Re: Help - B3 Intermittent loss of highs and intermittent hum

[Marco Montaruli <genpla@flashnet.it>]

At 13:13 29/12/95 -0500, edpayne@infi.net wrote:

>My B3 intermittently cuts out, best described as a loss of highs, diminished
>volume, and sometimes accomp'd by 60Hz hum (but not the steady "wire broken"
>variety).  Audio injected into the "phono" input suffers a similar fate, which
>leads me to the conclusion that the problem lies from the 12AX7 - 12BH7 onward
>including the Leslie 122.  I have replaced/substituted all tubes including
those
>within the Leslie with no relief.
>
>Interestingly, "thumping" the start switch aleviates the problem (it may
>intermittently return later) -- although I suspect this is due to injecting
>a big transient into the system, not any correlation to the start circuit.
>
>Has anyone out there dealt with a similar problem on a B3/C3/ect?
>
>Many thanks in advance from a new subsriber.
>
>edpayne@infi.net
>  Hello, my name is Ed and I'm a wheelaholic.

Ed, I have a similar phenomenon on my A-162, but didn' try "thumping".
It happens if it works for 2 hours or more, and is always accompanied by a
"bump" when I switch the leftmost tablet ("volume") to soft or normal.
Do you experience this too?

It normally lasts for about 10 to 15 minutes, then everything returns normal.

Changing tubes didn't fix it, and Leslie is not responsible: sound from
internal amp has the same noises.

Any help from listmembers?


  _____________________________________________________________
  Marco Montaruli, General Plastics - Rome <genpla@flashnet.it>