Simplistic NJFET RIAA

R2/R3 values

I was going through the parts again in order to put an order on connexion and I got a little confused with R2/R3 resistors...
My 2SK369BL are around 12.2 mA IDSS so I think I should go with some resistors aroung 5R1 and 5R6...
I got the following options on connexion...
  • PRP-76571 5R1 / 0.5 (1/2) Watt, Metal Film, 1%, 100ppm
  • PRP-76572 5R6 / 0.5 (1/2) Watt, Metal Film, 1%, 100ppm
  • CADDOCK-77400 5R / 0.75 (3/4) Watt, MK-132 Series, 1%
Are any of these fit for the case? The Caddock one is rather expensive and a has lower value than the requested for 12 mA IDSS...
Any help will be appreciated!
 
Up and running in new oak cabinet.

150ohms naked Z-foil as loading for my AT33EV cart

No dipswitch no shielding only twisted silver in cotton

Works sweet, the bass is more correct (the 100hz hump is almost gone)

This Riaa is really good, it reveals details like i have never heard before, but without the traditional analytic disadvantages some equipment are cursed with

Records are spinning as we speak

Thank you Salas and TB
 

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diyAudio Chief Moderator
Joined 2002
Paid Member
You are welcome. Now that's a very warm vinyl rig and preamp corner you have created there. Looks great.

P.S. Still surprising you don't get any 50Hz hum with such big toroidal transformers in same box and non shielded signal wiring in LMC high gain mode. Are the transformers magnetically shielded with a peripheral metal band under their translucent wrapping maybe?
 
Up and running in new oak cabinet.

150ohms naked Z-foil as loading for my AT33EV cart

No dipswitch no shielding only twisted silver in cotton

Works sweet, the bass is more correct (the 100hz hump is almost gone)

This Riaa is really good, it reveals details like i have never heard before, but without the traditional analytic disadvantages some equipment are cursed with

Records are spinning as we speak

Thank you Salas and TB

Hi

I owned an Well as well some decades ago when it arrived on thge market - a good turntable and I loved it.
You can "play" with the deepness of the paddle dives in the silicon. Add or remove and have a listen to it (but take your time). I ended up with a new arm rest at which you could adjust the vertical high of the paddle (without changing the vertical angle of the cartridge).

Good luck and have fun... btw. there is a dumb-formula for the cartridge loading: load is around 10 times the carts impedance
 
Thanx

Yes i love my WTT, some dont like the lack of a lift but after some training i find the way of operating the arm much more comfortable and secure (even after a few single malts)

My WTT is the Record player witch is the least expensive i believe the more expensive have more arm adjustments.

Possible upgrades will probably be be motor related.
 
You are welcome. Now that's a very warm vinyl rig and preamp corner you have created there. Looks great.

P.S. Still surprising you don't get any 50Hz hum with such big toroidal transformers in same box and non shielded signal wiring in LMC high gain mode. Are the transformers magnetically shielded with a peripheral metal band under their translucent wrapping maybe?


Quiet as the grave as the quote goes in Norway

The transformers are the best you can bay from Poland, audio quality and sheelded.

And yes there is a copper band around the windings i suppose thats connected to the eart wire,

Until recently had problems with popping sound (statics) especial when playing vinyl.

The sound came both when i touched pream, cd player and the metal om the record player.

After the final build for the folded i have no popping sound, dead quiet witch-ever component a touched.

My theory is that i now i have 100% earthed connections on all the components and the cables are 4mm2 earth + double sheelded mains industrial cable

Could of-course be the the introduction of the folded but i believe it got less noisy after going from the proto cabinet to the permanent case with proper sheelded mains cable connected to my designated mains 16A outlet (pure voltage:))

As for the unshhelded cables they are twisted very tight they dont like to sit ontop of a AC cable but they are quite sturdy against interference.

The whole idea of building the transformers in the same case is that i want to fully draw the benefit of the low Z-out on the transformers,
My theory and experience is that adding long cabels between the raw PS and the consumer adds both more capacitance and increeeces the outpot impedance
 
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diyAudio Chief Moderator
Joined 2002
Paid Member
A friend recently made an FSP and then one for a friend of his. He had it in p2p before. He used a big case (ferromagnetic). After he moved the trafos to an external box, for a test not for hum reasons as he did not had, he got surprised by a lift in resolution. But you got a wooden case and better trafos. So, different builds & parts lead to different experiences. But he describes the final sound as you do. The Well Tempered is a thoughtful very good TT by the way. Difficult to go wrong with it. They even have the LTD tonearm with integrated lift now. Did you experiment on VTF around my post #12326 BTW?
 
A friend recently made an FSP and then one for a friend of his. He had it in p2p before. He used a big case (ferromagnetic). After he moved the trafos to an external box, for a test not for hum reasons as he did not had, he got surprised by a lift in resolution. But you got a wooden case and better trafos. So, different builds & parts lead to different experiences. But he describes the final sound as you do. The Well Tempered is a thoughtful very good TT by the way. Difficult to go wrong with it. They even have the LTD tonearm with integrated lift now. Did you experiment on VTF around my post #12326 BTW?

Did a some test now with the same records i played before when the folded was on the proto bord.
The sound is more balanced now, and the bass hump is gone.
Fun fun

Will test more on PU weight and more later, next up is new permanent lid for the cabinet

Better to do final voltage adjustments after the temp in the box has been established
 
Its the 150R it loaded the 33EV better than the 100R and ironed out the upper bass in your system you think?


Could be,

But when testing out different transformer solutions and mains cables earlyer i found that the bass changed (got better) with better mains for the transformers.

I tryed to replace the 300VA R-cores in my BIII dac with the Shielded Torroids and the difference was not huge,
Could possibly had been some better resolution (hard to say) but i recognized the hump in the bass.

Thats when i tried to change to a better (audio) outlet without a jumper in between found that the bass was shaping up.

What i now hear now could be a mix of many: different load, less "micro-phonics" due to less vibration, better mains and shielded mains cable