Two interesting devices from two different and well respected manufacturers on the audio scene. Although, some may say that Japan's Teac's heritage and pedigree is more audiophile than NAD, but in my personal opinion, they are both leaders in their own right. NAD has been leading the way on innovation, more recently. NAD c658 is an example of new kind of dac/preamp that checks a whole bunch of boxes for a modern audiophile who may be looking for consolidation or on a somewhat limited budget.
I am not gonna go into a feature comparison between the two devices in this post, you can read that on their respective websites. I am here to share my own personal experience with the two. I'll just point out that NAD uses the ESS Sabre 32 bit chipset, whereas Teac uses 2 AK4497 32 bit flagship chipsets in dual monoaural configuration.
My setup is fairly simple. I used NAD and Teac both as pre-amp going directly into an Odyssey Kismet Extreme amplifier through RCA, which powers a pair of Paradigm Studio 60v5.
You can read my thoughts on NAD C658 in one of my earlier posts. To summarize, I really wanted to like this device, because it has the perfect feature set (albeit on paper, and not in reality pending unreleased features so far). I found the sound bright, edgy, clinical and unmusical in general. It was extremely fatiguing and listening to music became a disorienting chore. On the plus side, the sound was definitely revealing. The bottom is tight, fast and controlled. I found the mids to be recessed or always hidden behind the drums and the cymbals. I put on Hotel California by Eagles via Tidal, and I was amazed at the sheer amount of realism of fingers sliding on guitar strings that it revealed. Piano sounded real, and the weight behind the keys was immediately noticeable.
However, when lots of instruments played together, and on complex passages, the sound became congested. Add the slight edginess on higher frequencies, this made for a non-musical experience. In my opinion, NAD C658 struggles with congestion with the simplest of complex passages. While Carmina Burana, a classical piece, legitimately sounds flat, this behavior shows up even with moderately complex pieces. Case in point, in the first 50 seconds of School by Supertramp (MQA on Tidal), the crying, shouting children felt two dimensional. Even though, the dynamic range capability of the dac shines on this piece. So overall, I didn't find NAD C658 enjoyable. At no point, it got me tapping my toes even on my favorite music pieces.
Let's talk about Teac NT-505. I started with some Louis Armstrong in MQA streaming through Tidal, and was immediately floored by how smooth he sounded. All the details were there on the high-end that I was hearing on NAD, but there was something different. My first thought was that the highs have been mixed with sugar. They were sweet. Not syrupy, not edgy in any way, set just at the right place on the stage; they were exactly how music should sound like - pleasing. There was a sense of balance. The very next thing I noticed was almost a holographic sound stage. I wasn't ready to believe that because holographic stages are the realm of Tubes. This required some further listening. And that's what I did.
I've been listening to Teac for almost a week, and at this point, I can say with a lot of confidence that this Dac/Preamp can image extremely well, almost holographic, thanks to the separation of channels due to the dual monoaural configuration. I played School by Supertramp, and the difference between NAD and Teac was night and day. The sounds of children were coming from behind the speakers, behind the vocalist, from left and right walls. It was quite an immersive experience. The piano/keyboard sounded extremely well balanced and did not have a slightest bit of edge. I tried some Carmina Burana recordings and I was amazed at how well Teac NT-505 handles complex passages. It never broke a sweat. The imaging was so perfect that I almost forgot that one of the main reasons I bought C658 was because I thought I needed Dirac.
After listening for a week, I can say that Teac NT-505 is in a different league than NAD C658. In my experience, its as revealing as NAD, but at no point music becomes analytical. It has a lush midrange, maybe a little warm than neutral, but it makes for an enjoyable experience. The bottom end is tight. This was a point of concern for me, as I've read the reviews about the older NT503, and people have found the bottom end to be loose. On NT-505, the bottom end is controlled, tight, and authoritative. At no point, I felt that it was coloring the mid-range. The mids were always crisp, had a lot of texture and never muddied.
A word on the blue sound app vs Teac's HR streamer app. There's no comparison there, BlueSound app is the best out there. Its the best UX, period. Teac's HR Streamer app is the same app as Lumin. As a matter of fact, Lumin's app works with Teac too. It does the job. I got over it once I started hearing the music.
The volume control on Teac is pretty awesome too. I found that it was perfectly matched with my amp, and I was listening to it between 40% - 50% vs. Teac which provided similar gain between 25% to 40%.
Teac doesn't have Dirac, doesn't have multiple analog inputs like NAD C658, but it does one thing really well, and that's playing music. Teac brings the sweet, liquid, velvety gently warm sound to listening that can you tapping your toes.
So, I returned the NAD, and I am keeping the Teac. If I were naive, and didn't know that sonic impressions are subjective, I'd foolishly say that if you like NAD c658, wait till you try the Teac NT-505, you'd run away from NAD. But I won't say that. At least, not out loud.