The DITA Audio Dream XLS is 22Ω at 104.0 dB (no reference unit printed); the DITA Audio Perpetua is 20Ω at 108.0 dB (no reference unit printed). This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The Dream XLS needs 4.0 dB more than the Perpetua to reach the same loudness — 0.40 mW against 0.16 mW.
| Specification | Dream XLS | Perpetua |
|---|---|---|
| Impedance | 22 Ω | 20 Ω |
| Sensitivity | 104.0 dB | 108.0 dB |
| Sensitivity (voltage) | 120.6 dB/V | 125.0 dB/V |
| Power for 100 dB | 0.40 mW | 0.16 mW |
| Voltage for 100 dB | 94 mV | 56 mV |
| Current for 100 dB | 4.3 mA | 2.8 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.75 Ω | 2.50 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. DITA Audio Dream XLS and DITA Audio Perpetua printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them 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.
8 sources stay below the audible-hiss threshold with the Dream XLS but cross it with the Perpetua (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 5 more).
280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: DITA Audio Dream XLS and DITA Audio Perpetua. Each figure on this page is labelled on those pages with where it came from, including the ones DITA Audio never published — what that maker publishes, counted.