@imhififan i am in the the-lesser-the-better camp. So, I think I will try adding the diodes first. Thanks for the info though.
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There won't be another tube rectifier that will work better. The problem is that this circuit is designed to expect the voltage drop that exists with the 5U4 at the current at which its operating.
I gave you a range of capacitor values. But to be clear:
replace the 220uF units with 47uF. Replace the 100uF units with 22uF.
Once this is done you'll find additional diodes to be moot. They may also cause commutation noise by interacting with the inductance of the power transformer winding, which can manifest as an annoying low level buzz. If it were me I wouldn't bother and instead work on correcting the problem.
@atmasphere Thanks for the info. I think so will experiment the diodes approach first, because it is cheap and easy enough to do it myself. It is also a good learning experience for me. At the same time, investigate on changing the capacitors. It seems it is not too difficult to do as well, if the size are the same.
decay - Are you offended? Your multiple comments here were of no value. I was not commenting on you, as I do see that you do make valid contributions occasionally. My comments were meant to encourage imhififan and atmasphere to contribute more often. I have a lot of respect for both of them.
My 2cents - Seems clear that this an inrush current problem, which reducing the capacitor values would help to reduce. It has been my experience that reducing power supply capacitance does usually negatively affect low frequency capabilities. If I were going to reduce the cap values, I would not reduce more than necessary. Say from 220uf to 100 instead of going all the way down to 47uf. The diode idea was excellent. How about doing both, diodes and just the 220uf caps to start with?
A few years back I built an ANK Kit-1 300b stereo power amp.
The rectifier tube arked upon power up. I contacted ANK’s builder at the time and he suggest trying a new EH 5u4gb. Told me to buy two or three cause one might ark even new, so throw it away (and any other rectifier tube that arks at startup).
I bought three and only one arked at startup. I marked it and some others but never threw them away lol.
It’s been working fine ever since although I don’t use it constantly.
I did notice shortly after that ANK started including the EH 5u4gb with their kits. But that was then.
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