A simple stereo amplifier based on C3856

Discussion in 'The Projects Forum' started by tcdk, Jan 7, 2009.

  1. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    Hi

    I would like to build a simple stereo amplifier with only input/output, volume and on/off @ 2x50-80w (at least)

    I have some C3856 and A1492 laying around that I thought I could use for the project.

    I've searched through google after a schematic using C3856 (or similair) but haven't found anything yet.

    Does anyone have a schematic or something that I could use?

    Thanks
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If that's a 2SC3586, it's not gonna be easy. The transistor is rated for UHF and microwave amplification. Audio amplification would be an unusual application.

    You can always try it as a substitute for another type in an existing design.
     
  3. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
  4. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    It's a C3586. I got it from a Akai stereo amplifier that died.
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The number C3586 turns up things like furniture. It may be a non-standard transistor, and so will be impossible to get specifications.
     
  6. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    Sorry, it's C3856 and not C3586
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Ok, the 2SC2856 is an NPN transistor good for 150 watts, 200 volts, and 15 amps - the 2SA1492's are the PNP compliments. They will sub nicely for any design with 2N3055's and 2N2955's.

    There's a grunch here - http://www.hobbyprojects.com/A/audio.html - to choose from. If one is by Mike Leach, it is very good.
     
  8. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    Thanks!

    I can't find any with the specific transistor, but found this one very interesting and easy.
    http://sound.westhost.com/project19.htm

    The LM3876 chip is also pretty cheap :)

    Eg. @ futurlec.com the LM3876T is statet as "40W High Perf. Audio Amplifier"
    and other places as 56W - should I make any differents in the layout if or is it the same?

     
  9. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    What kind of transformer would you use for a amplifier like that? (35V)
    I found Hammond 266K35, but don't know if that will do.

    And where should I buy parts? I normaly buy from futurlec.com, maplin.co.uk and mouser.com - but no one have both the LM3876 and a transformer that suits....
     
  10. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Transformers are quite expensive - can you get to some sites that offer surplus items? Don't forget you need the current as well as the voltage. A 24 volt transformer will give close to 35 volts DC after rectification with good filter caps.

    You can always refigure resistor values if you go significantly up in voltage - say, 42 volts instead of 35. Your output transistors will handle the power, so see what transformers you can scrounge up and work with it/them.
     
  11. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    I just found out that I had a 40V transformer from a old amp.
    I altso has a several ~36V outlets to :)

    There was also a pretty large heatsink, some RCA chassis jacks, speakerouts and more.
    Yummy!
     
  12. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    That's why nobody who does electronics ever throws anything away.
     
  13. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,535
    Until the garage won't close. I'm so there dude!
     
  14. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    No, you just have to build some stuff and move it from the garage to the house.
     
  15. tcdk

    Thread Starter Member

    Jan 7, 2009
    23
    0
    true! true!
     
Loading...