Best method of insulating rack mounted components from each other?

[caz223]

I guess I should introduce myself, I'm a lurker and frequent the reviews section to try and get some background on individual pieces.
I have basic electronics knowledge, (was an electronic tech for 5 years, and still do basic side jobs for friends, as well as a lot of tinkering and obsessing.
I have a mid-fi system, and am trying to upgrade some pieces.
Anyway, I replaced my old overworked amp with an Adcom 555II.
I have the components installed in a computer rackmount enclosure (with an APC SU3000 rackmount UPS) (Dirty power, begone.)
I'm currently using an Adcom GCD-750 CD player, a rotel 1070 preamp (soon to be replaced with an Adcom GFP-750.)
I was thumbing through the online PDF for the 555II, and it says to insulate the chassis from other components it's connected to to prevent ground loops, and the resulting hum.

So background aside, has anyone else fought with this?
Any really easy, basic solutions?
I have the SU3000 in the bottom rack space (As is proper SOP), the amps will populate upwards, then the preamps, and finally the CD player, then my music server, and monitor (On a 0U articulated arm).
Am I breaking any cardinal sins here?
My first thought on insulating the amp was hockey pucks, but it's more involved than that, as the rails along the length of the rack ( Compaq 42U Rack by rittal with APC rack rails.)
Yes, I AM OCD.
Also, I'm gonna have to insulate the other components as well.
I remember the older components had a ground connector so that touching component chassis would not be a problem, but apparently, I am mistaken.
My older amp was a rackmount amp, and was designed for this, but it seems the Adcom amps are not.
My old amp=no hum.
Adcom=small hum, but way better sound.
A thin rubber rubber mat, perhaps?
A toolbox drawer liner?
A 17" wide 3/4" MDF shelf for the rails, complete with some hockey pucks?

***EDIT***
Duct tape on rack rails and nylon shoulder washers on front bracket?
Does professional sound equipment that's designed to be mounted in a rack have this problem?

[poppachubby]

I just went through all of this myself. I have built myself a rack which is wider than tall. Components now all sit side by side with plenty of space between tiers. That would be the best solution. However, check this link for varying styles and prices. There's sure to be something here to fit your needs/budget:

http://store.acousticsounds.com/c/61/Isolation_Devices

Personally, If you're serious about function and style too, these little babies fit the bill. They do more than just seperate components. Read the details on the page. As far as the price goes you're paying for quality and precision. It's my pick anyhow. Hope this helps....

http://www.ttweights.com/catalog/ite...71/6731515.htm

Happy Hunting!!

[Hyfi]

I buy 1 foot squares of 1/2 thick Sorbothane from McMaster Carr and cut them into 2-3 inch squares. I use Granite slabs under my speakers ans spikes.

[Richard Tory]

I guess I should introduce myself, I'm a lurker and frequent the reviews section to try and get some background on individual pieces.
I have basic electronics knowledge, (was an electronic tech for 5 years, and still do basic side jobs for friends, as well as a lot of tinkering and obsessing.
I have a mid-fi system, and am trying to upgrade some pieces.
Anyway, I replaced my old overworked amp with an Adcom 555II.
I have the components installed in a computer rackmount enclosure (with an APC SU3000 rackmount UPS) (Dirty power, begone.)
I'm currently using an Adcom GCD-750 CD player, a rotel 1070 preamp (soon to be replaced with an Adcom GFP-750.)
I was thumbing through the online PDF for the 555II, and it says to insulate the chassis from other components it's connected to to prevent ground loops, and the resulting hum.

So background aside, has anyone else fought with this?
Any really easy, basic solutions?
I have the SU3000 in the bottom rack space (As is proper SOP), the amps will populate upwards, then the preamps, and finally the CD player, then my music server, and monitor (On a 0U articulated arm).
Am I breaking any cardinal sins here?
My first thought on insulating the amp was hockey pucks, but it's more involved than that, as the rails along the length of the rack ( Compaq 42U Rack by rittal with APC rack rails.)
Yes, I AM OCD.
Also, I'm gonna have to insulate the other components as well.
I remember the older components had a ground connector so that touching component chassis would not be a problem, but apparently, I am mistaken.
My older amp was a rackmount amp, and was designed for this, but it seems the Adcom amps are not.
My old amp=no hum.
Adcom=small hum, but way better sound.
A thin rubber rubber mat, perhaps?
A toolbox drawer liner?
A 17" wide 3/4" MDF shelf for the rails, complete with some hockey pucks?

***EDIT***
Duct tape on rack rails and nylon shoulder washers on front bracket?
Does professional sound equipment that's designed to be mounted in a rack have this problem?

Hello caz 223,
I get the impression you are out of the house and in the garage. What are you doing use telecomms type racks? Get yourself kitted up with a solid Oak 3 to 4 tier spiked between shelves support table and it looks nice too!

[E-Stat]

So background aside, has anyone else fought with this?

If you truly have a ground loop, then hockey pucks, nylon and shuffling around placement will have little effect. Tying together all the components to a steel rack in an unbalanced system can create multiple ground paths. You must address that electrical issue directly. The ground loop problem I had with my HT system was due to the cable connection.

Any really easy, basic solutions?

The most common, although not always recommended way, is to use a "cheater plug" on one of the low powered devices. That breaks one of the ground paths. You really need one or more isolation transformers depending upon the source of the ground loop. Here are a couple of examples. One type is used through interconnects and another for coaxial video situations.

Am I breaking any cardinal sins here?

No, but I confess that I'm not a big fan of racks with high powered amps due to difficulties with air flow and proximity based hum issues. I prefer having nothing above an amp.

Does professional sound equipment that's designed to be mounted in a rack have this problem?

No, because they typically use balanced connections between components.

rw

[caz223]

So, if I use XLR connections, the ground loop might be minimized?
I figured they just isolated chassis ground from board return with some sort of LC circuit.
Maybe there's a flyback somewhere hidden deep inside the amp-ruining my day.
(doh, that's right, the 555II is direct coupled, I forgot.)
My new (To me) preamp will be XLR as well as my CD player.
So all I need is a couple of bridged Haflers?
Will I still need to insulate?
Maybe it's just my Rotel complaining about being put in service again.

Thanks for the help fellas, this audio noob needs all the help he can get.
Time to get out the table saw and cut out some 17" wide pieces of MDF.

It's not a telcom rack, it's a server rack, with no sides, there's plenty of ventilation.
As far as looks, I'd like to basic functionality first, and if there's money left in the budget...
Anyway, I got these server racks for my audio gear, as it doesn't get much better for adjustability than this....

[E-Stat]

So, if I use XLR connections, the ground loop might be minimized?

XLR connectors alone do not determine whether or not a device truly runs balanced. Balanced connections using balanced components minimize ground loops. Indeed, the Adcom does not apply.

rw

[caz223]

The amp is a fine amp, but if I can simply replace it, and be symptom-free- well, that's the easy way out. Everything else will be XLR, might as well go all the way-if it doesn't help it will be easier to rule out other stuff.

I'll wait until the GFP-750 is in place first, I guess.
24 hours or so...... (The waiting is the hardest part.)

[Hyfi]

I buy 1 foot squares of 1/2 thick Sorbothane from McMaster Carr and cut them into 2-3 inch squares. I use Granite slabs under my speakers ans spikes.

LOL, I'm a blind old man. I read Isolate instead of Insulate....sorry

[JoeE SP9]

You didn't say that you had a hum problem. If you don't have a hum problem you don't have a ground loop problem. Adcom was giving advice if you have a ground loop problem. If you did you would know it. A loud 60Hz hum is unmistakable. If you want a nice inexpensive rack check out the "Flexy" from TNT-Audio.
http://www.tnt-audio.com/clinica/flexye.html

Edit:
I reread the OP. Sorry, I missed the "small hum" part. The rack suggestion still applies.

[pixelthis]

If your rack is metal, then something might be connecting through that.
Also some sensitive gear might be next to a power transformer, and picking up the 60 hz from there. Could be enviromental, too.
Have rarely found a ground loop, but they do exist.