Simplistic NJFET RIAA

[Salas]

edit: Vd is ~14v so yep, higher than source.

OK, is Vg around 0.3V higher than Vs for Q5? Is it Q3 Base 8-9V and Q1 D about 0.67V lower? Is Q3 Collector about 5-6V lower than PSU?

 

[Salas]

I will have to check into this more tomorrow morning as my wife is pestering me (again). I suppose I have to give in sometimes, lol.

Many thanks for your help so far. Kind regards, Lee.

OK, it will be solved sooner or later. See ya.

 

[wrenchone]

I had another stab at the shunt regulator, as there was a late-night oops with my first implementation. I'll post the new design after dinking with it for a bit more. It's wise to have some reflection/cooling off period before posting a new design...

 

[nicoch58]

if you drink red wine , I suggestion Amarone...

 

[Thomo]

OK, it will be solved sooner or later. See ya.

Cracked it! One channel is working great now, and I'm just finishing the other. Sounds far better than the opamp based stage I used before.

It seems that I put the wrong label on my bag of matched fets, lol. I think I need to slow down and take things steadier.

Thanks for all your help, regards, Lee

 

[Salas]

It seems that I put the wrong label on my bag of matched fets, lol.

Idss follies. for the next channel. Let us know how do you like it in stereo. After 48 hours is going to settle, then you can play with capacitor qualities etc. What kind of PSU are you employing?

 

[Thomo]

PSU is just a Schottky rectifier bridge 10,000uF smoother & lm317 reg. This will all be upgraded once everything is working well.

I have used PPS (Polyphenylene Sulphide) caps for the filter as I've always had really good results with them in the signal path. Can you suggest any better please?

Regards, Lee.

 

[Salas]

Soviet NOS military surplus Silver Mica or Polysterene from E-Bay if you are lucky to find the values needed. Put a Mig in your system, you can!

 

[nicoch58]

MIG ? I want use a Stealth diode

 

[Salas]

You need to use a B52 PSU and a concrete bunker TT stand.

P.S. What really happened with Thomo? He must be listening for some hours...

 

[nicoch58]

like this....

An externally hosted image should be here but it was not working when we last tested it.

just arrived two heatsink 300x250x40....

 

[Salas]

What are you making? Pass main amp?

 

[nicoch58]

I'm in love with EB ! 25w inA

 

[nicoch58]

I will leave a space in the box for your shunt ,to play with drivers...

 

[Salas]

EB is most respectable. From fleeing his homeland during the1956 Hungarian uprising through an audio cycle from Norway to US to Switzerland, National Semi, Hafler, he still delivers. Respect to the architect! Yo!

 

[nicoch58]

A new challenger,I love my amp

what I like is NO cap on signal in my system

 

[Salas]

Means double the (symmetric) circuitry, some feedback, and some DC servo non the less. Technically superior, and sonically excellent the reports say. Looks like best studio quality circuitry to me, something along the J.C. design persuasion to my eyes. Must be ''clean but not edgy'' the first phrase that comes to mind when listening?

 

[Thomo]

P.S. What really happened with Thomo? He must be listening for some hours...

Something almost as good actually. I have been to my wife's mother's for a lovely meal.

Listening will be high on tomorrow's "to do list!", along with adding Salas' Shunt Reg design to my board layout.

Lee.

edit: Has anyone tried those huge awesome Mundorf caps?

 

[Salas]

I have Supreme Silver/Oil in mine at the output.
I have also used M-Lytic 500V on tubes. Good, a little trebly I think, but clean. Nippon Chemi-Con KMH 105 C are 90% that good at much lower prices.

Your both channels work OK now? Finished?

Here is your specific shunt reg, attached.

 

[nicoch58]

Hops !

I'm still building.....my amp is truepath from 41hz , better diy belcanto http://www.positive-feedback.com/Issue14/evo2.htm