Simplistic NJFET RIAA

[Salas]

Originally Posted by RCruz

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.

[massimo]

Salas, are you going to develop a HiGain version of the folded cascode RIAA with a pair of K369?

Of course Happy New Year 2U2!

[merlin el mago]

This one?

[merlin el mago]

I'm waiting news to make it.

[cdebien]

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

[massimo]

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

[merlin el mago]

So I have to wait like you?

[Salas]

I will delete Q5, I will use C2=15.2nF, R2,R3=3R, R6 3M3, R10 6.4K, R8 43R, R11 1.2K, R12 trimmer arrangement like in the folded pdf.

[Salas]

Originally Posted by cdebien

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.

[Salas]

Originally Posted by merlin el mago

I'm waiting news to make it.

There is nothing more to wait, if having 0.25mV cart that initial sketch is the proper arrangement to make, modified with the latest notes for it I just gave.