Operating Point and Loaded Impedance of 1/2 JJ ECC99

[WFCkeyman]

Hello!
Anyone has built an ECC99 (1/2) linestage with an output transformer? What are the operating point and loaded impedance would you recommend?

Thanks!

 

[NickKUK]

Not a LS op point but Broskie targets ECC99 at 24mA for OTLs.

 

[jhstewart9]

Hello!
Anyone has built an ECC99 (1/2) linestage with an output transformer? What are the operating point and loaded impedance would you recommend?

Thanks!

To keep D% low, triode load should be at least 4rp. The JJ spec sheet sez rp is 2.3 K when Ip is 18 mA. So Rl of 10K would be OK.

 

[Koonw]

I have 9k loadline drawn up, hope it might help if you want to draw you own.
http://nutshellhifi.com/Raven-MarkII.gif