DAC1 + 2*(Grace901) + HD650 = Great Fun!

[gerG]

It has taken a while, but I finally got a better source for my balanced Grace setup.

Listening impressions so far: hey, this really...holy snit!

Further bullitens as time permits.


gerG

 

[akwok]

NICE! Must sound marvelous. Sure looks nice!

 

[shplorgh]

That's frickin' sweet!

 

[ojnihs]

 

[jpelg]

What? No DEQ2496 equalizer???

Looking forward to a more detailed writeup, G.

 

[lan]

That's interesting. I can see if you like the sound of DAC1 and m901 how it'd be cool. For me I don't like either so it's a double negative.

Is this really balanced? Did you rewire the inside of the Grace?

 

[Hello]

Ian, there's no need to rewire the Grace to use it in balanced configuration. Just output the balanced right channel to one Grace amp and the balanced left channel to the other Grace amp. But, how do you keep the left-right channels at equal volume? Are you using the Dac-1 for volume control?

 

[lan]

Hello Hello

That takes care of balanced input but what about balanced output? I believe the term balanced headphone retermination here on head-fi mostly means balanced output drive.

 

[D.Holmes]

gerG, you should get the silver face plate for your DAC1 to complete the look

 

[darkninja67]

that's some serious chedda there. Nice set up/

 

[EdipisReks]

Quote:

Originally Posted by lan That takes care of balanced input but what about balanced output? I believe the term balanced headphone retermination here on head-fi mostly means balanced output drive.

i'm confused, too. if each Grace is just doing the normal thing, only applying it to one driver instead of both, i don't see how it could be much of a benefit, other than taking advantage of the noise resistance inherent in balanced inputs and not having both transducers returning to ground.

 

[jjcha]

Heh, even if it doesn't have the true balanced output to the cans, you've got to admire the beauty/madness of the thing.

Hmm. I need to find another m902.

Best,

-Jason

 

[Hello]

Ian Ian

One way of connecting the dac-1 to 2 graces for balanced drive:

dac-1 out -> left xlr + -> left rca -> in grace #1
dac-1 out -> left xlr - -> right rca -> in grace #1
dac-1 out -> right xlr + -> left rca -> in grace #2
dac-1 out -> right xlr - -> right rca -> in grace #2

So, you need two y-cables, xlr-female split to two femal rca. Persumably, the ground on the split rca is shared.

And, the headphone cable needs to be terminated with two 1/4 inch 'stereo' jacks (One jack per left/right channel).

So, instead of one grace having stereo, i.e. two channels which are left/right, think of one grace as having two channels +/-.

 

[Iron_Dreamer]

If he wired it such that each Grace is only recieving one channel of balanced input, but into the unbalanced RCA jacks (such that one side of the amp works on the R+ one on the R- signal, and so forth for the other 901), then it is a "true" balanced setup with all the benefits thereof.

 

[gerG]

Hello and Dreamer got it right. It is balanced front to back. Here is the original thread with pics of the cabling in the original setup. jpelg remembered it, well done.

http://www6.head-fi.org/forums/showthread.php?t=94795

The headphone cable is an Oehlbach rewired with a TRS plug for each channel, wired in conventional balanced configuration. The Oehlbach is shielded, so I did use that option on the plug.

The most greatest thing about this approach is that nothing is permanent. If I want the Sens back in single ended mode I just plug in a different cable. Likewise I can take the balanced signal cables off and have 3 conventional amps again. Like I said, lots of fun.

EDIT: doh! I goofed up the link somehow. All spliced and better now. Sorry 'bout that.

gerG