Re: Battery bias directly to grid

In article <4353775E.5B755A29@xxxxxxxxxxxxxxxxxx>,
Patrick Turner <info@xxxxxxxxxxxxxxxxxx> wrote:



> But the transients you speak of don't occur any more than with any other
> biasing method.
>
> Patrick Turner.
>


With the Dact 20K input attenuator, and a +2.4 volt dc source connected
to its wiper, you will see something on the order of a few tens of
millivolts being generated when changing the gain setting at the low end
of the attenuator. Feeding this to the input of a dc-coupled power amp
will give you low level, audible transients. Not a deal breaker, but not
good design practice.

Switching the attenuator from its lowest gain setting to off, or vice
versa, will give you a 2.4 volt step signal into your input. I would
call this a rather large transient, and not especially good for the
health of any speaker attached.

-bruce seifried
.

Relevant Pages

  • Re: Battery bias directly to grid
    ... >> millivolts being generated when changing the gain setting at the low end ... >> will give you low level, audible transients. ... >> Switching the attenuator from its lowest gain setting to off, ... and then it will rudely drop to zero volts. ...
    (rec.audio.tubes)
  • Re: Battery bias directly to grid
    ... > With the Dact 20K input attenuator, and a +2.4 volt dc source connected ... > millivolts being generated when changing the gain setting at the low end ... > will give you low level, audible transients. ... I don't understand how switching gain settings changes the tube bias; ...
    (rec.audio.tubes)