On Thu, 31 Dec 2009 14:42:24 +0000, Ian Bell wrote:

snip
It also has some serious drawbacks.

1. Some god awful current spikes going up and down a longish cable
radiating crap all over the place.


I hadn't considered that - good point.

2. AC inside a box where I am trying to keep it out by having an
external PSU


That makes sense too.

Incidentally, I used a flying lead from the PSU and a socket on the
amp. Fixed socket: RS 487-378
Cable plug: RS 487-384
These have a wider pin spacing than octal, so I didn't have any qualms
about using them, even though Bulgin don't give a DC rating for them.
The HT was switched by a relay as you described above, with an
electrical interlock so that the relay couldn't pull in until the plug
& socket had made.


Funnily enough, those are precisely what I was planning to use and I
even bought a few pairs. Trouble is they do not lock and can very easily
be pulled out.

I am now planning on using an 8 way Speakon locking connector - a tad
more expensive but you won't be able to pull it out.


I just relied on the fact that I was going to be in the room while it was
switched on. :-) At one point I even had bare HT terminals on the OPTs -
just for the melodrama, you understand... "It's got lit valves - dare I
touch it?" :-D I put the connector on top of the chassis, with the
umbilical going off backwards. It's easy to see and doesn't pull out
easily at all, as it requires pulling the plug upward. I wonder if you
could take out the centre pin and fit a retaining screw in that position
somehow? That would be neat.

The Speakons would be fine, but you can still undo them without a tool.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
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