Why aren't the Balanced Outputs on my Preamp Working?

[Ralf11]

I can't get any sound when using the balanced outputs on my ARC LS25 preamp, but the SE outputs are working fine. This is a new unit to me and was bought used just a few days ago. It had a lot of glitches at first but the single ended outputs seem to be working ok now.

 

I am wondering what circuit differences there are on the different types of outputs?

 

(I'd assumed that it just grabs one leg of the balanced output for the single ended ones, but I'm not sure).

 

I don't have another amp to test or any other balanced cables, so I can't absolutely rue out the Sunfire amp's balanced inputs or the cables either. It would be odd if both cables were bad tho.

[Jan Vegenfeldt]

Have you tried the 3 output?

 

 

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[mourip]

I can't get any sound when using the balanced outputs on my ARC LS25 preamp, but the SE outputs are working fine. This is a new unit to me and was bought used just a few days ago. It had a lot of glitches at first but the single ended outputs seem to be working ok now.

 

I am wondering what circuit differences there are on the different types of outputs?

 

(I'd assumed that it just grabs one leg of the balanced output for the single ended ones, but I'm not sure).

 

I don't have another amp to test or any other balanced cables, so I can't absolutely rue out the Sunfire amp's balanced inputs or the cables either. It would be odd if both cables were bad tho.

 

Some equipment uses the "+" leg to create a single ended output while others build two unique circuits.

 

It looks like yours gets the single ended output from the balanced based upon this schematic I found for the LS25

 

 

Also not everyone observes the same pinout standard for balanced output connectors. It looks like the ARC uses the standard pinout but your Sunfire might not.

 

I would contact ARC and Sunfire and describe your problem to them.

[4est]

Likely it is very simple, to the point where one needs to ask if perchance you have it hooked up incorrectly or wires reversed. Most, if not all, ARC gear is fully balanced internally and uses a Bal>SE circuit on the output. If SE works, balanced should too.

I can't get any sound when using the balanced outputs on my ARC LS25 preamp, but the SE outputs are working fine. This is a new unit to me and was bought used just a few days ago. It had a lot of glitches at first but the single ended outputs seem to be working ok now.

 

I am wondering what circuit differences there are on the different types of outputs?

 

(I'd assumed that it just grabs one leg of the balanced output for the single ended ones, but I'm not sure).

 

I don't have another amp to test or any other balanced cables, so I can't absolutely rue out the Sunfire amp's balanced inputs or the cables either. It would be odd if both cables were bad tho.

[Ralf11]

New data - last night i got a very thin, strained sound from the Balanced outputs.

 

Also, the SE outs had issues at first, but letting it sit with the power cord unplugged for a while may have cured the SE problems but not the Balanced problems.

 

It's possible both cables are bad or that the amp is bad, or I hooked it up wrong somehow (tho the SEs go into the amp right next to the Balanced plugs). Or maybe I am going insane...

[mansr]

Some amps have a balanced/SE switch. Does yours, and if so, is it set correctly?

[Ralf11]

Good point - I can't find one tho.

[speavler]

Literature mentions a toggle switch for se/bal

[Ralf11]

Really? It's not in the Owners Manual. Nor on the rear panel - I have the Cinema Grand - it's a 5 channel amp.

[speavler]

No, on the pre

[Ralf11]

oh, right - yes, those are set correctly (and would affect the SE outputs too)