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previous: Trace Hi all! I have an old tube... -- 11/15/1998 6:29 PM View Thread

Re: 7199 and 7408 anyone familer with these??

11/15/1998 7:40 PM
Re: 7199 and 7408 anyone familer with these??
Trace: The 7408 is an industrial version of the 6V6 - sort of a 6V6WGT. I don't know if an "A" version of the 7408 was made, if so the dissipation is 14w, if not 12w.  
The 7199 is a high-quality audio triode/pentode in one envelope and I can't think of any reason to replace them with 12AX7s unless the sockets are empty and your are having trouble finding the 7199s - if you've got the tubes they are probably US made and better quality than the current 12AX7 production.  
1- plate, triode  
2- plate, pentode  
3- screen grid, pentode  
4 & 5 heater  
6- cathode/suppressor grid, pentode  
7- control grid, pentode  
8- cathode, triode  
9- control grid, triode  
The triode section has a mu of 17 and the pentode has a transconductance of 1,500 - 7,000 umhos depending on circuit design.