GU50 Push-Pull version1

[Kay Pirinha]

primary (Raa) 14K
sec: 8

What a pity you made that mistake while ordering your iron.

A plate-to-plate load of 14k seems to be quite a lot for a pair of GU50's running at 650 volts. But perhaps you could get closer to the optimum by connecting your OPT to a 4 ohms load? Try it!

Best regards!

 

[matejsirk]

What a pity you made that mistake while ordering your iron.

A plate-to-plate load of 14k seems to be quite a lot for a pair of GU50's running at 650 volts. But perhaps you could get closer to the optimum by connecting your OPT to a 4 ohms load? Try it!

Best regards!

B+ was around 430V - see the post 14. Triode straped GU50. That amp I built 6 years ago - I was still novice in tube world.
There was custom build OT - toroidal. The guy who wound transformers ask me if I need 3.5K per tube or Raa. I told him per tube. Thats why Raa 14K. Sec was only one tape - 8.

 

[jazbo8]

What he meant was by using a 4 Ohm load/speaker, it lowers the primary impedance to 7k, which might be more suitable for the GU-50's.

 

[piano3]

3.5k per tube seems quite reasonable; why should matejsirk want to raise distortion by halving it?

 

[flint45]

How many GU50
tubes could your driver cope with?

 

[matejsirk]

How many GU50
tubes could your driver cope with?

Which schematic?

 

[odilon_df]

GU-81

I have the same experience. In my Bass Amp with 6 GU50 I have 950V of B+ (Idle), the resulting output power is 320Watts. Schematic is attached for info.

Do you think a possibilite to use only une pair og Gu-81 (I vave a pair for a long time....