Looking for MX121 Help

[B&W Driver]

I sold our MX121 to my younger brother a while back. He wants to use it for multichannel (MC) audio listening, so he purchased additional equipment to make this possible. The problem is that he doesn't seem to be getting any audio out of the center channel (C) jack on the rear panel of the MX121, which is found in the UNBALANCED PRE OUT section of RCA jacks.

I contacted McIntosh Labs, but the guy I spoke to seemed pretty busy, so he quickly suggested trying the test tones that are stored within the MX121. Has anyone on the McIntosh board actually tested output channels via this method?

Thank you for any help.

 

[TSmith8605]

I've never used that output so I can't answer your question.

But, have you verified that the program you're playing has center-channel content?

Is the MX setup for center-channel output and in the correct surround mode?

Have you verified that the issue is with the MX and not whatever is plugged into the center channel output?

 

[B&W Driver]

have you verified that the program you're playing has center-channel content?

Is the MX setup for center-channel output and in the correct surround mode?

Have you verified that the issue is with the MX and not whatever is plugged into the center channel output?

The purpose of the setup is to play multichannel (MC) audio music. At this point, the system has been converted from quad (4.0) to 5.1, so the center channel (C) and the subwoofer (SW) analog jacks - both inputs and outputs - will now be employed. The MC music in question has been verified on my system and, quite honestly, it sounds wonderful ... but I digress. The point here is that the digital MC music isn't the problem.

The MX121 is set up to employ its 7.1 channel multichannel analog input and output circuitry. In an effort to isolate the issue, the amplifier powering the center channel (C) - the center amp section of a McIntosh MC303 - has been tested by [temporarily] switching one of the front channel analog signals to the center. Both the amp and the center speaker sound great, so the issue is either within the MX121 or forward in the signal path.

The DAC in this system is an Oppo 103 and, because its HDMI video menu system is already connected to a monitor, the speaker configuration has been checked: both the center channel and the subwoofer channels are turned ON.

The fellow at McIntosh Labs in NY recommended that we start our troubleshooting by employing test tones for the center channel, so I'm interested in knowing if other MX121 owners have any experience with this type of testing. It's also been quite some time since I went through the internal video menus in the MX121, but I do recall enough to know that the menu system is quite complex, so, once again, I'm hoping to get some direction from another MX121 owner before trying to do this - remotely.

 

[damacman]

The tones he refers to are part of the setup process. So, great place to start.

Many reasons why the center output could be muted, so best to start setup from scratch.

 

[B&W Driver]

The tones he refers to are part of the setup process. So, great place to start.

Many reasons why the center output could be muted, so best to start setup from scratch.

@damacman - If you have any thoughts on which part of the manual we should start with, I'd love to get your recommendation.

 

[Yamaki]

Check the MX121 manual, page 17 for how to generate test tones as part of the Audyssey room correct process.

Also check the manual page 25 on generating test tones to check speaker output levels.

Don't forget to check the input & output connections on the MX121 & MC303 to insure they are seated properly.

 

[B&W Driver]

Thank you, Mister Y!