DIY XLR: To Ground or Not

[bhjazz]

Last year I built a pair of balanced cables to go between my Theta Pre and Classe amp. After they broke in, I was really surprised how good they sounded. I used DH Labs Pro Studio and a set of Neutrik connectors. The ground is connected at both ends. I've read that sometimes floating the ground is not a bad idea.

I now realize that I could probably live with this cable for a while. Yeah, I like it! I also need to move my gear from it's current location (in between the speakers) to it's new home, in a rack along the wall and off of the damned floor. New rack is in the works.

Anyway, I ordered a nice 50 foot section of DH Labs Pro Studio from Parts Connexion so that I can get the signal piped to the amp when my preamp and such are moved. The amp will stay between the speakers, 20 feet away. (Well, 20 feet of wire, anyway.) I was considering building an AudioQuest-style switch on the cable so that I could turn the grounding on or off depending on the equipment I use.

All this by way of saying: am I just wasting time and energy on this? Should I just connect the grounds (since I know it sounds fine) and get back to the music? Or should I opt for a larger degree of tweakiness and figure out how to add a switch to the ground connection?

Thanks!

[cetoole]

Try it, it is easy. Are you talking pin1 ground, or the shield?

[bhjazz]

I'm thinking shield.

I envision some geeking-looking heat shrink with some kind of cool barrel-type appendage which houses the switch. No, I have no idea where I would find something like that.

[Currawong]

The commercial cables I have only have the ground connected on one end to the shield. When I replied this to someone on HF asking about it, AMB replied that there were circumstances where it would be ideal to have the ground connected between two components, IIRC when it was ideal for their to be a common ground reference. I doubt it's critical though, but someone more knowledgeable will correct me if I'm wrong on that.

[bhjazz]

And that is precisely why I'd like to make it switchable!

I'm going to do some sleuthing around here as I know Nate has mentioned it somewhere.

If I head this route, I'll have to come up wiht some kind of switch that I can hang off the cable. That could either turn out really stupid looking, or tres professionalle!

[Nebby]

And that is precisely why I'd like to make it switchable!

I'm going to do some sleuthing around here as I know Nate has mentioned it somewhere.

If I head this route, I'll have to come up wiht some kind of switch that I can hang off the cable. That could either turn out really stupid looking, or tres professionalle!

Another possibility would be to wire in a ground loop breaker into the cable itself.

[dsavitsk]

I doubt it's critical though

Pin 1 Revisited

[n_maher]

There have been multiple occasions where I made cables for folks who requested they be built to the rane standard (pin one connected on one end only) and in all cases the cables have produced hum that was only cured by connecting pin 1 at both ends. Small sample size, but still...

Now if I were building shielded cables, which is to say cables that had both a conductor for pin 1 and also a shield, I would only connect the shield at one end.

[blubliss]

I disconnected pin 1 from the amp side of a DB25 to male XLR cable today, no hum.

[dsavitsk]

There have been multiple occasions where I made cables for folks who requested they be built to the rane standard (pin one connected on one end only) and in all cases the cables have produced hum that was only cured by connecting pin 1 at both ends. Small sample size, but still...

Where does Rane say that pin 1 is only connected at one end? Pin 1 is connected to the chassis at both ends. You would only need to disconnect one end if one side is improperly grounded. Here is what they say is the "The Absolute Best Right Way To Do It"

http://www.rane.com/note110.html

[Beefy]

This always comes up, and there is always the same qualifier...... that Rane "best way" only works for proper balanced amps.

For bridged amps - the sort built by the vast majority of DIY'ers and very popular amongst commercial headphone amps - need to have a signal ground connected. So I'm not at all surprised that cables Nate built without pin 1 connected have had problems with hum.

[bhjazz]

Okay. So I think since I am duplicating cables that already work, with all pins connected, and the shield connected at both ends...why would I do differently just because I am making a much longer version of it? I'll keep digging around, but much of what I've run across leans towards the Rane ideals. Cool enough. I was thinking of having the shield connected at just one end, and not pin 1, if anyone is keeping score!

Thanks, all!

[Dusty Chalk]

No, leave it be. The only time floating the ground would probably* sound better is if one or the other is doing something odd, and you would have heard that immediately.

* With the exceptions of magical fairies farting pixie dust in your cables right in the middle of you building them.

[n_maher]

Where does Rane say that pin 1 is only connected at one end? Pin 1 is connected to the chassis at both ends. You would only need to disconnect one end if one side is improperly grounded. Here is what they say is the "The Absolute Best Right Way To Do It"

Sound System Interconnection

Perhaps I'm thinking of another reference then, I know that at one time I'd found a page that described connecting pin1 (not just the shield) at only one end. I agree with the way rane has it shown in that image.

[digger945]

I've always had noticable hum when it's not connected. Maybe it's just my stuff.

[bhjazz]

I should probably change the title of this thread for posterity, and also because when I started the discussion, I was thinking of non-balanced cables with the ground being the shield being the...well, you know what I mean. I seem to have cause a bit of confusion. I always wonder why it follows me, then I realize I create it myself. Interesting.

Thanks for all the replies. This place rocks as usual.