[Amps] Flashover and QSK board in TT Centurion

[Ignacy Misztal]

On 10/1/07, Jay Musikar <af2c at yahoo.com> wrote:
> There have been a few factory mods made to the
> Centurions(422) over the past 9 or so years apparently
> due problems:
>
> 1. The 2N3055A (Q1)on the Filament Board has been
> replaced with a more rugged 300 Volt transistor.

This part is OK as the no-signal current is OK (150mA)

>
> 2. Corona dope has been added the H.V. Board at the
> transformer secondary input.

Perhaps this is it!

>
> and
>
> The QSK board had to be replaced. A simple task.  The
> board runs about $60.00. Complete replacement may be
> the best way to go considering cost of and labor
> related to replacing individual components.
>
> The question should now be...Why are their failures
> occurring in the TT QSK boards?
>
> The TT factory (Amp Section) has been very helpful to
> many of us who are willing dive into the amps. Try
> calling and asking about the problem.  I'd be curious
> as to their answer.
>
> 73,
> Jay/AF2C

I called them and the QSK board is in the mail. One suggested cause
was a surge in mains. Perhaps it makes sense to periodically send the
amp to the factory for updates. This adds $100 in cost of shipping but
perhaps might reduces future failures. I hate packing even though I
have their box.

Ignacy