Simplistic NJFET RIAA

Hello everyone , time to share my findings !

I'm realy happy with the results . The folded phono is sounding vivid , natural and dynamic . good stage and depth etc. very good given the relatively simple build . dead quiyet for 62dB / low MC input . In my opinion this phono preamp is a fantastic investment .
Besides the many phono preamps I already build , copied and or designed myself , I am truly happy with this one in my collection . Perhaps my all time favorit BF862 / E280F triode connected cascode provides a tad more dynamics and clearness .. air .. in direct comparison but hey ... that one took me ages to finetune and only the tube based regs and power transformers count , heater supplies are out of this world . i.e. much more money .

Thanks Salas and Thea Bag for sharing this great phono preamp design/pcb with us analog friends , thanks a million !

Happy Spinning ,
Paul
 
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sure !
 

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MKL capacitors comprising lacquer films (cellulose acetate) as dielectric and vacuum
deposited metal layers. In accordance with DIN 41379 these are
designated MKU1) capacitors.

Hello Salas , thanks ! yes those Siemens & Halske MKL caps are NOS units , dated month7 '65 . my goodness , manufactured a year before I even saw the light .
These seem to have been used with space tech. applications . they do sound extremely precise and well focused . I love to use them in combi with some copperfoil pio elsewhere . just to balance the sound a bit . works a charme btw . indeed .. I was after a classic tone but not to a level that would throw a blanket over the sound . just enough to mate the metal film thrill .

Happy Spinning ,
THX , Paul
 
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Hello Salas ,

40 volt AC xfr , 2 X 22R WW 7 Watt , MUR8100E bridge , 4700uF KMH Nippon Chem lytic 80 Volt , 2 X10K metal film 2 Watt load .

More or less according the guide .

Double shielded coax . No earth connection whatsoever , open air remoted PS for now . will put it inside an aluminum case at some point . but again , I never connect at any earth pot. I keep the environment clean , no switchers dimmers or any of those nasty things .
At 3/4 volume I can detect some small noise .. probably just thermal noise but I never come even close to that kind of output levels here .

It is very very quiyet phono preamp as is . Great sonics too .

Happy Spinning ,
Paul
 

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Hi Salas,

Been using your Phono stage for a while now and had the chance to run through some cap changes on C4. Started out with an Obbligato gold because I had them in my parts bin. The lead broke off on one which forced me to replace them with clarity caps which I also had laying around, the sound quality was really nice and not much different between the brands, and I lived with them for many months. A few weeks age I swapped in some Mundorf supremes and they did turn out to be a very worthwhile upgrade, noticeably improved all aspects of the sound quality. Now I'm listening to more vinyl than digital. Really elevated my vinyl playback chain.

PJN
 
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I wonder how other , perhaps modern smd junction fets would perform . Sources for affordable sk170 etc. become a real challenge .

With completely different smd FET types it would take a full redesign with possibly good results but certainly different. Most of those are conceived for other than audio purposes. This is the Toshiba NOS sound. Take good care of your FSP people because its one of the last Mohicans. There are still Linear Systems options like LSK170 etc. which are the closest to 2SK170. There is no 2SK369 equivalent though.