Both are desktop DAC/amps, $3500 against $3799. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
The Naim Uniti Atom Headphone Edition reaches 100 dB on 567 of the 567 models here, the Marantz SACD 30n on 552.
| Specification | Marantz SACD 30n | Naim Uniti Atom Headphone Edition |
|---|---|---|
| Power into 32Ω | 50 mW | 750 mW |
| Power into 150Ω | 11 mW | 160 mW |
| Power into 300Ω | 5.3 mW | 80 mW |
| Power into 600Ω | 2.7 mW | 40 mW |
| Output impedance | not published | not published |
| Output noise | not published | not published |
| Price | $3500 | $3799 |
| Headphones it reaches 100 dB on out of 567 | 552 | 567 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
| Load | Marantz SACD 30n | Naim Uniti Atom Headphone Edition |
|---|---|---|
| 32 Ω | Published | Derived |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Only one of these two columns starts from a power rating. Marantz SACD 30n publishes one at 32 Ω; Naim Uniti Atom Headphone Edition publishes none at any of these four loads, so its column is worked out from power it published at other loads. Both are arithmetic on a maker’s own figures rather than guesses, and the method used for the Naim Uniti Atom Headphone Edition understates rather than flatters — but at 32 Ω is the only load here at which its maker can be held to a figure.
What each of these labels means, and why a derived figure is still worth printing, is set out in how this data was built.
15 headphones reach 100 dB on the Naim Uniti Atom Headphone Edition but not on the Marantz SACD 30n — HiFiMAN HE-6se V2, HiFiMAN HE6 Remastered, HiFiMAN Susvara, 12 more.
552 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
The counts above say how many models the two treat differently. This says by how much. The same 8 headphones appear on every page of this kind, ordered from the easiest to drive to the hardest, so a row can be read across pages as well as across columns. Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Campfire Audio Andromeda 2020: Naim Uniti Atom Headphone Edition has +23 dB of headroom there against +5 dB. 18 dB is about 60 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Marantz SACD 30n and Naim Uniti Atom Headphone Edition because neither maker publishes no output noise figure. That is a gap in the specification, not a quiet amplifier, and it is left blank here rather than filled with a plausible number.
| Headphone | Impedance | Needs | Marantz SACD 30n headroom | Naim Uniti Atom Headphone Edition headroom | Marantz SACD 30n hiss | Naim Uniti Atom Headphone Edition hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +25 dB | +43 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +5 dB | +23 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +15 dB | +26 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +10 dB | +22 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +7 dB | +21 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +3 dB | +15 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | -1 dB | +11 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | -3 dB | +9 dB | not published | not published |
The Naim Uniti Atom Headphone Edition costs $299 more than the Marantz SACD 30n. Out of the 567 models here, that difference buys 15 more models driven to 100 dB.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Everything in this paragraph counts only figures the two makers published. An advantage on an axis one of them leaves blank cannot be counted, and is not counted — how often that happens is its own page.
Each has a page of its own with every power figure traced to what the maker published and a full headphone list: Marantz SACD 30n and Naim Uniti Atom Headphone Edition. Or put either against your own headphones in the source comparison tool.