Simplistic NJFET RIAA - Page 376

Salas · 30th May 2010, 03:44 PM

Quote:

Originally Posted by merlin el mago

What about subjectively speaking?

Don't know, I have listened to both balanced and unbalanced components in several systems but the parameters are too many so to speak confidently. A fair thing would be to make the same CCT in both guises with same parts and live with it enough before commenting. Me I always follow economy. Due to I am not an engineer, I try to make simplest before I lose the ball so I go SE. I am pro useful, i.e. easy to make and fulfilling most of my subjective needs, not unconditionally best, I can't be sure I can design or control such anyway. J.Gerhard had made many experimental CCTs in the course of his MPP thread and maybe he can be more adequate for adding his comments on your SE VS Balanced query, if you ask there. He is good in describing subjectively too.

Franz Gysi · 30th May 2010, 04:48 PM

Uuuups, Salas

I made wrong measurements yesterday!

Most of my 2SK170V are showing between 12 to 13 mA IDDS. Second most between 11 and 12 mA and a few between 10 to 11 mA.

So, no IDDS of 15.5mA.

What happened?

I measured yesterday with the mA function of my DMM. But today, I attached a 1k resistor and measured the voltage along this resistor.

So, I trust this measurements today much more.

Could you please simulate the circuit with 12.5 mA?

Never trust your own measurements (in German: wer misst, misst Mist)

Sorry again!
Franz

Salas · 30th May 2010, 04:52 PM

1k is too much it cuts VDS when from same B+, hence current. Measure a couple of noted ones with 100R to confirm. 12-13mA for most V seems low. I would expect them to range from 13-16mA by majority and narrow around 14-15mA.

Franz Gysi · 05:09 PM

Hi Salas

I can measure tomorrow again, with 100 Ohm. Thanks for the hint!

Tonight, no equipement available.

Franz

/Edit
Yes, I understand: I used 14VDC for measuring, having 10 to 13VDC drop on the resistor: nothing left for the SK170...

Salas · 30th May 2010, 05:16 PM

Use 10V and 100R. The datasheet quotes IDSS at 10V. So I will know the ballpark of the sim model after your final results.

Franz Gysi · 05:28 PM

A little bit off topic, but maybe interesting for some of you for positioning this fine phono preamp:

I used a EMT930 with a "Tondose" TSD15, followed by Lundahl transformers and an Aikido Phono pre.

And I was very happy and never tried the Pacific concept.

I compared the EMT solution with my musicserver source. Very very nearby, both solutions. Sometimes I preferd vinyl, sometimes the musicserver.

Until I needed money. So, I could sell my EMT together with the trannies and the Aikido for a good price.

What followed?

This sales reactivated my activities concerning vinyl.

I needed a cheap solution for listening vinyl. So I could buy cheap a Thorens TD160 and revised it completely. And mounted my DL103R. And adjusted everything.

Then I attached my phonoclone preamp.

The musicserver was still better, in every case.

I fiddled also around with some other MC (Technics 300MC) and MM (Shure M75 and Shure V15/III) pickups and a VSPS instead of the phonoclone.

The musicserver was still better, in every case.

Then, I began to reactivate my Pacific board, never used before.

Boahh, emotions, fascination! Not enough gain, of course, for the DL103R. So, I attached two Studer 1:6 trannies in front of the Pacific.

Great!

I have now at least the quality back, I had with my EMT solution, but for a fraction of the money...

Only difference: with the EMT solution, I could track up to 100u horizontal amplitude, with the Thorens/DL103R I reach 80u, what is still enough.

I am looking forward, to use the two stage concept of the simplistic (is it really simplistic?) pre without step up trannies.

Franz

Salas · 30th May 2010, 05:34 PM

How you will provide 45V B+ with LM317? Will ride it on diodes?

Franz Gysi · 30th May 2010, 05:44 PM

Hmmmm, you are right, LM317 is limited to 37V.

Not a problem right now. I will build first the simplistic amp, then the psu.

Maybe I skip the LM317 solution and go direct to a shunt regulated supply...

Have a nice evening!
Franz

P.S.
At the moment listening Les McCann, Talk to the people. A great record!

Salas · 30th May 2010, 06:01 PM

Quote:

Originally Posted by Franz Gysi

Maybe I skip the LM317 solution and go direct to a shunt regulated supply...

Nice photo, happy listening.

I highly recommend you go V1.2 remote sensing reg. You have seen the regs thread.

Franz Gysi · 30th May 2010, 06:09 PM

O.K.

Next project.

Or better: next step in this project?

Franz

30th May 2010, 05:05 PM	#3754
Franz Gysi diyAudio Member Join Date: Oct 2007	Hi Salas I can measure tomorrow again, with 100 Ohm. Thanks for the hint! Tonight, no equipement available. Franz /Edit Yes, I understand: I used 14VDC for measuring, having 10 to 13VDC drop on the resistor: nothing left for the SK170... Last edited by Franz Gysi; 30th May 2010 at 05:09 PM.

30th May 2010, 05:26 PM	#3756
Franz Gysi diyAudio Member Join Date: Oct 2007	A little bit off topic, but maybe interesting for some of you for positioning this fine phono preamp: I used a EMT930 with a "Tondose" TSD15, followed by Lundahl transformers and an Aikido Phono pre. And I was very happy and never tried the Pacific concept. I compared the EMT solution with my musicserver source. Very very nearby, both solutions. Sometimes I preferd vinyl, sometimes the musicserver. Until I needed money. So, I could sell my EMT together with the trannies and the Aikido for a good price. What followed? This sales reactivated my activities concerning vinyl. I needed a cheap solution for listening vinyl. So I could buy cheap a Thorens TD160 and revised it completely. And mounted my DL103R. And adjusted everything. Then I attached my phonoclone preamp. The musicserver was still better, in every case. I fiddled also around with some other MC (Technics 300MC) and MM (Shure M75 and Shure V15/III) pickups and a VSPS instead of the phonoclone. The musicserver was still better, in every case. Then, I began to reactivate my Pacific board, never used before. Boahh, emotions, fascination! Not enough gain, of course, for the DL103R. So, I attached two Studer 1:6 trannies in front of the Pacific. Great! I have now at least the quality back, I had with my EMT solution, but for a fraction of the money... Only difference: with the EMT solution, I could track up to 100u horizontal amplitude, with the Thorens/DL103R I reach 80u, what is still enough. I am looking forward, to use the two stage concept of the simplistic (is it really simplistic?) pre without step up trannies. Franz Last edited by Franz Gysi; 30th May 2010 at 05:28 PM.

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30th May 2010, 04:48 PM	#3752
Franz Gysi diyAudio Member Join Date: Oct 2007	Uuuups, Salas I made wrong measurements yesterday! Most of my 2SK170V are showing between 12 to 13 mA IDDS. Second most between 11 and 12 mA and a few between 10 to 11 mA. So, no IDDS of 15.5mA. What happened? I measured yesterday with the mA function of my DMM. But today, I attached a 1k resistor and measured the voltage along this resistor. So, I trust this measurements today much more. Could you please simulate the circuit with 12.5 mA? Never trust your own measurements (in German: wer misst, misst Mist) Sorry again! Franz

30th May 2010, 04:52 PM	#3753
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	1k is too much it cuts VDS when from same B+, hence current. Measure a couple of noted ones with 100R to confirm. 12-13mA for most V seems low. I would expect them to range from 13-16mA by majority and narrow around 14-15mA.

30th May 2010, 05:16 PM	#3755
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Use 10V and 100R. The datasheet quotes IDSS at 10V. So I will know the ballpark of the sim model after your final results.

30th May 2010, 05:34 PM	#3757
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	How you will provide 45V B+ with LM317? Will ride it on diodes?

30th May 2010, 05:44 PM	#3758
Franz Gysi diyAudio Member Join Date: Oct 2007	Hmmmm, you are right, LM317 is limited to 37V. Not a problem right now. I will build first the simplistic amp, then the psu. Maybe I skip the LM317 solution and go direct to a shunt regulated supply... Have a nice evening! Franz P.S. At the moment listening Les McCann, Talk to the people. A great record!

30th May 2010, 06:09 PM	#3760
Franz Gysi diyAudio Member Join Date: Oct 2007	O.K. Next project. Or better: next step in this project? Franz