Help needed please

[e_fortier]

Hi

I’m about to buy a pair of 6C4C tubes and the seller is giving me the choice between the following 4 pairs, I’ve selected 1964 but I’m wondering if I made the right choice…any feedback would be great.

1962 - 51 mA
1962 - 52 mA

1964 - 57 mA
1964 - 62 mA

1959 - 40 mA
1961 - 38 mA

1957 - 58 mA
1962 - 55 mA

Eric

 

[Positron]

Same brand pairs? Single ended or PP? 1964 has greatest emission and probably closer to new specs. In PP,
all would balance close enough, unless high speaker sensitivity, if B+ is filtered properly.

I would not worry about it. If need be, and PP, balance the cathode currents for minimum hum. If SET, balance
for equal output for balanced channels.

cheers

pos

 

[jan.didden]

Aside from the practical implications, why did you select the worst matched pair?
What is the reasoning here? Just curious.

Jan

 

[e_fortier]

Thanks for the answers, I had selected the 1964 because they seemed the less used from the bunch. This will be for single ended.

 

[grataku]

The eye is a very poor tube tester. I would have picked 1962.

 

[kevinkr]

I would have made the same choice as grataku.

 

[e_fortier]

Tubes were not shipped yet so I changed it to the 1962.
Thanks 👍