GDIY51X Headphone amplifier

[kante1603]

Humans win!

Changed the value for the shunt resistor to 4.7kΩ which seems to work.
Maybe some other prototype builders can try and confirm.

Cut off Frequency of this RC is around 3 Hz.
Maybe a higher value resistor is sufficient too.

Cheers,
Carsten

Cool Carsten!

Sadly I'm on holidays far away from home and don't have my proto with me to confirm,hahaha.....
But maybe Volker can do it?
I'll be back home end of august and can do it then earliest,sorry.......

Best regards,

Udo.

 

[culteousness1]

No problem, Udo. Enjoy your vacation!

I just uploaded the revised front panel file from reply #47.
Locations for the stereo jacks should now be correct.

Carsten

 

[kvothe]

Hello guys,

I just tested mine with my pair of Denon AH-D2000 25ohm. This is loud, even at about 9 o`clock. Peak led is just a little off/ late.
Sounds good and works with the pot of Udo´s BOM, but sometimes I feel the high frequencies bite a little on peaks, a bit like distortion, but not quite.
Did you mean this by "scratchy pot"?

here some pictures:

http://www.groupdiy.com/gallery/0/51388-110913082602-1821193.jpeg

http://www.groupdiy.com/gallery/0/51388-110913082602-181979.jpeg

Had to do the drilling by myself, a first time. The pot and Jacks are not centered, but hey, they work

 

[culteousness1]

So, you might had luck with your pot, but ours
are scratchy when moved. Seems to be a DC
issue coming from the NE5532 as Harpo already
pointed out.

After high passing the noise was gone when
moving the pot. Still waiting for Udo to confirm.

Best,
Carsten

 

[rob_gould]

How are things progressing with this one?  Any news?

 

[culteousness1]

I am fine with my fixed version. Dunno if Volker or Udo had a chance to double respectively tripple check.

Best,
Carsten

 

[kante1603]

Excuse me answering so late Carsten!
My notifications still don't work correct,I have completely missed what was happening here.
Also lots of other work,my real life has got me back now.

Anyway,did your mod and yes,my pot isn't scratching anymore....cool!

I was also wondering what would happen if the pot was a plastic conductive type.The idea came to my mind when I worked on my W492 clones which are full of NE5532s.I have Omeg pots everywhere in this build.

Who knows,

best,

Udo.

 

[[silent:arts]]

Since I still haven't had a chance to test it myself, I could implement the "Carsten" Mod and do a small run of PCBs.

I still do not get the problem (in theory I do), since I did open the original unit - and there is a much more worse (cheap) potentiometer inside.

 

[janczmok]

It's a perfect addition to my 51X rack. So count me in for one kit (or PCB with frontpanel or just PCB) definitely

good that the scratchy pot issue is resolved.

 

[culteousness1]

Since I still haven't had a chance to test it myself, I could implement the "Carsten" Mod and do a small run of PCBs.

I still do not get the problem (in theory I do), since I did open the original unit - and there is a much more worse (cheap) potentiometer inside.

Volker, before you dump the old run of boards, I could need two more.
I have no problem with freidraht-dengling the additional 4 parts...

Maybe you can put them on hold for me until my next order  ;D

Carsten

 

[kante1603]

freidraht-dengling

What a lovely word ;D

Udo.

 

[[silent:arts]]

Hehe. Well, the Beta-run was only 5 PCBs.
Nothing wrong with "freidraht-dengling", but - nothing left.

Will give it a go, PCBs only (with your mod).
No Brackets or Front Panels, no part kits.

Give me a few days for updating the (control) PCB.

 

[culteousness1]

All right. Just had the feeling that your boards were to nice to litter...
Will order from the new batch at a given time like everyone else.

Carsten

 

[rob_gould]

Hehe. Well, the Beta-run was only 5 PCBs.
Nothing wrong with "freidraht-dengling", but - nothing left.

Will give it a go, PCBs only (with your mod).
No Brackets or Front Panels, no part kits.

Give me a few days for updating the (control) PCB.

Coolio.  I am most certainly in for one when the PCBs arrive.  With these PCBs, the bracket from your shop and a panel from Frank I should be good to go. 

Thanks for sticking with it!

 

[Spiritworks]

How has this progressed? I would like to build one if a complete kit is available.

 

[rob_gould]

How has this progressed? I would like to build one if a complete kit is available.

Seems like this one's died a death.  And Silent Arts says specifically a few posts above that he would only sell PCBs anyway.

I'm giving this a go.  I thought it was a bit out of my comfort zone, but I've built one headphone amp already.  Making another couple of amps and the DA to split the incoming signal should be pretty straightforward...

http://groupdiy.com/index.php?topic=53523.0

 

[[silent:arts]]

Na, it didn't died a death. Sometimes there are more important things to do and to be cleared.
However, a good link if you want a headphone amp now!

 

[culteousness1]

Vorsichtiger BUMP... 

 

[[silent:arts]]

Ok, I'm back on this  8)

One week off in two weeks, so time to change the control PCB,
doing new 51X Backplane designs and order them together.

 

[culteousness1]

Finally ordered a front panel and finished the prototype:

The file I posted a while back needed a gentle treatment with the file.
A revised version can be found here.

Many thanks to Volker and the other prototypers!

Cheers,
Carsten