Will the sound quality be better than the Tone 1. I found the Tone1 lacked body, though the audio is very clean.

We will ensure that the performance of Tone2 Pro is higher than the Tone1. After formal tests are conducted with specialized equipment and test benches, we tend to leave this question to the reviewers who will review Tone2 Pro in the coming days. Qualitative sound-quality is highly subjective, with some people preferring a clean and flat output, whilst others prefer a warmer bass and a punchy high-range with more depth and space.

Did you fix the "ESS hump" issue in the Tone2 Pro?

Yes this issue has been resolved in our Tone2 Pro.


Coax is input or output?

Coaxial input. Originally we designed Tone2 Pro to support both Coax IN and OUT via the balanced RCA jack. You can use a standard RCA cable for Coax IN, and a balanced RCA cable for Coax OUT. But Tone2 Pro is likely to only support the Coax IN feature when it ships with the pre-installed firmware. The XMOS XU216 processer is already maxed-out to achieve all features such as MQA, SPDIF OUT and PCM768. We may release special firmware to support Coaxial OUT for users who want to use the Tone2 Pro as a USB to SPDIF adapter, just note that a special cable(balanced RCA to single-end) is required to support the SPDIF Coaxial OUT.

What is the voltage level of the RCA balanced connection, is it the standard 4V?

Yep, 4.0Vrms for balanced RCA mode, and 2.0Vrms for standard RCA mode (single-end).

What’s the spec-difference between Tone2 and Tone2 Pro?

Tone2 = Tone2 Pro - Headphone Amp - MQA. The Tone2 Pro is based on the XMOS XU216, whilst Tone2 is based on the XU208 (which is also used on Tone1). The Tone2 will have balanced RCA connectors, just like the Tone2 Pro.

Does Tone2 Pro support Bluetooth high-resolution input?

Yes the Tone2 Pro supports external bluetooth modules via the secondary USB-C port labelled I2S. Note that the pin-layout of the USB port is non-standard. Users can select the input source using the volume knob (rotary-push encoder). Input sources: USB Data, Bluetooth (via USB-C I2S port), and Coaxial S/PDIF IN

Does the Tone2 Pro support audiophile headphones?

Yes, we built-in a buffer stage amplifier to drive the headphones directly. They are connected with the hardware volume control, and each headphone has an independent amplification pathway. Headphone volume is independent from line-out.

Does the volume knob also control the output of the RCAs?

Our official firmware will only control the headphone volume of the headphone jacks, line-out will have a fixed output volume. It’s still possible for volume knob to control the output of line-out via adjusting the volume register of the ES9038Q2M DAC. In that case, there will be two types of volumes:

  1. DAC volume (digital) for both line-out and headphone jacks
  2. Hardware volume (analog) for headphone jacks only
But we believe two volume controls will be too complex for most users, so we just fix the DAC's digital volume at maximum (highest performance), and only apply hardware volume control for the headphone jacks. We may release dedicated firmware to enable control of the DAC's digital volume for the line-out, if this is required by specific users in the future.


What about balanced RCA to XLR-3 cables?

We will produce an adapter or cable for existing products with XLR-3 connectors:

  • Balanced RCA to XLR-3 male adapter (0.2m)
  • Balanced RCA to XLR-3 male cable (1.0m)
You may purchase them at Khadas Shop. We will also launch a balanced RCA cable when compatible products like Pre-Amp/Amp/Headphone Amps are available in the market.

What connection cables will you be providing in the package?

The Tone2 Pro packaging is designed to be small to save on space and materials, so only a 1m length USB-C to C cable is provided inside the box. Those who require extra cables and converters can purchase them separately from Khadas Shop.


Is there a version of the Tone2 Pro for the VIM3 also?

We will release a bareboard “Tone2” that can dock directly with VIM SBCs, in addition to the regular Tone2 that will come with an aluminium case, minus the headphone jacks. Tone2 Pro (DAC + HPA) will only be sold as a finished product due to the MQA license restrictions.

There is a Generic version and VIM version? Or is there just one version?

Tone2 Pro is a finished product, that has an MQA license and will be sold with a proper aluminum case. Tone2 will be a bare board suitable for docking with VIM SBCs.

Can the USB-C input be used with the USB-C output of my phone?

Yes, Tone2 Pro can be powered by most Android smartphones over USB-C. iPhone users will need an external 5V power bank connected to the secondary USB-C port labelled I2S, as the iPhone has insufficient power to drive the Tone2 Pro.

Is this an AMP + DAC combo?

Yes the Tone2 Pro is a DAC + Headphone AMP.


Will the Tone2 Pro be a development platform or an end-user product?

Tone2 Pro will sell as a finished product only. The MQA company does not allow us to sell any MQA products as bare/development boards to deliver better user experience. Khadas will develop & launch the Tone2 (not Pro) as a DIY Kit in the future, but without MQA support.

Will Tone2 Pro be open source like Tone1?

You can be sure that Tone2 will be open source like the Tone1. However we’re not quite sure about Tone2 Pro due the licensing restrictions.

Will it completely unfold MQA for Spotify?

Yes, full MQA decoding for both the MQA Core and MQA Renderer.

This new model is still a USB DAC that performs the same function as my original Tone Board?

Yes the Tone2 Pro is still a full-featured USB DAC, with the addition of a headphone amplifier.

If I connect Tone2 Pro to my PC, will I use the primary USB-C for signal and the secondary for power?

The primary USB-C supports both power and data from your PC, Laptop, Tablet or Smartphone. The secondary USB-C is for connecting 5V linear power supplies that will bypass the primary USB-C power.


Do you ship globally?

Yes we do, just provide a valid shipping address and working handphone number for the courier.

When will it be launched?

Pre-orders will begin on 16th December.