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Old 23rd April 2010, 07:27 AM   #11
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Originally Posted by FdW View Post
Let me know what you think of it


The rest i could probably live with but not the regulators.
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Old 23rd April 2010, 08:12 AM   #12
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Originally Posted by analog_sa View Post
The rest i could probably live with but not the regulators.
Can you elaborate a bit on that, and maybe hint at a replacement strategy?

Regards,
Frans.
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Old 23rd April 2010, 08:50 AM   #13
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I consider series regs, such as you are using, are as outdated for good sounding audio as paper in oil caps.

Constant current fed shunt regs are very little more complex to build, but offer huge sonic benefits. There are numerous CCS/Shunt circuits here on DIYAudio.

And I agree with the other poster - your input R's are WAY too large for SOTA noise levels - especially on the MM inputs.

Regards, Allen
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Old 23rd April 2010, 09:27 AM   #14
FdW is offline FdW  Netherlands
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Quote:
Originally Posted by Allen Wright View Post
I consider series regs, such as you are using, are as outdated for good sounding audio as paper in oil caps.

Constant current fed shunt regs are very little more complex to build, but offer huge sonic benefits. There are numerous CCS/Shunt circuits here on DIYAudio.

And I agree with the other poster - your input R's are WAY too large for SOTA noise levels - especially on the MM inputs.

Regards, Allen
What abouit upgrading to these
NewClassD UWB Regulator

The typical MM cartridge needs to see a 47k impedance, the selected values correspond with that. Is what you are saying, making a compromise on matching impedance in favor of lowered noise?

Regards,
Frans de Wit.

Last edited by FdW; 23rd April 2010 at 09:31 AM.
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Old 23rd April 2010, 01:23 PM   #15
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Nice job, well executed!
I have sterted an MC design using the SSM2017/INA217 as the front-end. Any thoughts on this, anyone? Thanks, E
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Old 23rd April 2010, 01:34 PM   #16
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Yes, the LME49990 is very good in terms of technical data and the circuit i build with it sounds very musical. Thanks for telling me what resistors you use. i know this ones and they have good properties. Have not tried them sofar.
Concerning PSUs for modern Opamps you have to consider that they have very good PSU
suppression so do not expect a miracle when you go to shunt.
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Old 23rd April 2010, 01:58 PM   #17
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Originally Posted by Joachim Gerhard View Post
Concerning PSUs for modern Opamps you have to consider that they have very good PSU suppression so do not expect a miracle when you go to shunt.
Yes I know, but this is an all out (at the least almost no expenses spared) design, if improvements can be made than I will consider.

On the other end, the PSU is really good filtered, I suspect that there is nearly no ripple at the regulator input, so the regulators are in a sort of constant current mode (the amount of current taken by the opamps is near constant) and there is a denoising stage after the regulators (using LME49710s) this should be nearly (if not totally) noise free (I suspect).

Any thoughts on this?

Regards,
Frans de Wit.

<at the least almost no expenses spared> For this type of design.
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Old 23rd April 2010, 02:26 PM   #18
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Originally Posted by mickeymoose View Post
Nice job, well executed!
I have sterted an MC design using the SSM2017/INA217 as the front-end. Any thoughts on this, anyone? Thanks, E
The INA217 looks interesting, maybe PBW and/or low frequency noise are a bit of a problem. You should definitely have a look at the CMRR, this is only 100db (compared to 120db for the LME49710). As I am a believer in simplicity it would not be my first choice, but one could make a little test and (almost) drop it in the schema I am using.
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Old 23rd April 2010, 02:32 PM   #19
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When i go after D.Self you already did a great job but on this forum are many fans of shunt PSUs. I compared the LC Audio Low noise supply ( series ) with the Twisted Pear Placid ( shunt ) and heard a small improvement in terms of sweetness of sound, low level resolution and bass quality but it was not night and day.
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Old 23rd April 2010, 06:14 PM   #20
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Quote:
Originally Posted by Joachim Gerhard View Post
Concerning PSUs for modern Opamps you have to consider that they have very good PSU
suppression so do not expect a miracle when you go to shunt.

I've been hearing this since the time of the LF351 but upgrading the 3-terminal horrors with superregs, or even better, shunt regs has always brought a very substantial improvement. Of course YMMV.
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