You need a crowbar to pry them loose. Never had any problems. In my EL509 things get very hot. No problem whatsoever. Mine is not heat resistant AFAIK.
I've heard of heat resistant silicone too though. Up to 200,300 or even higher.
Edit just did a search. Normal silicone sealant can handle from minus 40 up to 180 celcius.
I've heard of heat resistant silicone too though. Up to 200,300 or even higher.
Edit just did a search. Normal silicone sealant can handle from minus 40 up to 180 celcius.
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Bas Horneman,
Your project appears to be moving along.
In reference to your Post # 83, I agree, a high voltage delay and or soft start circuit is a pretty good idea.
(Normally, I use circuits that do not need delay / soft start).
But you have a slow warming EL84 filament & cathode structure for the input tube, when the tube is cold, the plate voltage is at B+, and then you DC couple [that B+] to the 2A3 grid,
With the fast warm up filament of the 2A3, it can be a power-up problem (here comes your HV delay & soft start . . . to the rescue).
I had a friend that had an input stage with filament & cathode, that was DC coupled to the 2A3 grid.
At power-up the 2A3 plate current was over 200mA!
Ouch!
Some special circuitry solved that problem.
Your project appears to be moving along.
In reference to your Post # 83, I agree, a high voltage delay and or soft start circuit is a pretty good idea.
(Normally, I use circuits that do not need delay / soft start).
But you have a slow warming EL84 filament & cathode structure for the input tube, when the tube is cold, the plate voltage is at B+, and then you DC couple [that B+] to the 2A3 grid,
With the fast warm up filament of the 2A3, it can be a power-up problem (here comes your HV delay & soft start . . . to the rescue).
I had a friend that had an input stage with filament & cathode, that was DC coupled to the 2A3 grid.
At power-up the 2A3 plate current was over 200mA!
Ouch!
Some special circuitry solved that problem.
It's alive. The quietest amp I've ever built! My son who can usually hear the hiss, buzz or whatever... cannot hear anything from 50 cm's! Only around 10cm from the compression driver does he hear some slight hiss. He was baffled....thought it was off. This is my first parafeed amp.
Coupled it straight to my dac because the pre has an occasional issue.
The bad news is that I've never had or listened to a 2a3 based amp before. So can't compare. But so far it sounds very sweet and natural. But also clean. My kids are saying this is next level.
Quick picture in its makeshift place so I could have a quick listen.
Coupled it straight to my dac because the pre has an occasional issue.
The bad news is that I've never had or listened to a 2a3 based amp before. So can't compare. But so far it sounds very sweet and natural. But also clean. My kids are saying this is next level.
Quick picture in its makeshift place so I could have a quick listen.