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Vintage threads from the first ten years

previous: Mark Buckingham I've used the c.t. style standby sw... -- 12/28/1999 7:57 PM

Re: placement of a standby switch

12/29/1999 3:42 PM
peter	Re: placement of a standby switch I have built a couple of amps with the standby switch in the center tap. The bias comes from the high voltage winding. When the amp is on standby, the bias voltage builds up to about DOUBLE the normal voltage. This is because the circuit is completed by a bleeder resistor across the filter caps, so you have the full PT secondary voltage instead of just half, charging the bias supply. Doesn;t seem to be a problem but the caps need sufficiently high voltage ratings.

12/29/1999 3:42 PM

peter

Re: placement of a standby switch

I have built a couple of amps with the standby
switch in the center tap. The bias comes from
the high voltage winding. When the amp is
on standby, the bias voltage builds up
to about DOUBLE the normal voltage. This
is because the circuit is completed
by a bleeder resistor across the filter caps,
so you have the full PT secondary voltage
instead of just half, charging the bias
supply. Doesn;t seem to be a problem but the
caps need sufficiently high voltage ratings.