A High-Quality, High-Power Headphone Amplifier

[gdan]

If you are interested for a headphone amplifier, you could find one in my article in Audioxpress June 2013. The article is also on line here:
Build A High-Quality, High-Power Headphone Amplifier | audioXpress

If you are interested for easy construction using a PCB, you could find information here:
http://www.diyaudio.com/forums/swap...headphone-amplifier-audioxpress-6-2013-a.html

 

[gdan]

A reminder for those who missed the initial post.

 

[npn]

Can you send me a Link to the protection circuit from Douglas self?

 

[gdan]

It is based on an old article in Electronics World magazine by D. Self: "Muting Relays", Jul 1999.

I don't know of any link that you could view this article online.

 

[npn]

Maybe its in the small signal Audio Design handbook from Doiglas Self? Pearl-hifi has the pdf to this book. Third google link.

 

[gdan]

I have ordered a new small quantity of PCBs for my Headphone amplifier.

Build A High-Quality, High-Power Headphone Amplifier | audioXpress

The cost is 50 Euros for the two boards that are needed for a stereo amplifier.

If you are interested, send me an email at: gntanavaras@gmail.com

 

[Koifarm]

This thread is commercial, please move to the vendors subforum.

 

[gdan]

If you are interested for the Headphone amplifier see the last information in my thread:
http://www.diyaudio.com/forums/swap...adphone-amplifier-audioxpress-6-2013-a-2.html

 

[gdan]

New information can be found here:
http://www.diyaudio.com/forums/swap...adphone-amplifier-audioxpress-6-2013-a-2.html

 

[gdan]

New information for the PCBs can be found here:
http://www.diyaudio.com/forums/swap...adphone-amplifier-audioxpress-6-2013-a-3.html

 

[gdan]

If you are looking to build a High-Quality, High-Powered Headphone Amplifier you may find useful information at this link:
http://www.diyaudio.com/forums/swap...adphone-amplifier-audioxpress-6-2013-a-3.html

 

[gdan]

Halldor Scheving Vidarsson who lives in Iceland send me a link with a lot of pictures concerning the build process of my Headphone amplifier.

I have some PCBs available if someone is interested to build this amplifier.

Here are two of these pictures:

 

[xrk971]

Gdan,
Thanks for bringing our attention to this amp - looks like a nicely designed full-featured HPA/preamp.

I like the implementation in a metal lined wooden case - nice!

I built a HPA using the OPA1688 in parallel, it can deliver 75mA ea, so would require only 4 amps (or 2 dual IC's or 1 quad IC) for the same power, and I think THD is slightly better. Here is a hand etched dual parallel implementation with a custom power supply using DC-DC for 24v rails and then TPS7Axxx low noise regulators for battery-like +/-18v supply. It sounds very nice - quite powerful at 150mA. I am working on a parallel x8 version.

Here is layout if anyone wants to try - super easy to make:

More info here:
Cheap as Chips OPA1688 Low-THD Muscle Amp

 

[gdan]

An construction note

The 9Volt output relay that is used in the Headphone amplifier is replaced with a 12 Volt relay which is more easily found.
Only some resistor values (R29, R35, R36) are changed for this.

 

[gdan]

Here are some very nice photos for the Headphone amplifier, build by John S. in England.

 

[gdan]

Matti Pussinen who lives in Finland build my headphone amplifier and was very pleased to send me this message:

"Dear George,
I have a very good headphone amp, yes indeed, so good, I like it.
Dead quiet, and all is there. Been listening almost my all cd collection. And vinyls."

He also send me some photos of the amplifier.

Here is the first:

 

[gdan]

and two photos of the inside of the amplifier:

 

[Osvaldo de Banfield]

If you use split power supply, then output coupling capacitors are useless.

 

[gdan]

No output coupling capacitors are used.
Instead a servo circuit is used.

 

[Osvaldo de Banfield]

Aha, then what are C134 to C138 intended for if they aren't coupling capacitors????