Tone2 Pro has no audio out

I received my Tone2 Pro yesterday. Connected the balanced cables I bought from you to my preamp, line input. Also tried single-ended (not balanced) cables, changed inputs on the preamp with no success. I’ve tried everything possible. There’s no audio out from the Tone2 Pro. Roon recognizes the Tone2 Pro perfectly; all settings are available and correct. Also verified the source to the Tone2 Pro is working perfectly. Also plugged earbuds in - and no sound, no matter how high I turn the volume.

It appears the unit is defective.

Where do I go from here?

Hi, if you have a computer as a source, update the drivers for TB2 pro, check the voltage, cables and the correct connection diagram of your entire connection system.
Good luck!

The Tone2 doesn’t need drivers (I have several friends that are using it in the same configuration, straight out of the box). The source is a RPi 4B running Roon Bridge. As I said, I’ve swapped out power supplies for the Tone2, swapped out cables, and of course, checked that they’re properly connected.

Left cable is the source from the RPi (verified it works). White cable is the Khadas supplied power supply, connected to a tested 3 amp block. The other cables are Khadas’ balanced cables to my Benchmark’s balanced input.

Thanks for your comments, but I don’t need “good luck”. I need a line level output or a refund.

Ok, have you tried other sources besides RPi?

I tested with another RPi, supplying the source to the Benchmark DAC3 HGC. And as I said, I also tested the RPi connected to the Tone2 with the DAC3. Both Pi’s work perfectly. The issue isn’t the source (Roon displays music is streaming); the issue is no output.

Unless Khadas or someone in this community can give me some reset or other instruction to solve this, it’s a defective unit. The path is extremely simple: valid source in, line out to a preamp. No sound, regardless of cables, Pi’s, changing inputs… this is pretty basic stuff. The Pi isn’t an issue (I have 6 active Pi’s working flawlessly).

The Tone2 can also get power form the Pi 4B, which has a 3.5 amp power supply. I tested that as well; the Pi works perfectly, however disconnecting the second power supply didn’t change anything.

And again, I have several friends running the exact same configuration, and it works perfectly for them.

Thanks for the suggestions, but Khadas needs to step in and give me a solution. I’ve waited a long time to get the Tone2. I expect line out to work.

Roon recognizes the Tone2 Pro; otherwise I’d never see this screen.

Hello, Have you checked the input mode of the T2P to make sure it is in Auto or the source you are using is selected? Possibly it has been inadvertently changed from the factory default of Auto. See manual for light ring indicators and button function for input mode.


Best suggestion yet. According to the manual, it’s “auto sensing”, and since there’s only 1 input and 1 output (no S/PDIF), it is =supposed= to select the correct input. I have done my best (I’m a programmer, so this “volume control” thing is ridiculous) to change inputs. But without any audio out, there’s no way to tell if it’s correctly changing inputs. My best effort to put in manual input select mode resulted in no change: no audio out.

If you have any ideas how to force a reset so it will autosense the input, I’d appreciate it very much. I’ll try anything…
Thanks very much for your comments.

@RDFTKV , Just tried changing the input thing with two clicks again, and it WORKS! Thanks for prodding me to keep at this… I now have audio out, and Khadas can ignore this post. My sincerest thanks to you!


You are welcome. Glad it is working. Enjoy.

@Bonehead By the way, If on Windows, regarding the Window’s default driver for the T2P. It is my understanding the the Window’s driver does not cover all features of the T2P, such as all sampling rates, etc. I am trying to locate where I read that, I will post it here when found. Disregard, I see you are using RPi4.

Regarding the button and other T2P info, both the Khadas Blog and the Khadas Youtube channel offer some additional information and examples. The volume knob and button, Part 1, Part 2 videos.


Yes, this is quite logical and I didn’t even suggest it, I thought it was quite understandable. Nevertheless, GOOD LUCK TO YOU! :wink:

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Nothing better than hearing music. Thanks again @RDFTKV . I thought I had worn the double-click select input (mess) out…


@Vladimir.v.v , I had tried this so many times… it appears I must have “clicked” too fast or too slowly for it to work. And while it’s logical, I expected Khadas to have autosensing working when I received it.

If =anything= comes from my frustrations, it’s that Khadas makes damn sure that, out of the box, autosensing is not only set to “auto”, but that it works as expected. It would have saved me (and possibly many others) a lot of time and frustration.

Thanks again for your suggestions; my best to you.


Yes, I understand you, maybe this will also serve as a lesson for me, I’m waiting for Tone2pro. I have another DAC available, there you also need to select the desired input / output mode. Tone2Pro - is a new challenge for all of us!


Yes, It is very new and we are all just starting to learn its features and use. I hope your T2P clears customs soon. The input mode was on my mind because last night I was playing with the button and I found the silence when I inadvertently switched input mode from Auto. :grin:

Bonehead, my T2P came with Auto input set as default, I just connected it and it worked. But due to unforeseen circumstances, it is possible your unit came with Auto not set as default. Probably a rare event in any case, time will tell. Be interesting to see if Vladimir.V.V’s T2P has the Auto set as default.
By the way, the button has single press functions, double press functions and even more like triple and long press functions, much to learn for me.


Thank you so much! Yes, in the meantime, I am very closely following what T2P users write on the Khadas forum and various YouTube reviews.:slightly_smiling_face:

Yes, I will certainly let you know! :wink:

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