MX135 comments

I'm using the MX135 and MC207, and am very happy with the sound. The pair seem to be one of the best options for both top-quality 2-channel audio and HT, and so I've been surprised by the lack of info on the MX135 (minimal reviews or comments) on the web. Are there many other MX135 owners out there?

The unit does surprise me in some areas of its functionality. It is unfortunate that I can only record a digital source to a digital output, and similarly a balanced audio source to an analog output. I wonder why I cannot use the MX135's prestine DAC/ADCs to record an analog source to DAT, for example. Perhaps I'm just missing something obvious, but the documentation seems quite clear on the subject.

The bass management is also not as flexible as it should be... for example, I prefer to use my main speakers for most of the bass and subs to supplement only the very bottom end (below 45 hz). Yet the MX135 is limited to only one sub and a crossover of 60 hz or above. It's not a big deal, but surprising considering the competition. I'm currently using the MC Bass Mode to turn on both my "large" speakers and the subs, and then setting the crossover in the subs... it roughly works, but it's not as flat as it could be with differing specs for each surround-type speaker. some competing A/V controllers allow you to set the sub crossover point for each speaker in your surround sound system -- this is the ideal.

There are other areas too where units such as the Anthem's offerings have better functionalilty at a much lower price point, but overall, I would of course much prefer the MX135. All the key areas are covered beautifully, and most importantly, it sounds wonderful. Even my wife forgave me when she heard it -- now she wants to try tubes!

Cat,

The MX135 was designed to equal the sonic performance of the two channel McIntosh separates while having full multi-channel functionality. The MX135 has the C45 pre amp functions built in such as phono section, two sets of stereo balanced ins and eight channels of balanced outputs.
On the sub crossovers the MX135 uses 24 dB per octave slopes. The analog stereo crossover is set at 80 Hz and the digital stereo or multichannel is adjustable from 60 to 120 Hz.
We assume that the MX135 will be used with high quality speakers in normal rooms. Almost all speakers roll off below 60 Hz, even ones with very large or multiple woofers. The first two octaves, 20 to 40, and 40 to 80 Hz are usually covered by most subwoofers which will flatten and extend the bass. Most crossovers are 12 dB per octave which will cause very large overlaps or a boost near the crossover point, so 24 dB per octave is desirable. If you are playing a lot of two channel it is critical that your sub is within a foot of the plane formed by the front two speakers. Once you move farther away than this the electrical crossover point will change due to comb filtering and room effects.
If a speaker is run full range at high volumed the upper part of the bass will be modulated by the deep bass. This is one reason why a sub will clean up the sound of the mains and lower their upper bass distortion. In pro sound it is common to use large subs up to 60 to 80 Hz and then cross over to multiple 12 or 15" driver cabinets. At high SPLs this will always sound clearer even though these main speakers can go as low as the subs. A properly designed sub should do its job of producing the first two octaves without any coloration or it is not a good sub. One more point though, it is always easier to seamlessly cross a sub over to main speakers which go low.
The MX135 has two pure stereo modes with both analog and digital paths depending on what the source is. Pure Stereo is the front two speakers with the sub, analog 80 Hz crossover or variable digital if the source is digital. The Two channel mode is the front speakers full range, no sub.
Years ago THX measured homes for the proper sub crossover point and 80 Hz was determined to work the best especially with low 8 or 9 ft. ceilings. I use a double 12" with a 1000+ amp for my sub and you can not locate it from 10 ft away crossed over at 80 Hz. Positioning is everything with a sub though. If you can not place your sub on the front plane you may want to just use the digital section of the 135 and make up the distance using the built in delays.
I am not sure why you want different crossover points for different speakers. All of the McIntosh speakers are solid to at least 80 Hz, including the in walls, dipole surrounds and small bookshelf models. This would hold for B&W, Kef, etc. also. Bose cubes need to be crossed over much higher of course!
One of the effects of having the surround speakers run down to 80 Hz. is the bass will be smoother throughout the room and standing waves will be broken up. What speakers are you using?
The record buss on the 135 is analog where the listen buss has a digital out. Most digital recording devices such as CD burners have Analog to Digital converters built in though.
Have you figured out how to adjust the DPL-II on the fly using the remote from your seat? It is important to set the center width to 3 or 4. I like the Panorama set to ON for most music also. A true out of box musical experience.

Ron-C

Mx135

Hi Ron,

Thank you for your very detailed response! I am using B&W 802s for the front L&R, HTM1 for center, and 703s for all four surrounds (7.1). It might sound odd to mix 700s with 800s, but domestic considerations prevailed... anyway, the mid driver on the 703 (unlike its 700 series siblings) is the same as the 800s, so the voicing sounds quite natural.

Home theater set-ups always involve compromises, especially when living in the center of a large metropolis. While your description of the MX135's bass management makes perfect sense, the acoustics in my living room do not. I have the sub next to the mains, and have tried other locations as well as two subs, but peaks in the bass remain evident throughout the listening area. Allowing the 802s to handle more of the bass, while no doubt introducing some of the issues you describe, does seem to ease the peaks and create more of a flat overall sound below 80 hz. I assume this is why Anthem and other companies offer these options -- more flexibility to deal with non-ideal acoustic environments. But certainly finding a more acoustically flat position for my subs would be best, no question.

You also mentioned in your note that DATs and CD recorders have their own DAC/ADCs -- do you mean to imply that this is a better solution than using the converters in the MX135? The MX135 converters sound top-class to me, and it seems a shame not to be able to use them in all occasions. The record outs (labeled "VCR") pass unbalanced analog inputs only, and the digital outs pass digital inputs only, correct? Do the "Monitor A" unbalanced analog outs pass digital inputs? That might be one way to at least use the ADCs. Also, do you happen to know if the MX135 can handle digital sample rates above 44khz? I've had difficulties using 16 bit 48khz sources (a DAT and a pro digital mixer), and would love to send it 24 bit 96khz signals as well if I could.

Lastly, I'd like to give the B&W 802s more power, and am considering buying two MC2102 to bi-amp the 802s, using the MC207 (one channel each) for the bottom end and one 2102 each for the top end (in mono for 200 watts/channel to balance the MC207). How do you bi-amp from the MX135? Should I use the unbalanced outs for one amp and the balanced for the other? I worry how this would effect the levels. The other option is just to get an MC402, but the MC2102s are intriguing indeed. Any thoughts?

Yes, I also played with the center width on DPLII, and love the sound it creates (I have mine set to 4). I'm not sure what you mean by the panorama setting, though. I haven't seen this anywhere.

Sorry to hit you with so many questions above! My dealer wasn't up on these details, and they're not covered in the manual.

Cat,
I am not sure which sub you are using? One of the mistakes made in system set up is how the sub crossover is managed. You need to bypass the crossover in your powered sub or if it does not have a bypass turn it all the way up, to the highest frequency possible. The crossover in the MX135 is steeper and better to what is used in most powered subs.
Where to place the sub? Put the sub where you normally sit and then listen to where the bass is strongest in the room, hopefully at the plane of the front speakers. Wherever the bass sounds best set the sub in this position and it will, sound this way at your seat. If you are using both the sub's crossover and the one in the MX135 you will have phase shift and timing errors. Try the system with the McBass shut off while you are dialing in the setup.
The digital outs on the MX135 are on the listen buss so anything you are listening to that is a digital source will pass through these.
You can bi-amp your 802s passively with many amps but this is not good with the tube amps. Tube amps need an electronic crossover as they are not happy working into a gross miss-matched load and will run very hot. You can use one of the SS amps like the MC252 which has a very smooth sound similar to our tube units.
The speakers you are using are all very high quality and should voice and match well all crossed over at 80, 70, or 60 Hz. You can have the four rears run in the large position is you want as long as you are not playing them at max volume. the MC207 is a very powerful amp, about 300 watts per channel actual power.
I have set up many theaters with the rears large and the large front speakers set to small with a sub. Since an aggressive film mix has the surrounds at about half the front L + R level, and the rear surrounds 25% of the fronts, while the center is 150% of the left and right front, this works out.
DPL-II, push the home button on your remote and you have 5 seconds to control the settings with the navigation keys. You can adjust width, panorama or dimension. The center button will turn panorama on and off, the up down keys set Dimension which is the forward or rear bias of the sound field, and the left right keys adjust center width. DPL-II is all about extracting information from the two channel mix. It does not add echo or delay and works well with many types of recordings. Play Abby Road in DPL-II and you will be surprised. Vinyl works well with this also.
Ron-C

Wow! I would never have known about the "dimension" and "panorama" settings. Thanks for the tip! This really should be added to the manual.

Thank you also for your advice regarding the subs. I will experiment some more. I also didn't realize the MC20 puts out 300 watts -- I knew Mcintosh gear is overbuilt, but my God. That's some extra room. Perhaps the MC252 will be a good match then.

Lastly, I would love to clear up the digital spec issues I raised in my earlier email. Do you know if the MX135 can handle digital input rates other than 44 KHz (such as a DAT at 48)? Or 24 bit signals? And can the "Monitor A" analog outs pass digital sources? It doesn't seem as though the digital outs can pass analog sources.

The MX135 or MX119 will accept various high band digital signals. This includes 14 to 24 bit PCM from 32 to 96 KHz.

Ron-C

Mx135

I've been having a problem with my MX135 for about a month and maybe you have some insight. While playing my phono the preamp somethimes locks up and the only thing I can do is reboot the system. This seems to be when I touch the system and a static charge leaves my finger. This never happen with my previous preamp Marantz AV9000. In addition I fried a channel (phono only). Mac replaced the board and said the output of my phono cartridge was to much. I'm considering purchasing a mc cartridge with a .5mv output. What's you thought???

M135 PREAMP
MC602 AMP
AUDIO RESEARCH PH5 PHONO PREAMP 57db gain
JA MICHELL GYRO SE MKII W/SUMIKO BLACKBIRD CARTRIDGE MC 2.5MV

That is strange. Make sure your AR phono section does not have DC on the outputs when running or turning on and off. Just put a DC voltmeter across the output jacks and turn the unit on and off. If you see DC please ask AR how to fix that.
If you use the built in phono section of the MX135 (bypass the AR) do you still have lockup? Microprocessors do not like DC spikes.
The knobs on all McIntosh gear have a plastic insert to stop static discharge. You must have a lot of static to bridge that. Put your hand on the side of the MX135 before you touch a knob so you will be discharged.

Thanks,
Ron-C

cnote said:

I've been having a problem with my MX135 for about a month and maybe you have some insight. While playing my phono the preamp somethimes locks up and the only thing I can do is reboot the system. This seems to be when I touch the system and a static charge leaves my finger. This never happen with my previous preamp Marantz AV9000. In addition I fried a channel (phono only). Mac replaced the board and said the output of my phono cartridge was to much. I'm considering purchasing a mc cartridge with a .5mv output. What's you thought???

Click to expand...

CNOTE, I feel your pain. I had an MX134 and it locked up all the time. It also had an annoying backgroung hum. Cheater grounds didn't help. I tried to "fix" power problems by spending 1200$ on a Richard Gray Line conditioner. This didn't help.

I sent the unit back to McIntosh. They returned it. Then I was getting distortion from my subout. I was pretty disapointed with the problems enough that I traded it in for an MX119. Loved it ever since. Not a lock-up yet.

jc

I owned MX134 #5 and it is now working in someone's home in San Fran. By nature HT processors are very complex but many MX134s were sold without problems. We have released a service bulletin on the MX134 dealing with hum issues in some installations. This has proven successfull in the MX134.
The MX135 and MX119 were developed together and both have been very problem free. I am not saying that none will never have an issue but nothing is showing up so far on these.

Ron-c

One of the stores I worked for back in the 70s had a bad static problem. We all learned to lay a hand flat on the side of the unit before touching a knob. This was done to prevent pain, not protect the unit. I kind of miss shag carpeting!

Ron-C

Static Can Be a Good Thing!

ron-c said:

One of the stores I worked for back in the 70s had a bad static problem. We all learned to lay a hand flat on the side of the unit before touching a knob. This was done to prevent pain, not protect the unit. I kind of miss shag carpeting!

Ron-C

Click to expand...

Ron, a nostalgia moment here: We had this one patron (he was not a customer - He never bought anything!) who was a real TK (Tire Kicker/Time Killer/etc.) who would try to consume enormous quantities of our time while referencing his current copy of "Stereo Review" or "High Fidelity" he always carried with him. You know the type. We tried everything, including abject rudeness, and he was oblivious to it.

However, our owner decided to install heavy shag carpeting in the front of the store because his brother needed to sell some to keep his job with the carpet company he worked for. The carpet really looked awful and was a bitch to clean, but we found a wonderful, unexpected use for it: Whenever we saw Mr. "TK" coming, we would rub our feet back and forth very quickly on the carpet thereby building a really enormous static charge on our own body.

Mr "TK" would enter the door and one of us would race to greet him and quickly shake his hand.

After his third visit AC (after carpet), he never returned !

Ron, checked out the Audio Research phono preamp and the unit is a-ok. However, my JA MICHELL GYRO SE MKII turntable does use a dc power supply. Should I have a concern here? I've changed my cartridge from the Sumiko Blackbird 2.5mv to the Sumiko Celebration .5mv.(both moving coil) Haven't locked or fried a line stage yet and when I approach the system I always touch another piece of equipment to avoid shock to the Mac. I also tried a few other things you pointed out to fatcat. I'm turned the crossover from my subs down to utilize the crossover from the Mac. I LIKE IT!! Also found out how to utilize the panorama" settings. This information should be in the owners manual.

CNote,

I think just the static zap from you caused the service issue. It is rare but can happen. If you puh the Home Button on the MX135 remore you can use the center navigation keys to trim Dolby ProLogic II settings. Keep the center width set to 3 or 4 for best sound. Panorama id cool on classical and some jazz. Phantom side imaged from behind the wall!

Ron-c

Is anybody listening to me concerning static? Walked in an audio store last Sat. to review and purchase an MPV861. During the interview I want to change the volume of a MX119 control center. When I got up from the chair, walked over to the unit, touch the knob, a static charge jumped from my finger to the unit. "THE DISPLAY WENT BLANK, THE MUSIC KEPT PLAYING BUT YOU COULD NOT CONROLTHE VOLUME!!! TO MAKE A LONG STORY SHORT, THE UNIT WENT INTO A LOOP!!!" This has happen to me several times with my MX135. I've explained this to my dealer, I directed this conversation to Mcintosh, and everbody acts like they don't know what I'm talking about. My dealer say's try touching something prior to touching the Mac. Let's be real. Someone else must have experienced the PROBLEM as well. I can't believe Mac has no cue to this problem. I just have to say, I went there to purchase a 861, not that day. I'm going to spend $4100 and nobody is listening? I should be screaming that the MX135 is Mac solid. It sounds great, but I have to handle it with kid leather gloves.

cnote,

Although we are not hearing this complaint from the field I believe you have a problem with static. We will perform some tests and see what we come up with. Stay tuned and please PM me with your serial number so we know the particulars of your unit. We have equipment to generate static and will try to duplicate your problem

Thanks again,
Ron-C

I've got the static issue with my 13 as well.
I can touch a light switch close to the unit and it goes down.
Mine must be missing the plastic liners, because I can shut it down every time I touch the volume.

MX134 too

The same thing happens to my MX-134. A static zap and it goes blank, and the sound goes right on. I have to power it down and restart it. I'm always afraid that it's not going to restart and be in one piece. My four-year old thinks it's very funny, so he runs around and then touches it, then says "Daa-ee, da-eee, I am magic!"

All McIntosh preamps have a plastic static blocking insert in the metal knobs. Just pull one off and you will see it. This gives good isolation until the static reaches many thousands of volts and then the spark will jump the insulators. Since all of the preamps use microprocessors these will shut down when a static charge hits them. Ditto for a computer chassis.
This will happen to brands that use micros which is all of them. If you are in a very high static situation with low humidity, forced air heating, static building carpet, etc. the only solution is to use the remote.
We have seen where some power conditioners make this problem worse but it is not all brands or conditioners.
Everyone has to design gear that will pass a static charge test to be certified for sale. Severe static can exceed this though.

Ron-C

Ron- For my 134, it's not the knobs that do it. It's the vertical metal strips on either end of the front panel. If you happen to get near one while going for a knob...poof.

As long as it won't damage the unit...why worry?