On Monday, November 12, 2018 at 4:26:13 PM UTC-5, wrote:


don't think I've ever seen an isolated variac.

Modern speakers are fine on valve amps really. Unless you want excessive volume, or the amp has all of 3W available.

http://www.byan-roper.org/steve/stev...-variable.html

I keep two of these. One in the travel kit, one permanently on the bench. The link shows the innards as well.

Most of the VIZ & Sencore units have leakage testing as well. By the way, VIZ, a Philadelphia company was a jobber for RCA, making many of their test equipment under either name.

Peter Wieck
Melrose Park, PA