new Renardson amp

[dimitri]

May I draw attention of the respected diyers to a new amp by Mr. Renardson
http://www.angelfire.com/ab3/mjramp/newamp2.html
The PCB will be available soon, if you need it, drop a note to Mr. Renardson

 

[dimitri]

another amp

And another amp based on the same principles from Czech
http://petrh.czweb.org/renardson.php

 

[PMA]

There is a cross-over distortion error correction in both schematics, listenning experience would be appreciated.

 

[dimitri]

I have simulated the output and would like to discuss it regardless of John Curl opinion:
”This fellow Renardson, is amazing! He re-invents all of audio circuitry, and then says that high power is not needed in the home”.

 

[dimitri]

Here are simulation results with R8 stepping from 100 to 1000 Ohm,
- transfer function of the output stage,
- current through nonswitching negative (lower) output device,
- transconductance of the output stage, please note the excellent linearity

 

[millwood]

There is a cross-over distortion error correction in both schematics, listenning experience would be appreciated.

I am curious about it too, especially why R9/11/15 are set up that particular way.

 

[sss]

does any 1 know how this distortion correction works?

 

[dimitri]

dear milwood and sss,
you can read there
http://www.angelfire.com/ab3/mjramp/
or I can send additional info to you

 

[PMA]

dimitri,

you are probably using MicroCap7. Have you tried harmonic analysis? I would like to know whether there are or not higher order harmonics, and of what value.

Pavel

 

[dimitri]

Sorry for my slip,
instead "current through nonswitching negative (lower) output device"
please read "current through nonswitching positive (upper) output device"
Pavel, yes, it is uC7, I have not tried harmonic analysis, don't trust simulators... But it is not a problem

 

[dimitri]

Dear Pavel,
Could you please translate the abovementioned pages:
http://petrh.czweb.org/renardson.php
http://petrh.czweb.org/renardson_2.php
I tried to contact Petr Holub several times but failed

 

[PMA]

Dear Dimitrij,

I am sorry but I have not that much time. There is nothing new compared to original Renardson's publication.

Regards,
Pavel

 

[dimitri]

I got several comments from the board members that the amp will have low disto only with active load, and with reactive loads it will be the same as ordinary class B.

Now Mr Renardson checked the 20kHz distortion with a parallel capacitance, and added the result to the test page. The distortion was higher than before, but the load impedance is lower, so some increase was expected, but there is no serious crossover problem.

 

[capslock]

Dimitri, what test page are you referring to? The angelfire page is not accessible.

 

[dimitri]

http://www.angelfire.com/ab3/mjramp/test.html
http://www.angelfire.com/ab3/mjramp/newamp2.html

 

[Nelson Pass]

Re: another amp

And another amp based on the same principles from Czech
http://petrh.czweb.org/renardson.php

Reminds me of the bias circuit for the A40.

 

[tiefbassuebertr]

Reminds me of the bias circuit for the A40.

this one ?
https://www.firstwatt.com/pdf/art_a40.pdf

And another amp based on the same principles from Czech
Neexistujici domena - Webzdarma.cz | Webzdarma.cz

URL is dead - go to
Zesilova? s korekc? p?echodov?ho zkreslen?
https://web.archive.org/web/20040409233632/http://petrh.czweb.org/images/renardson/renardson.gif

I am looking for commercial amplifier brands, who use this approaches.