Short answer
Both are dongles, both at $70.
On raw power they are level: each reaches 100 dB on 561 of the 567 non-electrostatic models here.
| Specification | Tanchjim Space | Truthear SHIO |
|---|---|---|
| Power into 32Ω | 125 mW | 125 mW |
| Power into 150Ω | 27 mW | 27 mW |
| Power into 300Ω | 13 mW | 13 mW |
| Power into 600Ω | 6.7 mW | 6.7 mW |
| Output impedance | not published | 0.3 Ω unverified |
| Output noise | 1.1 µV | 1.6 µV |
| Price | $70 | $70 |
| Headphones it reaches 100 dB on out of 567 | 561 | 561 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | Tanchjim Space | Truthear SHIO |
|---|---|---|
| Socket | 4.4mm | 4.4mm |
| Power into 32Ω | 500 mW derived | 500 mW derived |
| Power into 300Ω | 53 mW derived | 53 mW derived |
| Output impedance | not published | not published |
| Output noise | 1.3 µV | 1.6 µV |
| Headphones it reaches 100 dB on out of 567 | 566 | 566 |
Through the balanced sockets the two are level on the same test: each reaches 100 dB on 566 of the 567 models here. Derived figures are worked out from the loads the maker did publish.
| Load | Tanchjim Space | Truthear SHIO |
|---|---|---|
| 32 Ω | Upper bound | Upper bound |
| 150 Ω | Upper bound | Upper bound |
| 300 Ω | Upper bound | Upper bound |
| 600 Ω | Upper bound | Upper bound |
Neither maker publishes a power rating at any load. Both columns above are ceilings, worked out from a maximum output voltage on the assumption that the amplifier holds it into the load — the most flattering reading available for either. 24 of the 280 sources here are in that position. Whichever of the two looks the stronger on power, the difference is unproven; the output-impedance and noise rows are the ones to go on.
On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.
1 headphone stays below the audible-hiss threshold on the Tanchjim Space but crosses it on the Truthear SHIO (Tanchjim EA FORCE).
561 of the 567 models here reach 100 dB on both.
Headroom is at a 100 dB SPL peak.
Across all eight the two stay within half a decibel of each other, which is a way of saying that on power this pair is one product.
Hiss below about 20 dB SPL is inaudible in a quiet room.
| Headphone | Impedance | Needs | Tanchjim Space headroom | Truthear SHIO headroom | Tanchjim Space hiss | Truthear SHIO hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +29 dB | +29 dB | 15 dB | 19 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +9 dB | +9 dB | -5 dB | -1 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +19 dB | +19 dB | -7 dB | -3 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +14 dB | +14 dB | -11 dB | -8 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +11 dB | +11 dB | -12 dB | -9 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +7 dB | +7 dB | -18 dB | -15 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +3 dB | +3 dB | -22 dB | -19 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +1 dB | +1 dB | -24 dB | -21 dB |
These two cost the same, $70, so price settles nothing. Out of the 567 models here, the Tanchjim Space keeps one model below the audible-hiss threshold — and on the other side there is no such advantage at all.
Only published figures count here; blank axes are counted separately.
Each in full: Tanchjim Space and Truthear SHIO.