The EPZ Q5 Pro is 24Ω at 109.0 dB (no reference unit printed); the EPZ Star One is 64Ω at 100.1 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The Star One needs 8.9 dB more than the Q5 Pro to reach the same loudness — 0.98 mW against 0.13 mW.
| Specification | Q5 Pro | Star One |
|---|---|---|
| Impedance | 24 Ω | 64 Ω |
| Sensitivity | 109.0 dB | 100.1 dB/mW |
| Sensitivity (voltage) | 125.2 dB/V | 112.0 dB/V |
| Power for 100 dB | 0.13 mW | 0.98 mW |
| Voltage for 100 dB | 55 mV | 0.25 V |
| Current for 100 dB | 2.3 mA | 3.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 3.00 Ω | 8.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. EPZ Q5 Pro printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
1 source is low enough in output impedance for the Star One under the one-eighth rule but not for the Q5 Pro (Shanling H5).
10 sources stay below the audible-hiss threshold with the Star One but cross it with the Q5 Pro (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 7 more).
280 of the 280 sources here reach 100 dB on both.
The Star One is more demanding than 67% of the 567 non-electrostatic models in this database; the Q5 Pro than 13%.
| dB SPL | Q5 Pro power | Q5 Pro voltage | Star One power | Star One voltage |
|---|---|---|---|---|
| 80 | 1.3 µW | 5 mV | 9.8 µW | 25 mV |
| 85 | 4.0 µW | 10 mV | 0.03 mW | 44 mV |
| 90 | 0.01 mW | 17 mV | 0.10 mW | 79 mV |
| 95 | 0.04 mW | 31 mV | 0.31 mW | 0.14 V |
| 100 | 0.13 mW | 55 mV | 0.98 mW | 0.25 V |
| 105 | 0.40 mW | 98 mV | 3.1 mW | 0.44 V |
| Source | Price | Headroom, Q5 Pro | Headroom, Star One | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 22.5 dB | 11.9 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 32.3 dB | 20.1 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 29.2 dB | 17.1 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 61 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.
The cheapest of the 61 is the JadeAudio JA11, at $20. It leaves 22.5 dB of headroom on the Q5 Pro and 11.9 dB on the Star One, its output impedance is 0.5 Ω against a one-eighth limit of 3.00 Ω and 8.00 Ω, and its noise figure puts the hiss floor 10 dB and 23 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Q5 Pro | 20Hz–20kHz | not printed | not printed |
| Star One | 20Hz - 40kHz | not printed | not printed |
EPZ prints 20Hz–20kHz for the Q5 Pro and 20Hz - 40kHz for the Star One.
Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.
Not a measurement; maker by maker.
Both have a page of their own. In full: EPZ Q5 Pro and EPZ Star One. Each figure on this page is labelled on those pages with where it came from, including the ones EPZ never published — what that maker publishes, counted.