Headphone amp NE5532

[jayam000]

I want to make headphone amp with NE 5532. We have many in stock.
I have attached one circuit.
Guide me in the matter.
Any other suggestions are also welcome.

[ingenieus]

Here is a very interesting circuit for a headphone amp.

The bias for the output is controlled so that all of the output transistors remain on all of the time, thereby eliminating crossover distortion. The workings are explained in this article:

http://www.edn.com/contents/images/6702272.pdf

Hat tip to Bigun for this one.

[Elvee]

Originally Posted by ingenieus

Here is a very interesting circuit for a headphone amp.

The bias for the output is controlled so that all of the output transistors remain on all of the time, thereby eliminating crossover distortion. The workings are explained in this article:

http://www.edn.com/contents/images/6702272.pdf

Hat tip to Bigun for this one.

The circuit in post #1 is basically a method for paralleling a buffer with an amplifier, but it has little to do with the bias.

Also note that not all amplifiers will tolerate the additional phase shift.

Regarding this one http://www.edn.com/contents/images/6702272.pdf, it is instructive to look at J Broskie comments about it (bottom of the page):
http://www.tubecad.com/2010/04/blog0186.htm

[discrete]

What is the impedance of your headphones?

As hinted by the circuits above, you need some extra grunt to properly power lower impedance headphones to full volume (<250 ohm). Common op-amps do not do a good job by themselves.

Many popular headphone amps are based on this:

http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_2.pdf

It is a diamond buffer done with discrete components. Many common transistors can be used 2N4401/3, 2N3904/6 etc.

See part 1 for where the buffer fits into the op-amp circuit:

http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_1.pdf

[jayam000]

The headphone can be 32 ohm also.

Awiaitng comments on about circuit.
or
how about using single OPA 2134 for both the channels without buffer stage.

[Bonsai]

Try this.

If you have plenty of 5532's, then you can easily build a nice little HP amp with 60-80mA of drive which should be fine to drive a 32 Ohm set of 'phones.

Also, if you look at my website, I built and measured a very simple class
A HP amp that acheived great results.

[abraxalito]

Scale Doug Self's paralleled 5532 poweramp down a little according to the impedance of your phones.

Doug Selfs NE5532 Power Amp. Thoughts anyone !

[DualTriode]

Hello,

This TI circuit http://www.ti.com/lit/an/sboa031/sboa031.pdf is simple easy and cheap sounds ok too.
I built one using 5532’s.
Same curcuit as yours is on the TI site as an application note! it works!
DT
All just for fun!

[msdin]

I have a circuit for a headphone amp that I've been using since 1986.
It was design by late Barry Porter and has a current dumping output stage and works well with any phones from 32 - 600 ohms. I'll post the circuit later.

[jayam000]

Thanks for input from friends here. DualTriode, abraxalito & Bonsai.
I am waiting for the circuit from msdin.
The circuit of Mr. Bonsai is having 5 opamp in parallel as buffer.
do we need so many to drive 32 ohms load?
As per dual triode just one buffer stage ok.

Herewith attached one more circuit seen at the following post.

darlington/mosfet in emittor follower / headphone amp

Just one darlington transistor is used.

Kindly comment on this circuit.
which will be better? with 5532 as buffer ( 1st one) or Darlington BJT ( with this post) as output.