Iam a little curious as to why the new larger Power Transformer is designed to handle modern AC line voltages, why would we need A Variac to produce a lower AC line voltage?
Power Transformer and AC wall voltage?
Bob Latino- Admin
- Posts : 3262
Join date : 2008-11-26
Location : Massachusetts
music wrote:Iam a little curious as to why the new larger Power Transformer is designed to handle modern AC line voltages, why would we need A Variac to produce a lower AC line voltage?
You don't need a variac as long as your line voltage is 122 VAC or below. Above 122 VAC the internal voltages of the amps can get too high and cause shorter than normal tube life. This can be even worse if you have a vintage amp which has a power transformer that was designed for 115 - 117 VAC (which was the normal line voltages in the 1950's and 1960's) and try to run the amp on 122+ VAC.
As an aside > Some audiophiles try plugging their tube amp into a "power conditioner" because they know that their power conditioner can regulate the incoming line voltage. This is OK as long as you know that your power conditioner can put out a AC in the form of a true sine wave. Some power conditioners filter and manipulate the AC so that what comes of the AC outlets on the power conditioner is NOT AC in the form of a true sine wave. A tube amp will choke on any power source that is not a true sine wave. Blown fuses, shorter tube life etc.
Bob