Would somebody be able to explain to me why a tube with a lower plate dissipation than 25W results in damaged MOSFETs in the power supply? Thanks in advance 
I've been sticking all sorts of tubes in with the amp, with most of them being no more than 20W plate dissipation... but no problems yet...
I've been sticking all sorts of tubes in with the amp, with most of them being no more than 20W plate dissipation... but no problems yet...
That is because tube failures tend to cause temporary or permanent shorts between electrodes, and the excess transient current can easily kill solid state devices that are connected serially to these tubes.Would somebody be able to explain to me why a tube with a lower plate dissipation than 25W results in damaged MOSFETs in the power supply? Thanks in advance
I've been sticking all sorts of tubes in with the amp, with most of them being no more than 20W plate dissipation... but no problems yet...
The plate dissipation in the TU-8200 is about 20 Watts. Screen grid voltage is also a limiting factor, which is often overlooked. Pushing tubes to their limits shortens their lifetime and increases the risk of failure. You have simply been lucky.
Thanks for the explanation!
Hypothetically, could one alter the “REF” reference voltage to run the target bias cooler? Say if I want to run lower dissipation tubes
I’m not too afraid of popping parts since i’ll be using the original OPTs out of my TU8200R (which was upgraded to the lundahl transformers) to build a clone of the 8200R which I intend to use for such reckless experiments. (as long as i don’t burn up the OPTs themselves)
Hypothetically, could one alter the “REF” reference voltage to run the target bias cooler? Say if I want to run lower dissipation tubes
I’m not too afraid of popping parts since i’ll be using the original OPTs out of my TU8200R (which was upgraded to the lundahl transformers) to build a clone of the 8200R which I intend to use for such reckless experiments. (as long as i don’t burn up the OPTs themselves)
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