Kit 6550 documentation

[Revoli]

Hi
Can anyone send me the documentation for the WAD KIT6550 amp. I have managed to lose my original (with all my notes of mods etc etc). I would really like the full doc with all the test data et al as it’s been a while since lifted the lid on this. Needs a bit of maintenance generally too.

[Richard]

Well, hello again and welcome Revoli, good to see you back!

If you send me your direct email address via a personal message I'll send the stuff you need (PM doesn't allow attachments).

The test data etc is there and the tune up article but I'd caution about the Jensen (or any) paper in oil capacitors from that era. They were popular then (10-20 years ago) but we've had reports of them and other paper types leaking both physically oil and electrically.

In many applications they are used to couple the AC music signal but also to block the DC HT voltage. In a valve amp if the DC leaks it will "turn on" the following valve causing it to over-run. Worse, in extreme cases, the primary of the OPTX may fail due to the excess current. So if you have these fitted do at least check them carefully with a DC voltmeter