Optimal VAC

[Jerry G]

I have a Metro Plexi 100 and finally purchased a Variac.

I would guess 115VAC would be what the design was intended for.

Comments?

[GilmourD]

I have a Metro Plexi 100 and finally purchased a Variac.

I would guess 115VAC would be what the design was intended for.

Comments?

If memory serves, US standard wall voltage during the '60s was 110VAC. The spec has drifted upward to 117VAC now.

The sweet spot for Edward seemed to be around 92VAC to 96VAC, depending on who you ask and the particular amp.

Now, this is where a lot of the much-more-experienced tech geniuses here can help... Does the bias track with the change in input voltage or does that have to be adjusted any time one might futz with the Variac's setting?

[Jerry G]

Set the voltage to 110 VAC and taped the knob on the variac.

Re-biased to 60% plate dissipation and viola!! Instant improvement.

That was the best $70 I ever spent. The improvement was very noticeable.

Thanks Gilmour for the reply !!!

[GilmourD]

No problemo.