from what is indicated on the circuit board.
I replace the four main capacitors by removing the original capacitors from the cans and placing new ones. The original connector tags are aluminium and most of the times I remove it all. The hole it leaves in the covers allows for M4 thread to be cut so you can insert an M4 bolt and nut with a soldering tag to connect the new capacitors. 30 mm long bolts will allow for the capacitors to sit into the brackets of the circuit board with a locking washer and an M4 nut.
Of course it is worth noting how the polarity ends up, so all four labels are in the same direction once all four are inserted, as you can see, I got one wrong…
