The first product of my new company Suesskind is ready now. It is the Rauschfrei Balanced Phono Stage. The concept is based on the FPS i designed for Jan Diddens Linear 0 publication with a lot of refinements and some additions. I have now included an unbalanced input and output. All combinations work. So you can run unbalanced in - unbalanced out, balanced in - unbalanced out, unbalanced in - balanced out and balanced in - balanced out. The standard version is High Z with adjustable loading from nearly infinite to whatever low value you like. This is done by inserting Neutrik XLR´s in the back because many people think that DIP switches do not sound good enough. We build a somewhat more elaborate Low Z version that has a trans impedance input with 2.5 Ohm input impedance. That can be used balanced and unbalanced too like the High Z version. The circuitry is fully balanced from input to output so there are actually 4 RIAA circuits, two positive and two negative. That gives the ultimate in common mode rejection and distortion cancelation. Components in the chain are selected to 0.1 % relative, even the caps that we buy preselected for 1%. That is important in a fully balanced design to maintain high common mode rejection up to high frequencies and avoid phase and frequency cancelation in the RIAA. There is no hum whatsoever and wide band noise unweighted is -77dB against 0.5mV input. The stage can swing 20V clean at the output so dynamic range is huge. I think this design could also be used by professionals that do vinyl transfer to hard disc.
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That was an LA Audio Pre-Pre with tubes. I think is was 4 ECC88 tube sections in parallel.
I never could make it work without a lot of microphonics so it was rebuild by Jürgen Ultee.
It is now a Fet-Tube hybrid cascode like the Arthur Loesch circuit. It sounds nice and cozy but can not compete in transparency and dynamics with something like the Suesskind. I keep it though as a benchmark.
Thanks, Brian.
I never could make it work without a lot of microphonics so it was rebuild by Jürgen Ultee.
It is now a Fet-Tube hybrid cascode like the Arthur Loesch circuit. It sounds nice and cozy but can not compete in transparency and dynamics with something like the Suesskind. I keep it though as a benchmark.
Thanks, Brian.
Yes, Ricardo. The loading resistors or additional caps fit into the Neutriks. I use 2 x 300 Ohm with the Lyra Titan i and sometimes with a 1 to 10nF cap in parallel. The Rauschfrei Stage itself is factory equipped with 2 x 100kOhm. Natural input impedance is even much higher because i use J-Fets at the input that are hold under 4V from drain to source.
Under this conditions there is virtually no gate current so input impedance without loading in in the GigaOhm range, maybe even higher. This circuit could be used for brain scanners and the like to retrieve tiny signals.
Under this conditions there is virtually no gate current so input impedance without loading in in the GigaOhm range, maybe even higher. This circuit could be used for brain scanners and the like to retrieve tiny signals.
True "Ballanced" is the only way to the best possible sound
All the best with it . . .
Congratulation on a decision, and to unseen all hard work to achieve this final I suppose very fine sounding Vinyl playback preamplifier
All the best with it . . .
Original Arthur Loesch is a single WE417 in common cathode mode.
Think you are talking about Thorsten Loesch´s variations of that circuit.
Regards,
Reinhard
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Maybe a somewhat North-European preference ?
Me Thorens TD550 (SME312, the Nobile clone tonearm came out later), Classé Omega phono (RIAA part dual and part floating between phases), Classé Omega MKIII line, all balanced.
The Rauschfrei looks/reads very tempting.
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