Simplistic NJFET RIAA

Member
Joined 2009
Paid Member
Are NOS Texas capacitor (Tex-Cap was located in S.W. Houston until closure in the 1980s) series Forty teflon & aluminium foil, looks promising & better than mine SCR Obbligatos tin foil & about price are very affordable speaking "teflon caps", I imagine a sound more transparent, fast & direct than tin foil because use the same aluminium foil like mine output caps Obbligato Polypropylene film.
 
Member
Joined 2009
Paid Member
No expectations, I owned Hovland polypropylenes & aluminium foil & now I have Obbligatos also poly + alu foil, I own Mundorf poly + tin foil so more or less I know the sound & always is better 1st de dielectric & after the foil: 1st foil copper, 2nd aluminium & 3rd tin (I don't know any teflon film & silver or gold foil)

Yes I need a lot of TIME more or less about 400 hours to break-in well all teflon foils as per information I got in the net.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Don't know about so many hours, those rules of thumb come from enthusiastic audiophiles without controls around their listening sessions and lots of gear and set up tweaks along that time. But I know that a good day shows early in the morning, and you are sure its sunny by noon.:)
 
Hello salas and all,
i´ve been absent to this thread quite a while but i´m still interested in building
this pre. Postings and pages are a lot and searching schematics would be awful.

Would anyoney be so kind and post the actual njfet RIAA for cartridges like
lyra dorian and the like? And please add salas reg psu schematics once again
if available.

Aaaand please tell me what IDSS would be ideal for the fets

Thanks and greetings

ulf
 
Hi Salas,
i´m using two tonearms. One with Lyra Dorian which makes 0,60 mV
and another Tonearm where i can use Denon dl103 or AT33ptg. But
there i use a Valve Phonostage. Still on the hunt for a better partner for
the Dorian.

Greetings Ulf

P.S. what is the best way to measure idss? I´ve got a schematic from the
preamp cookbook by A. wright with constant current lm317
 
diyAudio Chief Moderator
Joined 2002
Paid Member
To me the most simplistic but sure way proved to use a 9V battery (+) in series with a good DVM's red probe in mA setting, black probe to drain, gate and source shorted and back from there to battery (-). Waiting for each reading to stop climbing, noting down on a white A3 paper, sellotape, stick the bug above the reading, make em an army, look for numbers afterwards and forever without mixing. A breadboard will help a lot, not to touch them much (they get upset), and avoid shorts that will blow DVM's fuse, they are tiny thingies. The 100R between drain and battery method and voltage taken across R, deriving mA was near but always a bit short, they tended to pull a bit harder when in circuit.