A misleading experience with a custom built amplifier - PLINIUS to the rescue! - John C. - Aussie

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A misleading experience with a custom built amplifier - PLINIUS to the rescue!

An audio friend of mine for 35 years has been dabbling in electrostatic speakers building and amplifier design for many years. 15 years ago he demonstrated that his speakers were better than Stax FS81's and also that his 200 watt mosfet amp gave better sound than the Perreaux 2150 then in use. Result was the purchase of his speakers and amp.
Last year was the start of a massive amplifier and front end upgrade to Plinius with the pleasing results previously posted. The mosfet amp was sent back to the designer for an upgrade so it would integrate more effectively in a side channel surround sound situation. Improvements were then concentrated on improvement of the ambient signal. A lexicon CP3+ gave initially pleasing results until it was realised it was reacting with the Bryston crossover and they could not both be placed on the same Plinius M16 preamp output. So the Fosgate 2 was called back into service with the "still odd" sound blamed on the processor.
Enter the Meridian 861 requiring a powerful centre channel amp so the mosfet amp was duly moved to centre channel position. Some of the weird sounds emanating were attributed to poor set up, maybe the 861 was not as good as reputed, wretched digital surround sound â€¦. And stereo mode remained the preferred setting for audio although some pretty impressive Dolby sound accompanied movies.
Last scene yesterday: enter another Plinius SA 100 put into the centre channel and voila! Superb sound. Then the penny dropped. The mosfet amp had been phase reversing and causing a mish mash of sound whether it was in centre channel or side channel position. UGGGGGGGHHHHH, how dumb!
Moral of this story is to be very careful about condemning the wrong component and custom made amps cannot be blindly trusted for correct phasing. I am still learning the hard way.
Anyway the end of the story at this stage is a happy one. The sound (basically with Plinius amplification) is rather startling in its clarity, purity etc. Back to the drawing board to reappraise the quality of surround sound. I'll post a report on the 861 when I fully understand how to optimally configure and use the beast. However the future is now looking much more positive and the sound much more impressive.
Peace at AA
John

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Topic - A misleading experience with a custom built amplifier - PLINIUS to the rescue! - John C. - Aussie 15:05:29 07/19/00 (4)

Re: A misleading experience with a custom built amplifier - PLINIUS to the rescue! - Des 02:24:23 07/20/00 (0)

Are all amps supposed to be non-inverting? - phenderson 15:53:34 07/19/00 (2)

Re: Are all amps supposed to be non-inverting? - hifitommy 16:32:18 07/19/00 (1)

Re: Are all amps supposed to be non-inverting? - tenor39 17:25:29 07/19/00 (0)

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