Official M2 schematic

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Joined 2012
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let me paraphrase what I already wrote ( as answer to same question ) on Baby DiyA :

consider that we have rails of +/-22Vdc

that means (not counting losses precisely) that we have 44Vpp envelope for output swing

amp's gain is 5V/V (autoformer ratio)

so , for full blast on output we need 44Vpp/50= 8.8Vpp at input

that's 8.8/2/1.41= 3.11Vrms

so , if there is any idiot available ( and believe me , it always is ) , he certainly will bang full blast of something into amp's input

in that case , output node (point where diodes are connected ) will try to go both to roof and cellar , resulting in heavy clipping and most probably even more damage

so , just imagine effect of clamping diodes (D1-D2-D3) - they are clamping output node to rails , limiting max . signal amplitude
NB that output node is in strong correlation with mosfet gates , so clamping of outout is in fact achieved with gate clamping

Q6 and Q7 are there to maintain no more than 1V25 across corresponding resistors , saving LED from nasty peaks and maintaining smooth biasing

btw. did you put second schematic , framed , on the wall ?

Thanks ZM ! Now I understand. No just pictures of precious VFETs on the wall ;)
 
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Joined 2009
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i was deeply impressed by these lines in Tone Audio December 2010 from Jeff Dorgey:

"Removing the $60,000 pair of Burmester 911 mk. 3 monoblocks in my reference system, the M2 held its own, with even slightly more inner detail than the German monster amps. This amplifier was able to take hold of the GamuT S9’s with enough control that a few casual visitors didn’t even know the Burmester amplifiers were no longer in the system!"
 
My German dealer says:
the WSM Series should be the equal to the PC Series a Little bit more wattage.
I want to use the WSM Series but im a Little bit concerned that it will vary to much from the PC Series.
Have someone a little bit experience with this transformers?
And can say somthing about it.

thanks Alex
 
My German dealer says:
the WSM Series should be the equal to the PC Series a Little bit more wattage.
I want to use the WSM Series but im a Little bit concerned that it will vary to much from the PC Series.
Have someone a little bit experience with this transformers?
And can say somthing about it.

thanks Alex

They are cheap. Buy both put one of each in separate channels, test which is best.
Job done.
 
Member
Joined 2009
Paid Member
My German dealer says:
the WSM Series should be the equal to the PC Series a Little bit more wattage.
I want to use the WSM Series but im a Little bit concerned that it will vary to much from the PC Series.
Have someone a little bit experience with this transformers?
And can say somthing about it.

thanks Alex

I think it's one is the right one, choose 600:15k.

https://www.edcorusa.com/pc_series

The German dealer is more expensive and doesn't have all types.
But even ordering in the States you have to wait 6 weeks for production.

I did.....:)

Look at the price!
 
Official Court Jester
Joined 2003
Paid Member
well , from my explanation and Papa's punch lines ......... I would say that 3 diodes aren't necessary for sane user , but two LM385 are necessary - for better sleep

really functional only in heavy load circumstances ....... but you never know what Cats in house are going to do with speaker cables/terminals/interconnects

if vacuuming the room and cleaning is your job , leave them out too; if Frau is doing at least part of that , put them in

;)
 
….because we never saw this features in F4 or F6 or J2 before I must conclude that

the day Nelson made the M2 circuit somebody new in the house was vacuum cleaning or it was his birthday and he spent some extra features to this amp……

:D

I think that without feedback linearity under all operating conditions becomes more critical. So I think that could have a lot to do with Nelson showing off. :)
 
... first heatsink mounting...

will modify the PCB for transformer shielding...

Jean-Paul
 

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