2. amps-preamps
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845 tubes for Cary 805 AE amplifiers

I have a pair of Cary 805 AE amplifiers and wish to upgrade the 845 tubes. Given the fact that both RCA and United NOS 845s are unobtainium, what have others been using as replacements for the stock Shuguang?

I have used both the Shuguang 845B and 845M tubes, but am of the opinion that neither of these really meets the original 845 specification for heat dissipation (supposed to be 100 watts). Even the new Sophia 845 is only rated at 75 watts dissipation, which is only slightly better than the 70W rating of the 845M and the new Psvane 845s.

Have any of you used the Sophia 845s in your 805s, and if so, are you still setting the bias on the 300B at the factory recommended 60 MA? Any feedback from experienced owners would be most appreciated.

Thanks,
Dean
theloveman

Showing 1 response by brf

brf
1,715 posts
 
The 845 graphite is NOT suppose to glow? ? ? Mine glow 15 minutes after I turn the amp off.

That's normal. You should not see a red glow through the white light when powered up. 15 minutes for the red glow to last after powered down does seem long.

The 845B is RCA spec standard i.e. 100w dissipation
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