Bee Pre voltages for PJ

[xcortes]

Took me much more than expected but here's some different tube data (filament/filament/plate):

TJ globe 5.2/9.9/143
TJ globe 5.0/9.8/124

EH 5.2/9.9/112
EH 5.1/9.8/115
EH 5.1/9.9/94
EH 5.2/9.8/105
EH 5.1/9.9/105
EH 4.9/9.8/98

Saludos

[xcortes]

One of the tj is dead, i guess that's why the plate v reading is so off. Still the filament voltages are relevant.

[Paul Joppa]

Thanks, everyone - that data so far will be a big help. I'll review the data and see if I can come up with any improvements.

Xavier, the 6A3s seem to be a bit greedy for current; they are running a bit low on voltage. As long as they are relatively new that should be OK, but if they are getting worn I would make adjustments before running them for a long time. The low plate voltage indicates they still have plenty of transconductance - have you listened to them carefully yet?

[xcortes]

You mean low on voltage on the filaments right? I plan to add a resistor in parallel to the 4 ohms to reduce the 4.2 volts to 3.7 or close to. They are NOS and no, no detailed listening yet, just finished the amp a couple of hours ago.

[keto]

Hey Xavier, which TJ's do you have?

[xcortes]

Some years ago I purchased a pair of 300B amps (sorta Parabee clones) for the iron. You have that iron now (050 Ni and exo 03). They came with a pair of tj 300b. These are identical to your pair although 5v instead of 2.5.