Simplistic NJFET RIAA

[paalj]

Salas thanks, I will try later with 300pF

Here is with your walues:
View attachment 870711

I will investegate the "rolloff". My ears are not able to hear the difference anyway. I think channel balance is more important.

The AT-OC10 was new 25 years ago and I have not used it much, so it should be to spec.

 

[Salas]

If the voltage divider on the gen output sees many pF from test cabling it may weaken its signal level at HF on 220R load. Its a heavy load. Measure on 47K load too.

 

[acidbrain]

Can i use Clarity Cap CMR 2.7uF for C4, 2.2uF CMR is sold out everywhere, i wonder why
Sometimes the size of the outputcap works as a rumblefilter ? Initial sound from the phonostage is very good, i will leave it powered for the next week. C3=Miflex C4= Auricap XO

 

[Salas]

What is the input impedance of your line preamp?

 

[acidbrain]

It's a Goldpoint 10K stereo Mini-V stepped attenuator

 

[Salas]

You may use 2.7uF-3.3uF but watch the dimensions are still fitting the board. What is the value of the Auricap XO?

 

[acidbrain]

The Auricap = 2.2uF, do you like them ? The CMR 2.7uF has the same size as the 2.2, i'm going to buy that one.

 

[Salas]

The Auricap is fine. C3 is more influential because it works on much smaller signal.

 

[acidbrain]

Okay, thanks for the information.

 

[Salas]

What TT and cartridge you use?

 

[acidbrain]

A seriously modified Rega P5 and an Ortofon Quintet Bronze MC

 

[Salas]

Not bad gear. It sounds good already on UFSP you said. Play records to discover details.

 

[acidbrain]

Yes, i will do that hear how it changes over time. It's nice to hear that my Xono clone does also well compared to the UFSP. The Xono has 6 BIB's, 4 for the MM stage and 2 for the PREPRE. But it sounds thicker and is not so quiet.

 

[Salas]

That's a very famous bigger complex design you are listening with plus its hot-rod so it seems like a good start for the small guy UFSP.

 

[acidbrain]

Dutch phrase :"wie het kleine niet eert, is het grote niet waard" He who does not honour the small things is not worthy of the big things

 

[paalj]

If the voltage divider on the gen output sees many pF from test cabling it may weaken its signal level at HF on 220R load. Its a heavy load. Measure on 47K load too.

Salas Hi,
Connected up once more and it was clearly a measurement error. I might have increased the generator signal a little this time, but the cables where the same. Input load was still 220R:


View attachment 870922

 

[donhughes111]

C3

I was just curious if anybody has tried both the Clarity CMR and Mundorf silver- gold-oil caps for C3 and what your observations/comparisons of the two are.
Thanks,
Don

 

[myleftear]

I was just curious if anybody has tried both the Clarity CMR and Mundorf silver- gold-oil caps for C3 and what your observations/comparisons of the two are.
Thanks,
Don

https://www.diyaudio.com/forums/analogue-source/129126-simplistic-njfet-riaa-1824.html#post6282957

 

[Salas]

Salas Hi,
Connected up once more and it was clearly a measurement error. I might have increased the generator signal a little this time, but the cables where the same. Input load was still 220R:


View attachment 870922

Hi, can you upload it directly here because the link leads nowhere for some reason? Press go advanced for reply and there is an attachments menu.

 

[paalj]

Strange.. It works for me.