How to check receiver subwoofer pre-outs

[Sylar]

I have a Marantz SR7005. My connection looks like this for the subwoofer.

Receiver sub out -> miniDSP -> Crown XLS

I had to redo some wiring, and in the process I might have screwed up while connecting inputs to the miniDSP. I did a quick debugging, connecting the receiver directly to the CrownXLS amp. I didn't see it detecting the Test Tone input for the subwoofer.

I suspect the pre outs have shorted. My other channels are working fine.

I have a multi meter. How do I check if the channel is the problem? Can I do this without opening the receiver?

 

[lovinthehd]

When you tried hooking up the XLS directly, I assume you had the gains up all the way on the XLS (and had a source with sub output)? Can't direct you on the multi-meter, but would think the instructions for the mm would include testing voltage of the pre-out at the rca jack without opening the receiver. Did you have the units powered while making connections?

 

[Sylar]

While connecting everything was off.

I had the gain at 0. And then slowly increased. I used the test tone from the receiver.

Wondering what voltage level should I expect to see at the sub pre out. I presume it's AC not DC.

 

[lovinthehd]

Hard to understand how it could short if there was no power on. I'd just go to full gain on the XLS to test if you're getting signal (using the signal indicator lights). Just for the heck of it I'd use something with normal .1 content and not just the test tone. Nominal sub pre-out level should be around 1V for most avrs, altho they may go up to 4-8V.

ps Also make sure volume and sub level are up to appropriate levels when not using test tones (which I'd assume would start at prescribed levels).

 

[everettT]

While connecting everything was off.

I had the gain at 0. And then slowly increased. I used the test tone from the receiver.

Wondering what voltage level should I expect to see at the sub pre out. I presume it's AC not DC.

Correct, AC. I made leads from old cable to test v from fear of shorting. IIRC there is a warning about minidsp connections in the literature, I'd have to check the online forum for it later.

 

[Sylar]

Correct, AC. I made leads from old cable to test v from fear of shorting. IIRC there is a warning about minidsp connections in the literature, I'd have to check the online forum for it later.

What is the expected voltage level? When running the inbuilt test tone from receiver.

 

[everettT]

What is the expected voltage level? When running the inbuilt test tone from receiver.

Over 2 vrms I'd expect before clipping. I use a 1khz signal and do a sweep as well.

 

[Sylar]

Found the issue. It wasn't the amp. A faulty wiring coming from the amp to the Mini DSP.

Thanks for the advise anyway.