The line stage sounds great but the phono has a pronounced hum at normal listening level (9 o'clock). Holger at TN has given me some suggestions but I find myself stumped, hoping for some more tricks from the group. Tubes in phono stage are brand new 12AY7 JJ.
Here's what I've checked so far:
1. Flip power plug over.
2. Turn off any dimmer/flouro/halaogen lights.
3. Move preamp away from other equipment, unplug other sources than turntable.
4. Try a variety of RCA interconnects.
5. Use shorting pins at phono in to isolate source of hum: hum still present.
6. Does hum follow volume? Yes.
7. Check for redundant ground wires: only one ground attached on Aikido line board IN and OUT.
8. Check that phono RCA grounds are not shorted to chassis.
9. Verify wiring/grounding of Volume/balance pots.
10. Reflow all solder points on PH10 PCB
11. Replace filament wires and power switch with 20ga stranded wire (was 24ga) double-checked all PS wiring at this time
12. Prod/poke wiring runs with plastic stick to see if hum changes as wires are moved (hum stays same)
11. Cleaned bottom of boards of any residue/solder debris
Have not tried:
Replace 12AY7 tubes (I currently only have these two, new JJ tubes)
Different power amp (hoping to try this today)
Pics are here (shown before smaller wire was replaced with 20ga to F+/- and power switch):
Sometimes it takes a few seconds for them to come into focus after clicking on them for some reason.
Thanks for any assistance!