Simplistic NJFET RIAA

[jam]

Thanks for the reply. I shall be waiting for the results if it is not possible maybe another stage is required.
I have seen MadK's version and it looks promising.

Regards,

Jam

[RCruz]

Originally posted by salas


Hi,

Look at the polysterene and silver mica tags at the bottom of the screen.

Hi Salas

I found most of the values

C3 seems to be difficult... did you use several caps to reach 15.8 or 16nF ?

How critical is this value ?

Ricardo

[nicoch58]

mulicaps polystyrene or pp the 15nf //1nf or add a small mica/styrene

my suggestion 15n RTX w/out
small mica /styrene to fine tunning
all PRP resistor , strategic position cartridge load/serie signal caddock132/riken/shinkor to taste

[Salas]

Nicoch46 covered it pretty well. And yes, that value is the most critical for HF balance.

[massimo]

Ricardo, the best way is to select them with a C meter
It shouldn't be that difficult, as, according to my experience, 5% caps have generally an effective value slightly lower than the nominal value stamped on them.
That means most probably a 15 nF cap is a 14,8-14.9 nF one. Once you find two right pieces, simply add two 1% (or selected) 1000 pF caps to get 15,8 nF.

[nicoch58]

or order matched caps for Riaa....

[RCruz]

Thank you for your answers.

So I must start with a precision 15n and fine tune with mica/polystyrene.

And this is the most critical point for RIAA high freq acuracy.

As I do not own a C meter I believe it must be done by trial and error.

PS

How is the cascoded version ? Better Bass?

Regards

Ricardo

[RCruz]

Originally posted by salas
Don't underestimate English 80's TT and arm technology or taste. They had a fresh, pacey musical approach that I don't find in many turntable$ of today. Lee is up for a surprise most probably. No CDP can even hint at the natural way of a good TT, warts an all. Just imagine that the record is picked up only, not synthesized from a code. A TT as a whole does 1-2% of mainly even order mechanical distortions and that's all. The signal starts a cm away from the groove as cut by the production, and gets routed directly to the phono pre. The poor CDP has to read well some modulation in an analogue way (like an optic TT), then translate it to a code, then translate again that code into signal, and then filter it! Its a miracle that a good CDP goes as far as it goes today. But its a digital synth, and it will always hint at that fact.

I agree with you but there are others that do not. I can understand the digital idea mainly after my latest CDP upgrades.

It is possible to have high definition highly musical and dynamic sound with CD.. (After two years modding, my CD53 souns awesome).

It is so good that now I need to upgrade my RIAA in order to balance things again.

Do not take me wrong... I still prefer the wide sounstage and high precision low distortion sound of a good TT... but I need some more speed and transient power now.

Note:
Yesterday I implemented the DIY armaggedon with a 220/110v 160va TX in my premotec....

Lower noise floor.... better detail retrieval.... (Like adding a dedicated psu on the CDP decoder).

I am amazed

Regards

Ricardo

[Salas]

Originally posted by RCruz
PS

How is the cascoded version ? Better Bass?

Regards

Ricardo

I won't tell before I make proper A-B. Nothing dramatic, want to see what is really good, not merely different. Had to play for a week, all components are new. I wanna be fair and look well in to the issues, not go on recommending more complex stuff for no real reason.

[Salas]

Originally posted by RCruz

I agree with you but there are others that do not. I can understand the digital idea mainly after my latest CDP upgrades.

It is possible to have high definition highly musical and dynamic sound with CD.. (After two years modding, my CD53 souns awesome).

It is so good that now I need to upgrade my RIAA in order to balance things again.

Do not take me wrong... I still prefer the wide sounstage and high precision low distortion sound of a good TT... but I need some more speed and transient power now.

Ricardo

That is why I used ''warts an all''. I have listened well and set up extremely expensive systems with digital front end due to my part time help for a prestigious dealership. I still have to hear for ''natural way'' when I play a funk tune on a CDP. All resolution and silence and solidity is in abundance, still my foot won't tap. When an accompaniment goes on from guitar or keyboards, when the bassist drives, it is still no real interplay. Never had a good Brazilian tune talk to me on CD like from a vinyl record, even when dirtier or lesser in resolution, turning on a humble but correctly set TT.