Short answer
Both are desktop amplifiers, $200 against $150.
The Geshelli Archel Pro reaches 100 dB on 567 of the 567 models here, the PreSonus HP4 on 558.
| Specification | Geshelli Archel Pro | PreSonus HP4 |
|---|---|---|
| Power into 32Ω | 1.8 W | 69 mW |
| Power into 150Ω | 500 mW | 52 mW |
| Power into 300Ω | 250 mW | 26 mW |
| Power into 600Ω | 125 mW | 13 mW |
| Output impedance | 0.1 Ω unverified | not published |
| Output noise | 1.5 µV unverified | not published |
| Price | $200 | $150 |
| Headphones it reaches 100 dB on out of 567 | 567 | 558 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Geshelli Archel Pro | PreSonus HP4 |
|---|---|---|
| 32 Ω | Unverified | Derived |
| 150 Ω | Unverified | Derived |
| 300 Ω | Unverified | Derived |
| 600 Ω | Unverified | Derived |
Geshelli Archel Pro publishes no electrical specification at all. That is true of 10 of the 280 sources here, and the figures in that column come from independent measurement rather than from a maker document — which is not worse, but it is not the same thing, and it cannot be checked against anything the maker will stand behind.
The PreSonus HP4 column stands on figures its maker printed, but not at these loads — every row of it is worked out from power published somewhere else. Reading the two straight across sets one kind of claim against another, and nobody has written down the conditions of both side by side.
9 headphones reach 100 dB on the Geshelli Archel Pro but not on the PreSonus HP4 — Moondrop COSMO, Moondrop PARA, Moondrop PARA 2, 6 more.
558 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 HiFiMAN HE400se: Geshelli Archel Pro has +22 dB of headroom there against +8 dB. 14 dB is about 26 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Geshelli Archel Pro and PreSonus HP4 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Geshelli Archel Pro headroom | PreSonus HP4 headroom | Geshelli Archel Pro hiss | PreSonus HP4 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +41 dB | +27 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +21 dB | +7 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +31 dB | +21 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +27 dB | +17 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +22 dB | +8 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +20 dB | +10 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +16 dB | +6 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +13 dB | +4 dB | not published | not published |
The Geshelli Archel Pro costs $50 more than the PreSonus HP4. Out of the 567 models here, that difference buys 9 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 has a page of its own with a full headphone list and the provenance of every figure — worth opening here, because Geshelli Archel Pro has published no electrical specification at all and everything above comes from independent measurement: Geshelli Archel Pro and PreSonus HP4.