Unfortunately I do not. I think it is a matter of taste whether you like one or the other. Also I've only tried the tungsol 6550 so that could also skew the results.
Out of all the tubes that I have/have tried, the 6550 tungsols are my favorite.
Out of all the tubes that I have/have tried, the 6550 tungsols are my favorite.
KT88 is overkill for TU-8200. It works, but not in its most linear part of the transfer curve. This amp is shipped with 6L6GC for reason.
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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Do not change REF voltage as it can cause auto bias to fail. The plate current is approx. 72 mA, which is set by R19-R22. The current is almost inversely proportional to the value of these resistors.Hypothetically, could one alter the “REF” reference voltage to run the target bias cooler? Say if I want to run lower dissipation tubes