Short answer
Both are dongles, $66 against $70.
The EPZ TP35 Pro reaches 100 dB on 561 of the 567 models here, the ddHiFi TC35Pro (Mountain2) on 554.
| Specification | ddHiFi TC35Pro (Mountain2) | EPZ TP35 Pro |
|---|---|---|
| Power into 32Ω | 65 mW | 112 mW |
| Power into 150Ω | 14 mW | 24 mW |
| Power into 300Ω | 6.9 mW | 12 mW |
| Power into 600Ω | 3.5 mW | 6.0 mW |
| Output impedance | not published | not published |
| Output noise | not published | not published |
| Price | $66 | $70 |
| Headphones it reaches 100 dB on out of 567 | 554 | 561 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | ddHiFi TC35Pro (Mountain2) | EPZ TP35 Pro |
|---|---|---|
| Socket | no separate rating | 4.4mm |
| Power into 32Ω | — | 262 mW |
| Power into 300Ω | — | 28 mW derived |
| Output impedance | — | not published |
| Output noise | — | not published |
| Headphones it reaches 100 dB on out of 567 | — | 565 |
Only the EPZ TP35 Pro has a separate balanced rating from its maker; through it, it reaches 100 dB on 565 of the 567 models here. The ddHiFi TC35Pro (Mountain2) may still have a balanced socket — its spec sheet simply gives no figure for one, so there is nothing to put beside it. Derived figures are worked out from the loads the maker did publish.
| Load | ddHiFi TC35Pro (Mountain2) | EPZ TP35 Pro |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. ddHiFi TC35Pro (Mountain2) publishes at 32 Ω; EPZ TP35 Pro at 32 Ω. The other rows are worked out from those.
The two publish at the same loads, which is the one case where the rows of this table can be read straight across.
7 headphones reach 100 dB on the EPZ TP35 Pro but not on the ddHiFi TC35Pro (Mountain2) — HiFiMAN HE-6se V2, HiFiMAN HE6 Remastered, HiFiMAN Susvara, 4 more.
554 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 Sennheiser HD 600: EPZ TP35 Pro has +3 dB of headroom there against +0 dB. 2 dB is about 1.7 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for ddHiFi TC35Pro (Mountain2) and EPZ TP35 Pro because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | ddHiFi TC35Pro (Mountain2) headroom | EPZ TP35 Pro headroom | ddHiFi TC35Pro (Mountain2) hiss | EPZ TP35 Pro hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +27 dB | +29 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +7 dB | +9 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +16 dB | +18 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +11 dB | +14 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +8 dB | +10 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +4 dB | +7 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +0 dB | +3 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | -2 dB | +1 dB | not published | not published |
The EPZ TP35 Pro costs $4 more than the ddHiFi TC35Pro (Mountain2). Out of the 567 models here, that difference buys 7 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 TC35Pro (Mountain2) and EPZ TP35 Pro.