Are these vintage vacuum tubes suitable.....

[69CamaroSS396]

for using in amplifier circuits? I had the good fortune(?) to get these at work before they were tossed in the dumpster. As a relative newcomer to DIY, and hoping to progress to building amps for my personal use, I am curious to know if any of these are good candidates. All are NOS. I have six 812A, 4 RCA and 2 GE, which I believe are RCA made. I have two GE 1623(pre WWII, in original boxes), two GE GL-809, two GE 10Y(ultra rare, I hear), and two Tung Sol 53. I did a search and found a couple of references, but nothing too in depth.

Thanks for any help!

[Eli Duttman]

The type 10 is a nice tube. I had the opportunity to hear them at NY Blast 2000. You need SERIOUSLY efficient speakers, as the available power is under 1 W.

TDSL is a terrific resource for obtaining info. about tubes.

The 812As seem to have potential in a SET amp. However, that project should wait until you are EXPERIENCED. A 1.5 KV. B+ rail is truly DEADLY DANGEROUS.

[arnoldc]

I love the 10Y! I use it in one of my amps and has this tonal character that is so nice and matches well with my Altec 406-8Y based speakers, which according to Altec documents are just 96dB efficient. They can rock, and loud!

[Zoran]

Hi,
10Y can deliver 1.8W
I listened 10Y with 6J5GT at input SE amp and gas rectifier i think AX50
was maybe the best...
output transformer was realy huge and from excelent quality (low capacitance, very high primary inductance more than 100H...)
off course hand made
(10 is similar but different type)
also is very interesting for the preamplifier design...
thanks

[Miles Prower]

Originally posted by 69CamaroSS396
I am curious to know if any of these are good candidates. All are NOS. I have six 812A, 4 RCA and 2 GE, which I believe are RCA made. I have two GE 1623(pre WWII, in original boxes), two GE GL-809, two GE 10Y(ultra rare, I hear), and two Tung Sol 53. I did a search and found a couple of references, but nothing too in depth.

The 809s might make a good choice for Class A2 SET monoblocks. They'll need a positive bias voltage to establish a useable Q-Point for SE audio amplification. Drive 'em with a DC coupled MOSFET driver and these just might be real good.

The 812s, however, will probably have to be used as Class AB2. In SE they need a rather high Zl= 8.6K. I was going to use them for a Class A2 SET, however, Jack at Electraprint couldn't guarantee that gapped OPTs that can match 8600 : 8.0 would perform up to Hi-Fi standards. Although, as a SE guitar amp, it just might have something. PP 812s would make one helluvabig audio rig. Just might be the thing if you need lotsawatts.

As for the rest, see Frank's

[rcavictim]

As Miles postulated, the 809 can indeed be employed successfully in A2 SET mode. The amp in my avatar is of my own design and employs SE 809`s in A2 with DC on all the heaters and it connects my loudspeaker voice coils to a tone source in heaven. 3.1 watts RMS per channel with 18 watts PD (which runs the 25 watt tube nice and easy). I drive them with a step down interstage xfmer. You could use your 10Y as a driver with an IT. I use a 1619 in triode mode. My circuit is unusual. You could call it a monkey, parafeed, ultrapath. I prefer to call it magic.

[69CamaroSS396]

Thanks for all the great responses.! I really appreciate the help.

How cool is this forum?