What's Up With Digital Amps?

*Christopher* · March 21, 2004

If you're new, then the world of Minidisc gear and technology must be overwhelming. It's completely understandable - there's been more than a decade and a half of innovation and research. One of the key components of tomorrow's [and some of today's] Minidisc units is the digital amp. Just before you assume they're all the same, halt.

Far from it. First off, catch up on this:

http://minidisc.org/classd_amp.html

Good bit of technical know-how, but it's important for you to read if you're seriously interested in a portable [or bookshelf/etc] unit that features this technology.

That aside, I've read a great deal of user opinions and reviews [some of my own] that reveal certain characteristics in the various brands and their digital amps. It's very surprising, actually, how some of the least popular brands can deliver sound that would absolutely surprise an average listener.

Remember: Regardless of the technology you use, there is a performance threshold when you compare it to a full sized solid state amplifier with a proper power supply.

-----------

Sharp?

For example, let's start with Sharp's 1-bit digital amp technology; they were the ones who started it all, at least in the portable sense. Sharp units have a very unique sound [focusing on detail, soundstage and clarity], and if you're a Sony-only user this depth and soundstage would leave you breathless upon first listen, since Sony units have a delicateness to them, so to speak. Newer-generation Sharp units usually carry a 8 or 5 mw output [at 32 ohms], and the sonics are extremely refined. Some have complained that bass is lacking on Sharp units, but I simply believe it's inadequate headphones. Regardless, a unit like the MD-DS8/DS70 [has an eq]/DS5, etc are an excellent starting digital amp player-only unit for the budding conisseur.

The portable recorders are even better.

Units like the MD-DR420/DR7/DR80/DR77, etc combine the modern and sophisticated sound of the digital amp with Sharp's highly respected recording features. The digital amp does not apply to the recording though, only for playback. I would definitely recommend one of these units as a great starting MDLP and/or NetMD unit for anyone. Definitely give off the best starting impression for the Minidisc format.

Sharp's bookshelf systems are in a class beyond the portable units. Featuring beefier output and better components to compliment the digital amplifier, most are extremely surprised upon first listen, even if they've been attuned to analog home theatres most of their existance. Unfortunately though, if you do employ a Sharp "Auvi" [this is what they've dubbed the home systems with a digital amp, and the older portables], they come with horrid stock speakers that need immediate replacement for the true quality in which the source can provide.

Luckily for a few of us, units like the SD-NX10, SD-SG11 [with Minidisc functionality] and a few others [look here in the bookshelf/audio systems in the Sharp section] were put on eBay by Sharp's factory outlet in 2003 for hundreds less than the MSRP and sold like wildfire. They still float around the internet, but not for the prices they once were.

I also happen to own a Sharp SD-AT100 combo dvd player/amp, and I will attest to that unit's fantastic picture quality and superior sound. There are also amp-only units like the SD-AT1000 with 5.4mhz oversampling and sound on par and better in some aspects than most high-end analog amps. As for oversampling, the highest they've gone is 11.2mhz; portables and most of the bookshelves are at 2.4mhz, and a few at 5.4. There are some flaws to oversampling at such rates, though..

On paper, the 1-bit amplifier will prove to be better because it addresses the weaknesses of portable audio. Portable amplifiers are weak because of size and power consumption. When you have a class-D amplifier that is suited for use with lower voltages [and lower power consumption], you'll get a better result than a standard amp which is squeezed for power. Sharp's 1-bit technology's supersampling techniques [interpolated] will contribute for better sound as well.

I definitely recommend a newer-generation Sharp 1-bit digital amp product. Unfortunately, there are no Sharp Hi-MD units.

-------------

What about Kenwood?

Most people associate Kenwood Minidisc products being Sharp MD unit clones with no differences - this is true in some cases, like the Kenwood DMC-S9NET and the Sharp IM-DR80; there are also older units as well that have similiar looks/functionality. Nonetheless, Kenwood did make a bite into the digital amp realm with their portable players, like the DMC-S33/S55/S77. These units actually sound different than the other brands. Owning the DMC-S55 myself, I was able to detect very early on that Kenwood's digital amp products do not have a detailed and wonderful natural sound like Sharp units, but more or less hovering above the muddy range. Kenwood features equalizers with these units [whereas most Sharp's don't, except for the DS70]. Once enabled, the Kenwood instantly impresses onto you a signature sound that will most likely be unforgettable. Everything I heard was so perfectly defined I actually couldn't believe I was listening to an ATRAC-encoded track! This is also known as "colored sound", which many people seem to be keen on.

The DMC-S** player-only series of units carry a 4.3mW [16 ohms] output, and actually sound a bit louder in areas than a Sharp. If you're interested in something different, and not to mention one of the best user interfaces [the remote is the best I've ever used] possible, give Kenwood a shot. The asthetics are a bit odd, but the units are absolutely fantastic. I expect great things from Kenwood in the future.

There are times I favor the Kenwood sound over a Sharp, but think of it as wine - each is favored for it's different color in taste.

Unfortunately, there are no Kenwood Hi-MD units as of yet.

-----------

What about Sony?

This is where the most common confusion begins.

There are actually two types of digital amps when you look upon Sony digital amp units, and they are the HD digital amp and digital amp. The difference is very important.

Newer Sony units like the MZ-RH10, MZ-RH910, MZ-E10, MZ-N920 have a different digital amp than the HD inclination, and it's just dubbed "digital amp". This is mostly in the power-consumption sense, and carry NO benefits towards the sound.

The only Sony HD digital amp units are found within the Hi-MD range, and they are: MZ-DH10P, MZ-NH1, MZ-NH900, the download-only unit MZ-NH3D, and the player-only unit MZ-EH1.

In regards to the HD digital amp, this review was written by bhangraman:

I did the iPod vs NH1 comparison... so now there's a footnote, the MZ-N10 vs MZ-NH1 comparison.
(A word of warning: From what other N10 owners who have tried mine say, apparently I have a particularly good one. However, I didn't feel it was any significantly better than the other N-series MD's I had... which means that some N10's must have been really bad?)
I've spent some time comparing the output of the MZ-N10 and the MZ-NH1 using SP (N10) and Hi-SP (NH1) recordings as my base comparison point. The optical digital recordings on both machines were made from the same deck (the Sony SCD-XA777ES) and the comparison CD used for the in-depth testing was Diana Krall's A Night in Paris. I'm using the Etymotic ER-4S earphone out of the Headphone Out mode, and also the Stax Omega II's through the Line Out modes.
The HD digital amp definitely seems to smudge the highs a little, and balloon the lows. Staging seems unaffected. The overall performance seems to be infinitesimally woolier than the N10. I will stress that the differences are very small... but what it boils down to is that there seems to be no measurable improvement apparent with the HD digital amp in terms of sound quality. There is a slightly different character in the base sound, but rather than being able to clearly say 'it's better than the N10', I can find more ways of describing it as worse, or at least undesirably different.
Should people be worried? I don't think so... as I said elsewhere, in isolation it sounds pretty good. But in terms of the new hardware, I've said it before and I'll say it again... I would not read anything into the 'HD Digital Amp' moniker.

..and Panasonic?

This review was written by Leon of his Panasonic SJ-MJ97, and is the only credible review of a newer-generation Panasonic digital amp unit.

Lemme start with my concluding thought: nice, but not spectacular.
Like other Panasonics, the MJ97 is ideal if you want to focus on the vocals. Whereas vocals can sound a bit distant and dry with Sony and Sharp, it's "wet" (no pun intended) and sparkling here.
You can hear it's a digital amp with the added clarity, but this is no Auvi [aka Sharp], there are no "spatial" revelations that'll send chills down your spine (Auvi owners will know what I mean).
:: the sound effects ::
The bass boost is typical Pana fare: instead of really boosting bass, they "add glamour" to the sound. Think Jamiroquai, or 70s soul/R&B - the Pana sound's really tailored to these music. If you're looking for punch (as demanded by your punk rock, alt-rock, lo-fi rock or hitomi-yaida-rock), buy a Sharp or Kenwood.
The surround effects, though, really stand out. There are 3 settings, 1 2 3 roughly corresponds to live-dome-studio in Dolby Headphone. However, Panasonic's surround seems to be far more accurate... I've never heard surround done this well on a portable Level 3 is very close to the normal sound - awesome for reducing the blob-in-your-head feeling. Maybe Panasonic used the software from their collaboration with Kobe University... they developed a virtual surround technology by simulating the acoustics of the outer ear canal, and measured a whole bunch of real ears in the process.
On a scale of 1-10, the MJ97 would be an 8... I bought it fully expecting this kind of performance. The Auvis would be 12...and the Sony E10 is... let's not talk about it.

-------------

Essentially, it's difficult to really establish what is better than the other. Each have their own merits, but obviously Sony or Sharp will be embraced by the novice; they both sound a bit different but share one aspect: a great impression and beautiful sound. Sony is actually more 'natural', but you lose out a lot of the high and low ends when you're listening with portable equipment - Sharp tend to place higher emphasis in these regions. Both Sharp (Auvi) and Sony lack real warmth, but Sony moreso because of the crippled bass response and weaker amplifier. Sony's highs are also harsh and sibilant, because the amp/DAC combo does a poor job at sound reproduction and so crap comes out.

You can't hold the amp 100% liable for this because it's not the technology on which the amp works, but how each company designs their electronics.

I would definitely suggest a Kenwood however [seems like the best in-between Sony/Sharp], if you can accept the asthetics; they have really come around with the user interface and remote design, and in the portable player-only sense this has been a nusance in recent times with Sony/Sharp. I honestly think each brand's digital amp is somewhat genre-specific, and one may excel in certain areas over the other.

----------

Want to purchase any of the aforementioned units? Click on a picture [or link below it] to go to a trusted e-tailer that sells these recommended units with digital amps.

[if pricing seems too high, try Froogle instead.]

Currently available Hi-MD Recording units with digital amplifiers:

----------

user posted image

[Purchase the MZ-DH10P]

Sign In

What's Up With Digital Amps?

Recommended Posts

Christopher

Link to comment

Share on other sites

Browse

Activity