DjLeco
Moderator
Upgrading this amp http://www.forum.poweraudio.ro/viewtopic.php?f=64&t=19182 with newer versions of Leco Amp modules, with the recovered modules from it, I decided to make another Leco Amp with transformer and those 2 modules.
Output devices used are a little special with SOA of 2,5A/80Vce/1Sec, MJL21195 and MJL21196.
http://www.onsemi.com/pub_link/Collateral/MJL21195-D.PDF
Power transformer is from Crest VS1100, wich assures after bridge rectifier and storage capacitors, +/- 78Vdc in idle.
http://www.peaveycommercialaudio.com/media/pdf/vs1100_5-20-97.pdf
As storage capacitors I used 4 pieces of 12000uF, 2 parralel on rail + 2 pieces of 3300uF per rail wich is around 27000uF/rail or 54000uF total storage.
Is one amp real 2 ohm load per ch, output current limiting occuring at 35A rms.
As relevant, Crown Macrotech 5000VZ has current limit set at 30A rms.
Suporta full 4 ohm in configuratie bridge, sau 2 ohm/canal si ofera un sunet exceptional de calitativ, pe drivre suna demential, cit si in bass sau full range.
Freq range with less than 0,5db deviation at extemes of bandthwith is 5Hz-50kHz at full power/2 ohm (approximed on oscilloscope readings).
Some pictures during construction:
I made some tests on different dummy loads, 4 ohm, 2 ohm, and 1 ohm, also with music on real speakers:
Testing output current at 4 ohm/50Hz:
https://www.youtube.com/watch?v=BwVYN2zZTeU&feature=youtu.be
Testing output current at 2 ohm/50Hz:
https://www.youtube.com/watch?v=7qaz_T0hb4c&feature=youtu.be
Testing output current at 1 ohm/50Hz:
https://www.youtube.com/watch?v=_s_fFe3W46g&feature=youtu.be
Testing squarewave 2 ohm 50Hz+10kHz+20kHz+40kHz:
https://www.youtube.com/watch?v=V9vQmmy6zNE
Testing squarewave 8 ohm (standard rise and fall times measurement):
10kHz+20kHz+40kHz+60kHz:
https://www.youtube.com/watch?v=ojQ0OBJAVxs&feature=youtu.be
Linearity on output between 1000Hz and 100000Hz:
https://www.youtube.com/watch?v=1vpoI9xnJEM
And final test on music on real speakers Ch 1 loaded with 2 ohms, Ch2 loaded with 4 ohms, choose 1080p on youtube for max audio quality:
https://www.youtube.com/watch?v=IZ5flhHV8C0&feature=youtu.be
Output devices used are a little special with SOA of 2,5A/80Vce/1Sec, MJL21195 and MJL21196.
http://www.onsemi.com/pub_link/Collateral/MJL21195-D.PDF
Power transformer is from Crest VS1100, wich assures after bridge rectifier and storage capacitors, +/- 78Vdc in idle.
http://www.peaveycommercialaudio.com/media/pdf/vs1100_5-20-97.pdf
As storage capacitors I used 4 pieces of 12000uF, 2 parralel on rail + 2 pieces of 3300uF per rail wich is around 27000uF/rail or 54000uF total storage.
Is one amp real 2 ohm load per ch, output current limiting occuring at 35A rms.
As relevant, Crown Macrotech 5000VZ has current limit set at 30A rms.
Suporta full 4 ohm in configuratie bridge, sau 2 ohm/canal si ofera un sunet exceptional de calitativ, pe drivre suna demential, cit si in bass sau full range.
Freq range with less than 0,5db deviation at extemes of bandthwith is 5Hz-50kHz at full power/2 ohm (approximed on oscilloscope readings).
Some pictures during construction:
I made some tests on different dummy loads, 4 ohm, 2 ohm, and 1 ohm, also with music on real speakers:
Testing output current at 4 ohm/50Hz:
https://www.youtube.com/watch?v=BwVYN2zZTeU&feature=youtu.be
Testing output current at 2 ohm/50Hz:
https://www.youtube.com/watch?v=7qaz_T0hb4c&feature=youtu.be
Testing output current at 1 ohm/50Hz:
https://www.youtube.com/watch?v=_s_fFe3W46g&feature=youtu.be
Testing squarewave 2 ohm 50Hz+10kHz+20kHz+40kHz:
https://www.youtube.com/watch?v=V9vQmmy6zNE
Testing squarewave 8 ohm (standard rise and fall times measurement):
10kHz+20kHz+40kHz+60kHz:
https://www.youtube.com/watch?v=ojQ0OBJAVxs&feature=youtu.be
Linearity on output between 1000Hz and 100000Hz:
https://www.youtube.com/watch?v=1vpoI9xnJEM
And final test on music on real speakers Ch 1 loaded with 2 ohms, Ch2 loaded with 4 ohms, choose 1080p on youtube for max audio quality:
https://www.youtube.com/watch?v=IZ5flhHV8C0&feature=youtu.be
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