The Stello DA100 Signature is a really good all around DAC that can accept almost any digital source. In addition the Signature can upsample to 24/96 or 24/192. As mentioned previously, and to be discussed later, the Signature offers the much requested upsample bypass feature. The analog output stage is fully discrete class A push-pull and the analog output offers Cardas single ended connectors and Neutrik balanced connectors. This DAC is certainly good size and feels quite substantial. Contributing to this is the large 25 VA Toroidal power transformer.
The front panel interface of the D100 Signature is very simple to use with the exception of one minor item. The Upsample button requires to user to remember what sample rate the colors green and red equate to. Sure this is very minor, but the model below the Signature has a toggle switch that says BYP and 192. This label leaves no room for error or questions. I'm sure if the Signature was my only DAC I would have no problem memorizing the color scheme. I can hear many of you right now using your best Thurston Howell, III voice to say, "So many DACs so little time, what's a guy to do?" For those not familiar with the TV show Gilligan's Island this meant to be a very facetious statement reflecting on my shortcomings more than anything else. Back to the front panel of the Stello DA100 Signature DAC from April Music. As you can see in the photos the input selector is a nice big and round knob. There is substance to this knob and it leaves no doubt you've selected the input of your choice. Other knobs on similarly priced DACs do not offer this nice feature. The Benchmark DAC1 PRE for example has a knob that also spins to select the input. However it is simple to spin past your intended target as the DAC1 knob offers nothing more than a blue light to notify you that you've selected a specific input. Plus one for the DA100 Signature! The last feature on the front panel is the lock notification light. Some people love this feature, which is why many manufacturers have started including it in their new DACs. I can think of one very respected high-end manufacturer that made a last minute change to its new DAC to add a lock indicator based on input from different people. I guess the people have spoken!
A few items that may or may not concern you are heat, lack of remote volume control, and input selection. The Stello DA100 Signature generates a lot of heat. If you plan on sitting near this unit you'll want to take this into consideration. Heck, you may even like this if your "man cave" gets a little chilly in the winter. While your wife is upstairs with the dog sitting by the fireplace you have your own little heat source. One item that would really make this Stello DAC stellar is a remote volume control and input selector. This would allow one to connect the DAC right to an amp bypassing any preamp sound signature and avoiding a pair of expensive interconnects. Since this DAC has five inputs and April Music touts the use of each one with a different source, it should have included a remote input selector. In addition to these items the Stello DA100 Signature does not support an ASIO driver. Windows XP users may see this as a show-stopper while others will say, "What's ASIO?" and move on to the next album. These are my only gripes for an otherwise very solid product. For less than $900 maybe I shouldn't ask for absolutely everything :-)
The April Music marketing material hit the nail right on the head.
"Try the DA100 Signature with any of your digital sources - computer, CD, DVD, cable or satellite TV receiver. You'll be amazed how digital sound can be transformed into something musically seductive and emotionally satisfying."
If you can't find an input on this DAC that your computer can connect to, then it's time to upgrade that Apple II, Commodore 64, or Windows 3.11 operating system. There are no excuses for avoiding the music server subject with this DAC. One thing that I really like about this DAC is that I will soon be able to use three of the five inputs and decide which one I like best. I don't currently have coax or I2S output on my Mac Pro music server. As I've discussed many times before there is no black & white answer to the question of which input is best. It comes down to the manufacturer's implementation, the listener's personal taste, and convenience. I know many of the readers use laptops and Mac Minis that offer USB and optical outputs. It's not real convenient or prudent to convert one of those connections to AES, so I won't even go down that path. At the time of this review my Mac Pro has a Lynx Studio AES16e card, but the AES cable did not arrive on time so I could not test the AES/EBU input on the DA100 Signature. No worries though, I spent plenty of time listening via USB and optical.
The Stello DA100 Signature natively supports up to 24/96 via all inputs except USB. The USB input natively accepts 16/44.1 material and will downsample anything above 16/44.1. April Music recommends upsampling all these signals to 192 kHz for most playback. After several long listening sessions I decided the Bypass mode via optical input sounded best in my system. This is just one of those things you'll have to try on your own. The cool thing is you have so many input options and possible combinations with Bypass, upsample to 24/96 or 24/192. You're bound to find a few that you really like.
The majority of readers on Computer Audiophile seem to like DACs that do not upsample. There really is no right or wrong method it's only about what sounds good to you. When I reviewed the PS Audio DLIII DAC I much preferred the USB input upsampled to 24/192. With the Stello DA100 Signature I much preferred the optical input without any upsampling. I guess this is part of what makes our wonderful hobby interesting. If there was one correct method that sounded superior every time we would be stuck with only a couple of products to choose from. Anyway, the upsample bypass on the Signature DAC means the digital output is exactly the same as the digital input up to 24/96 (excluding USB). Some DACs that do upsample use the upsample process as a method of reducing jitter. April Music has found other ways to reduce jitter including Asynchronous Sampling Rate Conversion using a proprietary and specially designed clock circuitry. April Music says it's a jitter-free timing circuit, but statements like this are often marketing terms because eliminating jitter 100% is something I've never seen done at any price.
As I mentioned earlier I much preferred the optical input with the upsample bypass feature enabled. This is highly specific to my system, my ears, and my listening room. Please don't take this preference for optical as a statement about any other optical connection on another DAC or as a statement against the USB input on the Stello DA100 Signature.
Blunt, forward, and unfiltered. This was my first impression of the Stello DA100 Signature DAC. I immediately noticed the Signature DAC's sense of in-your-face sound that was very blunt. What I mean is this DAC has a forward presentation and doesn't cover up for blemishes in the recording process. To paraphrase a slogan from EA Sports, "If it's in the song it's in the song." The Signature doesn't sound HiFi or smooth anything out. At times this DAC sounds a little unrefined compared to some of the best DACs I've heard in my system. The Berkeley Audio Design Alpha DAC and the Weiss Minerva come to mind as DACs with a more refined and transparent sound. But if you don't have an extra $4000 lying around the DA100 Signature is more than adequate. In fact the name Signature really doesn't help this DAC. There doesn't seem to be a sonic signature in the traditional sense of the word. The DAC doesn't have a mushy or dry or thin sound signature. The DA100 Signature doesn't imprint this type of signature rather it pushes out an unfiltered honest sound. I use the tern "push" because the DAC does have a very forward presentation. This will be a very good component for those of you with laid back systems who are looking to bring everything a little closer to your listening position. I can also see this DAC performing well in a desktop system where the user may play games and need that extra punch when throwing a grenade on the opponents. This DAC reminds me a lot of Klipsch speakers without the coloration of horns. (I'm actually a big fan of Klipsch as one of my first systems included Klipsch KG 5.5 speakers. Those KG 5.5 speakers made it to college with me and came very close to getting me several noise violation citations.)
The majority of my listening sessions were conducted using the optical input of the DA100 Signature. I did give the USB input plenty of time, but found it a little less musical and didn't get me into the music as much as the optical input. I used the built-in optical output of my Mac Pro and used iTunes 7.7.1 (11) with uncompressed 24/96 AIFF files for much of the review. Using the optical connection I was able to take advantage of my newly ripped DVD-Audio discs in all their 24/96 glory. John Hiatt's Bring The family is one of my new favorite albums. John's unique voice and acoustic guitar on Learning To Love You sounded fabulous through the DA100 Signature in bypass mode. During every review I make time for a little Morph The Cat from Donald Fagen. The 24/96 version of this really had punch through the Signature DAC. When the volume was cranked high enough I could feel a visceral impact with each pluck of the bass. The DA100 Signature was certainly not holding any of this recording back!
The vast majority of music available is still 16/44.1 so I made sure to spend enough time listening to the DA100 Signature with material of this resolution. I listened to many of my standard albums that I'm very familiar with. The Stello performed exactly as described above. The presentation was forward and unfiltered. What more could you want from a DAC than a predictable and stable performance. Whether it was 24/96 or 16/44.1 the Stello DA100 Signature did not change. There is nothing worse than a DAC that sounds good with one resolution and not another. If you're currently in that situation with your DAC the DA100 Signature model will be just the remedy you need.
Inputs, options, and impact. Three words that describe my experience with the Stello DA100 Signature from April Music. With five inputs and the ability to bypass or upsample to 24/96 or 24/192 my satisfaction was virtually guaranteed. The DA100 Signature is a DAC for almost anybody. Sure it runs a little hot and could use some enhancements, but the same can be said for every other DAC on the market regardless of price. The DA100 Signature should certainly be on your short-list if you're looking for a new DAC. Now that I've listened to the DA100 Signature I can honestly say you don't need to spend a grand to achieve high-end sound. The Stello DA100 Signature retails for $895 USD and is available via http://www.hifi500.com .
More information available from April Music.
McIntosh tube amp
Avalon Acoustics speakers
Benchmark DAC1 PRE
AVI ADM9 speakers
Kimber Select cable
Mac Pro w/ 10GB RAM, 8 CPU cores
Thecus 5200B Pro NAS
QNAP TS-409 NAS
AIFF files (16/44.1, 24/96)
MacBook Air & iPod Touch for remote control
Dedicated 20 amp power circuits