45 TSE Checkout Fail

[beeah]

Originally Posted by Alan Hope

Some background hum - hopefully casework, motor-run cap, will reduce that significantly.

Glad to hear you got it working.

I too just got a TSE 45 up and running, and I was disappointed to hear so much background hum, despite that fact that it made beautiful music. I replaced R4 with a 8H choke, and the hum has disappeared. YMMV, but I'd give that a shot before doing anything else.

[Alan Hope]

Originally Posted by beeah

Glad to hear you got it working.

I too just got a TSE 45 up and running, and I was disappointed to hear so much background hum, despite that fact that it made beautiful music. I replaced R4 with a 8H choke, and the hum has disappeared. YMMV, but I'd give that a shot before doing anything else.

THanks ... but I had a choke installed from the start. Adding the motor-run cap has made no difference. The whole thing is a breadboard tangle of wires at present - plenty of scope for hum. Anyway I will do the casework now, get the earths properly sorted, then see where I stand.

The music is sublime though! This will be worth it.

[jrobson]

Well done, how far are your OPT's from your input transformer and choke?

[Alan Hope]

Originally Posted by jrobson

Well done, how far are your OPT's from your input transformer and choke?

Transformer is at 90° to OPTs, they are in a line, fairly close - just as they are in many commercial / diy SET amps. Choke fairly close by, not much option on the breadboard. Inputs are twisted. Still got a multi-meter attached to B+.

I'm not going to systematically chase hum until these are all mounted on a sheet of aluminium with the power components on the left, OPTs on the rear, input paths well away from power components, and earthing properly done. I remember spending ages going through all this with my previous amp - it was a revision to the grounding which solved it there.

I won't be able to start casework until next week. Got the aluminium sheet and a set of drill-bits for the various holes required. Same basic construction as my previous amp, so I'm on familiar ground.

Previous amp:

External:



Internal:



Will post progress here ...

Alan