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Hoffman Amps Forum image Author Topic: vibrolux reverb aa964 voltages  (Read 2717 times)

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Offline bakerlite

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vibrolux reverb aa964 voltages
« on: March 20, 2012, 08:24:14 am »
hey folks - would anyone mind throwing their eye over these voltages?

http://www.el34world.com/charts/valve/ValveData.php?e=view&f=12884

amp seems more distorted tha i remember  - there seems to be little to no clean tone if i am honest the break up doesnt sound to bad but it shouldnt be there so early.

Does anything jump out at you?

-   Valve   Pin 1   Pin 2   Pin 3   Pin 4   Pin 5   Pin 6   Pin 7   Pin 8   Pin 9
V1   12AX7   213   0   1.42   *   *   225   0   1.60   *
V2   12AX7   198   0   1.62   *   *   201   0   1.61   *
V3   12AT7   393   1.2   4.6   *   *   393   1.2   4.6   *
V4   12AX7   212   0   1.9   *   *   161   0.76   1.9   *
V5   12AX7   331   -9.9   -003   *   *   325   -.01   .1   *
V6   12AT7   260   56.2   111   *   *   269   59.6   110   *
V7   6L6   *   *   407   407   -39   *   *   410   *
V8   6L6   *   *   410   409   -37   *   *   409   *
V9   GZ34   *   414   *   333   *   333   *   414   *
Cheers,
Bakerlite

Offline sluckey

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Re: vibrolux reverb aa964 voltages
« Reply #1 on: March 20, 2012, 09:14:38 am »
V3-2&7... you show 1.2v but I'd expect 0
V3-3&8... you show 4.6v but I'd expect approx 8V

V4-7  ... you show .76v but I'd expect 0v

V7-8  ... you show 410v but I'd expect 0v. (got to be a reading/writing error)
V8-8  ... you show 410v but I'd expect 0v. (got to be a reading/writing error)
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline bakerlite

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Re: vibrolux reverb aa964 voltages
« Reply #2 on: March 26, 2012, 07:45:58 am »
cheers sluckey
It turns out the tubes (which were ummarked) were incorrect - on placing 'known' 12at7's in the correct sockets most was remedied.
And that way a typo for the 410 sorry!

what a tryeuly stunning amp these are had never had the pleasure of hearing a vibrolux reverb and this one despite tired caps sounds just amazing.
Cheers,
Bakerlite

Offline spacelabstudio

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Re: vibrolux reverb aa964 voltages
« Reply #3 on: March 26, 2012, 07:53:35 am »
AA964 is a Princeton?

Offline bakerlite

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Re: vibrolux reverb aa964 voltages
« Reply #4 on: March 26, 2012, 07:58:00 am »
well spacelabstudio you could be right but I am pretty sure i had the rights schems and layouts:


Cheers,
Bakerlite

 


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