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19 Oct 2015

Marantz CD40 added a dedicated discrete mosfet output ......you can hear the bells of heaven!!!!



 King of the midrange





......the bottom of the PCB


......cutting the right channel path

......cutting the left channel path


......warp to the end of this job...it was really too intricate to find even the time for a picture ....this is the third project I've tested on board searchung for "nirvana".......

......mosfet BS converting the very low current of TDA1541 flowing on its source....two trimers to cut the input offset  much closer as possible to zero .....



......here you can notice a row of BF245 fet working very well in their current sink config.

......but to drift a bit down the impedance I added even a buffer to drive this shiny signal to the heaven!
...stoled the dual supply from the pin of the missing opamp ...added two inductors for the coupling to my circuit.....
...new Rubycon  10.000uF Low ESR capacitors in power supply bypassed by polypropylene, welded in the bottom PCB side ....it gives more clean feeding and more deepnes in the soundstage.....
......I took off all was no more necessary from the board : op-amps and capacitors ........the twisted wires stoles the current directly from TDA pins




......I had many troubles with its original "flying wires" they made "antenna effect" in my first attempt  ..... 
......BS170 not only a work  horse but even a delicious sounding mosfet



......damped here and there to avoid vibrations trouble!!!







......here you are a new giant killer indeed!
In my opinion it beat easily many expensive players!
I tried it in comparison with the NAD C521i (wich isn't properly a giant but even not so bad) and after few seconds wasn't  hard to say wich one was the best of the two......
The scene is focalized in a superb way in the centre of  the frequencies band : piano is simply superb , the voices articulates and natural , the microdetails very accurate .....the soundstage isn't particulary open like many 24bit DACs such as Cyrrus Logic or Asahi Kasey but  wide enough to enjoy all his musicality and so particularly detailed!!!! 

No comparison at all with the original one wich is muddy dark and undetailed .......uninvolving at all!
This modded one plays on the blue side of tonality with an accurate and very shaped.....you can listen to it like you listen the  water of a brook  flowing ....... piano and voice are intimate and always in foreground....



 ......the schematic with the arrows highlighting a mod for better linearity........

and now just enjoying the music!!!!!!!!!!


see also another oustanding job with "discrete output" :
http://maoaudiolab.blogspot.it/2013/02/yamaha-cdx397-cs4392-dac-with-bf245.html

The very same circuit is used for yamaha CDX630E:


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