Channel 1 hums

[primeholy]

Nothing but hum. Which preamp tube should I swap out first?

 

[Rkorn]

It's all in the manual. You can download it from MB website. Don't know each tube function without looking manual

 

[SteveO]

V1 and V3 are the two tubes that contain all the gain stages for channel one.

 

[primeholy]

V1 and V3 are the two tubes that contain all the gain stages for channel one.

Thanks.

 

[>Photi G<]

V1 affects all channels. If you are getting hum across the board, then V1 should be replaced; with an SPAX7 if possible.

V3A is the buffer amplifier for all 3 channels as well, but V3B is the final gain stage for CH1, so you will probably be fixed if you swap out V3.

 

[primeholy]

V1 affects all channels. If you are getting hum across the board, then V1 should be replaced; with an SPAX7 if possible.

V3A is the buffer amplifier for all 3 channels as well, but V3B is the final gain stage for CH1, so you will probably be fixed if you swap out V3.

Thanks Photi G. I replaced v3 and played for about 20 minutes or so and no problems. Oh, I did look at my manual Rkorn.....to make sure where v3 was :mrgreen:

 

[>Photi G<]

Oh, I did look at my manual Rkorn.....to make sure where v3 was :mrgreen:

:lol: Yeah, V3 is in that weird cluster of tubes behind the OT. Sort of hard to find, isn't it?

 

[fr0sty]

And a bi-otch to change. Do most of you pull the chassis?