813 trioded Datasheet and curves

[vega65]

Hello
I am looking for datasheet and curves for the 813 trioded.It seems to be a little hard to find.I have found some old links but they are all dead...

[Bas Horneman]

They can be found on my site

http://basenjes.de/tubes/813.htm

[vega65]

Wow thank you so much for a very fast reply. I am writing on my mobile phone . On my way to the mountains for a quiet weekend . I am about to check out the possibilities for making a se amp with this tube .will return with more about the project later

[Bas Horneman]

Enjoy your weekend!!!

[andyjevans]

I too am waiting to build an amp with the 813.

One of the big questions is AC or DC filaments.

DC filaments are going to be 50 watts, so think BIG heatsinks and corresponding ss devices.

Who can offer opinions on whether AC will hum too much?

My speakers are about 86db efficient so hum might just about be inaudible.

Ideas?

andy

[Gluca]

Originally posted by andyjevans
I too am waiting to build an amp with the 813.

One of the big questions is AC or DC filaments.

DC filaments are going to be 50 watts, so think BIG heatsinks and corresponding ss devices.

Who can offer opinions on whether AC will hum too much?

My speakers are about 86db efficient so hum might just about be inaudible.

Ideas?

andy

mmm ... CLCL filtering doesn't need heatsinks

[andyjevans]

Originally posted by Gluca



mmm ... CLCL filtering doesn't need heatsinks

So for a PP amp I need 4 chokes just to start with, and 8 chokes for CLCL.

Any idea what size in Henries and where I get these things? I know current is 5 amps, but what value in Henries is large enough to be useful? Farnell just lists CMCs at up to 3 mH which doesn't sound very useful.

Andy

[Koifarm]

I have a 813 se amp and it has DC heater supply.

[rdf]

Hi Koifarm. Is that amp of Asian manufacture? The picture suggests the outputs are the massively heatsinked FU-13 variant. How do you like it?

[hemgjord]

Hello

I am also planning to build a trioded 813se. I have been using Paul's curves when doing the basic calculations (many thanks 7N7)
As I wasn't sure about the status of my tubes and they are after all Philips QB2/250, listed as eqvivalent to 813 but you never know...AND I am planning to go A2 as well so I started to measure a set of curves myself.
(If I could just figure out how to post files here I could share them. Anyone knows why some members have problems posting files. Yes they are smaller than 100K and they are .jpg and should be OK)
The curves are generally somewhat "less steep" than Pauls. If this is because the tubes are used or because they are QB2/250 I don'know. (I have four pieces from at least two sources and they all measure within 5% from each other.)

One interesting thing is that I do not see the somewhat strange tightening between the curves VG=0 and -10. There IS however some 0,5-1 mA grid current at Vg=0. So a low impedance driver with no caps is recommended if you want to get "full" A1 power.

I am also interested in the heating issue, if anyone have any good ideas, without cooling fans and the need of forklifts for installation, please share them.
I will start breadbording with AC filaments so if you aren't in a hurry I will post some feedback o hum levels when it's done. (don't have too much spare time right now)

/Olof