Tube cross ref

[nitroturbo4u]

I'm bidding on some new tubes on ebay....Ending soon.
The blj 300 i have has 23js6 in it 1 driveing 4...
Everyone i have contacted has 20lf6 in theirs.
Anyone know if these will cross????
Thanks.:bored:

 

[Shockwave]

The 20LF6 tube has a little more dissipation and the filament is 20 volts rather than 23 volts. The pinout is nearly identical too. The one difference is some 20LF6 tubes have a pair of pins connected to the cathode terminal to support more current. One of these extra pins is not used on the 23JS6. In some cases the amp builder will make use of the blank pin on the socket. That can cause a short to occur and burn open the cathode connection inside the tube.

This is rare but I've seen it happen before. The pin is question was number 7 as I recall. Check your tube sockets to see what is connected to pin 7. If anything is connected it should be a short jumper between pins 2 and 7. It would also work with nothing connected to pin 7. If something else is connected to pin 7 and it's not a jumper to pin 2, you may have a problem.

I've seen people use these tubes in amps that were wired with pin 7 incorrect. To prevent damage the operator simply cut pin 7 off the tubes. I don't like this idea because you have to be real careful how you plug the tube in after this because it will fit two ways.