Fidelity Research FR-64 vs. FR-54

Raul,
It is possible your preamp is quite good. ’State of the art’ unlikely from what I’ve seen. For a start the casework and circuit board physical attributes utilised in the Essential in of themselves induce significant hysteresis distortion. Your circuit boards are nothing special. What is "state of the art". "state of the art" implies state of the current art, but what you don’t understand is that there are many design engineers out there in non audio industries that are operating at design levels way ahead of current audio "state of the art".

I have access to 2 engineers who work outside the audio spectrum - one can reproduce any solid state phono stage currently in existence with improvements - you want a vendetta why ? I can build you a Blowtorch with enhancements. Halcro in this forum had a fault in his Halcro preamp, my tech can read the circuit and chips used from the topology even without removing the masking paint from the board and components. You want the noise floor of the latest Burmester preamp lowered - no problem. You want to improve Lewms tube preamp - no problem - we can go in there and do onboard regulation using new state of the art stacked op amps that no tube manufacturer would even be aware of unless they were designing in the digital domain as well. Why doesn’t he produce audio equipment - because commercial audio product cannot bear the cost of a design engineer who is operating at a level above current state of the art in our hobby.

You want a phono stage unlike any other produced - easy - the other engineer built his own phono stage designed specifically for MC’s with output down to 0.1mv and below including compensation for known cutterhead/amplifier deviations from RIAA using proprietary Burr brown chips. Can it be produced commercially - no because the chips are 1 off advanced research chips not even available to any current audio designer including the likes of Bob Stuart at Meridian - we are talking 3 generations ahead of current technology when it was produced.

So my friend take it from me - anything available commercially is out of date even before it is released to market, and significantly off true "state of the art" for which my definition is "in advance of what is currently commercially available by a significant margin".
Your Essential preamp is irrelevant to this forum - it is not available for audition anywhere commercially and if you think it is more advanced than anything else, then you are deluding yourself, there is always something out there better.

Cheers

Raul -
2 further thoughts on your system. You will be pleased to know that like you I use outdated bipolar devices for optimum LOMC amplification, mine designed and hand built by Reto Andreoli. It is vastly more transparent and than anything else I have heard including my old Klyne 3.5 and some pretty exotic SUT's.
As far as the Levinson mono blocks, the mods you describe make good sense, but at the end of the day those amps are slow. I would only use them for boat anchors. You might want to look at replacing those in my view,

Cheers. 

One full mistake from my part:

" poor design ", I'm not refereing to it self design on those tube electronics but to the poor technology.

R.

Dear @dover : Hysteresis distortion?, well that kind of distortion has different sources and of different kind ( existe magnetic hysteresis, example. ) and can detected as: spurious components/non-linearities in the signal frequency bands, especially on amplifiers. You don’t have to worried about in our design.

Well our four layer circuit boards could be not espcial if I don’t know what you mean for special. Our circuit boards were made it in Silicon Valley and choosed after we tested 4 different build materials in the circuit boards. This is an example only on how the Essential was builded and one of the many reasons the Essential performs with that so high excellence levels.

You name it the Vendetta and Blowtorch ( I don’t know why. ), well no one is a good reference for me. Our non-State of the ART Essential outperforms both easily. Btw, our design handle LOMC cartridges with an output level as low as 0.01mv. The Essential use only bipolars in gain stages and not FET/MOSFETS as the Blowtorch/Vendetta and uses no single internal wire but everithing input to output is hand soldered to the circuit boards.

Btw too, we don’t use it any single chips in the circuit not even the discrete ones but the B&B buffer. Btw, I was in one of the B&B facilities that’s nothing less than " impressive " and that was in Tucson, AZ.

As a comercial product the Essential is irrelevant to the forum but way releveant on what we can have and a target to fulfill.
I don’t know but thinking on people as M.Lavigne could made that I take again the flag of my latest Essential again and produce it. No, it’s not for you. You can stay with your engineering friends that are years a head the legitimate State of the Art: good for you.

Anyway, thak’s to your contribution.

Regards and enjoy the MUSIC not Distortions,
R.

Good to read that finally you are using SS technology with LOMC cartridges. A very good link to start and I hope that step by step and carefully you can follow doing in the time in the other system links.
Btw, that gentleman Andreoli is the same whom took the 103 inexpensive motor and created the Blue Magic cartridges in a price range from 3.5K to 7.5K dollars?

Raul
My MC pre eschews the use of circuit boards, has no wiring, every component is soldered to the other components in free space ( in a 3 dimensional array to minimise component interaction as is done in the Mares Connoisseur ).
For your next build you might want to look at eliminating the circuit boards, and eliminate the resonant and hystereses inducing metal chassis, and all switches in the signal path. If your circuit is as good as you claim, then eliminating the circuit boards, resonant chassis and switches should be an audible improvement of a significant margin.

The answer to your question is yes, the same Reto Andreoli that builds cartridges selling up to $50k and for which he has an 18 month waiting list. Personally I don't use his cartridge but he has some interesting ideas on cartridge tracking/cantilever/stylus profile and the issues of how to minimise distortion on playback. He is a fan of the cantileverless Ikeda MC that I use which is very close to emulating the cutter head action in playback resulting in very low mechanical distortion and phase anomalies on playback.