Ceriatone Forum

British Style => JTM 45, 50 => Topic started by: sgmezei on February 04, 2013, 10:00:26 PM



Title: JTM45 BB, tubes and voltages
Post by: sgmezei on February 04, 2013, 10:00:26 PM
Hi folks,

I was contacted to fix this ceriatone JTM45 Bluesbreaker that has no output and some funky issues (voltages).
I replaced all the tubes except for the power because I didn't have a pair of KT66's. I put in a weber solid state rectifier. Still, no output

I will post all my voltages later today, but first I have some questions.

On this circuit, what needs to be changed to swap between different tube types?

What tubes are folks putting in these?

Thanks for your help team. I have built two overtones and a couple Weber kits but haven't worked on this circuit before.

Scott


Title: Re: JTM45 BB, tubes and voltages
Post by: sgmezei on February 06, 2013, 12:02:17 AM
VOLTAGES
V1 12AX7
1) 33.1
3) 0.27
6) 34.4
8) 0.27

V2 12AX7
1) 33.6
3) 0.08
6) 49.6
8) 33.8

V3 12AX7
1) 47.9
3) 2.87
6) 46.7
8) 2.87

V4 KT66
3) 66.2
5) -95.6
6) 66.2

V5 KT66
3) 65
5) -95.3
6) 66.2

V6 12AX7
1) 37
3) 0.22
6) 64.1
8) 37.9

V7 GZ34
2) 5.3
3) 1
4) 383
5) 383
6) 357
7) 357
8) 66.4 DC