What EL84 tubes do you like?

[6A3sUMMER]

Possibly an honest mistake regarding the SV83.

Reminds me of the honest mistake of the Svetlana 6N1P data sheet.
They swapped the numbers of the transconductance, Gm, and the plate impedance, rp.
The usable area of the plate curves, at legal plate dissipation, shows a much more accurate Gm and rp, versus the
typographical errors for Gm and rp.

 

[stenak]

Anybody out there who have ordred tubes from Ukraine in the last couple of weeks? I got a package just a couple of days before the war started.

 

[radiotron]

Do you have a schematic for this screen supply?

Here's a drawing from notebook, very simple, just make sure to use a N-channel enhancement mode MOSFET with gate protection diodes, I used a 2SK3563 because I had some. And use a carbon comp for gate stopper. Adjust zener string to suit voltage reqd , remembering that ~4volts less out due to VGS drop.

 

[radiotron]

Very interesting! Am I understanding correctly the difference was positive - that you prefer the sound of your Tubelab SPP with “stabilized screen voltage” in Pentode connection over the Ultralinear connection?

Yes, I think it works better than UL in my amp, and it makes for very stable operating conditions for the tubes, noting that pentodes are "programmed" for plate current by screen voltage, and the self compensating nature of cathode bias. I used 330ohms per tube for Rk, for plate dissipation of ~10 watts using 330V plate supply and just under 300V on G2.

 

[Francois G]

Here's a drawing from notebook, very simple, just make sure to use a N-channel enhancement mode MOSFET with gate protection diodes, I used a 2SK3563 because I had some. And use a carbon comp for gate stopper. Adjust zener string to suit voltage reqd , remembering that ~4volts less out due to VGS drop.

I don’t see a drawing. Forgot to attach it, perhaps?

 

[Steve Morley]

for you guys in Europe soviet.vintage.electronics.shop (on eBay) in Romania has Russian EL84 equivalents. I bought some 6P3S-E from him. Not exactly cheap but good, well matched NOS shipped quickly.

S.

 

[radiotron]

I don’t see a drawing. Forgot to attach it, perhaps?

I did a drag and drop in the browser, looks like it didn't stick even though I can see it now. Sorry about that, now a proper attachment.

 

[alain98]

Thanks Radiotron!

 

[huggygood]

for you guys in Europe soviet.vintage.electronics.shop (on eBay) in Romania has Russian EL84 equivalents. I bought some 6P3S-E from him. Not exactly cheap but good, well matched NOS shipped quickly.

S.

I have done well to stock up in recent years!😬

 

[OldHector]

Everyone talks about how NOS EL84 are multiples of the price of modern tubes, but 8BQ5 and 10BQ5 NOS can be had for around 7 bucks? If NOS makes a difference (and I think it does), then aren't these an option, with an extra heater transformer?
Tube Depot 10BQ5

 

[kodabmx]

Even a crappy Delon would make 10V from 6V although you might run out of current.