AudioChainsDB
JDS Labs

Atom Amp+

interface_dac

$99

Used market: $60*

Manufacturer datasheet

Specifications

5 of 10 values have a recorded source
Type
Analog Headphone Amp·
Bus Powered
no·
Max Gain dB
13.1✓
Analog Inputs
RCA line in, 3.5 mm line in·
Analog Outputs
6.35 mm TRS headphone, RCA preamp·
Digital Inputs
·
Min Usb Power W
0·
Headphone Output
Max Voltage Vrms: 9.05 · Output Impedance ohms: 0.7·
Max Input Level dBu
20.1✓
Phantom Power Provided
no·

Expert Audio Engineering Commentary

Headroom Notes

9.05 V into 600 ohms and 1 W into 32 - and the two figures disagree, which is the useful part. At 32 ohms the amplifier delivers only 5.66 V, meaning it runs out of current, not voltage, on low-impedance loads. For a 300 ohm HD 650 it is a nine-volt amplifier; for a 32 ohm planar it is a five-and-a-half-volt one.

Gain Staging Advice

Two gain settings, 1.0x and 4.5x - the 13.1 dB stored here is that ratio in decibels, as JDS itself writes it for the Element IV ('5.0x (+14dB)'). Output impedance is under 0.7 ohm, so damping is not an issue with any headphone.

* Estimated with the depreciation fallback (~61% retained value). · checked on 8/5/2026