You find wide discrepancy between the 2 channels in THD+N. The lm3886 in stand alone with the same gain, measures <0.002% @8 ohm 55w. The unlucky channel got nothing better and the lucky one, less than 4 times better, why?
This amp is a counterfeit version of Nickolai Shveydky's ZD-50, copyright 2007 version. You find the English translation of 2008, last version bellow. It was developed on Russian website vegalab.ru where you find the gerber files to download for free as it is in public domain.
This circuit needs high precision (instrumental) opamp as error corrector and requires trimming, that the counterfeitor doesn't know about it.
I have posted a better version of ZD-50 on DIYaudio website which got erased on the demand of the counterfeitor, it could be switched ER-composite and get 2 different sounds.
Luckily, an unsatisfied modulus86 customer, @wwwtttwww, took back my circuit and elaborated it into 286 and 686 versions.
www.diyaudio.com
He has developed a circuit after several trials and measures that you can populate it as 86 or 286. PM him to obtain his gerber files.
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This amp is a counterfeit version of Nickolai Shveydky's ZD-50, copyright 2007 version. You find the English translation of 2008, last version bellow. It was developed on Russian website vegalab.ru where you find the gerber files to download for free as it is in public domain.
This circuit needs high precision (instrumental) opamp as error corrector and requires trimming, that the counterfeitor doesn't know about it.
I have posted a better version of ZD-50 on DIYaudio website which got erased on the demand of the counterfeitor, it could be switched ER-composite and get 2 different sounds.
Luckily, an unsatisfied modulus86 customer, @wwwtttwww, took back my circuit and elaborated it into 286 and 686 versions.
A New EC-Composite LM3886 Amp
This Error-Correction/Composite Combo amp is based on Mr Evil "Unnamed feedback method explored" and Nickolay Shvydky "My ZD-50 ultralow distortion chipamp" Output power at +/-29.5V: 8 ohms clip at 42W, 4 ohm clip at 65W. It is very stable in both EC and Comp mode. Ans it behaves very well...
