MPP

[RCruz]

Would you share the anti riaa circuit you are using ?

 

[Hans Polak]

Would you share the anti riaa circuit you are using ?

Here it is.
You can use either a source of 0 Ohm or 50 Ohm by changing the value of {Cx}.
Input is at the top, output has to be loaded with 10 Ohm.

 

[RCruz]

You have C=6.1135 nF at Rin = 0 ohm but .param C=6.1135 why not nF?

 

[Hans Polak]

You have C=6.1135 nF at Rin = 0 ohm but .param C=6.1135 why not nF?

Read the next line:
Rx=C*1e-9

 

[Hans Polak]

Typo: must be Cx = etc

 

[RCruz]

Thank you

Would you also share the math behind your calculated values ?

 

[Hans Polak]

Thank you

Would you also share the math behind your calculated values ?

Laplace with the 3 time constants

 

[RCruz]

Thank you so much Hans

Now I have another question..... is it possible to use your tech http://www.diyaudio.com/forums/anal...universal-diff-diff-head-amp.html#post5428617

To eliminate current in the IPS on the original Paradise ?

 

[Hans Polak]

Thank you so much Hans

Now I have another question..... is it possible to use your tech http://www.diyaudio.com/forums/anal...universal-diff-diff-head-amp.html#post5428617

To eliminate current in the IPS on the original Paradise ?

It was not my intention to be so active in Joachims thread.
Maybe you should ask the question in the other thread and explain the same time what you mean with IPS.


Hans

 

[RCruz]

Good

 

[Joachim Gerhard]

Just for completeness I found this rather interesting MC Pre-Pre.
I can improve it, sure.

 

[Joachim Gerhard]

A J-Fet version can be made.

 

[EUVL]

Doesn't seem to have much PSRR ?


Patrick

 

[Joachim Gerhard]

I have not simulated nor measured it.

 

[FdW]

O.k. a quick sim, all BC-327/337(40)'s
Gain about 28dB
Noise about 24nv/Hz1/2
THD near -85dB
PSU-load 75mA

As one can see, the design has a 'not do good' PSSR and the 75mA (per 15V rail) is thus demanding, it (the PSU) needs to be firm and precise.

The output offset (with the ideal transistors) is 11mV (not to bad at all).

 

[FdW]

P.S. the calculated noise of Zion is 351nV/Hz1/2 (1kHz) and 232nV/Hz1/2 (10kHz) at a gain of 60dB (more than 100x 28dB ) and including the passive (parallel) RIAA correction.

 

[Joachim Gerhard]

With other transistors noise of the circuit I have shown will be lower. Anyway, I did not put it here because I think it is great. It is for completeness and maybe inspiration.

 

[Joachim Gerhard]

For less noise R10 and R11 could be lower. That will effect distortion somewhat.

 

[Joachim Gerhard]

Here is an idea for a J-Fet Version. The J-Fets can be cascoded.

 

[EUVL]

As shown I think :

1) phase is inverted;
2) PSU noise goes 1:1 to output.


Patrick