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Posted 2nd April 2012 at 08:37 PM by DigitalJunkie

So,one of the monitors I use decided to die yesterday,it came back from standby,but had rainbow lines all over the screen..Something in the TFT panel itself,COF or something.Gaw.

Anyways,it had built in sound,using a TDA7496L chip for the amp..I got to looking at it,and decided to pull it off the PCB and build a (headphone)amp with it.

It's basically the schematic on the datasheet,with slightly larger input and output caps,and it's all powered by a 3-cell Li-ion pack for a Vcc of about 11-12V.

Here's the datasheet.

It doesn't sound tooo bad,really. It's not the best thing ever,but for a couple hours of tinkering with junk that was on the bench, I'm pleased.
It's got more than enough power for 'phones,some care needs to be taken to prevent any accidents.

So yea,yesterday was more or less; Troubleshoot monitor,discover it's FUBAR..then build an amp from it's guts!
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Total Comments 3


  1. Old Comment
    rjm's Avatar
    The performance of that chip really blows. 0.5% distortion over the entire output power range at 15k? Yikes!
    Posted 3rd April 2012 at 02:48 PM by rjm rjm is offline
  2. Old Comment
    Yea,it's your average cheap little chip-amp. The performance isn't anything to write home about.
    Overall,the sound is okay,considering. The treble seems to have a bit of sibilance at times,probably from the not-great HF distortion. The other thing,is that it's kinda noisy,There's a good amount of hiss with the input shorted.

    But,for watching Youtube videos and stuff,it's better than the PC's regular output. I've noticed that most PC's seem a bit anemic driving headphones,even on the dedicated "headphone output". This little amp adds some 'grunt' to it.

    I've been thinking about building a decent headphone amp for a while,and after tinkering with this thing,I think I'm right in thinking that I need one.
    I'm thinking of a Mosfet Class-A setup... Maybe something like this:
    DIY IRF610 MOSFET Class-A Headphone Amplifier Project
    Posted 3rd April 2012 at 09:55 PM by DigitalJunkie DigitalJunkie is offline
  3. Old Comment
    rjm's Avatar
    Did I hear someone say MOSFET class-A headphone amplifier?

    J-Mo, J-Mo mk. ii, Szekeres VE, Twilight
    Posted 4th April 2012 at 02:54 AM by rjm rjm is offline
    Updated 4th April 2012 at 05:57 AM by rjm

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