VARIAC: Procedure??? 2 old 30 wpc tube amps, unused for 4 years


Two Fisher 80Z, made 1958, overhauled 6 years ago, not used for 4 years

https://www.hifiengine.com/manual_library/fisher/80-az.shtml

Borrowed my friend’s VARIAC.

How many volts ___ to start?

Progress in ___ Steps?

How much time _____ each step?
.................................................

I found this, but always seek and welcome advice here

https://www.circuitspecialists.com/blog/using-a-variac-to-power-up-an-old-radio-or-amplifier/

says sniff/look for smoke while:

slowly dial up to 50V; 30 mins (pre-heat tubes; reforms electrolytic capacitors)

slowly                75V; 30 mins (power transformer/windings/drives out moisture)

slowly .............. 90V; 30 mins (if hum replace electrolytic capacitors) (old capacitors: replace em anyway).

slowly up to 110/120V
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I’m gonna drop my Cayin off to have it’s internal bias adjusted by Steve at VAS

so, a chance to use these beauties (beautiful sound, actually hard lookers) with my McIntosh mx110z for the 1st time.

They will be driving the Electro-Voice speakers they were paired with in the 1958 Fisher President II I inherited. Always gives me good memories of my Uncle Johnny.

He had a fabulous apartment in NYC with one of a matching pair of Steinway Concert Grand Piano’s from the 1934 Chicago Worlds Fair that my Grandfather bought. My Uncle Bill had the other one. Trust Funds for the brothers, but not for my mother or her sister, they were expected to marry well. My aunt married into the Vanderbilt family, not my mother. Hence I’m the DIY bargain hunter.


elliottbnewcombjr

Showing 1 response by lubachl

One simple solution is to use an inrush current limiter.  You just plug your amplifier into it and flip the switch.  Maximum voltage is applied in about 15 seconds.  I purchased mine at sigtomics.com, however I see that website is no longer active. The email address on my unit is tsiglin@sigtomics.com.

hope this helps.