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
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
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
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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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.
when looked at in that light the price is really not bad.
.. and I have a 200w electrostatic headphone amp on my desk 😛
Can't wait for the finalized design, the AMB Beta22 is still my reference headphone amp, nothing surpasses it so far.
The reason I have adopted a 5pin output is to bring out a ground connection to also support single ended headphones (headphones wired with a common ground) from a single jack (assuming a bridged balanced output). Team 5-pin!
Everyone to his liking. The 5-pin solution will suit all.
And it is also size compatible with a Neutrik 6.35mm stereo phone jack socket.
So no changes in mechanical parts required.
We thought long about all these before starting.
🙂
Patrick
And it is also size compatible with a Neutrik 6.35mm stereo phone jack socket.
So no changes in mechanical parts required.
We thought long about all these before starting.
🙂
Patrick
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 😉
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.
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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Hey again, I notice you have changed your recommended Mosfet Cascode device from 2SK1529 to 2SK2013, have you done this for reasons of availability, or some other desirable characteristic?
