Short answer
Both are dongles, $189 against $190.
The Moondrop Moonriver 2 Ti reaches 100 dB on 565 of the 567 models here, the ddHiFi TC44 Pro on 561.
| Specification | ddHiFi TC44 Pro | Moondrop Moonriver 2 Ti |
|---|---|---|
| Power into 32Ω | 120 mW | 280 mW |
| Power into 150Ω | 26 mW | 79 mW |
| Power into 300Ω | 13 mW | 53 mW |
| Power into 600Ω | 6.4 mW | 26 mW |
| Output impedance | 0.4 Ω unverified | not published |
| Output noise | 2.5 µV unverified | 1.5 µV |
| Price | $189 | $190 |
| Headphones it reaches 100 dB on out of 567 | 561 | 565 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | ddHiFi TC44 Pro | Moondrop Moonriver 2 Ti |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Published |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. ddHiFi TC44 Pro publishes at 32 Ω; Moondrop Moonriver 2 Ti at 32 Ω and at 300 Ω. The other rows are worked out from those.
So the two columns are not equally firm row by row: at 300 Ω only the Moondrop Moonriver 2 Ti figure is the maker’s own. On those rows the derived number is the one to doubt first.
4 headphones reach 100 dB on the Moondrop Moonriver 2 Ti but not on the ddHiFi TC44 Pro — Moondrop COSMO, Symphonium Crimson, Symphonium Helios, 1 more.
561 of the 567 models here reach 100 dB on both.
Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Audio-Technica ATH-R70X: Moondrop Moonriver 2 Ti has +13 dB of headroom there against +7 dB. 6 dB is about 4.1 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for ddHiFi TC44 Pro because that maker publishes no output noise figure.
| Headphone | Impedance | Needs | ddHiFi TC44 Pro headroom | Moondrop Moonriver 2 Ti headroom | ddHiFi TC44 Pro hiss | Moondrop Moonriver 2 Ti hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +29 dB | +33 dB | not published | 18 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +9 dB | +13 dB | not published | -2 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +18 dB | +22 dB | not published | -4 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +14 dB | +20 dB | not published | -8 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +11 dB | +14 dB | not published | -9 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +7 dB | +13 dB | not published | -15 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +3 dB | +9 dB | not published | -19 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +1 dB | +5 dB | not published | -21 dB |
The Moondrop Moonriver 2 Ti costs $1 more than the ddHiFi TC44 Pro. Out of the 567 models here, that difference buys 4 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.
Only published figures count here; blank axes are counted separately.
Each in full: ddHiFi TC44 Pro and Moondrop Moonriver 2 Ti.