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North Star Model 192 - DAC & upsampler 24/192

Digital fingerprints into analogue domain

[North Star Model 192]

[Italian version]

Product: DAC & upsampler 24/192 North Star Model 192
Manufacturer: North Star - Italy
Approx price: 1200 Euro/$ (your mileage may vary)
Reviewer: Lucio Cadeddu
Reviewed: June, 2001

Two years ago I reviewed the first DAC by NorthStar, the Model 3, which was able to convert 24/96 digital data. It was a very good sounding DAC, ready for what seemed the next-to-come digital standard: DVD-Audio at 24/96.
Things have changed a lot in the meanwhile and nobody seems to care of the 24/96 standard now, as SACD and 24/192 are still fighting their neverending battle for the market leadership.
So far, it seems a clear winner has still to pop up.
We poor audiophiles, always caught in the middle, have just one secret weapon left: our freedom of choice. Hence, as I have always suggested, let's wait till the holy war comes to an end! In the meanwhile, let's try upgrading our existing digital source...
This leads immediately to the crucial question: should I upgrade my digital source, now? My advice is, yes, if you're planning an upgrade of your system, don't forget to consider a new CD player or a new, modern, D/A converter. Today many good sounding and reasonably priced digital machines are available. Some of these, as you may have noticed (dCS, Perpetual Tech. etc.) use "upsampling".

At NorthStar it seems the secret password is "upsampling". Indeed, after the aforementioned Model 3, the brave Italian Company designed an add-on upsampler, called, guess what?, Model 4. Matched to this upsampler - that converts 16/44 into 24/96 - the Model 3 was able to fully exploit its internal 24/96 D/A converters and improve its sound considerably.
At the end of 2000, Giuseppe Rampino at NorthStar was ready with a new, more powerful D/A converter: the Model 192, an all-in-one package which includes a 24/192 upsampler and a 24/192 DAC.
The cabinet is always the same, with a radically different front panel, now finished in a perfect Jeff-Rowland-ish style.
Using this DAC is simple: all you need to do is connect the digital output of your CD transport or CD player to one of the 5 digital inputs (2 RCA, XLR, optical, I2S) of the Model 192.
The 16/44 datastream coming out of your trasport will be immediately upsampled to a 24/192 digital signal, then converted into analogue, ready for your preamp or integrated amp. No settings to adjust, no inputs to select, the Model 192 will get the dirty job done before you can say "Cool!".
Of course, don't forget to connect an AC power cord (possibly, a good one) to the IEC socket in the rear and to press the on/off switch close to it. While you're there, please leave the unit always switched on, since this is the way it will sound better, unless you use to listen to your system just once in a month or so.

Technophiles out there may want to read all the techno-babble at the recently revisited NorthStar web site or at the bottom of this page where the designer himself gives a short technical explaination on why upsampling WORKS, in his opinion.

[North Star Model 192 - inside]

NorthStar Model 192...sexy looks...inside!

The test of this Model 192 has been one of those looong ones, thanks to Mr. Rampino's infinite patience I've been able to compare it head to head with its ancestors (at 24/96), the pair Model 3 + Model 4 (no longer available, the manufacturer can only supply DIY kits of these).

Digital fingerprints into analogue domain

Well, if you have always considered the digital sound way too...digital but never felt compelled to shell out big bucks for esoteric D/A converters...this could be the DAC right for you. Yes, its sound, though definitely digital, is terribly close to that of a good analogue playback system. It is smooth, silky and armonically rich, very far from the edgy, hyper-detailed sound of some CD players and DACs.
Harshness? What's that? There's no trace of this in the musical stream that flows from the Model 192 right to your ears.
Completely different from the Model 3, which sounded a bit "in yer face" and sometimes aggressive, this new toy from NorthStar succeeds improving even the musical performance of the 24/96 previous pair (Model 3 + Model 4)
Actually, the upsampling process made wonders to the sound of the Model 3 as standalone unit. It gained smoothness, warmth, detail and depth of the soundstage.
The new Model 192 does even better so it wins the head to head comparison hands down. Simply, there's no competition.
I don't know if this is due to the higher upsampling (24/192 instead of 24/96), all I know is that - besides maths, formulas and sampling rates - at NorthStar must have some good set of audiophile ears, too, and I can't believe they got such a good improvement only by means of formulas.
The balance among all the frequencies of the audio spectrum is almost perfect: mids and highs sing together in perfect harmony, with plenty of class and liveliness.
The bass range is a good mix of extension and control, while the midbass appears a bit shy, especially on electric bass notes. This character, considering the "smooth" and never aggressive personality of the unit, sounds just logical to me.

It doesn't really matter if you're a classical Music fan or a die-hard rocker, the Model 192 will make you enjoy your CDs for many hours without the urge to turn that volume knob volume down.


The Model 3 and the pair Model 3 + Model 4 were extremely good at this: they sounded explosive, fast and extremely punchy. So I was expecting a similar performance by the Model 192.
The family feeling has been preserved, indeed, though the Model 192 appears to sound smoother, hence dynamically less aggressive than the previous models. It is a solid, fast and lively performer but there's always a sweet note that makes the listening experience always enjoyable and relaxing.
In the microdynamics department the Model 192 performs extremely well, it is more detailed and accurate than the pair 3 + 4 though don't expect a kind of X-ray inspection sound.
It does investigate deeply into the musical patterns but it does that in a very natural way.
Again, it is the mid-bass range to appear less lively than the rest, as already noted above.
Once again, even the dynamic performance of this unit reminds me that of a good analogue playback system, sweet and strong, instead of the usual edgy behaviour of many digital playback systems. And if you're thinking a vinyl can't sound dynamically challenging even when compared to a good digital source, perhaps you've never listened to a good analogue set-up :-)

3D soundstage

Soundstaging is one of the best qualities of this digital machine. Width, height and depth are so realistic that your room will be literally embedded into a fully live musical experience. Considering the price tag, the size of the soundstage this Model 192 is able to generate is simply outstanding and well above the physical space between your speakers.
Size aside, the whole scene is extremely realistic thanks to the precise location of instruments and singers, too. The contours are on the "soft" side and the scene is never "in your face" as it was with the "monitor-like" North Star Model 3.
If you're used to this kind of sound, like razor sharp contours and in your face image, perhaps the soundstage created by the Model 192 will appear unrealistic to you.
In my opinion, especially if one thinks at the blurred stage you get from a real live performance (think of an orchestra, for example), the "monitor-like" kind of soundstaging is too far from the real thing so I prefer a wider and softer 3D scene to a narrow, 2-sized, pin-pointed one.
A matter of taste, perhaps, but in my opinion the Model 192 represents a GIANT leap forward with respect to the Model 3 and even the pair 3 + 4.

Some advice

I've already pointed out the need to leave the Model 192 permanently switched on if you listen to your system frequently. Anyway, don't think this unit needs hours of warm-up to sound well: 30 minutes are normally enough.
The digital inputs to use are closely linked to the kind of digital outputs your CD transport (or player) has. If possible, use the XLR or the I2S ones, as technically better. Then RCA coaxial - there's two of these! - and lastly optical.
The AC cord isn't included in the package (funny, uh?) so you are forced to buy it. While you're there, buy a good audiophile-grade one, better if one of the "digitally filtered" kind. Many companies make such cords (for example, JPS makes the Digital AC, reviewed here on TNT-Audio), with built-in filters so to avoid the digital garbage escapes from the unit :-)
Anyway, you can even use one of our humble DIY designs, like the TNT TTS or the easier to make TNT Merlino.
Coupling/decoupling: the Model 192 uses four soft rubber feet, not bad but certainly they can be bettered. Have a look at several such accessories we have already reviewed here on TNT-Audio...
The choice mainly depends on your personal taste and the kind of rack/table you'll be using with the unit.
Digital interconnects: yes, I know 0 is 0 and 1 is 1, but - believe it or not - a good digital cable can make quite a difference. So, after having bought such a good quality D/A converter, do not limit its performance using poor quality cables (I'm currently working on a mid-budget "digital cables shootout", so stay tuned).


Manufacturing and finish.
The new front panel is cool but it has two problems: it doesn't welcome digital...ahem....fingerprints :-) and it does not match well (IMHO) with the rest of the cabinet, which is plain black. The quality of the finish is top-notch.
The AC mains cable is lacking. I understand the manufacturer's aim - as reported in the manual - since he wants the owner to buy a good cable....but in my opinion ANY HiFi component should be sold READY to work. For example, a coaxial digital cable should have been included, too.

Every time I've tried to complain about something, the price tag of the Model 192 came to my mind :-)
Oh yes, perhaps a more solid mid-bass and a less sweet performance with certain aggressive kinds of Music would have been welcomed BUT! this is the personality of the Model 192, either take it or leave it.
After you have listened to it for a couple of hours, I'm pretty sure you'll forget all my ramblings as this DAC will let you concentrate on Music alone.
DO NOT judge its sound after 10 seconds, this is the worst thing you can do this excellent digital machine.


Did the Model 3 impress you? Did the Model 3 + Model 4 fascinate you? Well, this Model 192 will make you fall in love with digital audio without mortgaging your house again.
Into its price range and even slightly above, this unit is a real masterpiece. As remarked above, listen to it for a couple of hours and you'll understand.

Thanks to Giuseppe Rampino of North Star for his patience and collaboration.

Why upsampling works (by NorthStar)

First of all, let me point out that there's no kind of magic here, as everything can be explained technically.
First of all, let's say the upsampling method CAN'T improve anything. The sound of a digitally upsampled DAC is better because it is the non-upsampled one to be worse.
For, let's see what happens to a standard 44.1 kHz digital signal when it is converted directly by a DAC. Before going into analogue, the digital signal crosses a digital filter that oversamples it (normally 8 times, 8x oversampling, as usually called) and a second digital filter with very high slope that cuts off all the garbage above a certain frequency, quite close to the audio band.
Once the signal has been converted into analogue, it crosses another filter, an analogue one, normally of the 2nd or 3rd kind, that introduces phase rotations into the audible spectrum.
Now, how can we consider the effect of a phase rotation in the time domain?
Let's suppose to have a musical instrument that plays its fundamental tone and its harmonics. The first ones normally are reproduced fine...but the higher order ones are delivered to your ears with a phase rotation (with respect to the first ones) and hence with a time delay that can be heard as distorion.

What happens with upsampling? The standard 44.1 kHz digital stream is interpolated and the samples are calculated as the original signal had a 192 kHz sampling rate. BUT!!!! This process adds NOTHING to the original signal!!!! Even at 192 kHz the signal is still extended till 20 kHz!
The difference now is that the signal crosses digital filters centered at 96 kHz and the following analogue filter will be centered far from the upper limit of the audio band (actually, near 96 kHz!!!).
This means the analogue signal coming out of the DAC will be more faithful to the original one in the time domain (less phase rotations, that is).
© Copyright 2001 Ing. Giuseppe Rampino - NorthStar

© Copyright 2001 Lucio Cadeddu - http://www.tnt-audio.com

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