6973 tube question

zincman

Active Member
I have an read that 6973 tubes can be substituted with 6cz5 tubes. My question is I know the 6cz5 has to be jumped to work but since the plate voltages are different will the 6cz5 overheat? Is there other subs to use? I have found the 6cz5 has several subs to it, would it be safe to try them? Thanks in advance
Tim
 
What matters isn't the max plate voltage for the two tubes compared with each other, but if the max plate voltage (or plate dissipation in watts, or ...) for the circuit you want to use them in.

The 6973 (which is a cool tube!) may not have been pushed for plate voltage in your circuit. So... what's the circuit?

I can only name a few units that used that tube. Knight made some, some organ amps used them, and some recording units...
 
I have also read about converting the circuit over to use EL84 or 6V6GT. Can someone provide some insight into how hard this is for a novice or should I just send out to have it done.
Tim
 
I have used 6L6GC as a sub...seemed to work O.K. Mounted the 6L6GC's on an outboard chassis. I don't think 6V6 or EL84 has enough plate dissipation capabilities to sub for 6973. However I think there may be a new 6973 being made (Electro Harmonix?). 6973's are used a lot in jukebox amps.
 
Chad thanks for the info EH does have a 6973, I have never been real impressed with their tubes but at $29 a pair sure beats NOS prices. Thanks again
 
zincman said:
I have an read that 6973 tubes can be substituted with 6cz5 tubes. My question is I know the 6cz5 has to be jumped to work but since the plate voltages are different will the 6cz5 overheat? Is there other subs to use? I have found the 6cz5 has several subs to it, would it be safe to try them? Thanks in advance
Tim


6CZ5 & 6973 are identical except for the pin 1 to 8 jumper. The difference in the ratings is due to 6CZ5 being rated as a TV tube rather than for audio use.
6CM6 works in place of some 6973 in some cases, same jumper issue, depends on how hard the tube is being run. Many later 6973's looked just like 6CM6.

Replacing with EL84 is a socket-wiring and biasing issue, in some cases it's not easy to rewire the socket, but I've known a few Europeans to do it in jukeboxes they imported from the USA, despite the sockets in some Seeburgs being turret sockets jammed down in between vertical terminal boards...

I've got about 100 NOS RCA 6973's, but we want a little more than $29 a pair for them ;-)
 
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