The Qudelix-5K thread

[C_Lindbergh]

Exactly! If Qudelix came up with a TWS version of the 5K right now, with its hardware and, especially software expertise, it would be killer. Hardware wise, Fiio is very good but on the software front, not very competitive with Qudelix. I've had both the UTWS5 and the 5K. The UTWS5 has an advantage on convenience but the 5K is better in all the rest.
Make it AptX Lossless compatible (1.2Mbit) along with a compatible USB-C trasmitter and who needs LDAC/LHDC anymore

Yeah... I really want a proper tws adapter!

But sadly Qudelix seems like a dead company, even their new dac/amp that was supposed to land in early 2022 is nowhere near to be seen.

I'm guessing the inflation and supply chain issue caused major damage.

 

[xSDMx]

Yes. Miter sells a really nice leather one, although I can't find a listing right now. It wasn't cheap, but I like it.

Full leather is long-gone. They have a synthetic leather version now. Including international shipping fees, it's $58 total from South Korea to the US. That's about half the cost of a new Qudelix 5K. Rain check on that one!

 

[xSDMx]

Yeah... I really want a proper tws adapter!

But sadly Qudelix seems like a dead company, even their new dac/amp that was supposed to land in early 2022 is nowhere near to be seen.

I'm guessing the inflation and supply chain issue caused major damage.

It's a bummer Qudelix has been quiet. It seems like sales volume is good and they don't have issues with inventory/supply, so I'd assume their logistics are solid and cash flow is positive. But you can never totally know looking in from the outside. I was bummed re: the AptX-LL discussion over on their official forums. Basically, tl;dr "we can technically do it, but Qudelix 5K users are audiophiles and don't want AptX-LL". IMO they could easily expose it as an optional codec (the hardware supports it), but it's another indicator they aren't doing much active development.

 

[DeJaVu]

It's a bummer Qudelix has been quiet. It seems like sales volume is good and they don't have issues with inventory/supply, so I'd assume their logistics are solid and cash flow is positive. But you can never totally know looking in from the outside. I was bummed re: the AptX-LL discussion over on their official forums. Basically, tl;dr "we can technically do it, but Qudelix 5K users are audiophiles and don't want AptX-LL". IMO they could easily expose it as an optional codec (the hardware supports it), but it's another indicator they aren't doing much active development.

If i recall correctly, the issue was space constraints. They would need to remove some other codec to be able to add aptx LL. Or maybe im imagining and that was a discussion about some other receiver.
Either way, the engineer that started the Qudelix company is coming from the ES100 project, and the ES100 has a buffer length setting. 5K has A2DP latency option which i think is very safe to assume is the same thing, as lower latency is achieved by lowering the buffer, same trick manufacturers that have sets with "gaming mode" use but dont support aptx LL.
Since aptx LL codec is a variation of aptx with just lower buffer, why not use aptx codec + Agressive(or Moderate if agressive gives you issues) for the A2DP Latency setting?
Also not that noticeable difference between aptx and aptx LL, on a blind test you would have very hard time telling which is which, at least with movies. Did the comparison on Linux which supports practically all codecs and you can switch them on the fly.

 

[xSDMx]

If i recall correctly, the issue was space constraints. They would need to remove some other codec to be able to add aptx LL. Or maybe im imagining and that was a discussion about some other receiver.
Either way, the engineer that started the Qudelix company is coming from the ES100 project, and the ES100 has a buffer length setting. 5K has A2DP latency option which i think is very safe to assume is the same thing, as lower latency is achieved by lowering the buffer, same trick manufacturers that have sets with "gaming mode" use but dont support aptx LL.
Since aptx LL codec is a variation of aptx with just lower buffer, why not use aptx codec + Agressive(or Moderate if agressive gives you issues) for the A2DP Latency setting?
Also not that noticeable difference between aptx and aptx LL, on a blind test you would have very hard time telling which is which, at least with movies. Did the comparison on Linux which supports practically all codecs and you can switch them on the fly.

IIRC the space constraint conversation was re: the "startup sound". I think the same person originally asking about AptX-LL was also asking about custom startup sounds and the conversation got mixed up. FWIW the BTR5 has pretty much the same hardware and supports all the same codecs as the Qudelix 5K and AptX-LL. Was unaware of AptX being a modification of the base AptX codec. Will definitely have to play around with the A2DP Latency settings and see if AptX is passable for a/v sync. Thanks!

 

[xSDMx]

@subtec:

ES100 doesn't support AptX-LL(Low Latency).
Instead, we're considering providing a buffer length option for trading-off the latency vs. the stability.

Shorter Buffer length (Aggressive, may not be safe in poor RF environment)
vs.
Longer Buffer length (Moderate, Safe streaming)

We're expecting the buffer length option would be useful for those who don't have AptX-LL encoder and have stable RF environment.
The latency can't be shorter than AptX-LL, but at least you may be able to shorten it than the current.

Thanks,
WS

Found the original Head-Fi post from the ES100 engineer. There seems to be some extra secret sauce beyond just the buffer length inherent to Aptx-LL working well.

Also, it looks like AptX-LL requires a separate antenna? So, maybe that's the actual limitation with the Qudelix 5K? Interesting.

 

[MisterMudd]

Nope. Sticking with the K5. So good that I haven't caught upgradeitis. But I understand the quest. Size and price keeps rising on these "portable dacs" and I want small.

 

[DeJaVu]

BTR5 has pretty much the same hardware and supports all the same codecs

BTR5 has aptx LL, but doesnt have aptx Adaptive which the 5K has.

Also, it looks like AptX-LL requires a separate antenna?

Doesnt make sense, and since its wikipedia ill take the option of doubt. Maybe for signal stability? because it would be more sensitive to interference and drop out easier because of the lower buffer. Transport is same for all codecs, A2DP, and codecs are not really hardware bound(you just need enough bandwidth) but encoder/decoder software with different parameters. You get aptx LL(and everything else up to LDAC) on Linux with practically any BT dongle(BT2.1+ EDR and up) thats supported by the distro. Im using some cheapo BT4.0 one (CSR8510 chipset based) and i can promise you i didnt need to add any antennas to get aptx LL support. The dongle has just the one printed on the pcb 2.4GHz antenna.

 

[DeJaVu]

The latency can't be shorter than AptX-LL, but at least you may be able to shorten it than the current.

This statement from the engineer says that latency cant be lower than LL and that it can be lower than the default config. But this could be interpreted that it might be the same as LL? As it doesnt say it is higher, not really 100% clear. Since theyre already very close, feel free to think it brings it to the same level , and be happy .

 

[SomeGuyDude]

I can honestly say even if Qudelix never makes another product I'll probably keep my 5k for a few years until it either breaks or the iFi Go Blu drops to $100.

 

[CactusPete23]

Are some folks using Aptx-LL to mean LOW LATENCY, and Others to Mean LOSSLESS? It seems like things are a bit confused.

Pretty sure that everyone knows that Low Latency is different from the New Aptx Lossless that sends 16/44.1 without any compression.

Might be best if we say "lossless" if that's what we mean; And as "LL" is Low Latency?

 

[silentraindrop]

Are some folks using Aptx-LL to mean LOW LATENCY, and Others to Mean LOSSLESS? It seems like things are a bit confused.

Pretty sure that everyone knows that Low Latency is different from the New Aptx Lossless that sends 16/44.1 without any compression.

Might be best if we say "lossless" if that's what we mean; And as "LL" is Low Latency?

I hope no one is really confusing LL as lossless. LL has been always low latency. Not arguing with you but since there is no "lossless" on Aptx, why not call it by it's official name? AptX HD, and AptX Adaptive should be used.

 

[SomeGuyDude]

I got ten bucks that if I sat someone down with this thing and let them listen to their favorite album, and I randomly switched from LDAC to AptX to AptX HD, no one would ever, ever notice.

 

[xSDMx]

I got ten bucks that if I sat someone down with this thing and let them listen to their favorite album, and I randomly switched from LDAC to AptX to AptX HD, no one would ever, ever notice.

I can definitely notice AptX vs. AptX HD and LDAC. AptX sounds a bit "thin". But AptX HD and LDAC sound pretty much the same to me.

 

[jkc1]

I got ten bucks that if I sat someone down with this thing and let them listen to their favorite album, and I randomly switched from LDAC to AptX to AptX HD, no one would ever, ever notice.

I probably wouldnt notice, its my favorite album after all, would probably be jammin out too hard