Kora Triode 100 SB Mono Block Power Amps


I have recently agreed a deal to buy a pair of the above from a pre-owned hi-fi dealer and who has sent the amps off for testing prior to sale and his engineer will be renewing the MOSFET capacitors and repairing a valve connection.  

Back in 1997 these amps were measured, reviewed and recommended by Bascom H. King, so I thought that was a good reference point to begin my first venture into valve amps. 

I would be very grateful to know if any members here have owned or heard these amps in the past and in a particular if they have any experience of biasing with this model?

Here’s some more info from the net:

“These mono blocks use the Russian 6C33CB output tube, 6922 for input, and the 6BQ5WA for driver stage to achieve 80 watts output power. An incredibly high 115db signal to noise ratio, superwide 10Hz to 60kHz bandwidth, and a low rated distortion of only .07% @ 1 watt might just make those 'tube measure bad' naysayers finally concede in defeat. This triode amplifier uses metal film resistors, polypropylene capacitors, silver solder, gold connectors, double-sided circuit board and more make this unit so good and reliable that Kora guarantees this unit for two years"

Thanks very much.    

soma70
A nicely restored pair of Dynaco MkIII's would be a much better (and cheaper choice). Don't believe the hype that single-ended is better than push-pull. It is not! Getting 80 watts out of a SE 6C33 is nonsense! And their future availability is questionable. Stick to the proven 6550/KT88 PP output circuit! I own a pair of rare Paoli-modded MkIII's (TAS past recommended tube amp). I wouldn't trade these for a Kora!
Roberjerman, the amp in question uses two 6C33C-B tubes per monoblock.  And although I could be wrong, I suspect the two tubes are used in push-pull, rather than being paralleled in a single-ended configuration.

Regards,
-- Al 

Al makes a good point on the tube sockets, as these 6C33B tubes tend to more quickly eat through them than most any other.

I remember being around the Cosmos(?) monoblocks from Kora.  Beautiful sounding, if bass shy, amplifiers using 6AS7G triode output tubes.  From what I heard from their owner, he faced some idiosyncratic issues with them probably of the sort @roxy54 mentioned.  Had a chance to buy them from him cheap, and always sort of regret not doing so, as I found them something quite different than the norm.  Wish you good luck with these!