TOPPING DX1 II: tune on a PC, check power on a phone

AV Watch’s October 1 review of the TOPPING DX1 II describes a compact USB DAC/headphone amplifier with PC-based EQ and USB-C bus-powered use. It also reports a direct iPhone connection that did not work, so using it with a phone calls for checking both power and compatibility.

The DX1 II has 3.5 mm single-ended and 4.4 mm balanced headphone outputs, with an ESS ES9039Q2M DAC inside.

Adjust the balance and keep your settings

The TOPPING Home Web APP offers a 10-band parametric EQ, with profiles stored on the DX1 II for later recall. It uses WebHID and requires a compatible PC browser; according to the review, phone and tablet browsers cannot use it.

EQ changes the balance of frequencies. Applying a curve associated with another headphone does not recreate that model exactly or guarantee better sound, but it gives you a way to adjust the balance without changing headphones.

The phone setup needs a power check

AV Watch reports that the DX1 II was not recognized by the iPhone 17 Pro when connected directly with the supplied USB-C cable. The DX1 II requires DC 5V/1A, while that phone is reported to supply up to 4.5W. This was one review setup, not evidence that every phone—or every iPhone—will fail.

The reviewer used a USB hub, including a setup supplied with external power from a mobile battery. An older iPad Pro also worked through a direct connection. Neither result makes an unpowered hub a universal fix for insufficient power.

The review also describes the separately sold TC-OTG-Y20 cable, which separates data and power, but the reviewer did not have it available to test. Before planning a phone connection, check the device’s compatibility and whether a suitable data/power separation arrangement and external supply are needed.