Nick Sukhov Su-XXI MM Phono stage -85 dBA SN ratio...

Guten Morgen involved people,
I would like to show you nice solution for MM cartridges from Nick Sukhov. He is a legendary audio circuit designer based in Kyiv, Ukraine.
MM Phono stage-XXI (Su-XXI) by Nikolai Sukhov, thanks to the "aperiodic" HF correction invented by him back in 1980 [first described in the article "High-quality preamplifier-corrector" in the USSR Radio magazine No. 3/1981 pp. 37-40, which became “The best publication of the year” in 1981] allows you to get rid of the input circuit resonance "MM head inductance + cable and phono stage input capacitance", due to which, above the resonance frequency (usually in the region of 14 ... 16 kHz), a frequency response decay is formed with a significant slope of 12 dB / octave ( like a second-order low pass filter). With aperiodic correction, such a drop is eliminated and the sound of $50 MM cartridges becomes as transparent and detailed as that of top MC k$ cartridges. Similar circuit solutions appeared 20-30 years later among high-end Phono preamps under the names "Neumann pole", "Damped EQ", "Enhanced RIAA - eRIAA", "Phædrus Phlux active phono cartridge". Thanks to the original "passive cooling" solution with 150 kOhm input resistor instead of 47, the Su-XXI provides an unprecedentedly low noise level of -85 dBA in full compliance with the standard input level of 5 mV @ 1 kHz (and not the "maximum input" - a typical marketing trick) and with an equivalent input MM-source 500 mH / 1 kOhm connected (and not the "shorted input" - another trick of the steamers). Finally, thanks to the use of a high-output impedance voltage amplifier stage with a load Z(f) in the form of an RIAA-chain (overall gain 1+Z(f)/R, voltage amp open collector stage gain is also proportional to Z(f)+R, so loop gain is almost constant across the entire audio band), a "passive-active" frequency-correcting circuit is formed with an almost unchanged feedback depth from 10 Hz to 50 kHz (55 dB constant loop gain). This design of the deep RIAA freq response correction of 40 dB eliminates the “diseases” of both excessive gain at high frequencies and insufficient gain at low frequencies, which provides both a high stability gain margin (22 dB) and a uniquely low THD of 0.00006% at a nominal input voltage of 5 mV @ 1kHz and 0.0006% at +20dB overdrive.
 

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dreamth

Member
2010-11-18 9:12 am
So somebody expect us to understand russian or ukrainian...I have no ideea what carts have their resonance btw 14...16 khz and I see no way to load pasively or actively that cartridge in his schematic .I couldn't find proof for 14...16khz resonances here:
https://www.diyaudio.com/community/...or-flat-frequency-response-and-max-f3.365853/
I know about some of the works of Sukhov, just because I was raised behing the "Iron Curtain" and some of his work was translated in our magazines, but no russian speaker felt like his work should be translated in english...Here's the only ukrainian genious whose language is well known:
 

dreamth

Member
2010-11-18 9:12 am
No way. It isnt commercial. Just for the talk
And it isnt Kenwood clone. Its perfect
Actually it is commercial and contains plain lies in english and russian content that we don't understand. You even misspelled the author's name which can't be Nick...One of the policies of this forum is the use of english..And nothing's perfect...vinyl included.
 

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dreamth

Member
2010-11-18 9:12 am
I think it is always better if the original author presents his circuit idea.
He probably does it very well in that movie just it's in russian...He's of age and he might not know english.If a professional translation would be done for that movie then maybe it will all be ok.As far as I know Sukhov is kind of a russian N.P. so no disrespect for him if everything is well proven so that everybody can understand...
 
And it isnt Kenwood clone.

With the exception of a current source, a bypass cap on the common emitter stage, some tiny details relating to phase correction and the addition of Neumann's pole it is a copy of the Kenwood topology.

The large input resistor coupled to low input capacitance does indeed push the MM electrical resonance beyond audibility but only if the tonearm wiring adds no extra capacitance. Mounting this phono stage inside a turntable will work, but how realistic is this in practice?

Still, a very nice phono stage and a great update upon classic circuitry. Must sound really well if the circuit has captured Mr Sukhov's attention over more that 40 years.

Thanks for bringing this up.
 
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dreamth

Member
2010-11-18 9:12 am
Few people are realistic about vinyl reproduction noise anyway..the vinyl itself won't be able to surpass even a 2 stage regular low noise (3dbNF)discrete bipolar input phono stage...I consider input noise the last problem you need touching when dealing with phono preamps.
 
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Few people are realistic about vinyl reproduction noise anyway..the vinyl itself won't be able to surpass even a 2 stage regular low noise (3dbNF)discrete bipolar input phono stage...I consider input noise the last problem you need touching when dealing with phono preamps.
the difference between the noise of vinyl and the corrector will be heard by everyone
 
He probably does it very well in that movie just it's in russian...He's of age and he might not know english.If a professional translation would be done for that movie then maybe it will all be ok.As far as I know Sukhov is kind of a russian N.P. so no disrespect for him if everything is well proven so that everybody can understand...
Sukhov and me- Ukrainian. Bur speak Russian. Nick speak English pretty good, but he doesnt spend time in the forums and his main auditory is domestic. It his hobby, no more.
About this solution. IMHO its the best for MM. each cascade, all together… thats why I made this topic
 
To a thread titled "Ripping off Kenwood since 1981"?
Kenwood - 83 дБ with shortcut input? And 0,03%. But SU-XXI has a little different.
Are you up to it?? Perhaps it is another curcuit, or?...
Do you see different of shortcut and real Phono stage? I hope so.
I know you didn't get it...it's allright!

I'm certified electronics and speaker designer, classical and rock musician
find an opponent of your level
 

dreamth

Member
2010-11-18 9:12 am
Well ...what's the SNR of Mr Sukhov phono preamp with shorted input then? Vinyl noise is at -60...-70db which is already 12db over Kenwood's specs.Some of the best phono preamp has that SNR at -73 db for 0.1mv MC carts.Guess what? That's 3 db better than the minimum noise level on the best vinyl...you said you're a rock musician...Messa Boogie dual (triple) rectifier on RED channel has a live SNR of about 30...35db...Apparently John Petrucci likes it.
 
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