Tubes

[Johnandjohn]

I have a very old tube radio receiver. The receiver has a 6v6 tube amplifier. One of the 6v6 tubes is CBS JAN tube, another is National Union JAN 6V6. I search but found little information on the CBS and National Union Jan 6V6 tubes.
My questions are:
1. How are CBS and National Union Jan 6V6 rated? Are they good tubes?
2. Obviously they are not matched 6V6 tubes. Is it really worth of buying another pair of 6V6s?
3. Can I expect a significant increase in sound quality of the 6V6 amp by getting a pair of RCA tubes?

Thanks for the advice.

 

[kvflyer]

I have a very old tube radio receiver. The receiver has a 6v6 tube amplifier. One of the 6v6 tubes is CBS JAN tube, another is National Union JAN 6V6. I search but found little information on the CBS and National Union Jan 6V6 tubes.
My questions are:
1. How are CBS and National Union Jan 6V6 rated? Are they good tubes?

Those tubes are OK as long as they are not worn out. For that matter, if they look to be made of similar construction, they may have been made by the same manufacturer. Many tube companies bought tubes from their competitor and branded them with their name. RCA 7591 tubes were made by Westinghouse or Sylvania. JAN stands for, "Joint Army Navy". That means that the tube was made to military specifications.

2. Obviously they are not matched 6V6 tubes. Is it really worth of buying another pair of 6V6s?

It depends. If they test strong, no reason to replace them. However, I guess you would need access to a tube tester.

3. Can I expect a great increase of sound quality of the 6V6 amp by getting a pair of RCA tubes?

Only if your present tubes are defective. Often times the problem with vintage amplifiers are coupling capacitors and electrolytic filter capacitors. Tubes are farther down the list.

Thanks for the advice.

Hope that helps. I am trying to be very objective and not confuse the issue. Keep us posted, do some follow-up!