RPi4 and Khadas Toneboard

Hi there.

A bit late to the party. I just got me a Toneboard. @89€ I considered it a nice catch.
(OK. There seems to be a V2 around the corner. But that one probably won't get launched at such a ptag)

The idea was to find an alternative and competitive solution to the known RPi HAT solutions.
The measurements over @audioscienereviews show an equal performance to
e.g. the very well performing $250 Allo Katana solution.
That's promising.
Reviews and feedbacks were mostly quite positive.

The Toneboard is a USB DAC though. Something I havn't been considering
over the last couple of years.
For sure I would not consider the Khadas SBC solution. If SBC, IMO RPi is the way to go.


The DAC is hooked up to the RPi4, which comes with a much better USB design
compared to its predecessors. USB DACs were IMO NoGos on the predecessors.

Networking is done via onboard Wifi.

An iFi iDefender3.0 is currently used to run two different 5V supplies to DAC and RPi.

An Allo Shanti is used as PS.


As OS a recent Raspbian with stock 64bit RPi foundation kernel is used for now.

Playback software is squeezelite.

On the SW side this or that optimization is being applied. (It's IMO really worth it)


Considering that I just have it all arranged with standard USB power cabling for now,
I have to say I'm impressed.
Not sure if any of the DACs I have around here performs much if any better.


* my Audiophonics iSabre9038 wasn't working anymore on the RPi 4,
* I never really liked the IMO rather demanding Katana approach and
* I really couldn't decide to go for Ians driverless DualMono 9038 IMO rather expensive and complex ( with it's numerous enhancement options)

this Khadas Toneboard seems to be a really well performing, highly competitive, no frill RPi4 audio option.

A look in the nice documentation and schematics (yep, documentation is possible at 89€) shows the pretty advanced
engineering under the hood. Different LDOs on every rail, synchronous clocking, adequate local buffering, sturdy RCAs, asf.
All that looks like the well known recipe for quality DAC implementations. And the measurements prove it.


* there's an annoying really bright white LED onboard
* the XMOS firmware SW volume control mixer naming sucks
* mounting hole locations ( I do not expect a RPi compatible scheme, which would of course be very nice, but the hole between the RCAs is a bad joke)

Let's give it some more days. And see how things are developing. :D

Enjoy. I do. ;)
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Wow. Time flies. It's been November since I got my KDB.

Just reread my review.

That's exactly what I'd write again about it. :D

However. I'd add some minor items that I'd critisize.

* The on-dac volume control is not the Sabre DAC VC! Therefore it's useless for DOP.
* The DAC requires VCC and GND to be present via USB, even if selfpowered.

The KDB is a still a great DAC. Price/performance ratio is great. There wasn't a single day when wishing a Katana or Audiophonics DAC back.

Meanwhile Soncoz launched their new DACs. The Soncoz founder/designer (Ben) is the
guy who designed the KDB. Bad luck for Khadas.

The new Soncoz DACs outperform - on paper - the KDB in several areas. Come with
IMO very attractive cases and prices. The cases IMO look really nice and professional ( Allo are you watching? I'd say your upcoming Revelation DAC is facing a tough ride. ;) )

The SGD1 had been measured on ASR. Pretty impressive
for a first try. It's a dual-mono Sabre.
And then it also supports Bluetooth HD. Using BT on such a DAC could revolutionize the whole streaming approach (RPI, USB Bridges etc.) by e.g. streaming Qobuz straight from your smartphone at highest quality.

They are still working on and improving the firmware though. Here and there some minor issues are popping up.

And the issue of not having access to the Sabre controls (vc, filters) and outputs via USB driver is one of the downsides.

I'll have a look at that device the next audio season (9/2020). I hope the dust has been settled by then.

Yep. I know it's not DIY. However. I realized quite some time ago that it's almost impossible to achieve these performance levels on digital equipment by hand soldering stuff or tweaking.
And fact is, 99.999% of us DIY people are not able to run the necessary measurements afterwards to verify what's been done to the device.

Regardless of whatever they say at ASR, Katana has *far* more potential to sound good than Toneboard does. Hook up some 5v and +-15v linear power supplies with some film caps on the +-15 rails and Katana starts sounding pretty darn good. Can't do anywhere near the same with Toneboard.
I own a Katana and I own a KTB.

For me there's no reason to run the Katana.

And if the Soncoz stuff is even better. Great.

And at ASR they do not just "say" or "talk" like most of the tweakers and wannabe experts around here.
Usually you also find high quality measurements supporting what's being said.

And not to forget. Allo was keen to get their DACs also on that ASR list. The ranking speaks for itself.

And IMO you'd better question any product which needs extensive tweaks
to sound ""really"" good.

And IMO you'd better question any product which needs extensive tweaks
to sound ""really"" good.

Makes Katana a diy product, for sure. It works though. Main problem now is that a full-blown Katana setup probably costs $400 - $500 to put together, and then only works with RPi. For not that much more money someone could get a Topping D90 and have a better sounding general purpose dac.
Non of the Allo products are "real" DIY DAC products. All you do is attaching
power supplies.

There's simply no way to tweak highly integrated stuff without having top level measurement gear (and related knowledge) at hand.

No surprise Allo moved on to a fully integrated USB DAC.

However. If a USB DAC still needs highest quality USB transports to "sound"
good, something pretty much went wrong with the DAC design.
I keep the fingers crossed that Allo's upcoming device doesn't require a
quality transport to sound "really" good.

The target here is: No matter what source, the sound is gotta be perfect as long as
the bit values arrive as sent.
I think i do agree to the statement that DAC diy time is over, since the market is flooded with good and cheap chinese ones. I do currently enjoy a Topping D90 with Allos USB bridge and a Shanti. I must admit that i enjoy the AKM sound flavor over my other ESS Dacs and USB input works pretty well. Next is to try the Topping over I2S with IANs Fifo and HDMI on top and see if there is any difference ..