Article: Chord Electronics QuteHD Review

[ted_b]

Richard,

Thanks for the detailed foillow up review, as well as the full disclosure of your dealer status, etc.

 

I am easily confused so bear with me: how do you surmise that you are powering the Hugo with a dc power supply when what I see is that you are simply powering your AP2. No power is getting through SPDIF connections, just a clean bitstream. Isn't the Hugo still being powered by its own battery?

Ted

[aumamp]

Richard,

Thanks for the detailed foillow up review, as well as the full disclosure of your dealer status, etc.

 

I am easily confused so bear with me: how do you surmise that you are powering the Hugo with a dc power supply when what I see is that you are simply powering your AP2. No power is getting through SPDIF connections, just a clean bitstream. Isn't the Hugo still being powered by its own battery?

Ted

 

Hi Ted,

 

The USB cable coming from your computer normally carries a huge amount of RF noise into the USB port.

 

By using an external USB power supply, we typically are able to run cleaner power into a DAC's USB port and and this will normally result in higher quality sound quality, but not with the Hugo.

 

In the Hugo, the battery is supplying the power for the DAC and even though power is much cleaner than a cheap wall wart would supply, it too has its degree of noise remaining.

 

Instead of trying to lower RF noise by working with the USB port (the Hugo doesn't gain any improvement by connecting an iFI iUSB or Teddy Pardo USB power supply), we can still gain a substantial sound quality increase by improving power through a good external +5VDC power supply and then passing it into our USB to SPIDF converter into its USB port.

 

I've found the Audiophilleo AP2 converer to be perfect for this. It has two modules. One is the ARM RISC processor and USB interface and is powered by the computer. We connect here the clean power from the external +5VDC power supply instead of using our "noisier" power that is carried on the computer's USB power wires. Those wires are shunted with a resistor and the cleaner power now comes from the external power supply.

 

Module 2 in the Audiophilleo has the ultra-low jitter clocks and S/PDIF output stage. These are also powered by the clean 5VDC external power supply.

 

The +5VDC external power supply lowers the RF noise passing into the S/PIDF port and creates an analog-like smooth sound with even more detail since it can now rise to the surface rather than being covered over by the noise carried on the USB cable coming from the computer. The background becomes "blacker" and the sound stage and separation improves.

 

You are correct. The battery supplies the power to the Hugo. However, what I'm doing is reducing RF noise by using the SPIDF port. This technique works really well for the Hugo and improves the sound quality beyond just using the HD USB port. It's interesting to discover that the various +5VDC power supplies that are available to us each sound very different. The power supply somehow carries with it an ability to fatten the sound while either covering over details or it can instead allow them to rise to the surface.

 

I haven't figured out what is the exact cause of how well a power supply improves the sound but I have discovered that ones with a toroidal transformer sound the best. The iFi iUSB and the Audiophilleo PurePower don't sound as good as a Teddy Pardo supply for example. Of the three, only the Teddy uses a toroidal transformer with typical bridge, cap bank, and regulator circuit that we use in many other DC components. The iFi is powered by a wall wart and the PurePower is powered by a battery.

 

I hope this helps. I definitely am not an expert in understanding what is going on here. Instead, I have enough experience using these components that I dig deeper to find out if I can use them to improve sound quality. The Hugo sounds really good using the custom transformer that I've been designing and improving step by step. It sounds much better than Teddy's commercial unit. I've just about got it perfected as much as I sense is possible. Sound quality is really nice and a perfect match for the Hugo. Much better than using the HD USB port.

 

Richard

[ted_b]

Richard,

I was reacting to the statement

"In summary, I can share with you that the Chord Hugo, powered by a custom USB power supply, run through an Audiophilleo AP2 converter......."

The Hugo is NOT powered by a custom USB power supply, it is powered by the battery. Unlike the Qutes of my review (which are using the Hynes) the Hugo has no external power alternatives.

 

You went on to talk about reducing rf noise, etc...which is great. We've all been trying to reduce noise in a DAC, and things like the iFi USB (my first review way back when) are breakthrough products. I was simply pointing out that although you have found a nice clean source of 5V power for your external USB/SPDIF interface, it ain't powering the Hugo, it's simply letting less noise in (which is wonderful).

 

By the way, I have another way that I'm doing a similar thing with the Qute EX (and hope to with a Hugo once I get my hands on one). I am using the JCAT USB card, which allows me to not use ANY power to the USB cable. I have the top port of the card powerless (and bottom port powered via a custom Acopian 5V) and use it for DACs that need no 5V (like the Chord). The combo of that card and then JCAT's own USB cable is quite something (mini-review coming). It has me thinking twice about whether the USB port on the EX is any worse than the SPDIF (those comparisons continue...will report back).

 

Anyway...thanks for showing us how you are pushing cleaner music through the Hugo.

[ted_b]

Well, I think I'm gonna pull the trigger on a Hugo. They are unavailable as demos since they sell out at each shipment (note: this is the 3rd US shipment and it is confirmed that the RCA case enhancements have been delivered). I will put my name on one of the 4th shipments, due in a few weeks.

 

I will put the Hugo through the same paces as the HD and EX. Anyway...stay tuned.

[wisnon]

Hahahahahaaha,

 

I was waiting for this.

 

I too like the concept of the Hugo...its a killer portable dac/headamp! I just need to sell my HD and move up.

 

I dont need another desktop Dac, as the Lampis cant be beat for me as desktop Dacs.

[Melvin]

 

[snip ...] It has me thinking twice about whether the USB port on the EX is any worse than the SPDIF (those comparisons continue...will report back).

 

Hi Ted .. FWIW I wondered about this regarding the QuteHD and reconfigured my system a month or so ago. Now it looks like this:

 

Mac mini > iFi USB cable > iFi iUSBPower > Black Cat Silverstar! USB > QuteHD (w/Teddy Pardo PS) > ect.

 

Subjectively speaking (of course), the SQ is fantastic and I now find a USB-SPDIF converter unnecessary. Of note, I replaced the iFi DH Gemini cable with the Black Cat and I prefer it. I like the simplicity and was reminded of what Barrows has often stated about properly done async USB .. we shouldn't need a converter. Definitely worth checking out.

[ted_b]

Melvin,

good stuff. For me the HD was clearly improved going SPDIF (even with my inexpensive X-SPDIF) but the EX is less obvious so far. But maybe its the susceptibility to rf, cuz I now use powerless USB, and you now use a cleaner iFi USB signal path. Always learning...what a PITA.

[wisnon]

Guys, this is what Lukasz says about Power supply in Digital:

As we know POWER IS EVERYTHING. We effectively listen to power supply modulated by the signal. So the power supply is even more important than the output stage circuit itself. Thats why 70 % of budget of the DAC goes to the power supply. It starts with selection of sections, how many points we need to supply and with what voltage and what amperage. In basic Level 3 DAC there is 10 sections, going up to 20 and more in Level 5. Every section has separate transformer winding so we must design custom transformers with many specialized windings. This is an expensive way of doing thinds but we believe it is the only way.

 

For filtering we use different techniques, but lets focus on the most important supply - for the tube anodes. We use TUBE RECTIFIER, not silicon, even in DAC3 and in every higher level as well. after the tube rectifier we install capacitive output, followed by the big iron choke, followed by more capacitance and another choke. Yes, even lowest level 3 has CLCLC filter per tube. This technique is RIDICULOUSLY EXPENSIVE. Other companies use CRCRC which has three caps for 1 dollar and two resistors for 1 C each. Our approach is to use film capacitors instead of electrolytes and chokes for resistors and it cost 100 times more. That is our way of doing it.

[ted_b]

Norman, I love you, man...you just can't stop your Lampi love..I understand. But this is my Chord DAC thread, and you must have anticipated that I'd respond. As you know I had three (3) of Luckasz's DACs in my home, and all three threw so much DC into my signal path that I feared for my amps' life. They would shut down violently (thank goodness they shut down). I realize it's only my system (and likely other systems that are not dc coupled) and that the exact same DAC, sent on to Bruce, was found to be one of his all-time favorite DACs. Go figure.

 

My point is that I could not sit still and hear about Lukasz's substantial design on this thread and not comment. Something he does (likely chipless design) is incompatible with my system. YMMV.

[wisnon]

I read this somewhere:

 

Batteries vs Linear Power Supplies

Batteries are low noise, right? That's why people want to use them in audio

systems. Because they are pure DC they must have no AC noise, right?

Therefor a battery is better than any other power supply. Not quite.

 

How a battery produces power

Batteries produce power through a chemical reaction. Every type of battery

will have a slightly different chemical mixture that is used to generate power.

Batteries have a voltage rating and a current/time rating called Amp-Hours.

Amp hours basically say how many hours the battery will last if it's drawing

one amp of current. Because many systems draw variable loads a 10Ah

battery will not necessarily last 10 hours. It may last 20 or it may last 2 hours

depending on the system it is connected to.

 

A battery is pure DC. That means if you invert the battery's polarity you get a

negative voltage. So a battery generally will produce a + voltage and we

normally use - as ground to complete the circuit.

 

As a battery drains the amount of chemical compound available to produce

electricity drains. That means there's an exponential decay on the amount of

power a battery can product. So a battery at 100% will have far more capability of producing fast transients than a battery at low charge.............................

 

Enter the Linear Power Supply

Linear power supplies are going to be larger than batteries. But unlike

batteries they can be built to a much higher bandwidth that functions

consistently. A well-designed linear power supply can be considerably lower

noise, faster, and higher bandwidth than any battery. Linear power supplies

can filter the incoming AC noise, eliminate ripple to exceptionally high

frequencies, and have much higher slew rate and current output. This means

their sound will always be consistent and their potential much greater.

Comparing a battery to a SMPS or entry-level power supply will put a battery

ahead as the clear winner. It will be much lower noise than a SMPS. But a

well-crafted Linear power supply has several advantages and should be the

only consideration when looking for the ultimate power solution.

capability of producing fast transients than a battery at low charge.

[wisnon]

Norman, I love you, man...you just can't stop your Lampi love..I understand. But this is my Chord DAC thread, and you must have anticipated that I'd respond. As you know I had three (3) of Luckasz's DACs in my home, and all three threw so much DC into my signal path that I feared for my amps' life. They would shut down violently (thank goodness they shut down). I realize it's only my system (and likely other systems that are not dc coupled) and that the exact same DAC, sent on to Bruce, was found to be one of his all-time favorite DACs. Go figure.

 

My point is that I could not sit still and hear about Lukasz's substantial design on this thread and not comment. Something he does (likely chipless design) is incompatible with my system. YMMV.

 

Its not about Lampi, it about a series of opinions on Power Supply value in Digital. I had 3 takes and you unfortunately jumped in after point one. Something came up at work that delayed me posting the other 2 quickly. I am trying to create a train of thought that may explain why Richard gets better results the way he does.

 

Dont forget I have a Chord Dac too ( for 15 months now, long before most here) and am interested in tweaks for it.

[wisnon]

PC Audio:

 

The Power Supply

Arguably the most important piece of the music server is the power

supply. The bandwidth of the power supply directly correlates to

the resulting sound of the system. Digital is impacted by much

higher frequencies of noise than analog systems due to the concept

of quantization error where frequencies above the clock rate are

folded over into the base band and cause amplitude distortion on

the square wave. While error correction and interpolation can

estimate whether a one is a one or a zero a zero, it cannot correct

the amplitude distortion on the square wave that gets imprinted on

the file. Every process that runs on the computer takes power from

the power supply (and any noise imprinted on it) and applies that

voltage to create the new digital signal based on an algorithm. So

where a faster CPU allows for less mistakes, the power supply

prevents the CPU from coloring outside the lines. A power supply

that generates noise or is too low bandwidth will do more harm

than good in a computer--based audio system.

 

Noise

One of the biggest concerns with computer audio is being able to

navigate all of the EMI radiated from the motherboard. But the

EMI radiated from the motherboard is actually one of the lesser

evils that plague computer audio systems.

Noise is any signal we don’t want. Because we are playing back

audio signals in the 20hz--20khz range anything outside of those

realms can be considered noise. In digital audio there are clocking

frequencies in the mhz range, which means that any frequencies

above that are susceptible to fold--over and quantization error. This

noise generates additional harmonics and data that doesn’t exist on

the recording and imprints it on that signal.

Noise is a voltage. This is why it’s generally measured in uV.

While this may be a trivial voltage compared to the voltages

running through an audio signal, when you have several uV being

added every microsecond from different sources it adds up in a

hurry. These uV add and subtract from the voltages on the digital

signal so a 3.3V (one) becomes 3.2V or 3.4V or greater. This slight

variation in noise doesn’t confuse the system away from thinking

it’s a one, but that amplitude distortion and timing confusion gets

imprinted on the digital signal and translates to added harmonics.

Every digital signal contains timing information, amplitude

information, and channel data. That information gets imprinted on

the square wave that is then read by a computer. The imprint is

created in spite of noise, which distorts that imprint that’s created.

Noise comes from all places. It can be high frequency noise caused

by wireless interaction, it can be light, vibration, heat, resistance,

or any number of elements.

 

Power Supply Noise

The ATX--specification switchmode power supplies purchased

with most modern computers are noisy monsters. Not only are

switchmode power supplies limited in bandwidth by their

switching frequencies, but the higher the switching frequency the

more noise they generate.

It is for this reason a linear power supply with a high bandwidth

should be used. A HQ power supplies will have up to 18ghz

bandwidth and have a slew rate of 5600V/uS. This means they

have a very high bandwidth and are extremely fast. The additional

speed allows them to react quickly to the transient demands of the

computer system. The high bandwidth helps to eliminate fold--

over and quantization error.

The voltage from the power supply is used to create every signal in

the audio system. So any high frequency noise or ripple directly

relates to distortion created by every single algorithm and process

run in the audio system. Every process takes

voltage from the power supply and applies it regardless of whether

it’s clean or dirty. The cleaner the better.

[ted_b]

Gang,

When responding with a 3rd party diatribe, please just include the link. We can read it from there. If the link is not relevant (i.e important info needs to be edited out of a much more vast article) then reformat for this thread. It's only human nature but when someone sees a response that goes on for almost half a page (mainly due to poor formatting) many of us lose the essence of the post..as good as the info might be.

[ted_b]

Norman, you may already own a Chord dac, but when your response (now finding it was just part one of many) was 100% about the Lampi, and ended with "that is our way of doing it" I had to assume the post was ALL about the Lampi. Cuz it was. I (or any readers at the time) had no possible way of knowing it was just the first part of a lengthy educational post. I am sorry for that, but in hindsight maybe let us know where you are going.

[wisnon]

Work pressure… not as much time to edit properly as I was in and out all day, plus 2 of the 3 posts are NOT online….

 

For me, when the info is good, format be damned, I make a printout and read at my leisure to digest the complex ideas.

[Bob Stern]

I read this somewhere:

 

As a battery drains the amount of chemical compound available to produce electricity drains. That means there's an exponential decay on the amount of power a battery can product. So a battery at 100% will have far more capability of producing fast transients than a battery at low charge.

 

Linear power supplies ... unlike batteries they can be built to a much higher bandwidth that functions consistently. A well-designed linear power supply can be considerably lower noise, faster, and higher bandwidth than any battery. Linear power supplies can filter the incoming AC noise, eliminate ripple to exceptionally high frequencies, and have much higher slew rate and current output. This means their sound will always be consistent and their potential much greater. Comparing a battery to a SMPS or entry-level power supply will put a battery ahead as the clear winner. It will be much lower noise than a SMPS. But a well-crafted Linear power supply has several advantages and should be the only consideration when looking for the ultimate power solution. capability of producing fast transients than a battery at low charge.

 

I don't know where you read that, but I believe it is wrong.

 

The only current surges in a DAC are those caused by digital logic transitions in response to every clock pulse. To minimize jitter, these surges must be suppressed by voltage regulators and capacitors mounted close to the DAC chip on the DAC circuit board, regardless of the type of power supply. The current draw from the power supply should be constant. There is no need for the power supply to supply "fast transients".

 

It is true that a battery does not have a low output impedance at RF frequencies, but that also is a problem with the large electrolytics required to filter 50 or 60 Hz mains power in a linear AC power supply. In both cases, the solution is to add small value filter capacitors and/or high speed voltage regulators having low RF impedance.

[Geardaddy]

Great review Ted. I am too am a fan of MA recordings. Norman has been telling me quite a bit about the Hugo in our recent discussions as a dac option (in the context of our ongoing convo about the Directstream dac). He has been a Chord fan for longer than most inhabitants of this forum.

 

Norman, which is your source of those quotes? I wonder who it is that propagated this apparently incorrect info?

 

Bob, do you design or manufacture electronics or are you repeating what you yourself have read?

[bmoura]

I am using the JCAT USB card, which allows me to not use ANY power to the USB cable. I have the top port of the card powerless (and bottom port powered via a custom Acopian 5V) and use it for DACs that need no 5V (like the Chord). The combo of that card and then JCAT's own USB cable is quite something (mini-review coming). It has me thinking twice about whether the USB port on the EX is any worse than the SPDIF (those comparisons continue...will report back).

 

The JCAT USB cable is creating quite a stir after PS Audio noted it made a big difference when used with their new DirectStream DAC. Sounds quite intriguing.

[Bob Stern]

Bob, do you design or manufacture electronics or are you repeating what you yourself have read?

 

The latter, but my judgment as to what makes sense and what doesn't is strongly influenced by my degrees in electrical engineering.

 

(We all know that many subjectivist audiophiles believe science is counterproductive to audio, so let's not turn every thread into a re-hash of that argument.)

[Geardaddy]

The latter, but my judgment as to what makes sense and what doesn't is strongly influenced by my degrees in electrical engineering.

 

(We all know that many subjectivist audiophiles believe science is counterproductive to audio, so let's not turn every thread into a re-hash of that argument.)

 

That is fair, but engineering is not necessarily synonymous with science. There is a lot of insufficient data in audio and science (IMO) involves an exploration to fill in those gaps.

[Geardaddy]

The JCAT USB cable is creating quite a stir after PS Audio noted it made a big difference when used with their new DirectStream DAC. Sounds quite intriguing.

 

Interesting. What I gleaned from Ted's ramblings is that the Directstream was supposed to be more impervious to input typology?

[ted_b]

Ted Smith, not Ted Brady. I don't ramble.

 

JK...Ted Smith knows his Sh$t. I wouldn't call it rambling...but I understand your point.

[koyie]

wisnon is quoting from Core Audio Technologies' technical articles:

Battery Power Supply | Battery vs Linear Power Supply | DAC Power Supply | Core Audio Technology

Core Audio Technology | Articles and White Papers

 

I read all of them when I was researching linear power supplies after reading this article.

The articles seem impressive, but I do not have the background to know if the information in them is correct.

[xamastrok]

Sorry to hi-jack this thread, but the QuteHD thread seems dead, and I could find nowhere else better to post this to.

 

I am using Qute EX and JRiver 19 on Windows Server 2012 core. Whenever I press pause JRiver hangs and I have to reboot my music server. So, basically, I cannot pause. Has anyone noticed this behaviour? What did you do to overcome it?

 

I had no such problem with QuteHD and JRiver 18. I upgraded to EX and bought JRiver 19 at around the same time, so I cannot judge whose fault this is, but I guess it's the new EX's drivers that cause it. There are newer updates of JRiver 19, but I haven't bothered installing them yet, since I am in core Windows mode, and I have to change shell.

 

You can send me a pm if you think that this subject is out of scope for this thread. Thank you.

[ted_b]

Sounds like a JRIver install problem. I run exactly the same (but WS2012 in GUI mode on controlpc) and have zero issues (JRIver 19, Chord Qute EX). I'd take this up on the JRIver tips and techniques thread.