Simplistic NJFET RIAA

[massimo]

Originally Posted by atupi

What would better for interstage cap: FT-1 0.022uf 2 pcs paraleled or a single FT-3 0.1uf ?

FYI FT-2 0.047uF is also available Russian Teflon Capacitor FT-2 0.047uF 200V 47nF 1pc. or more | eBay

[The Space Egg Corp]

Hi Salas

I had an 'old' schematic from before the PDF.
I am though, working from the PDF, on both the Shunt & NJFET.
I just have 100n interstage, NOT the 47n as the PDF.

You just answered in part my question, a couple of posts back...
...I was wondering how much of the VVVLF 'filter' came from the 'interstage cap'...
...and how much comes from the 2.2uF 'output cap'.
I have some 'un-authorised !' 6uF 'output caps' I would like to try.

I obviously have to wait to test Toshiba's to get an idea of 'gain'.
Also I still don't exactly know what cartridge I will end up with.
Although I am working from the PDF 'hi-mc' eg. DL-160 schematic.

Just drew a MKI & MKII board layout yesterday.
MKII looks OK, we get it 'perfect' for MKIII !!!

I am thinking that having a 'permanent pot' for 1st stage gain would be an advantage for me.
Perhaps a fraction of the total value leading to 1st stage, say 100, 200 or 500R ?
A small amount of adjustment would make setup much easier.
I'm sure a decent 3/4 Watt 20-turn would be OK left in-circuit.
Any 'authorised' standards here ?

Cheers

Si.

Anyway...
...this is FUN !
We scribble some Shunt-Reg board layouts tomorrow !

[Salas]

Doing a portion of the 1st stage's loading does things to the Riaa. Better do its source resistor. The output cap does whatever portion it does with your amp's Rin in line level. Rest is what 47n or 100n do to 1 meg. See, combine, decide, listen, tweak. Do bib 1.1 for reg.

[The Space Egg Corp]

My friend tells me Denon have discontinued the DL-160.
I thought it was a popular, well spoken of product.
I think the DL-110 ( nearly the same ? ) is still being produced.

Anyone know why Denon pulled the DL-160 ?

Si.

I have a 'cartridge grave-yard' here !!!
Might have a rumage through, see what junk I can come up with to 'bolt-on' to the SME...
...at least for a laugh !!!

How annoying is it that some carts don't have 'holes' all the way through ( ie. Denon )...
...AAArrrggghhh!!!

[Salas]

Some prefer the 110 even. Its very good. Bit different highs and stage. Maybe more forgiving.

[The Space Egg Corp]

Thanks Salas

So maybe 50R pot for adjustment on source.

SO...BIB is best !!!
( great name !!! )

Yes maybe a VVVLF r/c calculation...tweek...etc.

[Salas]

100R pot and 100R shunt to keep some quality.

[The Space Egg Corp]

Salas !

Top-man !

Yes...100R pot + 100R 50 Watt wire-wound !
Perfect...

Jee...now I'm getting 'audiophille stress' about that little pot !!!!!!!!!
Maybe should eventualy replace with 'fixed'...
...just to sleep good !!!

Si.

[The Space Egg Corp]

You are right of course Salas...

...If I get my Toshiba's sorted & matched good...
...bung in 'authorised' 33R (Felipe 'calibration-grade') resistor...
...Bob's yer uncle...
...perfect gain = good nights sleep !

Good night !
I have some BIB time reading to do...
...ZZZzzzz...

Cheers

Si.

[luxury54]

dear Salas,
thanks for the link and for your efforts to modify the RIAA and publish the NAB EQ curve; I am lucky cause 7 1/2 IPS has the same EQ curve just like the 15 IPS that is published in the schematic, only the 30 IPS NAB curve is different to these