Axiom Home Page Forums General Discussion Technical Questions cd mods...Music Hall MMF-CD25

I'm not sure if this is the proper place to start this thread, but I've got the upgrade bug thanks to my new m60s. So first, has anyone picked up a music hall cd25. If so some feedback...please.
And finally what is the actual 'real' audible difference (if any!) in these so called upgrade mods on the cd25 and other units? The mod details for the cd 25 are available at

http://www.underwoodhifi.com/mod_musichall.html

Thanks for the help folks!

http://www.underwoodhifi.com/mod_musichall.html

Curt, modern players provide audibly flawless CD reproduction. Any "mod" which would actually cause an audible change would therefore be by definition a degradation of sound quality. Don't be fooled by the charlatans floating around the audio world.

JohnK, just curious, but do you base your statement on theory or have you compared the sound of different CDP's?

As for me, I have auditioned CD Players and have heard a definite, not so subtle difference.

I have always hated the term "Mods" when it comes to this stuff. When you break it down, it's an upgrade from stock components.

Now that I have that out of the way, I'm with 2X6, I have seen a few players that benefited greatly from being upgraded. I should note however that most of the upgrades that I have seen have all for the most part been on the video side.

Now the bad part. The price most of these guy's charge for "Mods" is brutal to say the least.

I believe in better capacitors when it comes to CD players and of course DAC's but some of the stuff is pure smoke and mirrors.

I agree, NH. I see what they're getting to upgrade to Burr Brown OPA 627's, an arm and a leg. Interesting, I upgraded my Ah! with 627s for about $50, and then swapped the Burr Browns out for the Upsampler.

In any case, reviewers seem pretty uniform in their praise of Music Hall equipment.

Before you hand over cash for the MMF-CD25, you might wanna check out the Onix XCD-88...same thing, different box, LOTS less money. Any "mods" done on the MMF can be done on the XCD.

And I gotta agree with 2x6 AND NeverHappy.

The mods can make things better - but this player is pretty dang good to start with. Also, the price for the mods is an outright fleecing, so watch out. Those new op-amps are nice, for instance, but a "pricey" op-amp is in the $10-20 range bought one at a time - and it takes about 30 seconds to change it out.

There are other changes they throw in there, but this discussion has been about the SOUND, not the rest, like gold plated connectors and the like.

JohnK, I was once skeptic about it too. But "audibly flawless" and actually flawless can be worlds apart. I don't know if I'd hear a difference if I "modified" my Onix, because it's soooooo good right now, that last 1/1000% of change is probably NOT audible. But I blind A/B'ed it (as is) with my $39 kmart special - and you can absolutely hear a difference. (I'm trying to avoid saying it's "better" - that part's up to you!)

Abe
Not sure if this will be much help or not. I did a lot of research on CD players and auditioned quite a few in the 500.00 to 1200.00 range. As you know this is a fiercely competitive price point for the person that is looking to get into "entry level audiophile" territory. Along the way in my research I hit an article on 6 moons site on the Music Hall explaining all the upgrades levels and pricing. That led me to the Underwood site. The guy that runs Underwood is right here in Atlanta. At this point I had already decided to purchase the NAD 542 new unless I hit on something great on ebay which I had bee searching regularly. I was just about to order the NAD when there was an auction on a mint condition Music Hall CD25 with a level 1 upgrade and portions of the level 2 upgrade already done. I decided to wait out the auction and if I didn't get it I would then order the NAD. Well I won the bid and got the unit for $400.00
Since the upgrade was already done I have no before / after evaluation on the effect of the upgrade. But I can tell you the Music Hall sounds as good as anything I have auditioned up to the $1200.00 range. The highs are not bright at all. I dare to say it actually has a more analog sound to it. (please don't flame me too bad guys I'm new here) The main reason I decided to go with the MH was that it was HDCD compatible. I love the Music Hall but I don't particularly like the remote. It has small buttons and feels weird. This is easily fixed with a universal remote if it becomes a real problem. The previous owner who had the upgrades done claimed it added much more to the bottom end and cleaned up the sound overall.

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But "audibly flawless" and actually flawless can be worlds apart.

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This is not a thumb in the eye to the "brand name IC snobs", but rather an educational post for those who don't understand quite what we're talking about when we say audibly and just how good CD playback is, no matter WHAT chip is used.

I'd prepared 3 sample wave files, listen to them on your home stereo, burn them to a CD, loop them, do whatever you want to to compare them. If someone can tell me which is which after listening (and no cheating, don't go using a spectrum analyzer or other equipment, just your ears!) I'll send you out a golden ear trophy.

The three files are (in no particular order) - all are just shy of 6 seconds in length:

Album cut - exactly as the line appears on the album - I used the song Tender Feet by Liza May Johnson, a Christian Contemporary artist, as it's pretty listenable to anyone's ears (rather than say, Argh, F***, Kill by the Dayglo Abortions) and is a good master recording.
Elevated analog noise floor - this one will probably come back to bite me in the arse. I've mixed in a false "noise floor" at 21dB below program audio (to give you an idea how loud that is, most HTIB would perform about 50ish in S/N ratio, this is a LOT louder than that - every 3dB is twice as loud!)
Extreme jitter errors - I've falsely put 6 jitter errors (at maximum points) into the waveform (that is, single samples inverted - the biggest possible error) that equals almost one 16-bit jitter error a second. This is a ludicrous amount, even a cheap player without a 1-bit DAC with a dusty lens might exhibit at most 10 in an entire song, here you have 6 in a 6 second clip.

Listen for yourself - if you can pick out all three (hopefully at least the noise floor one) and which is which, congratulations, you hear a LOT better than the rest of the world.

And no, there are no tricks here, I'm as curious as anyone, so I've made sure that I've far overcompensated and used some worst-case examples. These are really as I say they are, no trick questions where I uploaded the same clip 3 times or anything.

Here they are:
Clip 1
Clip 2
Clip 3

Bren R.

BS! thats the same track three times..

i couldnt hear no difference.. of course, thats with my windows media player here at work, and a 10 year old pair of headphones.

very non-scientific...these burdens are too heavy for me..

bigjohn

I promise on my family's graves three generations back that the supplied files are exactly as I have suggested (within the limits of integer math - for instance if a sample of noise is at 5/65536 of full scale and you half it, it'll be rounded up to 3/65536 since digital samples are never expressed in floating point math) but obvious caveats aside, this is a more than fair assessment of all these numbers and discrepancies everyone throws around but hardly anyone understands.

Bren R.

That's excellent Bren.
I can't hear much of anything on my computer system, but then again even with decent speakers the hum of my computer, trucks outside the window and such really don't help the critical listening process. However, i will be burning a new reference disc at some point so i will run these through my Axiom basement setup and see what comes of it.
If you have anything else to throw together like that for a 'test' disc, i would certainly love a copy.

Wow - that's excellent!

Nope, I can't take the trophy.

But some comments anyway - 3db is not twice as loud - it's "slightly louder" according to Axiom's own articles. 10db is twice as loud. Your point is still valid though - it's much greater than even an average HTIB.

6 jitters - each less than 23microseconds long. If there were simply six wrong notes that long, you wouldn't hear those either.

To put it in perspective (if ya don't wanna bother doing the math) there's room for 264,000 errors in that six second clip. Roughly.

This isn't to say you're aren't 100% correct in your test idea - it's a GREAT idea! I just think the sample isn't suitable for this type of test.

Try the intro of Beethoven's Pathetique. Or nearly anything off Johnny Cash's first American Recordings CD (can't recall the name of it...starts with Delia's Gone).

A blatant error by the guitar player would barely be noticable in your tracks - that music is busy!

One sample jitter is 23 microseconds of change. The noise floor, while HUGE by the standards of silence, is tiny compared to the busy tune. These things are heard during subtle quiet accurate clean nearly-naked pieces of music, especially during decays and rests.

I think your effort is fabulous - and although I didn't hear a difference, we all know there IS one (or two) now!

I'm just not convinced (yet) that I'd NEVER hear it, given the right piece of music, whatever that is.

I not really sure one "jitter" (the 23uS) is even audible - I think our limit of discrimination is more like 30uS. But I think my kmart cheapie on a bad day strings all six screw ups together, and THIS, you might hear.

Intersting notes BR.

My take on it:
You bring up a good point that i look at as an idea that goes towards the futility of trying to find audio perfection. Although some errors MAY be delineated on certain music passages, a person should ask, "how often does such a condition occur to warrant the requirement for an amazingly refined piece of equipment when even an overdone error [such as Bren has put forth] is incredibly hard to hear on a relatively simple music selection?"
To hear even a truly blatant error (and anything beyond HTIB spec has to be beyond blatant), one must be listening to a specific music piece, recorded with utmost precision (a massive caveat in its own right), and only during a quiet passage?
There is a strive for audio perfection and then there is going overboard. If anything, ppl should be striving for a demand in better quality recordings, not just for the boutique name music groups, but for all bands, even the Spears and boy bands of our time, rather than pursue the beyond human limits equipment that will do so little to the sound reproduction itself (too many previously mentioned limitations).

Audio is still about the hobby though and one's perception of the fun of it. I love to think my shiny new cdp is actually better than my old one in some respects. I certainly have a pride in ownership once i buy something. But the reality of the finite occurrences, under which i've described, that a person could potentially hear a slight difference in sound fidelity is so incredibly remote, is it worth the cost of some of the crazy "upgrades" people buy?
Some will say "yes", and some will say "no".
Personally, i'm in the no camp. I view it as a situation where one worries the spec of sand on the 10 mile beach is not as brown as all the others. First you have to spot it!

Kudos for the sound bits though. These types of tests are good fun to challenge ones ears. Hopefully the Axiom folk with have a good demo setup for the picnic. It looks like i will be attending at this point. Hmm, perhaps an addition to the picnic thread to see who will be going is in order.

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But some comments anyway - 3db is not twice as loud - it's "slightly louder" according to Axiom's own articles.

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Correct, a logarithmic scale, twice the power (watts) is a 3dB increase, 6dB is twice the signal, and 10dB is perceived as twice as loud. Was rushing through what started out as just a message and ended up as a theory lesson and made a mistake of logic.

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Try the intro of Beethoven's Pathetique. Or nearly anything off Johnny Cash's first American Recordings CD (can't recall the name of it...starts with Delia's Gone).

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PM me with a way to get a clip (uncompressed WAV/AIFF/etc) of it, and I'll do the same for it.

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One sample jitter is 23 microseconds of change. The noise floor, while HUGE by the standards of silence, is tiny compared to the busy tune. These things are heard during subtle quiet accurate clean nearly-naked pieces of music, especially during decays and rests.

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Again, my model took into consideration an insanely large amount of white noise - enough that it was clearly audible by itself. You'd definately hear that much during a rest. The actual amount of noise differential we'd be talking about between DACs would be a LOT lower, to the point where giving your ears a good cleaning before each listening would do much more for your enjoyment than the chip would.

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I not really sure one "jitter" (the 23uS) is even audible - I think our limit of discrimination is more like 30uS. But I think my kmart cheapie on a bad day strings all six screw ups together, and THIS, you might hear.

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Then the player should be thrown out. Even a CD-ROM that was packing it in on one of my computers could manage 1-3 jitter errors per track on average (while ripping at 4x). We're talking a CD-ROM that would take an extra 5-6 seconds to recognize a CD and bit the bullet about 2 weeks later.

Bren R.

Ok, I'd like to take a stab at this, here is what I think they are:

Track 1 has the jitter errors
Track 2 the higher noise floor
Track 3 is the original

Bren, I can't disagree with anything ya said there.

Again, I think it's a great effort. And I DID throw that cheap player out!

That's because - whatever number of errors in a row or per track or weak DAC or whatEVER it takes - there was no doubt that (during the musical conditions I described before)I could hear a difference between THAT player, and my XCD88.

I'm not saying it's a $2000 difference - but the better hardware, a hefty case, some cool features, etc., and the very subtle but better sound - it IS worth $200 more - to me!

Chess - I agree with the "grains of sand" thing too. I'm not one of those people either. But - while those moments of music are rare for you, perhaps, they are common for me. That IS what I listen to - as much Mozart as Metallica. I'm fairly diverse.

One random point to ponder - nothing cracks me up more than an "audiophile" in my house picking on "sonic discrepancies" that can't tell me if a piano or guitar is out of tune, or if the singer was on pitch.

"Strive for better quality recordings..." Absolutely. Without that, nothing else matters. I have no interest in accurately reproducing other people's mistakes!

Anyway - I still think it's a cool idea - thanks for the effort.

"Any "mod" which would actually cause an audible change would therefore be by definition a degradation of sound quality."

The above is a statement of opinion. ("degradation of sound quality"). Quality? Huh? If the mod leads the user to enjoy the sound, it is an improvement. Who wants "perfect" sound if it sucks? This kind of statement is also irrelevant when applied to home audio equipment in an environment which can't even come a million miles close to a real live experience, ie, getting "perfect sound" doesn't really matter anyways.

If the "sound quality" is moved closer towards reproducing the performance, then it's "better" by anyone's book. If you prefer to modify the sound to suit your preferences, then it's "different" - and "better" to some but not to others.

In general, the "live performance" (having seen a few - and participated in a few) - is rarely - almost never - as good as it is in my living room. Sure, the "ambiance" and so forth is unrivaled, but I could say that for a Larry the Cable Guy CD too. The balance, the mix, the artist's intentions - these are usually better in my living room.

Live performances are full of "soft" edges from echo, errors by performers, gear that malfunctions, and people that scream over my favorite parts. NOTHING is like a live performance, no doubt. But it doesn't usually sound "better" if you define "better" as "closer to what the songwriter hoped you'd hear."

Having said all that - if the recording sucks, then, yeah, I wanna hear it that way. Anything else is cheating!

Casaba - I won't spoil the fun yet with an "answer key" but rest assured, I will provide one soon (probably next Monday as I'm heading out to NeverHappy's neck of the woods tomorrow)

Bren R.

hey Bren,
bring some nice weather with you would ya?

We don't need no more steenking rain!

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bring some nice weather with you would ya? We don't need no more steenking rain!

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That's all we got here, too... weather trends move west to east, I check with you guys to see what we'll have soon.

Looks like it might not be too bad by the weekend.

Bren R.

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That's all we got here, too... weather trends move west to east, I check with you guys to see what we'll have soon.

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Yeah, unfortunately, just hoping you might bring something nice with you....we actually did have a system move east to west last week, weirdest thing I've ever seen. Of course then there was the system that moved through SW MB last week - straight north dumping up to 12" of rain along the way! The view of the new lakes along the TransCanada should be quite nice.

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The view of the new lakes along the TransCanada should be quite nice.

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Sadly, I'm flying. Yeah I know, it's a 7 hour drive... but with the time difference, I almost arrive before I leave! So my keister will be in a DeHavilland DH3 and I will probably laugh out loud again when I look out the window and see them firing up the props.

Bren R.

No kidding and again today. It's been raining non stop all morning and from looking at the clouds, it's not going to stop anytime soon.

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DeHavilland DH3

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i thought the DH series were 'watercraft'.. ?

please tell me your airport isnt a lake..?

bigjohn

It's a little TurboProp...

Bren R.

I'll vote clip 2 as the original, but it was pretty hard to hear on this crummy laptop.

my bad.. i just looked it up, its the DHC class that is the 'watercraft'. i used to be into planes when i was a kid, but you cant blame me for forgetting some of it..?

bigjohn

BR, this discussion is fascinating, but how about getting on to something that really makes a difference; what's your favorite recording of the Pathetique?

I was just about to post something about the pilot of the DH3. I think he has a small magnet on the co-pilot's seatbelt buckle. He swears it makes the plane fly better. He doesn't have any proof, and the co-pilot thinks he's goofy, and there is no (known) reason whatsoever that the magnet affects the aerodynamics - but dangit, he paid $2,000 dollars for that thing at AeroPhile.com, and he is POSITIVE that plane is flying better now...

Alright, enough of that, sorry...heh heh...

Assuming you're serious...My only recording here is Alfred Brendel, 1975 or so. Tempo's just right for me. There are so many great recordings though - it's impossible to prefer the same one two days in a row!

But the intro has lots of silence and fading notes - perfect for this type of "testing." The beginning of the d-minor("tempest") 1st movement has similar good quiet moments.

Absolutely serious, BR; I've got about a thousand classical CDs, and of course it's the music that's really the bottom line. If you search old posts for a topic such as "classical" you'll find me(along with the sorely-missed sushi)as a frequent contributor. Unfortunately there hasn't been much traffic in that area recently.

On the Pathetique, my favorite is Arrau on Philips(along with Appassionata and Moonlight), stately and dynamic in turn, with good sound from the '60s. I've listened to others and borrowed some from libraries, of course. The Brendel that I heard and liked was his digital re-make from the '90s.

Dang, John, that makes me sad a little bit.
FWIW, the Rachmaninov that you recommended gets alot of play time at my house - particularly Concerto #1. I love that piece.

Yeah Mark, it is a little bit sad. There's a whole world of beautiful music waiting for us out there if we'll just listen.

Nope, not the same track.. I compressed them all with FLAC and got pretty different bitrates for each one even though all the WAVs had the same filesizes and bitrates.

I'm using Shure e3cs. The output is from a hissy, poppy laptop headphone out, but I don't hear anything different using pcabx..

Johnk, that's great, really - and you're absolutely right, it's all about the music.

The Brendel I mentioned is also a Philips - my "moonlight" is Maurizio Pollini (Deutsche Grammophon). The only Appassionata I have handy is by the - ahem - world renown Daniel Barenboim (also DG), I lucked out there, most others I hear seem too fast at the end.

In the meantime, Thasp, I haven't counted the bits on the tracks myself, so I'm sticking with "They're all the same! I know it! I know it!" Maybe your bit-counter doesn't have the correct weight of golden feet on the bottom, and this has thrown it off.

I tried again without ABXing. Even with placeabo as a factor, they all sound the same.

I suppose these differences in a $100-$300 refurb NAD orHK CDP and a $5000 krell CDP really aren't anything to go nuts about. I'm going to try a spectral analyzer next, since I already know that without assistance I'll have no clue whatsoever what to look for.

Maybe I should wait until I get my ears drained before I try this stuff. Heh.

Bren R.,

Well I know you did not get the response you were hoping for with this test, but gives us the answers, pretty please.

Johnny

Sorry wasn't holding out... was out of town (sorry we missed each other, NeverHappy) and now into the busy season...

The answer key is:
1 - Jitter errors (evenly spaced)
2 - Elevated noise floor
3 - Clean

Bren R.

Wow. Johnny was right on.

I would've never got that.