WAD6550 (kat) fuse blowing

[KC Jones]

My WAD 6550 recently started blowing fuses, so I replaced the standard one with a higher rated fuse 3.2a I think, but this also belw.
A quick call to Bob Orbell and I dropped the offending object off with him as I passed his front door.

After removing a couple of resistors, one which was knackered affecting one f the rectfier valves and fitting a higher rate fuse; next day it was fixed.

sorry about the lack of technical content, maybe Bob will elaborate.

I finally got around to plugging it back into the system last night. Ah, thats the sound I remember, god knows how long it has been off sync but it's amazing what you don't miss after a while.

So a big thanks again to Bob for fixing it for me, excellent work.

Bob also made 4 feet for it (machined aluminium, with rubber inserts) the 6550 now sits in silence and doesn't budge an inch, far better than the wooden feet that were fitted previous, causing hum and vibration.

....and you should see his home made speaker stands, simply stunning!!

Cheers Bob.
Many thanks - Kevin

[bob orbell]

Thank's Kevin, so glad all is well, to explain, KC Jone's told me his 6550 kept blowing fuses, a quick check of the transformer pri. revealed no nasty's, so a 2 amp fuse was fitted and powered up with a variac, no fuses blowing, but one rec. valve very hot, a look inside reviled balancing resistors on the AC side of the rec. valves, two of which were OC, as a result the amp. was working on half wave DC, so the other two resistors were removed, I had no 2 amp antisurge fuses so fitted 4amp quick blow, a reading of current draw was 3.2 amps switch on surge, settling to 1.3 con. This may help Luca in Italy, as he has posted a problem with his 6550. BOB