Pics of my Cresendo Amp

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Samuel Jayaraj said:
eD, the schematic you have posted is not that of the Crescendo but modified version of the Hexfet Amp. Your simulator version has a cascoded VAS and runs off higher rails.

Hi Samuel,

the schematic that I had attached is on "Elektor Electronics-UK " april/2001 issue BUT it has a few modifications :

1) the input offset circuit : idea from Hexfet

2) output mosfets: I don´t have spice models of
2SK1530/2SJ201 used on original article , so I use
IRF´s.....they works well

3) I made one VBE multiplier from BD139 because I don´t have
spice model of 2SK537 - used as vgs multiplier.

4) I changed the gate resistors from 220ohm to 22ohm. I has
increased the margin phase ( simulator ).

5) the parallel resistor with output coil I changed from 1ohm to
2,2ohm.


All of the rest is from Elektor-april/2001 issue ( it includes value of power supply ) BUT the attached version not includes others circuits from original article ( power suply , protection circuitry and offset comp.)

So, it is almost the same from elektor. Between all mods, I believe ( regarding sound quality ) only the output power mosfet ( IRFs ) will effect ( or not ! ), because the audio signal path has not changed.

regards

eD
 
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