SSP to Amp Balanced Pinout - Ground Lift: Yes/No?

[HedgeHog]

Hi all,

I was wondering what the consensus is for balanced cables between an SSP to the amp? Googling seems to indicate a preference towards ground-lifting at the pre/pro side to eliminute buzz/hum (except for mics). However, the SSP-800/CA-5200 manuals hint at all pins connected. Tom @ Classe also suggested the latter.

What's everyone doing for their balanced cables? And, we go straight through from SSP to CA, would it be recommended to do the same from SSP to a sub?

TIA.

-H

[Nolan B]

I JUST did a test here with some interesting results.

After plugging my SSP 600 to my 5100 by balanced I notice a high pitched buzz/hum with my ear about 2 feet away or closer. Just for fun I decided to switch out the center balanced output for a regular king cat RCA. Guess what? No hum from that channel.

Means one of two things.

1.) The balanced connections are creating this noise by either the 6db gain or an internal issue with the amp or SSP.

2.) I am using Mono price $4 XLRs and I switch on out for a kingcat single end. I HIGHLY doubt it, but is it possible that its a cable quality issue?

What else is likely happening to my audio besides this hum using XLR?

what to do.

[Glen B]

Did you swap channels to see if the buzz follows ? Use a process of elimination. Connect the the processor balanced center channel output into another channel of the amp to see if you still get the buzz. Similarly, connect the amp's balanced center channel input to another balanced channel output of the processor.

[Nolan B]

Did you swap channels to see if the buzz follows ? Use a process of elimination. Connect the the processor balanced center channel output into another channel of the amp to see if you still get the buzz. Similarly, connect the amp's balanced center channel input to another balanced channel output of the processor.

yes I changed channels. All channels buzz with balanced, wen i switched 1 out for RCA it did not buz.

[HedgeHog]

Nolan,

Do you have a multimeter? If so, check to see if Pin 1 on both ends are connected. A ground lift will disconnect that pin and, apparently, will eliminate the hum/buzz.

Guess, I'll make my cables with it straight through first...I can always desolder later on.

-H

[Nolan B]

Nolan,

Do you have a multimeter? If so, check to see if Pin 1 on both ends are connected. A ground lift will disconnect that pin and, apparently, will eliminate the hum/buzz.

Guess, I'll make my cables with it straight through first...I can always desolder later on.

-H

I read your post 3 times...sorry I don't get what you are suggesting. What is a multimeter?

[Glen B]

Pin #1 of the XLR connector on each end is connected to the cable shield. Using a multimeter set to the ohms/continuity scale, touch its two probes to the #1 pins on either end of the cable simultaneously and see if it reads zero ohms (which would mean the shield is connected). Disconnecting the shield on one end of the cable should break its continuity and eliminate the buzz.

A multimeter is a test instrument used to take various electrical measurements, like resistance, voltage and current. More elaborate units include additional features. Its called a "multi" meter because it combines more than one type of meter (like ohmmeter, voltmeter, and ammeter) in a single unit. Any serious audio enthusiast should have a a basic, inexpensive digital multimeter for taking simple measurements.

Multimeter: http://www.radioshack.com/product/in...ductId=2103176

Video tutorial - How to use a multimeter: http://blip.tv/file/138422

[Nolan B]

Pin #1 of the XLR connector on each end is connected to the cable shield. Using a multimeter set to the ohms/continuity scale, touch its two probes to the #1 pins on either end of the cable simultaneously and see if it reads zero ohms (which would mean the shield is connected). Disconnecting the shield on one end of the cable should break its continuity and eliminate the buzz.

A multimeter is a test instrument used to take various electrical measurements, like resistance, voltage and current. More elaborate units include additional features. Its called a "multi" meter because it combines more than one type of meter (like ohmmeter, voltmeter, and ammeter) in a single unit. Any serious audio enthusiast should have a a basic, inexpensive digital multimeter for taking simple measurements.

Multimeter: http://www.radioshack.com/product/in...ductId=2103176

Video tutorial - How to use a multimeter: http://blip.tv/file/138422

Great post :T

ill buy a multimeter today

How do you disconnect the shield?

Why should someone have to do this to eliminate the buzz? Should the connection just work?

Is this a fault of the Classe, the cable, power??

[Glen B]

Post deleted.

[Nolan B]

Canbus Die!!!

Through trouble shooting and process of elimination I discovered what was causing the high pitched hum.

I had a CAT cable plugged between my amp and ssp 600 (no CANBUS BOX). That little sucker created the sound and when I removed it the sound totally disappeared.

***sigh or relief***

now i can watch Vancouver beat Chicago tonight without worrying about a buzz.

[Glen B]

Great. See, you did have a loop.

[Nolan B]

Great. See, you did have a loop.

Thanks for your effort Glen. That was my first and (and hopefully last) ground loop.