i like the design of this amp and will like to increase the out put power, to do this i tried some spice sim and is working (sim) not so good, never achieved 20 watts with out heavy distortions.
i am referring to so called “final version” +/- 20vdc and 20 watts out put.
who tried to increase the out put pwr over 20w, which will work properly from the original schematics?
your answers will be very much appreciated
best regards
Williams
i am referring to so called “final version” +/- 20vdc and 20 watts out put.
who tried to increase the out put pwr over 20w, which will work properly from the original schematics?
your answers will be very much appreciated
best regards
Williams
Hi,
I'm just finishing the first of a pair of monobocks based on the Hiraga class A schematic. I'm getting around 40W. I don't know how much distortion you consider 'heavy', but I'm measuring bellow 0.1% (using my laptop and a software called 'Audio Tester'). I didn't do any changes to the original schematic other than raise the rails to +/- 35V and adjust quiescent current to 2A. Output devices are 2SC2922, drivers 2SA968 and the rest BC550C.
I've been posting about this project on a Portuguese forum (maybe you don't understand Portuguese, but the thread has a number of pics).
http://forumhifi.com/board/index.php?topic=6108.0
J.Guilherme
I'm just finishing the first of a pair of monobocks based on the Hiraga class A schematic. I'm getting around 40W. I don't know how much distortion you consider 'heavy', but I'm measuring bellow 0.1% (using my laptop and a software called 'Audio Tester'). I didn't do any changes to the original schematic other than raise the rails to +/- 35V and adjust quiescent current to 2A. Output devices are 2SC2922, drivers 2SA968 and the rest BC550C.
I've been posting about this project on a Portuguese forum (maybe you don't understand Portuguese, but the thread has a number of pics).
http://forumhifi.com/board/index.php?topic=6108.0
J.Guilherme
hi,
really sorry i am short in Portuguese but I will translate it some how.
thanks for the answer. in my sim I couldn't get the components
from the schematic " the final version " so the substitutes are?? so and so. the heavy distortion is at close to max pwr. it is very promising to go on with this. what schematic did you use, there are about four of them?
what is the pwr of you trafo? any help is very much appreciated.
best regards
Williams
really sorry i am short in Portuguese but I will translate it some how.
thanks for the answer. in my sim I couldn't get the components
from the schematic " the final version " so the substitutes are?? so and so. the heavy distortion is at close to max pwr. it is very promising to go on with this. what schematic did you use, there are about four of them?
what is the pwr of you trafo? any help is very much appreciated.
best regards
Williams
The replacements I used are listed bellow. I used a 500VA trafo with 25+25 secondaries, 40000 uF per rail capacitance and MUR 1560 diodes on the rectifier. I followed the schematic on this site: http://www.tcaas.btinternet.co.uk/hiraga3.htm, then added a few bells and wistles of my own (temperature indicator, soft-start, clip indicator and mute).
I'm driving it with the 'composite opamp' described by Jung ( AD744/AD811). I like the sound very much, enough to retire my Plinius integrated.
2SC1775 -> BC550C
2SA872 -> BC560C
2SA634 -> 2SA968
2SC1096 -> 2SC2238
2SD188 -> 2SC2922Y
2SA627 -> 2SA1216Y
J.Guilherme
I'm driving it with the 'composite opamp' described by Jung ( AD744/AD811). I like the sound very much, enough to retire my Plinius integrated.
2SC1775 -> BC550C
2SA872 -> BC560C
2SA634 -> 2SA968
2SC1096 -> 2SC2238
2SD188 -> 2SC2922Y
2SA627 -> 2SA1216Y
J.Guilherme
hi J.Guilherme,
thanks a lot for the information. in short time i will start the project.
best regards
williams
thanks a lot for the information. in short time i will start the project.
best regards
williams
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