Sound Analysis and Comparison.
I find Opus#1S to have a very neutral tonality across entire frequency spectrum. While listening with different IEMs and full-size headphones and comparing to other DAPs, #1S sounds like it adds zero coloring to the sound, trying to keep it true to the original recording. That can give you a perception of sound being a little colder and a little more revealing which is good when you are analyzing your headphones to hear their signature without any coloration. Perhaps, it’s lacking some body, especially in lower mids, but I think it’s just part of a neutral tuning to stay as close as possible to the original recorded source.
Soundstage is wide, for sure #1S is wider than original #1. Also, the sound has a black background, making it tighter and faster, with faster transient of notes on/off, making details pop up with more clarity in comparison to #1. The vertical expansion of sound dynamics is good, not on the flagship level of other DAPs, but still pretty good for a mid-fi model which leads to a decent layering and separation of the sounds.
Comparison of #1S vs #1.
Though these DAPs have a similar neutral tonality, when it comes to a technical sound performance, there are some differences. The improvement in signal-to-noise ratio will be noticeable in #1S where you have a blacker background and nearly zero hissing, while #1 has some hissing with sensitive low impedance IEMs. #1S also has a better dynamics expansion and improved layering and separation of the sounds.
Another noticeable difference is #1S having a wider soundstage expansion, while depth perception remained the same. Other improvement is a higher output power where on average #1S is about 20 volume clicks lower than #1. Also, IPS display of #1S has a deeper and richer colors and wider viewing angle in comparison to #1 which is not IPS. I also noticed that #1 next to my phone has more EMI interference while #1S had no issues under the same test conditions, probably due to a better internal shielding. And last, but not least, I didn’t have to select BAL output in #1S like I have in #1.
Comparison of #1S vs #3.
This is another interesting comparison since I found both DAPs to have nearly an identical sound, including the same soundstage expansion, the same dynamics expansions, and the same level of transparency, layering, and separation. Also, they both have the same black background and tight/fast sound with faster transient response of notes.
Where you find a difference is in output power, with #1S being more powerful, about 15 clicks difference in higher volume for #3 to match #1S. When it comes to a display, though both have IPS, I find #1S to have richer and more accurate colors. Also, dual uSD support gives #1S an upper hand when dealing with storage of high res files. But at the same time, #1S is an audio only playback device, while #3 has Bluetooth to connect to wireless headphones and WiFi with the ability to side-load apps, including for streaming. Last, but not least, #3 has a physical volume wheel while #1S has buttons like in original #1.
Other DAP comparisons.
Opus #1S vs FiiO X5iii – 1S has a wider soundstage; X5iii has more hissing with sensitive low impedance IEMs while 1S has no hissing; 1S has a blacker background, lower noise floor; 1S sounds more dynamic, airier, with more sparkle, while X5iii is less dynamic (a little more compressed peaks), not as layered, and not as much air between the layers. Both have the same internal 32GB storage, and two uSD cards to expand the storage. Both have a responsive touch screen, but FiiO runs full open Android with Wifi, Google Play store, and support of streaming apps while 1S has a closed Android system with no wifi and no app support. Also, X5iii has Bluetooth support to connect wireless headphones. Both have 2.5mm balanced output. Overall, FiiO has more features, while Opus has better sound quality.
Opus #1S vs Shanling M3S – 1S soundstage is a little bit wider; both are hiss-free and have a black background; I hear a difference in tonality where 1S is a little more neutral while M3S has a little more body in lower mids; also, I hear 1S to have a little more dynamic sound expansion with more airiness. In terms of the sound quality, the gap is not that big, though I find 1S to have an edge with a more neutral and transparent sound. The bigger difference is in overall design where M3S has no internal storage and only 1 uSD, while 1S has 32GB internal and 2 uSD card expansion. Both have balanced 2.5mm output. Also, M3S has a smaller display and no touch screen, while 1S has a big bright display and a very responsive touch screen.
Opus #1S vs Cayin N5ii – 1S soundstage is just a tiny bit wider in comparison to N5ii; both are hiss-free and have a solid black background with a low noise floor; 1S tonality is more neutral while N5ii has a little more body; in terms of a dynamic expansion, I hear 1S just a tiny bit better, but it’s a small gap. Both have the same internal 32GB of storage and external dual uSD, and both have a balanced 2.5mm HO. While the sound quality is close, the biggest difference is N5ii having Bluetooth (wireless headphones connection) and Wifi with access to Play store and streaming apps.
It’s clear that #1S offers a higher output power than #1, and as a result you can drive your headphones more efficiently since you don’t have to push the volume higher. In general, I didn’t find higher power to affect performance of IEMs as much, besides the differences I already noted above, such as wider soundstage and blacker background with less hissing. But full-size headphones with large dynamic drivers or higher impedance earbuds can have more sound improvement when driven with a more powerful source. Here are a few examples comparing Opus#1 vs Opus#1S performance, both in medium gain, playing the same track, where I also noted the volume “v” level and BAL (balanced, 2.5mm) vs SE (single ended, 3.5mm). Below is how I’m hearing the improvement going from #1 to #1S.
Beyerdynamic T5p2 (BAL) – #1 (v105) vs #1S (v85): wider soundstage, tighter sound, blacker background, more textured bass, a little more sparkle in treble; overall a touch less veiled.
Oppo PM3 (BAL) – #1 (v110) vs #1S (v90): wider soundstage, blacker background, everything else is identical.
Audeze EL8C (SE) – #1 (v130) vs #1S (v110): just a little wider soundstage, blacker background, and more body in mids.
Audio-Technica ATH-R70x (SE) – #1 (v140) vs #1S (v114): hard to spot a difference using these open back cans, but #1S sounds a little more transparent to my ears.
VE Zen (SE) – #1 (125) vs #1S (v105): very similar soundstage expansion and overall tonality, but #1S does have a blacker background and tighter sound.
Even before I received Opus#1S for review, I got many questions asking how it compares to the original Opus#1 and if it worth the upgrade. If you are trying to decide between #1 and #1S, I would personally recommend go for the latter one since I found the sound quality improvement to justify the extra cost. As I mentioned already, #1S has a blacker background, tighter sound, better dynamics, and wider soundstage expansion, all of which makes this DAP more enjoyable. Also, higher output power will open a door to a better synergy with more demanding headphones.
In terms of an upgrade, the market has changed a lot since the original Opus#1 was released, and now you have more choices. If a pure music playback without Bluetooth and without access to Google Play and streaming apps is what you are after, and you want a straight forward simple audio interface with dual uSD (over 800 GB of internal storage) or you have a DAC/amp with an optical input and looking for a touch screen digital transport – Opus#1S is a very good option. In general, with so many choices, try to make a list of all the available DAPs within your budget, write down their Pros and Cons, figure out your priorities, and then decide which one is the right one for you.