• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

MX-121 vs MX-119 -- AC3 LaserDisc Playback -- Doesn't Work on MX-121

F

feinstei

AK Member
I have run into a curious problem that I wonder if any of the geniuses here on AudioKarma can help me with...

I've got a McIntosh MLD-7020 LaserDisc Player hooked to the "matching" McIntosh RFD-2 AC3 Demodulator. This allows me to play specially encoded AC-3 LaserDiscs which output multi-channel sound.

I've just replaced my MX-119 home theatre system with the newer MX-121.

When I plug the optical output cable from the RFD-2 into the MX-119, it plays back the AC-3 encoded discs (as well as the standard stereo LaserDiscs) perfectly.

However, when I plug the same optical output cable from the RFD-2 into my new MX-121, I get no sound on AC-3 encoded discs (but standard stereo LaserDiscs still play back perfectly).

Does the RFD-2 output some sort of bizarre obsolete multi-channel audio format that the MX-121 no longer supports? I had thought that the RFD-2 outputs standard Dolby Digital at a maximum bitrate of 384 kilobits. Is this format unsupported on the MX-121?
 
Register to hide this ad
I know thee RFD-2 worked with my 119 perfectly as well as my 120. I'm really curious about the 121 issue. I was thinking about up grading to a 121 myself soon.
 
twiiii said:
I know thee RFD-2 worked with my 119 perfectly as well as my 120. I'm really curious about the 121 issue. I was thinking about up grading to a 121 myself soon.
Click to expand...

Hi... I figured out what was going on and got everything working again on the MX-121. Remember that the MX-121 does NOT have an S-Video input like the MX-119 did. Thus, I had to purchase a little device to upconvert the S-VHS video from the MLD-7020 laserdisc player to HDMI:

http://www.amazon.com/gp/product/B003NS0UUQ?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

This device works extremely well upconverting the S-VHS signal from the laserdisc player to either 720p or 1080i HDMI (720p looked much better and was less bouncy).

The problem is due to a software bug on the MX-121. When I plugged the HDMI cable from the upconverted laserdisc video into the MX-121, it did NOT allow me to override the audio -- in other words, the MX-121 thought that the audio was on the HDMI and refused to pay attention to the fact that I changed the audio input (in the MX-121 Setup) to be one of the optical inputs. Thus, the MX-121 tried to play the audio from the HDMI even though there was no audio present there (the audio was being supplied by the RFD-2 over an optical input)...

The problem was solved by doing the following:
My Sony HDTV has several HDMI inputs. I simply connected the upconverted laserdisc HDMI to one of the Sony HDTV HDMI inputs. The audio from the RFD-2 was sent to the optical digital input on the MX-121. Thus, the MX-121 was only handling the audio from the RFD-2 and the TV was only handling the video from the laserdisc player. The MX-121 was no longer confused, because there was no HDMI cable connected to it from the laserdisc player.

It kind of sucks because the MX-121 is SUPPOSED to handle situations like this (where the video comes from the HDMI and the audio comes from an optical or RCA input), but there's a bug in the firmware which ALWAYS looks to a plugged in HDMI cable for the audio and refuses to pay attention to the setting in the Setup program which tells it to look to the optical input for the audio. It sucks because you cannot use the ARC HDMI control feature of the MX-121 under these circumstances.

Of course, since McIntosh has no competent software engineers working for them, this problem will never get fixed. Everything product that McIntosh has ever put out has very poorly designed and buggy firmware (I bricked my MR-88 doing an upgrade because McIntosh was too stupid to provide a firmware update program that ran on Windows 7, 8, or 10 -- it only ran on Windows XP or Vista and only on Intel processors -- it would fail if you tried it on an AMD processor -- Luckily, I found a buddy who still had an old laptop running Vista and was able to do the firmware upgrade on his machine -- otherwise, I would have had to ship it back to McIntosh in New York -- not a cheap proposition and it would have sat in their shop for several months).
 
twiiii said:
I know thee RFD-2 worked with my 119 perfectly as well as my 120. I'm really curious about the 121 issue. I was thinking about up grading to a 121 myself soon.
Click to expand...

BTW: The MX-121's audio capbilities are head-and-shoulders above the MX-119. The phono section is noticeably more "tube-like" and the DAC's do a fabulous job with CD, DVD-A and even SACD (converted to PCM since the MX-121 cannot directly play DSD).
 
You must log in or register to reply here.
Back
Top Bottom