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In the Forum: Audio Discussions
In the Thread: Initial thoughts about new/old Lamm ML2s
Post Subject: Socket removal etc.Posted by jessie.dazzle on: 6/22/2010
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skushino wrote:

"...I was operating my amp around 275mA for the same reason as you, to have a margin before V2 runs off the cliff..."

About that cliff... As a result of not fully backing off the plate current trim pots (thinking a few turns would suffice) when swapping out V1/V2 tubes, I once accidentally allowed an old V2 tube to be driven to 900mA for a very short time (the phone rang while the amps were nearing the end of their soft start phase). When I returned, one half of one of the tubes had become a very bright orange; but surprisingly did not fail. Lesson? Backing off a couple or even a few turns is not always enough; best to be safe and back the plate current all the way off when changing these tubes.

"...If I understand you correctly you are referring to crushing / breaking the old sockets for removal?..." 

Correct.

"...I think it's easier to simply remove the wires and four screws, then removing the old socket is straightforward and simple, without having to destroy it and having to remove debris..."

Yes, for the 6C33C sockets.

"...The other (non-6c33c) tube sockets might be more 'interesting' to replace - at least it looked more difficult to me.  These sockets are attached directly to the board, without direct access..."

I have not been inside the ML2 amps, but you are not the first to mention limited access, but in replacing the sockets on an L2 pre-amp for example, I see this crushing as the best technique. I would say the same holds true for any board-mounted component having multiple "legs"; if it is not possible to crush the component, its legs can sometimes simply be cut before unsoldering. I guess I have a fetish for neat solder work.

"...Will post here if the problem doesn't go away..."

I'd be interested in knowing your results in either case.

jd*

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