You do not have a power supply, instead you have a DC to DC converter that has a lot of 100kHz switching noise.
The original circuit that amplified the power supply noise would be clipping with all this noise. Therefore the 470nF filter capacitor I added to the voltage divider and third and fourth bias resistors are important.

Many Thanks you for all your help on this. Will draw up new schematic for your suggested Circuit.
Cheers

 

What produces the +5V power supply? if it is a phone "charger" when it might produce a hum and/or whining sound. Therefore the opamps should be biased like this:

Hi Audioguru,

For Your Circuit posted, can i use the OPA2134UA as the dual Opamp, as I have found this in a SOIC8 package
which fits with my needs.

Thankyou

 

Hi Audioguru,

For Your Circuit posted, can i use the OPA2134UA as the dual Opamp, as I have found this in a SOIC8 package
which fits with my needs.

Thankyou

Its minimum supply For an OPA2134 is 5V when it produces a small output level into a high load impedance. It will be fine if your headphones amplifier has enough gain.

 

Its minimum supply For an OPA2134 is 5V when it produces a small output level into a high load impedance. It will be fine if your headphones amplifier has enough gain.

Thanks again for your insight on the subject

 

Its minimum supply For an OPA2134 is 5V when it produces a small output level into a high load impedance. It will be fine if your headphones amplifier has enough gain.

I noticed that the TI website recommended the OPA1656 for higher bandwidth (53MHz), lower noise (4.3nV/√Hz), and higher output drive (100mA). Is there any reason not to use it in this case? Just curious

 

The spec's for the OPA1656 are excellent and its high cost shows it.

 

The spec's for the OPA1656 are excellent and its high cost shows it.

I'm confused. If I'm reading the TI website correctly, the quantity one price for the OPA1656 is lower ($2 vs ~$3.50)

 

At Digikey, if you buy 2500 OPA1656 ICs then they are $1.20US each. If you buy only 1 then it costs $2.73US on tape or $2.94US in a tube.

 

At Digikey, if you buy 2500 OPA1656 ICs then they are $1.20US each. If you buy only 1 then it costs $2.73US on tape or $2.94US in a tube.

But it seems the "inferior" OPA2134 is more expensive there too. At digikey the quantity 1 price of the OPA2134 is between US$4 and $5depending on the variant. The 2500 unit price is just over $2. Is there something about the OPA2134 that justifies the higher price?

 

Maybe the newer and better OPA1656 costs much less than the older OPA2134 because it is newer?