Quick recap of mods and parts needed:
1. Input capacitors: (next to opamp socket), I upgraded to 2x 10uF 16V Nichicon BP, arrow, mouser and digikey code UES1C100MDM
2. Output capacitors: 100uF 16V Nichicon BP, code UES1C101MPM
3. Opamp gain reduction (reduces noise and distortion at max level, tapers volume pot): 11kOhm resistors across opamp terminals 1-2 and 6-7, I suggest 0603 SMD, for example CRCW060311K0FKTA
4. Power supply capacitors: 4 x 470uF 16V, for example UHD1C471MPD should work and it is smaller than the one I used.
5. Single ended buffered output mod requires SHORT 3.5mm panel mounted socket (like this one:
https://goo.gl/q25TL9 ) and a miniature 6 pin DPDT switch ( like this one:
https://goo.gl/LdWSmZ ) They will require a bit of filing to make them fit.
Cables should be wired as per image below (central pins of the switch should be connected with a jumper cable and to the ground, connect 3.5mm socket's ground to them as well,
5 on the image below), when switch is engaged L and R negative outs (
2 and
3) are grounded, as per SE buffer operation requirements:
Hope it helps.
PS: wire #1 at 2.5mm socket is tricky to solder in as it is way to easy to jump ground sleeve wrapping around the front of the socket from #3 with excessive solder. Insure that there is no solder (and no electrical contact) between solder joint #2 and the sleeve right above it.
F1 + Nichicon BP audio caps: