In Reply to: RE: Improved Marantz 9?? posted by tube wrangler on March 21, 2017 at 18:14:38:
The Marantz 9 runs the tubes conservatively at 55 ma with 440V on the plates. The output tubes last a long time on it. I have been running two quads of NOS Mullards and the getter flashes look nice and shiny after 3 years of use, averaging a few hours a day.The amplifier also runs very cool. After 3 hours the transformers are barely warm to the touch. All components run as conservatively as possible.
As for instability, it is rock stable needing only occasional bias tweaking. Remarkable considering the push pull parallel design.
The only minor criticism is the slightly over elaborate input stage. But this was done to facilitate connecting a phantom center channel speaker, which was a feature used back in the early 60s to combat the so called "hole in the middle" caused by the speakers of the day. An added side effect of this is the ability to invert the phase or polarity of the signal, which can come in handy at times...
I think most folks disparaging the amp, gave it away for peanuts back in the 70's and now are kicking themselves.
Or folks who cannot afford a pair...
Edits: 03/23/17 03/23/17 03/23/17
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Follow Ups
- This is a bunch of B.S. nonsense.... - crooner 12:11:07 03/22/17 (6)
- look closer.... - drlowmu 13:04:01 03/22/17 (5)
- RE: look even closer... - Steve O 15:22:09 03/22/17 (4)
- RE: look even closer... - PakProtector 04:02:37 03/23/17 (2)
- Maybe ... - Steve O 05:59:47 03/23/17 (1)
- Thanks Steve for the technical clarification (nt)... - crooner 07:57:36 03/23/17 (0)
- RE: look even closer... - drlowmu 21:47:32 03/22/17 (0)