[Triode User]

Sorry but Startup Power: 360 Amps is Cold Cranking Amps (CCA) for a battery NOT the battery capacity - measure the discharge load in amperes that a new, fully-charged battery can deliver for 30 seconds, while still maintaining terminal voltage equal to or higher than 1.20 volts per cell in a cold environment (0°F/-18°C).

what you linked is 41A capacity battery, so you are wrong

my question to Rob Watts still remain

I’m not sure what your point is apart from proving pedantry. If a battery can deliver 360A for 30 secs then for sure it is capable of providing far more current than any of the other two types of power supply (unless you think different but you haven’t said that). So what is your point? Do you think the current delivery from the battery is inferior to the other two supplies? After all, the battery was only used as a reference point to establish whether other supplies were inferior and if they weren’t then it was fair to assume that they were not affecting the sound quality.

 

[agedbest]

I’m not sure what your point is apart from proving pedantry. If a battery can deliver 360A for 30 secs then for sure it is capable of providing far more current than any of the other two types of power supply (unless you think different but you haven’t said that). So what is your point? Do you think the current delivery from the battery is inferior to the other two supplies? After all, the battery was only used as a reference point to establish whether other supplies were inferior and if they weren’t then it was fair to assume that they were not affecting the sound quality.

I think you want to belittle my speech
and I do not think this is the right way to approach
if a question has no answer .... or the answer is vague

I found an inaccuracy said by Rob, and I pointed it out, as I did with your previous answer.


my point of view seems clear to everyone,
I do not find absolutely correct to compare the PSU with a battery that has the same problems, as it has an internal switch for DC / DC conversion, and can not be considered free of contamination ......
if you can explain to me that it has none, I will be happy to listen to you.

The question will remain unresolved until a test can be carried out with a source free of contamination. also it's a common misconception that a battery supply is best PSU

 

[Skampmeister]

I’m kinda hoping for a next week delivery in Australia for mine. My 2qute has already been paid for in advance by a keen, but patient buyer

 

[jayz]

what you linked is 41A capacity battery, so you are wrong

They are on sale, just get Ten and wire them parallel - bingo.

 

[agedbest]

They are on sale, just get Ten and wire them parallel - bingo.

the question was: there is a 300A 12v DC on the market?
also you was not able to find ...so there isn't
Rob Watts had one? ....

 

[mtmercer]

As someone who knows absolutely nothing about power supplies but reads various discussions about how power supplies impact DAC/Amp performance, would running the Qutest from a USB battery bank such as an Anker or this, http://a.co/9NioTd5, possibly improve performance of the Qutest?

 

[panditji]

I don't understand the obsession of people wanting Rob Watts to admit that power supplies make a difference when he has said otherwise time and again... He admitted that they made a difference with the Qute but not with the 2Qute... And if you still believe that power supplies make a difference on the 2Qute, then spend your money and buy one.. Why the obsession with convincing Mr. Watts? It's his product and he was not able to differentiate when he experimented... If you can, then do report on the forum and let people decide if they want one....

 

[agedbest]

As someone who knows absolutely nothing about power supplies but reads various discussions about how power supplies impact DAC/Amp performance, would running the Qutest from a USB battery bank such as an Anker or this, http://a.co/9NioTd5, possibly improve performance of the Qutest?

it's a common misconception that a battery supply is the ultimate PSU.

Furthermore all the powerbanks on the market use an internal battery of different amperage (capacity), but with same voltage of 3.7v, then by a switching DC / DC converting circuitry,
without any filter, it exit at 5V. any converting makes interference, regardless of the quality, brand, appearance, cost, etc., etc.
any powerbank can not improve your audio system, definitively powerbank can NOT be the solution. would waste your money unnecessarily.

 

[Rob Watts]

the question was: there is a 300A 12v DC on the market?
also you was not able to find ...so there isn't
Rob Watts had one? ....

It was a "portable" battery to enable you to start cars with flat batteries, and was rated at 300A, but I am sure that is just peak surge current rating. It doesn't matter whether it is 300A or 3A; all that is important is ultra low impedance, and ultra low noise, which a car battery has plenty of, way better than any mains linear PSU.

 

[flyte3333]

and not useable as refence for Qutest because there is not a 5v DC battery....
nothing without an internal swich....switch can output same noise of PSU added in the box
for this reason a 5v powerbank can not be used to compare the factory PSU

Sure there is - here is a big capacity one in a sensibly sized package: https://www.tp-link.com/uk/products/details/cat-5689_TL-PB20100.html

Regarding the output noise you mention, I don't think this is what Rob is talking about when he discusses RF...

I think it's the fact that the USB battery power supply is not connected to mains power, therefore no path of leakage currents via this power supply, therefore no RF pickup and RF getting into the DAC via this micro USB power cable

The output noise of the USB battery pack, which can be no different to an SMPS, will be regulated inside the DAC anyway... the leakage currents can sometimes pose a bigger issue, depending what the DAC is connected to.

I'm sure Rob will correct me though! I THINK I've understood his and John Swenson's posts on leakage current loops but may have it wrong!

 

[agedbest]

Sure there is - here is a big capacity one in a sensibly sized package: https://www.tp-link.com/uk/products/details/cat-5689_TL-PB20100.html

surely not
also the battery that you have linked use six lithium battery of 3.7v then then by switching DC / DC converting circuitry, without any filter, it exit at 5V. any converting makes interference.
on the market there is no 5v battery, at least not yet.
and in any case it would not be possible to use it, without a regulator and stabilizer to meet USB standard input / output power rate.

 

[flyte3333]

surely not
also the battery that you have linked use six lithium battery of 3.7v then then by switching DC / DC converting circuitry, without any filter, it exit at 5V. any converting makes interference.
on the market there is no 5v battery, at least not yet.
and in any case it would not be possible to use it, without a regulator and stabilizer to meet USB standard input / output power.

But this isn't what the testing with a 5Vdc USB battery pack (trying before buying a linear PSU) is about... it's not about the voltage output/ripple. It's more about blocking a path of leakage currents and RF pickup by the microUSB power cable, into the DAC...

I already mentioned "The output noise of the USB battery pack, which can be no different to an SMPS, will be regulated inside the DAC anyway... the leakage currents can sometimes pose a bigger issue, depending what the DAC is connected to."

 

[agedbest]

also battery has Power Supply Noise...also without a switch converter
so add battery noise to switch noise, without any filter, is not the right way to go

if someone already owns a powerbank he can try ....
but I would not feel advised to buy it specifically to try ..
because I do not consider it suitable for the purpose.

 

[jayz]

My Qutest has had some workout now and have to say this thing is starting to sound phenomenal.

Last night I ran the Isotek system setup CD http://www.isoteksystems.com/products/essentials/ultimate-system-set-up-disc which I use to fine tune speaker placement and toe-in. It got to Track 12 which is the last of the soundstage test. This track involves a castanet being played and moved around a room in a circle and the person describing it moving in the same circle at the opposite end. Imaging was one of the strengths of my system even before but with the Qutest it is almost surreal to hear this track. Even during the brief moments when the presenter pause between words, you could tell he was on the move. It was as if his breath was filling that void between the words but you couldn't actually hear him breathe.

 

[dac64]

I'm expecting a Chord Qutest soon, uses OPPO SACD/CD player as source, maybe a Win notebook later, and HDMI to optical converter to output DSD directly from OPPO to Qutest.

I also found a portable car battery, with 2x 5V/2.1A USB outputs, may get one to compare with the stock power supply.

https://www.amazon.com/Portable-Starter-INTELLIBOOST-Flashlight-Charging/dp/B01AKQPBE8/ref=sm_n_se_dkp_SG_pr_sea_0_3?adId=B01JJZQPB4&creativeASIN=B01JJZQPB4&linkId=87e95546861770e55aa8605ae1b6eb12&tag=cbccnsatop-20&linkCode=w42&ref-refURL=https://www.carbatterychargerscentral.com/car-starter-top-7-compact-battery-jump-starters/&slotNum=0&imprToken=VbPiQAw5FvGltP4LABGzZw&adType=smart&adMode=search&adFormat=grid&impressionTimestamp=1518917562495&th=1

Well, if car battery is way better than any mains linear PSU, we could have save some money!