Quantum ES 4
interface_dac
$299
Used market: $210*
Specifications
8 of 13 values have a recorded source- Type
- Audio Interface·
- Ein dBu
- -129✓
- Bus Powered
- yes·
- Max Gain dB
- 75✓
- Analog Inputs
- 4x XLR/TRS combo (Mic/Line), 2x 1/4" (Instrument)·
- Analog Outputs
- 2x 1/4" TRS (Main), 2x 1/4" TRS (Line), 2x 1/4" TRS (Headphones)·
- Digital Inputs
- USB-C·
- Min Usb Power W
- 13✓
- Headphone Output
- Max Voltage Vrms: 1.838 · At Impedance ohms: 50 · Output Impedance ohms: 22·
- Max Input Level dBu
- 14✓
- Max Sample Rate kHz
- 192·
- Phantom Power Provided
- yes✓
- Release Year
- 2024·
Expert Audio Engineering Commentary
Gain Staging Advice
75 dB of digitally controlled analogue gain with a -129 dBu EIN and a +14 dBu ceiling: enough for an SM7B or a ribbon with margin left over, and enough headroom that the same preamp takes a line source without a pad. The Auto Gain button sets the level from a ten-second listen, which is the one feature that separates this generation from the Studio 24c it replaces.
What the datasheet actually says
Quoted verbatim from the manufacturer’s own page, with the date we checked it. We state what is printed, not what anyone intended by it.
«Headphone Outputs … Impedance Working Range 22 Ohms»
A single number cannot be a range. PreSonus's own owner's manual for the same series lists the same 22 Ω under 'Output Impedance', which is a different quantity: output impedance is the resistance in series with the headphone, while a working range would say which headphone impedances the output drives. The distinction decides whether a 16-32 Ω headphone keeps its tonal balance.
checked 8/5/2026«Instrument Inputs … Maximum Input Level +15 dB (unbalanced, minimum gain)»
The owner's manual writes the instrument input's ceiling as '+15 dB', with no reference, while the product page gives the same field as '+15 dBu'. A level in bare decibels names nothing; the neighbouring rows in the same manual table use dBu. The catalogue takes the microphone input figure, which both documents write as +14 dBu.
checked 8/5/2026* Estimated with the depreciation fallback (~70% retained value). · checked on 8/5/2026