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Khadas Tone 2

Veri

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#21
It makes sense in a really small chassis like the KTB though. Can just buy it with a Bal-RCA>XLR cable in the future hopefully, the drawback is that you likely won't be able to use that cable with much else really. I don't see the harm in it.
 
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#25
Not sure I like this balanced RCA idea. I can see a number of cons right off the bat:
  • Cable is visually nearly identical to unbalanced RCA, but unbalanced RCA is not forward compatible with this jack, this could lead to a lot of user error and confusion.
  • Jack is visually nearly identical to unbalanced RCA, again begging for user error and confusion.
  • RCA interconnects are comparatively fragile vs XLR (extremely robust).
  • Unnecessary proliferation of standards https://xkcd.com/927/
  • Lack of compatible gear leads to dongle life (do we really need more of this?).
  • One physical port with 2 electrical standards, never a great idea, just look at all the NEMA plugs.
Hopefully my pessimism is unwarranted.
For better or worse, RCA is still standard in the audiophile world, so I can see there being a market for it. Sticking a standard RCA cable into a balanced RCA socket shouldn't cause any problems as I understand it, the question is what happens if a balanced RCA cable is stuck into an unbalanced socket? Visual similarity isn't a big deal IMO, it's the same with balanced and unbalanced 1/4" jack's.
 
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#26
I feel like it’s odd to see the recommended maximum headphone impedance be only 150 ohms. Why would that be? Any idea of the power it puts out?
 

somebodyelse

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#27
Sticking a standard RCA cable into a balanced RCA socket shouldn't cause any problems as I understand it, the question is what happens if a balanced RCA cable is stuck into an unbalanced socket?
It probably won't fit, but given how much pressure is required by some RCAs people might force it. The hot connection is the same diameter as the usual RCA pin. The cold is a larger diameter, so shouldn't fit, but it will depend on the specifics of the socket. Given the position of the shoulder close to the start of the ground contact, and the frankly excessive force required by some RCA plugs at that phase of connection, I can imagine some people forcing the balanced connector into the unbalanced socket. The result is again dependent on the specifics of the socket; breakage, connection of both hot and cold to the same contact, or connection of cold only.
 

buz

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#28
Would this give an *audible* benefit over the Qudelix 5K on say a HD600 (original cable) and not listening very loud?

Somehow I doubt it but who knows.
 

Veri

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#29
Would this give an *audible* benefit over the Qudelix 5K on say a HD600 (original cable) and not listening very loud?

Somehow I doubt it but who knows.
How does the qudelix drive your HD600 currently, are you using balanced output? If you are maxing it out then yeah, maybe this will sound better. Otherwise, will sound pretty much identical really and you'll lose the built-in EQ...
 

buz

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#30
Thanks for the confirmation.

Using it single ended right now - not quite maxing it out either so I doubt it is stretched to the limit.

Guess I might get a cheap balanced cable on aliexpress if I feel like I need more volume...
 

TimW

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#31

somebodyelse

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#34
https://dl.khadas.com/products/tone2/manual/tone2pro_user_manual.pdf

Oh man this thing has more functionality then I thought. The programming is done via RGB color changes similar to the Chord marbles.
I was wondering about the I2S silkscreen on the PCB - hadn't spotted it on the back panel. The simultaneous SPDIF in/out could be interesting too, depending on exactly how it works - USD to SPDIF out to a DSP box, then back in to the DAC/headphone amp perhaps? That might even offer a way to have DSP with unfolded MQA content (even if that would mess it up according to the original explanation of what it was supposed to do...) Not seen a cable for that one though, and it'll be sharing a common ground so not isolated like my M-Audio cards' SPDIF out.
Now I really want to see a get-your-hands-dirty hardware manual...
 

TimW

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#35
I was wondering about the I2S silkscreen on the PCB - hadn't spotted it on the back panel. The simultaneous SPDIF in/out could be interesting too, depending on exactly how it works - USD to SPDIF out to a DSP box, then back in to the DAC/headphone amp perhaps? That might even offer a way to have DSP with unfolded MQA content (even if that would mess it up according to the original explanation of what it was supposed to do...) Not seen a cable for that one though, and it'll be sharing a common ground so not isolated like my M-Audio cards' SPDIF out.
Now I really want to see a get-your-hands-dirty hardware manual...
How would simultaneous SPDIF in/out work? I see the SPDIF connector is their special balanced RCA as well and they sell adapters for both Male and Female XLR connections. Is this for AES/EBU or what?
 

TimW

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#37
I feel like it’s odd to see the recommended maximum headphone impedance be only 150 ohms. Why would that be? Any idea of the power it puts out?
1608240969229.png

Edit: If you look at the spec sheet they only give a max power output spec @ 300 ohms for the 4.4mm output. Looks like 150 ohms may be their recommended max for the 3.5mm output.
 
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somebodyelse

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#38
Well here's a partial answer:
View attachment 99852
You need a special cable just to use SPDIF output apparently.
My interpretation is that the 'tip' is the input, the 'ring' is output and the 'sleeve' is a common ground - I'm not sure what the correct terminology is for the contacts in the new connector but I hope it makes sense. I haven't seen a cable for that yet - just the XLR ones tat are listed but you can't get to.
 

TimW

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#39
My interpretation is that the 'tip' is the input, the 'ring' is output and the 'sleeve' is a common ground - I'm not sure what the correct terminology is for the contacts in the new connector but I hope it makes sense. I haven't seen a cable for that yet - just the XLR ones tat are listed but you can't get to.
Hmm that makes some sense since the standard RCA "tip" would only interact with the input of the balanced RCA SPDIF connector. And you would then need their special balanced RCA connector to get to the "ring" contact for output.

Looking at the manual, the input switching only allows you to select one input at a time. So the USB interface would have to be always accessible by your source device as an output device, and always outputting SPDIF, even when SPDIF is selected as the input. I think this might be how my Topping DX7s works.
 
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