Sounds OK.

-Steve

Finished ... passed smoke test ... voltages within range ... music!

Heard enough (last 4 hours) to know that this amp is something special ... details later.

But constant and significant background mains hum R+L. None at zero volume, progressive rise with volume, no change when I touch the pot shaft, nor the chassis. So sounds like mains interference getting into the signal inputs. Or ? grounding.

Not sure where to start re the hum. Do I screen my input leads? These are about 8cm long and pass between the output transformers to the circuit board. They attach where the kit connectors should have been.

Or do I shorten the output leads from the mains transformer which describe a kind of loop before attaching to the circuit board.

Or do I detach my grounding from the chassis and put is straight to mains earth as per sebrof (prev poster)?

Suggestions?

Sebrof - can I presume your amp is quiet?

Chasing hum, what fun  >:(

Fitted a temporary, grounded, screen the length of my input leads. No improvement - removed it (for now).

Rewired chasis ground to chassis / iec earth pin using various arrangements. No difference.

Shortened all transformer leads to minimum length. No difference.

At this point (blush) I disconnected my inputs and switched on again. Ah - a difference. Amp silent to half volume, then sudden onset of irregular valve noise - jittery, slightly whistling sound.

The reason I had not done this before is that my other valve amp, and my T-Amps were silent, and this was just a drop in. Seems they filter out the noise somehow.

OK - external problem. Disconnected most of the chain, leaving just input from the DAC straight into the Kit1. Sounds good - but the Kit1 volume very sensitive (must check the Beresford DAC output specs, but I'm pretty sure they weren't higher than 2). Maybe just my efficient giant horns with no power-sapping crossover. Volume levels seriously staggering for 1.8 watts (8ohms) what was I worried about. My daughter just in from other side of the house complaining it was disturbing her playing Guitar Hero!

Anyway, hum now acceptable, and not intrusive from listening position. But can't go on like this, because I need more inputs, and these are on the TVC ... so major tidyup of wiring. Reconnect chain. Run things with TVC volume high and Kit1 volume low. Much better.

Must look at house earth.

Amp still burning in ... listening impressions to follow, including A/B comparison with Charlize+Auricaps. Should be interesting.

Alan - Wish I could help more, I didn't have any issues with hum. To answer your question (sorry I missed it), my amp is very quiet. My 104db Klipschorns only have a slight hum at about 1:00 on the volume. That's about as quiet as one can expect from any tube amp I would suspect. More quiet than a Jolida I had when I first had the Klipsches.
My kit is not in a case, isolated from the sheet metal it sits on (may as well be sitting on wood, electrically speaking).

The only ground I did was to connect the third pin of the IEC connector to the circiut board connection (I believe was labelled gnd, the only open spot where the other power transformer wires go).

Finished mine last night, at about 2 oclock on the dial if I put my ear right up to the speakers I can hear a little hum, otherwise this thing is dead silent. So far... I'm in love. Though I will need to upgrade my speakers to something more efficient. Granted my current Klipsch Synergy B2's are 92db@1w I tossed some GEM at it this morning that has some really deep bass and the amp struggled with it if I turned it up past the 2 oclock position. Down to 1 oclock no problems and reasonable volume, this thing is awesome. After I get some more hours on it, I'll have to connect it up to my pre and see how things change.