Wednesday, May 5, 2010

Class-A 2SK1058 MOSFET Amplifier

For my first amplifer project, i decided to build this simple amp based on Mark Housten ZCA design. You can visit http://www.diyaudioprojects.com for more information. 



Single-Ended Class-A MOSFET Amplifier Schematic


 For the power resistor I used one 15ohm 100w wirewound resistor from Arcol. Instead of a potmeter on the input I used one 47,5kohm resistor. As I plan on using the volume control on my PC, I dont want any unnecessary parts to ruin the sound. The mosfet I got from Ebay. Bypass Caps are Mundorf Mcap supreme. I just happend to have them laying around. I belive there are other cheaper caps that will do the job just as good. The wire from the RCA connectors are pure silver with teflon insulation. The rest of the wires are cheap solid copper. 




Class-A MOSFET Amplifier Power Supply Schematic

For the choke I used two 4,7mH, one at the positiv rail and one at the negativ. The big electrolyt caps are 15000µF from rifa(x4)


















4 comments:

  1. You may cook those really nice M-Caps sitting over the heat sink. This amp gets extremely hot and I can see those caps melting to a black goo.

    It appears you have used two power trannies or are they chokes. Your PS has to be very quiet for anything class A so lots of big caps and a choke help. Also choked amps (I think) sound better than non-choked. This applies to SS amps also.

    Mark Houston - creator of the ZCA.

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  2. This may interest you.

    http://www.diyaudioprojects.com/Forum/viewtopic.php?f=10&t=3942

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  3. It looks so nice and I'd like to biul one.
    But I have some questions.
    1. Can I replace 2SK1058 to 2SK1529 or something else (like IRFP240) ?
    2. Can the 40W resistor be replaced by a light bulb?

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  4. What??? You added a 47k ohm at input!! That's mute man !!!

    ReplyDelete