Chord Qutest

[Jeremy Anderson]

I’ve found that a linear power supply (in my case an LH Labs LPS4) and the PowerAdd Pilot Pro 5 battery in turn each made a positive impact on my musical enjoyment of the Qutest.
 

(I haven’t done a strict A|B yet, but I can say that each offers noticeable sonic improvement over the stock wall wart.)

 

Oh, and I had Ghent custom roll me a USB (power-only) JSSG360 A-to-micro-B cable plus a custom USB female to DC barrel plug (male) adapter so I could also use it with supplies like the UpTone LPS1.2. (Adapter is made of Neotech 7N 18AWG, one end of USB-A(female), another is Oyaide DC-2.1G(5.5/2.1)

[ecwl]

I think Rob Watts has said on Head-Fi on a number of occasions that if you change the power supply and you think the music sounds better but also slightly brighter, he believes it’s because there is more RF from the power supply, causing more noise floor modulation which seems to give more detail.

 

Specifically referring to the Hugo TT2 and M-Scaler switching power supply (but Qutest has a different one), Rob Watts has also said that he chose that supply because it has the best measured and sound quality performance, measuring similar to battery power supply, even though there is a 100uA leakage current to ground in that power supply.

 

He acknowledges that if the upstream devices have leakage ground currents, then it would affect the performance of Qutest but he really thinks that’s the problem of the streamer and not of his DAC power supply. 

 

Moreover, he also fully acknowledges the possibility that the switching power supply could affect the performance of your amplifier but he sees the issue as the amplifier being sensitive, rather than a DAC design issue. He also thinks the problem is rare because most amplifiers are well-designed.

 

While I really admire Chord DACs, I’m a bit less dogmatic about the power supply. My take is that for most people, if they want to hear their DAC as the designer intended, just connect the DAC to a battery-powered USB source or via Toslink to stop the ground noise. However, I am aware that there are battery-powered USB sources (usually very old laptops) that are so noisy that Chord DACs can’t completely filter.

 

But for most people, we would use a grounded computer/streamer to feed USB to Qutest so if replacing the Qutest power supply gives you a better sound, and at a lower cost than upgrading the streamer, why not?

 

More importantly, just like there are people who love Chord DACs, there are others who think that they are just like any other DACs and prefer other DSD DACs or R2R DACs. Since personal preferences sometimes kick in here, if people try a power supply and believes it to be superior to the stock one for the Qutest, even if the designer thinks that the new power supply is actually worsening the performance of Qutest, I’d once again say why not? Your system, your sound, your call.

 

With all that said, Rob Watts has used the PowerAdd Pilot Pro2 when travelling to power some of his devices. He said it’s actually a noisier power supply but at least there are no mains borne RF noise and that at least Hugo2 has enough filtering to filter out the noise coming from the PowerAdd Pilot Pro2.

 

For those who’s interested in the designer’s thoughts on power supply, I’ve done a search specific for Qutest:

https://www.head-fi.org/search/1205039/?q=Power+supply&t=post&c[thread]=869417&c[users]=Rob+Watts&o=relevance

You can click on the individual comments to read more about it. There are only like 12 posts so it’s not a hard read.

[asdf1000]

2 hours ago, ecwl said:

Specifically referring to the Hugo TT2 and M-Scaler switching power supply (but Qutest has a different one), Rob Watts has also said that he chose that supply because it has the best measured and sound quality performance, measuring similar to battery power supply, even though there is a 100uA leakage current to ground in that power supply.

 

All good points.

 

Also something to consider - he has said linear PSU's MAY be better but MAY also be worse (poor or no RF filtering).

 

Also something to note - Rob can't have possibly measured every linear PSU on the planet when he says his chosen PSU is the best he's measured.

 

 

[ecwl]

1 hour ago, asdf1000 said:

Also something to note - Rob can't have possibly measured every linear PSU on the planet when he says his chosen PSU is the best he's measured.

I totally agree. Moreover, I’m sure Rob Watts only tested power supplies that would be reasonable to include in a product that’s Qutest price range. Like he’s not going to test a power supply that costs 25% of Qutest MSRP. 
 

On the flip side, the challenge for all of us is that if there’s an alternative power supply that costs 10-25% of Qutest, there’s no guarantee that it performs better than the stock switching power supply. And even if the pricier power supply outperforms the stock switching supply in some characteristics, the internal power filtering of the Qutest is probably optimized for the stock power supply. So let’s say the stock power supply has more non-RF noise and less RF noise and the Qutest internally filters out the non-RF noise, you can potentially get a pricy power supply that has no non-RF noise but more RF noise so Qutest could perform worse. I don’t really understand the details of how Qutest filters the power from the stock power supply but according to Rob Watts, it’s quite extensively. 
 

Ultimately, I think people interested in trying other power supplies should do what they want and see if it sounds better as long as they don’t accidentally blow their DAC with the wrong voltage. 

[jos]

I just want to mention that in a Chord Qutest review in HiFi News, the iFi iPower was giving a better sound quality then the power supply that comes with the Qutest. They thought there was something wrong with Chord power supply. Right now, I am using the Chord Qutest with the new iFi iPower X, and before with the old one. To be honest: I can't hear a difference with my old ears.

[Superdad]

1 hour ago, jos said:

Right now, I am using the Chord Qutest with the new iFi iPower X, and before with the old one. To be honest: I can't hear a difference with my old ears.

 

Do you have a modest linear PS to try with your Qutest?  Lots of leakage (common-mode AC traveling over DC connections) from those iFi iPower SMPS units. (Same with all SMPS.)

[asdf1000]

46 minutes ago, Superdad said:

Lots of leakage (common-mode AC traveling over DC connections) from those iFi iPower SMPS units.

 

While leakage is common to all SMPS’s, have you measured the newer iPower X he mentions?

[jos]

21 hours ago, Superdad said:

 

Do you have a modest linear PS to try with your Qutest?  Lots of leakage (common-mode AC traveling over DC connections) from those iFi iPower SMPS units. (Same with all SMPS.)

No, I don’t have and Chord was telling me it’s not necessary to have one for the Qutest. But my trust is with HiFi News I highly respect (and UpTone Audio of course). I Was also reading there is no leakage with the new one; type X. Perhaps John Swenson can test one. Maybe I will buy an LPS for my ultraRendu, but I’m still not sure. A Farad3 is tempting, but so expensive, so maybe a second iFi iPower X.

[Blake]

I have been using the stock power supply with my Qutest in my system at work over the last year.  I brought the Qutest home this weekend to try running it with my Uptone LPS-1.  I really enjoy my Qutest with stock supply in my work system.  However, in my much more revealing home system, the Qutest with the stock supply was a big let down from my Terminator.  Sure it sounded nice and if I hadn't been used to the performance of the Terminator, I might have enjoyed it.  But frankly, with the Qutest and stock supply I just didn't want to listen.  The magic was gone.  

 

I then swapped in the Uptone LPS-1.  Big difference- not subtle!   The LPS-1 is so much better than the stock power supply with the Qutest.  Some of the Terminator magic is back and I wanted to listen to music.  The Qutest/LPS-1 is definitely not at the level of performance of the Terminator, but it is so much better now with the LPS-1 in place.  

 

 

[Miska]

On 6/7/2020 at 3:01 AM, Superdad said:

Lots of leakage (common-mode AC traveling over DC connections) from those iFi iPower SMPS units. (Same with all SMPS.)

 

Not with the medical grade ones I use...

[Superdad]

21 minutes ago, Miska said:

Not with the medical grade ones I use...

 

Those do still have 'Y' capacitors and have a form of leakage. See:

 

[Miska]

29 minutes ago, Superdad said:

Those do still have 'Y' capacitors and have a form of leakage. See:

 

 

I didn't open it, but works very well and is specified to have leakage currents below 1 µA. I use those for my NAAs, I have bunch of those, don't cost much and give enough power (5V 6A). No ground connection (floating), and coaxial power cable with proper ferrite built in.

 

[macuniverse]

On 6/11/2020 at 7:18 AM, Miska said:

Not with the medical grade ones I use...

 

Do you have a link to these?

[Lauritsvd]

I Got a Chord Qutest, and enjoy it a lot.
It is realy an amazing DAC. 
Tried a powerbank as ps for the 5v, and liked the better resolution, but the Music was missing some attack, and dynamics. 
But since it made a difference compared to the stock supply, I wanted to make a better ps. I already had a good expirience with MPAudio ps, and ordered a 

SLS-HPULN PS With double lt 3045 regulation, and an Audio grade transformer.  This is what came out of a few hours of work. The cabinet is from an Old pc.  DC wire is Gotham in a 360 layout.    To my ears, this is just as big a step forward Soundwise, as the Qutest was In the first place. (coming from an Arcam Irdac) Very high resolution, lots of attack, but No rough edges, If that makes sense.  English is not my native language.   Now back to happy listening.  There is still room for another powercable, and a better fuse.  I even made space for one more PS in the box. Lets see what hoppens next.

 

[johndoe21ro]

I've also tested MPAudio with excellent results. I'm afraid Qutest scales a lot with better equipment (reclockers, galvanic isolators, pigtail, linear power supply, power cord for the linear power supply, isolation feet, streamers, renderers, etc.). I think my system is the listenable proof for that! 

[OldBigEars]

Assuming for a moment that Rob Watts knows his product better than anyone, and that a battery pack is "the perfect PS" for this product - does it matter what kind of cord connects it to the day?  Or would an $8 Anker USB micro cord be as good as anything?

[barrows]

3 hours ago, OldBigEars said:

Assuming for a moment that Rob Watts knows his product better than anyone, and that a battery pack is "the perfect PS" for this product - does it matter what kind of cord connects it to the day?  Or would an $8 Anker USB micro cord be as good as anything?

With no disrespect to Mr. Watts, I would not be so quick to assume that.  Many users have found that a well designed linear power supply provides the bet performance with the Qutest.  Note that USB "battery packs" for cell phones etc, usually have noisy switching regulators inside.

[Middy]

Apart  from barrows adopting you and making making another custom PSU... i live in hope ..😀 to me, a known good PS improved the SQ to my ears..

The quad cable from John S suggestion pre 360 makes a small difference but noticeable. Ghent do a good job of the canare cable for not a huge price. At the very least it looks nice... i bought an adapter for the Qutest but  i believe you may be able to get one terminated.. DC barrel to Micro...

For the cost minded its painful with the cost to squeeze that extra diminishing returns. My suggestion is to try one of the LT3045s regs boards on top of the stock supply. Under $100 then invest in a good PSU if you feel it did some good in your system.

If you hear a difference get an uptone 1.2 or what you feel is right in your system. The LT3045 regs can be added onto the new PSU if you invest again and remove the wall wart.

Maddening that there is always room for improvement even the ultra highend segment but psu engineers/companys do what they do best..

 

Good luck

David

 

[barrows]

24 minutes ago, Middy said:

Apart  from barrows adopting you and making making another custom PSU... i live in hope ..😀 to me, a known good PS improved the SQ to my ears..

The quad cable from John S suggestion pre 360 makes a small difference but noticeable. Ghent do a good job of the canare cable for not a huge price. At the very least it looks nice... i bought an adapter for the Qutest but  i believe you may be able to get one terminated.. DC barrel to Micro...

For the cost minded its painful with the cost to squeeze that extra diminishing returns. My suggestion is to try one of the LT3045s regs boards on top of the stock supply. Under $100 then invest in a good PSU if you feel it did some good in your system.

If you hear a difference get an uptone 1.2 or what you feel is right in your system. The LT3045 regs can be added onto the new PSU if you invest again and remove the wall wart.

Maddening that there is always room for improvement even the ultra highend segment but psu engineers/companys do what they do best..

 

Good luck

David

 

Considering the cost/performance ratio of the Qutest, i do not find it maddening that adding a really good power supply can improve the performance.  Even adding a $500.00-$600.00 high performance linear power supply to the cost of the Qutest still results in an overall quite affordable DAC which will perform much better than many competitors at the same (combined) price level.

[kennyb123]

7 hours ago, OldBigEars said:

Assuming for a moment that Rob Watts knows his product better than anyone, and that a battery pack is "the perfect PS" for this product - does it matter what kind of cord connects it to the day? 

 

I just wanted to point out that it would be a fallacy to assume this.  

 

An Appeal to Authority is a fallacy with the following form:

• Person A is an authority on subject S.
• Person A makes claim C about subject S
• Therefore, C is true.

Claims aren’t proven true by who made the claim.  

[OldBigEars]

41 minutes ago, kennyb123 said:

 

I just wanted to point out that it would be a fallacy to assume this.  

 

An Appeal to Authority is a fallacy with the following form:

• Person A is an authority on subject S.
• Person A makes claim C about subject S
• Therefore, C is true.

Claims aren’t proven true by who made the claim.  

 

Ummm, no but the probability is high if Person A happens to have designed that product.

Person B claims are probably BS  

[kennyb123]

1 hour ago, OldBigEars said:

 

Ummm, no but the probability is high if Person A happens to have designed that product.

Person B claims are probably BS  

 

There is a higher likelihood off an opinion being true if the opinion is offered by an expert in a particular area. Per the dictionary, an expert is "a person who has special skill or knowledge in some particular field".  Just because someone is an expert at designing DACs doesn't automatically make them an expert at power supplies.  It also doesn't automatically make them an expert in music servers.  In fact, they could be novices in both those areas as they lack hands-on experience.

 

I think many you dismiss as "Person B" are folks I would consider to be experts as they've built their knowledge through doing experiments. 

 

Lastly, it should be pointed out that the power supplies in most Chord digital products weren't designed by Chord.  They were selected based on a set of measurements.  

[Middy]

@barrows

Costs/value yes...In this game its not really, weighted on not that much disposable income and wanting something for nothing. Relatively i found the Qutest to be good value as Chords are out of my price range so it was great to finally get on the ladder.  I should be happy its cheaper and sounds fantastic. 

I should be glad it can be leveraged.. but secretly i hope that was it.. no more extras. Been fun though i listen to your advice and never been happier... 

 

Stay happy and safe

Dave😀

 

[OldBigEars]

2 hours ago, kennyb123 said:

 

There is a higher likelihood off an opinion being true if the opinion is offered by an expert in a particular area. Per the dictionary, an expert is "a person who has special skill or knowledge in some particular field".  Just because someone is an expert at designing DACs doesn't automatically make them an expert at power supplies.  It also doesn't automatically make them an expert in music servers.  In fact, they could be novices in both those areas as they lack hands-on experience.

 

I think many you dismiss as "Person B" are folks I would consider to be experts as they've built their knowledge through doing experiments. 

 

Lastly, it should be pointed out that the power supplies in most Chord digital products weren't designed by Chord.  They were selected based on a set of measurements.  

 

Not to be confrontational...but the design process, when done properly, involves lots and lots of testing of each component, within the context of the total product.  The designing of a power supply does not assume any one dac that it will be used with.  The "expert" in terms of which power supply works best with this specific product is most likely it's designer, tester and project lead.

 

But thankfully it's still just about a free world and we are able to experiment and select to our heart's content if we want to ignore this advice. Watt's design made that easy.

[kennyb123]

40 minutes ago, OldBigEars said:

 

Not to be confrontational...but the design process, when done properly, involves lots and lots of testing of each component, within the context of the total product.  The designing of a power supply does not assume any one dac that it will be used with.  The "expert" in terms of which power supply works best with this specific product is most likely it's designer, tester and project lead.

 

Yes "when done properly".  Designers are human and just like the rest of us they have their biases.  

 

Confirming whether the designer is an "expert" in a particular area is awfully easy.  When their claims are put to test, we should see uniform consensus favoring the designer's claim.  And we should most certainly not see the opposite where pretty much anytime a well-regarded power supply is tried with the designer's product it's claimed to have made a improvement that's indisputably positive.  

 

Rob's claims about the importance of accurately reproducing timing information align fully with what I hear from his products - and I'm not alone.  He's clearly an "expert" in that area.  Power supplies, maybe not - but that's a lot to expect of one designer.  Many other products have the design shared amongst several designers who have deeper skills in different areas.