Thiel Owners

I know nothing about this particular unit, or of the feedbackless seller, but if one could get an in house audition and pick up directly, this looks like a potential killer bargain, even if by chance it might need some maintenance, for some Thiel owner.:
https://www.audiogon.com/listings/amplifiers-threshold-s500-a-ab-amplifier-2017-04-10-vintage-equipm...
FWIW, it has more Class A output than Nelson Pass's later similarly powered Pass Labs X250's. Will work with many ss and tube pres (Audio Research is often cited).

That could be a smoking deal for someone on a high current amp!  

The guys at Coda Technologies may be able to help with service if needed. Not sure on this, but they were part of the Threshold team in the mid 80's 

Jon Soderberg of Vintage Amp Repair,  as well as the current owners of Threshold can service these older Thresholds.

Nice counter points- prof

I can only speak to the newer (not vintage models) in that they do require tons of current!  Otherwise, you are spot on.

Happy Listening!

Right On! unsound-

Happy Listening!