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Review and Measurements of WesionTEK Khadas Tone Board DAC

zermak

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Hello guys,
I am using my KTB with my PC as input (via USB) and the two amps I own (an Objective2 for my K712 Pro headphones and a Bantam Gold for my fullrange bookshelves) and I am very happy with it even if the board is a little warm for my taste; I mean physically hot, not sound-wise (I put the board in a 3D printed case and besides the higher temperatures it works flawlessy so far but I may be make or buy a metal box considering that Summer is here and temperatures are rising and I don't want to melt it ahah).
Anyway I am writing here because I am interested in buying another one and use it with an ICEpower module (probably a 125ASX2) and I am wondering if I need an input buffer between them (ICEpower 125ASX2 datasheet says that "the input impedance of the signal in-put section is minimum 8kΩ over the audio bandwidth") or if the Khadas Tone Board RCA output impedance is low enough (I read it is 100Ω somewhere in this thread) to be connected directly to the ICEpower module without any possible sound degradation.
Thank you for the support.
 

somebodyelse

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[QUOTE="zermak, post: 184452, member: 7925"Anyway I am writing here because I am interested in buying another one and use it with an ICEpower module (probably a 125ASX2) and I am wondering if I need an input buffer between them (ICEpower 125ASX2 datasheet says that "the input impedance of the signal in-put section is minimum 8kΩ over the audio bandwidth") or if the Khadas Tone Board RCA output impedance is low enough (I read it is 100Ω somewhere in this thread) to be connected directly to the ICEpower module without any possible sound degradation.[/QUOTE]
100Ω series resistor shown on the schematic. The rule of thumb is that input impedance should be >= 10x output impedance, so there shouldn't be a problem connecting the Tone Board directly to the 125ASX2. You should probably check the input sensitivity to see if you need any extra gain.
 

zermak

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I have read few things about it (beyond that rule of thumb that with further readings it is pratically not actually a good suggestion but a starting point to choose the best fit/value for your needs/boards specs) and it looks like I'll need to use a buffer/preamp anyway considering that I want to control the volume with a potentiometer which without the buffer/preamp will mess up the frequency response of the ICEpower board pretty bad (on another forum someone has tested the input impedance over the 20Hz-20kHz frequency range and it goes under 6kΩ at 20kHz; so 2kΩ under the ICEpower specs).
I am going off topic now so if someone has suggestions or already made and valid solutions/preamp board can PM me, thank you.
 

Kalander

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** For the ATTENTION of any Khadas Support people that may monitor this thread **

In the interest of getting the best and the improvement of the Khadas Tone Board I respectfully point towards a thread in the Moode Player's forum. The thread is dedicated to the Khadas Tone Board and at some point one Moode Player user has highlighted an issue happening during the use of the Player with a KTB. The Support chaps have started to look into helping/fixing the problem and the latest post points towards the KTB current firmware (post here: Moode Player / issue with KTB )

MoOde Player is a leading audio player developed for use on Raspberry Pi devices.
 
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Doesn't DSD have to run at 100%?

Volumio + KTB works fine and offers hardware, software, and none for volume if you need something now. I've played DSD files with it.
 

Nango

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** For the ATTENTION of any Khadas Support people that may monitor this thread **

MoOde Player is a leading audio player developed for use on Raspberry Pi devices.
Are you salesforce with Moode ??
 
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hi guys. i read the reviews of khadas tone board. this seems to be a real contester to the topping d50 i am considering, at half the price. id like to ask some questions if that is alright.
first of all, this doesnt need any external power adapter? it is powered just by usb? wouldnt think this is possible.... or am i wrong?
would you describe tyhe sound as neutral? anyone compared it to topping d50?
i didnt understand what a vim is. could someone explain? i need to connect my pc to the dac and the dac to my amplifier. that is all.
i see some diy cases have also a fan. does khadas run hot?
would khadas be considered a portable dac? could i buy a usb type c to type c cable and hook this up to my phone for example? (not that i need that, but i got curious)
i see that it supports up to dsd 256 (topping supports dsd512). is that something that i will miss (dsd 512). i suppose not but i thought id ask.

from all the above questions, obviously most important is if this is great sounding and also neutral .thank you
If you don't have dsd files you won't miss it at all
 

somebodyelse

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Khadas Tone Board ,which version should i get?
Only one version available.
The VIM and non-VIM boards are electrically identical, so @Nango isn't wrong. The difference is that the VIM version has pin headers for connection to the VIM already soldered, while on the non-VIM version you would have to solder them yourself. The VIM is a simgle board computer similar to a Raspberry Pi but with different pin assignments on the header. If you just want to use the TB as a USB or SPDIF DAC then get the non-VIM version.
 

maxxevv

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Hello guys,
I am using my KTB with my PC as input (via USB) and the two amps I own (an Objective2 for my K712 Pro headphones and a Bantam Gold for my fullrange bookshelves) and I am very happy with it even if the board is a little warm for my taste; I mean physically hot, not sound-wise (I put the board in a 3D printed case and besides the higher temperatures it works flawlessy so far but I may be make or buy a metal box considering that Summer is here and temperatures are rising and I don't want to melt it ahah).
Anyway I am writing here because I am interested in buying another one and use it with an ICEpower module (probably a 125ASX2) and I am wondering if I need an input buffer between them (ICEpower 125ASX2 datasheet says that "the input impedance of the signal in-put section is minimum 8kΩ over the audio bandwidth") or if the Khadas Tone Board RCA output impedance is low enough (I read it is 100Ω somewhere in this thread) to be connected directly to the ICEpower module without any possible sound degradation.
Thank you for the support.
The output impedance values of the KTB RCA outlets can be found on the technical data documents from the Khadas site.

Dunno about ICEpower, but mine runs barely warm.
The KTB actually can run pretty warm if you set digital volume off the computer / play source to 100%. I do that what its connected via the JDS Atom or my other headphone amp the HPA-3B, and after an hour, it does get pretty warm.
 
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The VIM and non-VIM boards are electrically identical, so @Nango isn't wrong. The difference is that the VIM version has pin headers for connection to the VIM already soldered, while on the non-VIM version you would have to solder them yourself. The VIM is a simgle board computer similar to a Raspberry Pi but with different pin assignments on the header. If you just want to use the TB as a USB or SPDIF DAC then get the non-VIM version.
Thanks
 

zermak

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The output impedance values of the KTB RCA outlets can be found on the technical data documents from the Khadas site.
Yes, I have seen it and there is a 100Ω resistor before the RCA out but I am not sure if that's exactly the real impedance of the output.
The KTB actually can run pretty warm if you set digital volume off the computer / play source to 100%. I do that what its connected via the JDS Atom or my other headphone amp the HPA-3B, and after an hour, it does get pretty warm.
I use it at 100% from my PC and it does indeed run pretty warm but so far so good despites the high temps. Maybe I'll print a bigger case with even more ventilation holes on bottom just to be sure.
 

Badger

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I put little rubber feet on the bottom of the (audiophonics) case I have the tone board in and it helped with the heat quite a bit
 

zermak

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I have to put the rubber feet on it but I still don't cause I am about to make a larger box; I designed and 3D printed a tiny box with ventilation on bottom of the board but you can touch the plastic underneath and it is warm XD (sure no actual ventilation becasue the box is on the desk and there is no gap but the TB runs hot anyway on its own).
 

Nango

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MoOde Player is a leading audio player developed for use on Raspberry Pi devices.
I was looking for an alternative as I want to stop using Volumio because of it's crappy forum and tried Moode during a few hours but it is really far away from the usability of Volumio. Is there a different interface available for Moode or just the one regular?
 

zermak

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True, the Volumio forum is pretty inactive. I used to ask few questions, even applied to give my help to compile it for a new platform/board (I am pretty newbye aboiut it but I am a good reader and learner so), but I never got an answer. Anyway what's your problem? I was able to try Volumio on a S912 box to evaluate it before spending my money on an SBC and build my own portable box.
 

Nango

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No probs, I like it, it is very easy to use and powerful, I even made a donation but I just want to try a different app. I wasn't able to setup DietPi, I tried Moode but it is not really nice and easy to use.
 
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