The DAO SE all-FET Class-A ZGF Headphone Amplifier

Following my publication of the article "Alternative Configurations of the Simple JFET Source Follower" in 2008 :
http://www.diyaudio.com/forums/pass-labs/128571-some-other-source-follower-configurations.html
and the subsequent publishing of the DAO headphone follower circuit using the Loveltech LU1014 power JFET :
http://www.diyaudio.com/forums/head...follower-headphone-amplifier.html#post1130743
there has been a few private builds, as well as a few evolutions since the first circuit.

In August this year, we promised to publish an updated version with a few added features. This we now called DAO SE :
http://www.diyaudio.com/forums/pass...ce-follower-configurations-9.html#post3126245

More information will follow later in the next weeks, but here is a teaser first from our proto build.
It still needs cleaning and then final assembly.
The front hole will take a 5-pin Mini-XLR socket for our AK701 headphone.

:)


Patrick
 

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Two channels of the DAO followers alone dissipate a total of 15W.
And I guess you do not want a headphone amp on your desk at 60°C.
So the heat sink is not too over-dimensioned.

But yes, there is actually enough space to house 2 channels of LM3886 GainClone, plus a 300VA Plitron transformer.

We use a 5-pin Mini-XLR because the AK701 has a 4-wire cable (as any headphone should for best channel separation).
The 4-pin Mini-XLR has a rather asymmetrical pin layout.
Hence the 5-pin.


Patrick
 
nice work Patrick! why not use the lemo 4 pin? perfectly symmetrical and would seem more in keeping with the quality of your chassis.

the switchcraft mini XLR are very good, I just find the Lemos a higher quality. pricing is a bit better than it used to be now too, since its now more widely available mouser/digikey/markertech etc
 

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Joined 2006
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Following my publication of the article "Alternative Configurations of the Simple JFET Source Follower" in 2008 :
http://www.diyaudio.com/forums/pass-labs/128571-some-other-source-follower-configurations.html
and the subsequent publishing of the DAO headphone follower circuit using the Loveltech LU1014 power JFET :
http://www.diyaudio.com/forums/head...follower-headphone-amplifier.html#post1130743
there has been a few private builds, as well as a few evolutions since the first circuit.

In August this year, we promised to publish an updated version with a few added features. This we now called DAO SE :
http://www.diyaudio.com/forums/pass...ce-follower-configurations-9.html#post3126245

More information will follow later in the next weeks, but here is a teaser first from our proto build.
It still needs cleaning and then final assembly.
The front hole will take a 5-pin Mini-XLR socket for our AK701 headphone.

:)


Patrick

NICE !

:D:D

Great looking work Patrick.
 
only 2008 for me =) I love them and use them whenever I can. i'll take a finely machined Peek/Copper/Gold connector made for Aerospace/MIL/Nuclear Science, over any 'audiophile quality' XLR made from cryoed petrified Virgins Blood of any price.

when looked at in that light the price is really not bad.
 
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Joined 2009
Two channels of the DAO followers alone dissipate a total of 15W.
And I guess you do not want a headphone amp on your desk at 60°C.
So the heat sink is not too over-dimensioned.

.. and I have a 200w electrostatic headphone amp on my desk :p

Can't wait for the finalized design, the AMB Beta22 is still my reference headphone amp, nothing surpasses it so far.
 
oh sure, I just dont quite understand that solution, I cant think of another situation where you would need to cater for both 3 wire and 4 wire cables on the 1 amplifier and if you have this connector and socket on the amplifiers/headphones, you have either built/modified them yourself, or changed the connectors.

So this means the only situation it would help with, would be people who are willing to reterminate their headphones that have a common ground wire, but are not willing to recable them; every other situation can be handled with 4 pin and suitably wired amp/headphone

and honestly I think the world needs another balanced headphone 'standard' like it needs another Pol Pot....

sorry I dont mean to be a pita about this, people will do what they please as you say. I've made this unholy proliferation of different balanced headphone 'standards' a bit of a pet cause and I get on my soap box every time a new one is introduced. We now have something like 6 different connectors in use because everyone wants to be individual, thats ridiculous....


also Lemo make a 5 pin, up to 6-7 pin I think in that 0B size ;)
 
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it means I end up with jobs like this; which i'm not sure is a blessing or a curse... more work, but it means I have to keep more different connectors in stock.

anyway i'll let the thread get back on track, I know of quite a few people that have been waiting for this amp to be made more publicly digestible, I actually get messages about it on head-fi reasonably regularly. I built it up rough point to point (taylored) and like it a lot, but since I prefer balanced and all my sources are balanced, the circlotron version holds more interest for me.
 

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