Keep loosing smoothing cap on OD tube

[Blind Lemon]

I'm using the tweeked build and it will sound get for a while but I have lost 2 silver mica smoothing caps on pins 6 to 8. The caps are rated for 500v I have never had this problem before. Any thoughts?

BL

BTW the plate voltage at pin 6 is right at 200v

[overtone]

there was a run of failing 500V silver mica caps over here in Germany about eighteen months ago. No one got to the bottom of it, but there was a consensus that you have to be really careful with the heat when soldering them now. A bit like with the Styroflex caps.
I prefer the older domino type of mica caps, if one can get the voltage rating.
Best, tony

[Structo]

First I heard of that, good to know.

Blind Lemon, how are you determining that they are going bad?

[Blind Lemon]

Structo, They are leaking voltage. I can lift one leg and the channel comes back, found it by only having about 35v on the plate of that triode and the other side having normal ~200v on the plate. The OD channel was not workings, you can guess, happened 2 times in about a month.

Overtone, thanks for the heads up, I hate to throw these away but I can,t have this happening.

I'm going down to a local parts place today and see what they have in stock.

BL

[Structo]

I'll have to check mine, because it seems my OD volume is down a bit.

[Blind Lemon]

Went and got some new ones this morning and letting it burn in for a couple of hours.

Will let you know.

BL

[Blind Lemon]

Cooked it for about 3hrs and played it for another 45min. Working good, hope that did it.

BL