Simplistic NJFET RIAA

Hi salas and all,

just came across this thread again i´m just curious how the
folded simplistic will compeed against my build njfet version.

As i have most of the parts in my boxes 😀 i´m just thinking
about the sslv1.1. What version did you exactly recommend at
the moment? And yes i have a pair of BiB-boards as well 😀

greetings and all the best for 2013

Ulf
 
The conversion was a total success. Just finished modding my 48dB 28V reference build with the new folded cascode input, running at 35v.

As for repeatibility so far so good. Ultra low noise, ample gain and sounding even more dynamic than the "Wallis experiment".

I did not touch the riaa filter (just adjusted the 47k to suit better the 2k2 folded cascode load)

On second stage I use 2k2r feeding the buffer so I get 10v out of second stage and 20v over the buffer. (I had to build a BiB to power a breadboard where I reproduced second stage to find the best resistor combinations)

It is sounding really serious right now....
Pics latter 🙂

Learning question: How high output can I choose for a cart with this configuration ?
What happens If cart output is too high.. clipping ?

Why did it not happen with the "normal" simplistic ?
 
Learning question: How high output can I choose for a cart with this configuration ?
What happens If cart output is too high.. clipping ?

Why did it not happen with the "normal" simplistic ?

Its a matter of the signal not exceeding the VPP bias capability across the input stage load. Since Riaa has about +20dB at 20KHz, it depends on disc modulation and transcription tracking distortion. The "normal" has a telescopic cascode that leaves more choice for upwards voltage biasing. I.e. It will happen on any when mismatched, but here it can't be very flexible. I have installed the folded at 58dB gain with the 0.9mV Goldfinger Statement cartridge and it did not clip or latch on pops with heavy cut 45RPM special reissue discs. So up to 1mV nominal carts should be safe. I would prefer circa 0.5mV which is designed for, so to stay on the safe side, and have optimum THD.
 
This one?
 

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Hi all and happy new years to everybody.

Ouf ! Impressive thread. I try to begin to read it and after 100 pages I lost too many technicals details to understand all. My technical knowledge in electronic is very small...

But I'm very interesting to build my own phono stage with RIAA compensation. I see on ebay few kit (with or without parts) but I really don't know witch is better than other. Also, I see somes kit from few web sites and I have the same problem.

What is the better kit/board (no tubes) can I build myself at reasonable cost.

Thanks

Cyr-Marc
 
Not exactely Felipe, the lastest should be without 2nd stage cascode....
Yes, we could double up the K369 and the source resistor, then halve the drain/emitter one et voilà!
But devil is in the details and Salas might add something more to his design 😉
 
Hi all and happy new years to everybody.

Ouf ! Impressive thread. I try to begin to read it and after 100 pages I lost too many technicals details to understand all. My technical knowledge in electronic is very small...

But I'm very interesting to build my own phono stage with RIAA compensation. I see on ebay few kit (with or without parts) but I really don't know witch is better than other. Also, I see somes kit from few web sites and I have the same problem.

What is the better kit/board (no tubes) can I build myself at reasonable cost.

Thanks

Cyr-Marc

See the RJM phonoclone thread.