ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

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

Re: 7199 and 7408 tubes...is anyone familer with these??

11/15/1998 7:40 PM
Graywater
email
Re: 7199 and 7408 tubes...is 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.  
 
Pinout:  
 
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.  
 
GW