Qudelix-5K Bluetooth DAC & Headphone Amp

[tifune]

View attachment 92348

This got me wondering - what is the maximum possible SINAD of a 990 LDAC connection? 90dB? Above, because there's a 1.8dB disparity between channels, I'm assuming the device is getting in the way.

 

[Atanasi]

This got me wondering - what is the maximum possible SINAD of a 990 LDAC connection? 90dB? Above, because there's a 1.8dB disparity between channels, I'm assuming the device is getting in the way.

I could try to measure it using BC3 outputting SPDIF, which can be captured.

 

[tifune]

I could try to measure it using BC3 outputting SPDIF, which can be captured.

That would be great, seeing APT-X limited at 66dB gave me a stark reminder if what's achievable vs what's actually audible.

 

[Cahudson42]

Can't beat a direct otg USB connection, though. Remember even a $30 android 8 LG Rebel 4 TracFone works this way as a wifi DAP.. Yes, another device. But it's small and thin..

 

[Atanasi]

The best result for a simple sine wave was THD+N 0.00024 %, which corresponds to SINAD 112. The result depends on the used window and other parameters, so this is not comparable with AP numbers. This used 7-term Blackman-Harris.

 

[Stan Smitchen]

Does it make sense to replace a radsone es100 with the qudelix 5k? I wonder if the music sounds better with the qudelix 5k. I mostly use a koss ksc 75 (60 ohm), venture electronics ve monk plus earbud (60 ohm), Sennheiser momentum 2 on ear (18 ohm i guess...).

 

[Atanasi]

Does it make sense to replace a radsone es100 with the qudelix 5k?

Would you use 5K's PEQ? If yes, it could make sense.

 

[jhaider]

Does it make sense to replace a radsone es100 with the qudelix 5k? I wonder if the music sounds better with the qudelix 5k. I mostly use a koss ksc 75 (60 ohm), venture electronics ve monk plus earbud (60 ohm), Sennheiser momentum 2 on ear (18 ohm i guess...).

It can sound better, or worse, depending on the EQ profile used. Replacing a dumb component with a flexible upgrade makes sense IF you intend to use the enhanced functionality. If not it’s just buying stuff to buy it.

 

[tifune]

The best result for a simple sine wave was THD+N 0.00024 %, which corresponds to SINAD 112. The result depends on the used window and other parameters, so this is not comparable with AP numbers. This used 7-term Blackman-Harris.
View attachment 121766

Wow that is significantly higher than I expected. I expected the compression and rolloff to have far more impact, thanks for illustrating it !

 

[Joel]

I make no claim to have a set of "golden ears" but I'm loving my Qudelix 5k so far. My primary headphones are a pair of DCA Aeon 2 Flow Closed. The unbalanced connection really didn't have enough power to drive them (no surprise). It took several week for me to get around to making a custom cable (think the cost of Sennheiser balanced cables is bad? Every cable for DCA headphones has to be custom built!) but the difference is astounding. Highly recommend it to make the Aeon 2s actually portable.

I'm using iOS devices—Apple Music—with the 5K set to balanced, 4V, and "Performance". Haven't settled on a baseline EQ but the built-in ones are great with this combo. The app—while complicated and deep—is well laid out and very detailed.

 

[Not dave]

Ive just received my Qudeliz and surprised that the max volume is not that much different to the apple usb dongle.
I understand that balanced output will give more power. so what balanced leads to people recommend for Sennheiser HD650?
Ive found the following that I can get to the UK

These are original sennhesier leads with the connections changed, £40 from UK - approx $55.

Drop do one for $50, plus $15 shipping, probably plus 20% tax, so nearly $80

Then there are a number on Aliexpress. Here are four with across a variety of prices. Will there any audible difference between these cables?

$20 inc taxes and shipping - 3.5mm 2.5mm Balanced Pure Silver Plated Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx LN006192

$30 inc taxes and shipping - 8 Core Black Balanced Pure Silver Plated Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx LN007038
"This is Silver Plated+OCC wire Cord."

$55 inc taxes and shipping - LN006730 XLR Balanced 16 Core 99% 7N OCC Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx Headphone
"This is 16 cores 99% Pure 7N OCC Copper Cable."

$82 inc taxes and shipping - Thouliess Hi-Fi 1.8Meter 2.5mmTRRS Balanced 8Croes Silver Plated Headphone Upgrade Cable for HD600 HD650 HD525 545 565 580
"Cable: 8 cores 8x0.72mm (19*0.07mm ) 7N OCC single crystal cooper wire braided divided into"

 

[DanTheMan]

I’d probably get the original with the balanced plug In your situation. I just bought the Drop for myself because I bought a short Chinese lead for these a few years back and the cable is stiff and noisy when you walk. It looks very pretty though—almost like jewelry, but functionally it’s not great. It saved me $5 over the Sennheiser model, but I later bought the Sennheiser so I lost in the long run. The Drop one should be as good as the original or perhaps better in those regards. The original never bothered me.

 

[d1m0n]

Ive just received my Qudeliz and surprised that the max volume is not that much different to the apple usb dongle.
I understand that balanced output will give more power. so what balanced leads to people recommend for Sennheiser HD650?
Ive found the following that I can get to the UK

These are original sennhesier leads with the connections changed, £40 from UK - approx $55.

Drop do one for $50, plus $15 shipping, probably plus 20% tax, so nearly $80

Then there are a number on Aliexpress. Here are four with across a variety of prices. Will there any audible difference between these cables?

$20 inc taxes and shipping - 3.5mm 2.5mm Balanced Pure Silver Plated Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx LN006192

$30 inc taxes and shipping - 8 Core Black Balanced Pure Silver Plated Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx LN007038
"This is Silver Plated+OCC wire Cord."

$55 inc taxes and shipping - LN006730 XLR Balanced 16 Core 99% 7N OCC Earphone Cable For Sennheiser HD580 HD600 HD650 HDxxx HD660S HD58x HD6xx Headphone
"This is 16 cores 99% Pure 7N OCC Copper Cable."

$82 inc taxes and shipping - Thouliess Hi-Fi 1.8Meter 2.5mmTRRS Balanced 8Croes Silver Plated Headphone Upgrade Cable for HD600 HD650 HD525 545 565 580
"Cable: 8 cores 8x0.72mm (19*0.07mm ) 7N OCC single crystal cooper wire braided divided into"

If you're skilled enough (or know someone who is) and know how to use a soldering iron + multimeter, the cheapest way is to DIY + you get the length you like. 2.5mm Plug at Ali ca. 3€ + Original Senn replacement cable ca. 10€. Other than that I would just pick the one you like the most for its flexibility, look & feel, microfonics etc.

 

[Not dave]

So have been playing round with the unit and have found that the EQ settings in the HD650 thread (this post) make the output very quiet. Changing the preamp to 0 improves things, and increasing to +5 is too loud for me.
Is the reason for the -8.5dB to avoid distortion when driving the headphones hard?

 

[abdo123]

So have been playing round with the unit and have found that the EQ settings in the HD650 thread (this post) make the output very quiet. Changing the preamp to 0 improves things, and increasing to +5 is too loud for me.
Is the reason for the -8.5dB to avoid distortion when driving the headphones hard?

You need to keep it at -8.5dB or otherwise you will have clipping in the digital domain.

Feel free to raise the volume in the analog domain as much as you want after digital processing, but no sample should ago above 0 dBFS by the end of digital processing.

 

[Not dave]

Thanks abdo.
I am trying to understand how the -8.5 figure is derived. The two low shelf filters when combined with the preamp put the line on the peq graph close to zero.
however, the built in eq settings (eg bass booster) use no preamp and use a 5db gain.
why don’t the built in eq use a negative preamp?

When you mention that digital clipping will occur, presumably this will be audible at all volumes?

The hd650 settings I am using
Preamp: -8.5 dB
Filter 1: ON LS Fc 40 Hz Gain 5.0 dB Q 1.0
Filter 2: ON LS Fc 75 Hz Gain 3.0 dB Q 1.0
Filter 3: ON PK Fc 7600 Hz Gain 4.0 dB Q 3.0
Filter 4: ON PK Fc 13700 Hz Gain -3.5 dB Q 4.0

 

[Not dave]

Ps. is there an auto off setting on the Qudelix? Seems a curious absence if there isn’t.

 

[DanTheMan]

I haven’t found one. Mine is set up to turn off if you squeeze the bettom half of the buttons simultaneously or if you plug it in.

 

[TK33]

Does it make sense to replace a radsone es100 with the qudelix 5k? I wonder if the music sounds better with the qudelix 5k. I mostly use a koss ksc 75 (60 ohm), venture electronics ve monk plus earbud (60 ohm), Sennheiser momentum 2 on ear (18 ohm i guess...).

I did and have not regretted it. My ES100 was perfectly fine but it is now just sitting unused. The PEQ is a fantastic feature on the 5K if you plan on using it. It is a bit of a work in progress but in a good way as they have been constantly adding features (I have had it since launch when PEQ didnt even work yet). LDAC 990 seems to work better on the 5K (usually had to force my ES100 in Developer Options on android and it would stutter...maybe it was just mine but no such issues with the 5K).

 

[TK33]

Ps. is there an auto off setting on the Qudelix? Seems a curious absence if there isn’t.

Maybe request it on their official forum if it is important to you? I found them to be pretty responsive.

Edit: like the previous poster, i also have my 5K set to power off by squeezing the bottom half of both buttons. It has worked for me although there were definitely times when I forgot and was wondering why I didnt hear anything through my phone when picking up a call only to find out the audio was being routed to my 5K (and ES100 before that).