• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Min 9-pin or 7-pin sockets to fit octal-sized holes?

ray_moth

diyAudio Moderator Emeritus
2004-01-27 8:55 am
Jakarta
If I have to use B9A or B7G tubes but my chassis already has holes and screw-centers for octals, does anyone know where I can get suitable bases to fit the holes? I've tried Googling but without knowing what search parameters to use it's like looking for a needle in a haystack.
 

ray_moth

diyAudio Moderator Emeritus
2004-01-27 8:55 am
Jakarta
Hi Poinz,

I haven't any specific use in mind right now but there are some 9-pin and 7-pin tubes that interest me, and the tube holes I've drilled in my chassis are for octal bases, with a couple B7G.

Right now, I'm using 6SL7, 6SN7, 6D22S and EL34 types, plus a pair of 6AU6s as CCSs. The results with these tubes are good enough but I love to experiment. The types I'm interested in trying one day include EF86 (or EF40), ECC40, EC91, 6DJ8/E88CC.
 
I'm with you, Ray,

I've been searching the manuals and datasheet sites for neglected gems and have come up with a couple real winners, both 7-pin. 6GK5 is a mongo driver tube that can do away with input tubes; rp=8K, gm=8.5S. 6T4 I'm using as a line amp tube; rp=1.8K, gm=5.6S. No sections-in-a-bottle matching difficulties, they're both teevee tubes, so when I asked my vendors, they said, 'We got millions, how many hundred you want?'.

There are some cool devices out there in the dusty bins, we just got to do our homework.

Aloha,

Poinz