2A3 filament voltage...

[Ivan303]

That's a Vishay LVR03.  Those are more or less NLA, but you could use a Vishay AC series in parallel with it:

https://www.mouser.com/ProductDetail/Vishay-Draloric/AC03000004707JAC00?qs=sGAEpiMZZMtlubZbdhIBIBpEgVvVFfjkwWNI4DU7AcM%3D

Thanks and done.

 

[Paul Birkeland]

A higher voltage rated capacitor on the socket from the same series will also usually trim the voltage up slightly.

 

[Ivan303]

A higher voltage rated capacitor on the socket from the same series will also usually trim the voltage up slightly.

 
Oh NO!  Please don't start me Cap Rolling again!!!    OK, it's a reasonably priced electrolytic so...

Last pair of caps I rolled into these amps cost me $100!  But worth it.  Generally, I don't expect much difference with coupling cap changes, be they film cap to film cap, but those green Solen Teflon caps are magic.  Smooths out the top end while still providing plenty of detail.  For the most part I find with 'smooth' and 'detail' you can only have one or the other while the Teflon seems to allow one to have both.

 

[Ivan303]

Line voltage seems to be between a low of 119.4VAC to 123.5VAC over the last days (most of this during the day time but more measurements will be done for sure.

With a .56 Ohm 3W  ww resistor added in parallel with the existing 0R10 3W ww AND an additional Nichicon 10,000 ufd 12V electrolytic in parallel with the existing Cap, I get a heater/filament voltage of 2.521VDC when the line voltage is 121.5VAC.  We'll see what the filament voltage drops to if and when the line voltage drops to 119.5VAC or 120VAC later tonight.

Line voltage is about 121VAC +/- 2% and that puts us pretty much 2.5VDC +/- 2% so we are fine!