[Christer]

Yes a car battery is the best possible PSU - huge dynamic current, ultra low impedance and no noise. But the real benefit is batteries, and isolation from the mains, so a car battery is not needed; just use a USB power bank.

TT2 doesn't benefit from it anyway, because of the super caps and the filtering; disconnecting the PSU has no change in measurements or sound quality. The M scaler is helped by using a battery, as it eliminates the 2GHz ground return currents, solving at a stroke the BNC cabling issue.

Thanks, "straight from the horse's mouth" I haven't followed this thread closely for quite a while and may have missed similar statements in earlier posts from you.
But this post as I understand it, confirms what I have easily and CLEARLY heard since day ONE comparing the stock psu of my Qutest with the battery powered usb supply I also have.
With the usb battery psu I hear a calmer, warmer,fuller, timbrally more accurate and simply more realistic and detailed SQ than with the supplied wallwart psu that came with my Qutest.

At home I only use my Qutest in combination with my Mscaler and with Wave Storm BNC cables.

But during my only one month tropical escape from the dark and wet and horrible winter in Sweden in February /March I did not bring my Storm BNC cables and instead only used the stock BNC that came with my Mscaler and the difference was MUCH more obvious than expected.

I have to say that without the Storm or Stream BNC SQ via Qutest/HMs was not nearly as satisfying as I am used to at home.
I would go as far as saying instead of only "the surface of the icing on the cake" the ice had irritating wholes in it with the stock BNC in Thailand.
Yes it was bit hot in the tropics as expected.

But I am reading your message above as saying that all I would have had to do would have been to use a powerbank with my HMs instead of these very expensive BNC cables to achieve the SQ I have come to expect from my Q/HMs combo?
Or even better?
Aren't you now also stating that to perform optimally the Mscaler also needs to be removed from the mains????
And if that is the case, why is it then supplied and sold with a psu that sends "2GHZ ground return currents" back into it?
Is the much debated and at least for me easily heard BNC stock cable problem completely or only partly solved, simply by isolating the HMS from the mains?

The only problem I have with the battery powered usb supply I am currently using with my Qutest is that it runs out of juice after three-four hours and has to be re-charged every day. And I also often forget to unplug it only to realize that when I want to listen again it is dead.
I would like to have at least a day of listening without having to think of re-charging or having to plug in the imho not so good supplied psu in the middle of my music listening when I least expect it.
How long would the HMS run on a good quality car battery or a good suitable powerbank?
And how does one connect the HMS to a car battery if that is the solution that would let me forget about charging for the longest period of time possible?
Do you have any suggestions of good brands and types of car battery to use?
PS I am also still waiting for your updated advice on which power bank to use with HMS since the one you originally suggested has been out of stock new for a couple of years.
Eagerly awaiting a SOTA portable battery-powered digital headphone amp that effortlessly drives even power hungry beasts like Susvara and most importantly also works directly without the need of a dac in between, with HMS from you sooner rather than later.
Cheers CC

 

[Christer]

I'll have a go. After all, the battery isn't needed in my car at the moment!!!

Hi Nick, do let us know how you safely connect your HMS to the car battery. Cheers CC

 

[Triode User]

Hi Nick, do let us know how you safely connect your HMS to the car battery. Cheers CC

It is easy as long as you get the plus and the minus the correct way around!! By the way, there are so called leisure batteries which are designed for steady state discharge in caravans and the like rather than the high cranking amps needed for a car battery. One issue with using a lead acid battery is that they are best kept at or near full charge and they do not respond well to deep discharges.

 

[uzi2]

It is easy as long as you get the plus and the minus the correct way around!! By the way, there are so called leisure batteries which are designed for steady state discharge in caravans and the like rather than the high cranking amps needed for a car battery. One issue with using a lead acid battery is that they are best kept at or near full charge and they do not respond well to deep discharges.

These batteries are more common now as they are used for the 12v systems of electric cars.

 

[audio_1]

Hi Nick, do let us know how you safely connect your HMS to the car battery. Cheers CC

I use a 12 volt 36 Ah Gel vehicle or solar battery on the receiver side of the Opto-DX. hazebattery.com This battery is suitable for cycling use and deep discharge. I made up a cable with an Oyaide DC-2.1 G 5.5 x 2.1 mm connector. The battery has convenient m6 screw connections that accommodate 6 mm cable lugs. The Mscalar and TT2 require a 5.5 x 2.5 mm connector.

 

[gnomen]

Makes me wonder if the biggest benefit from the Opto-DX comes from using batteries with it as recommended

 

[audio_1]

Makes me wonder if the biggest benefit from the Opto-DX comes from using batteries with it as recommended

I changed to the Farad Super 3 power supply due to the hassle of charging the battery. I didn't notice any reduction in sound quality.

 

[474194]

Yes a car battery is the best possible PSU - huge dynamic current, ultra low impedance and no noise. But the real benefit is batteries, and isolation from the mains, so a car battery is not needed; just use a USB power bank.

TT2 doesn't benefit from it anyway, because of the super caps and the filtering; disconnecting the PSU has no change in measurements or sound quality. The M scaler is helped by using a battery, as it eliminates the 2GHz ground return currents, solving at a stroke the BNC cabling issue.

Thank you for satisfying my curiosity. I like the low or close to zero impedance and dynamism aspect of a car battery versus USB battery banks:

Battery Type	Dynamic	Impedance
Car Battery	X​	0.02 ohm
LiFePo4	X​	<8mohm
Supercapacitor	X​	<3.2mohm
USB Battery Bank	​	Unknown. Assuming > [Car Battery, LiFePo4 or Super caps]

USB Battery Banks costs at least twice as a lead acid battery. It may make sense to go with the better performing, lower cost solution:

versus the more expensive battery bank:

This will give me motivation to explore what's out there for car battery. It may make sense to go car battery > usb battery bank. Always off mains so no worries there.... Thanks again.

 

[ecwl]

Thanks, "straight from the horse's mouth" I haven't followed this thread closely for quite a while and may have missed similar statements in earlier posts from you.
But this post as I understand it, confirms what I have easily and CLEARLY heard since day ONE comparing the stock psu of my Qutest with the battery powered usb supply I also have.

And if that is the case, why is it then supplied and sold with a psu that sends "2GHZ ground return currents" back into it?

So I’m always under the impression that a battery supply for Qutest or M-Scaler would “improve” the sound if there is ground return currents from your grounded digital USB (or S/PDIF) music source into the M-Scaler/Qutest. If you’re using a laptop that’s not plugged into the mains, an iPad or iPhone connected to the M-Scaler/Qutest or if you’re using the optical input of the M-Scaler/Qutest, you should not need to use battery supplies to squeeze out the last bit of sound out of the Qutest/M-Scaler, because there won’t be any ground return currents.

So in my mind, I have often debated whether it’s Chord’s job to minimize the effects of ground return currents (which as I understand Rob Watts has already done lots to achieve that), or whether it’s the designers of digital streamers, not to name specific brands, to minimize their ground return currents that can flow into DACs. Unfortunately, I still haven’t arrived at an answer but I’m leaning towards that it’s not Chord’s job but the digital streamers’ job. That said, with my UltraRendu, I have used a supercapacity power supply, grounded my NAS & router and cable modem to get as low amounts of ground currents as possible. While I was very happy with my results for a couple of years, In the end, I threw up my hands a month ago and switched to optical input into M-Scaler to squeeze out that tiny bit of sonic improvements.

Would be interested in others’ thoughts on this one...

 

[474194]

I think I'm getting the grasp of this concept via powerwerx. I think the safe choice is LiFePo4. Car lead acid battery if your adventurous. Both provide huge dynamic power swings if your genre is classical. Both about the same price.

 

[AndrewOld]

Hi Nick, do let us know how you safely connect your HMS to the car battery. Cheers CC

£2000 jump leads.

 

[Christer]

So I’m always under the impression that a battery supply for Qutest or M-Scaler would “improve” the sound if there is ground return currents from your grounded digital USB (or S/PDIF) music source into the M-Scaler/Qutest. If you’re using a laptop that’s not plugged into the mains, an iPad or iPhone connected to the M-Scaler/Qutest or if you’re using the optical input of the M-Scaler/Qutest, you should not need to use battery supplies to squeeze out the last bit of sound out of the Qutest/M-Scaler, because there won’t be any ground return currents.

So in my mind, I have often debated whether it’s Chord’s job to minimize the effects of ground return currents (which as I understand Rob Watts has already done lots to achieve that), or whether it’s the designers of digital streamers, not to name specific brands, to minimize their ground return currents that can flow into DACs. Unfortunately, I still haven’t arrived at an answer but I’m leaning towards that it’s not Chord’s job but the digital streamers’ job. That said, with my UltraRendu, I have used a supercapacity power supply, grounded my NAS & router and cable modem to get as low amounts of ground currents as possible. While I was very happy with my results for a couple of years, In the end, I threw up my hands a month ago and switched to optical input into M-Scaler to squeeze out that tiny bit of sonic improvements.

Would be interested in others’ thoughts on this one...

Thanks for your advice and thoughts.
In my case and in my system both via headphones and big speakers and powerful amp system where the PSU of my amp weighs in at 70lbs or 32 kg apparently some serious thoughts dedicated to delivering clean power from the designer of that amp, I can clearly hear the improvement that the battery powered usb PSU/Qutest brings both with my mbp and usb on running on battery and plugged in.
I don't hear much of a difference between my mbp plugged in or on battery.
Not even sure I'd be able to spot it in a blind test.

But but, the difference between the supplied psu and the battery powered usb one is VERY obvious to me both via usb mbp and either of my two cd players via optical with complex well recorded acoustic music material.

But to complicate matters a bit, there is also a clear difference between my two cd players and optical via Mscaler as well.
With cds one of them sounds clearly better than the other.
And the better one also sounds better than if I play the same disc ripped via usb/mbp.

But the absolutely best most realistic SQ I can squeeze out of my Mscaler /Qutest combo is still native well recorded HI RES via usb/mbp.
Looking at it from a positive side ,the Mscaler/Qutest on battery powered psu has totally changed the way I listen to and enjoy my music.
I can now listen to cds both via optical from cd player and ripped with great enjoyment on a daily basis.
But I have to re-charge the damned thing daily.
Cheers CC

 

[Widell]

Oddly enough I was thinking about such a post later this week - I am awaiting a delivery and will post something when it comes.



I can't comment about the jitterbug directly - but USB is important for two reasons - the RF noise that enters the DAC, and signal correlated noise, which degrades depth perception. This is both due to currents flowing into the DAC - stop current flowing in the ground, and you eliminate the issues. Random RF noise is important as it creates intermodulation distortion with the audio signal, and if the RF is random, the intermod products are also random, and dependent upon the level of the audio signal. Now all this, if the levels are large enough, are easily measurable on a DAC that has zero measurable noise floor modulation; the only contentious issue is the audibility of noise floor modulation - and that's down to doing listening tests. My listening tests have shown noise floor modulation from -180 dB to -200 dB as easily audible; but of course people that never do listening tests will claim that this level is inaudible. That's the heart of the argument between those that listen and those that don't.

Note that all current Chord DACs employ extensive RF filtering or galvanic isolation on the USB, so further treatment is unnecessary.

Hi Rob, Many thanks your exhaustive feedback, always makes me feel I should know and learn more about all these technicalities.
Today I experienced a new phenomenon as I listened to Kraftwerk in view of late Florian Schneider, and while steaming their music via Qobuz, multiple albums and songs I realized that basically any volume above blue colour on CH2, via USB, Jitterbug to MBP made very little difference in sound output to my HD800, while I did think as this is electronica music so I thought this is the reason but listening to Daft Punk proved differently and volume was back to normal, then I played Avishai Cohen, Big Vicious and volume control was also normal, why is that some kind of recording limitations?? Sorry for my ignorance if stupid ??? just don't understand it...

 

[kennyb123]

Yes a car battery is the best possible PSU - huge dynamic current, ultra low impedance and no noise. But the real benefit is batteries, and isolation from the mains, so a car battery is not needed; just use a USB power bank.

TT2 doesn't benefit from it anyway, because of the super caps and the filtering; disconnecting the PSU has no change in measurements or sound quality. The M scaler is helped by using a battery, as it eliminates the 2GHz ground return currents, solving at a stroke the BNC cabling issue.

I found a strong preference for powering my TT2 with a Pro Pilot2 battery over the stock power supply. Recently I placed a dual stage LT3045-based regulator after the battery. The TT2, like most digital components, seems to very much delight in being powered the lowest noise and lowest impedance power supply it can be provided. The improvements were quite astonishing: greater separation of instruments, better timing/PRAT with notes stopping and starting more naturally, and lower noise/greater naturalness.

The HMS seemed to liked additional regulation also, but didn‘t respond as well as the TT2. A single stage was certainly worthwhile, but I didn’t hear much further benefit from a second stage.

These are the devices I used:

https://www.ldovr.com/product-p/dxp-1a5dsc.htm
https://www.ldovr.com/product-p/dxp-1a5s.htm

These boxes are small and something you could easily include with the gear you travel with, Rob.

 

[474194]

Mother Of Tone Link

Air and Electric Current

What do air and the electric current have in common ?


They are both media needed for musical recording and reproduction.


As air is the medium in front of the microphone and again after the loudspeaker, the electrical current is the musical medium for all processes between the microphone and the speaker.


If you want to listen to music the very first prerequisite is silence, that means the absence of any disturbances in the medium air.


You cannot record or enjoy music while someone operates the vacuum cleaner in the same room. It is impossible.


The same holds true for the electrical current. You can neither record nor reproduce a musical performance in high-fidelity, if your recording or replay-equipment is powered from disturbed current.


As a vaccum cleaner makes unwanted noise in the air, there can also be unwanted noise in the electrical current.


This is a point that is often overlooked, but as a matter of fact, the quality of the electrical current that powers your equipment has the same influence on the sound, as for example the circuitry that is used.


The great majority of hifi-equipment is mains (AC) powered. But not only your hifi-stuff is mains powered, but many electrical devices in your house, neighborhood, block, region. You all virtually hang on the same wire. As any electrical device is powered on or off, a ripple is generated on the AC-wave. So if you live in a large city or near an industrial complex, your AC mains voltage can be quite noisy. This AC-induced noise also enters your hifi-system and generates signals that are not on the recording you want to listen to.


A practical proof for the above statement is the variety of products that are available in order to improve the current that enters your hifi-system: All kinds of purifiers, filters, power conditioners, power cables are available just to clean the AC-current before it enters the hifi-system.


The following 10-sec. scope-shot shows you the voltage variation on the transformer secondary of a mains powered audio amplifier (no signal or load applied to amplifier):






As you see, there are some larger drops, but also take a look on the smaller ripples.


If you think your hifi-system sounds much better in the night-time, this is not necessarily related to the amount of beer or wine you drink, it can also depend on the AC-current that is naturally cleaner during night, since less electrical consumers are active.


But let's assume, you live in a remote region with only few electrical consumers and your AC is clean.


The 'clean' mains AC voltage (110 .. 250V) is reduced to lower voltages by a transformer. Since all hifi-gear needs direct current, the lowered AC voltage must be rectified. This is done by a couple of diodes which load a capacitor in a switching manner, that means when the capacitor voltage is lower than the tranformer voltage the diode is switched on, charging the capacitor. As soon as the voltage across the capacitor reaches the actual level of the transformer secondary voltage, the diode switches off.


Let's take a closer look. The following shots show the voltage across one diode of an audio amplifier's full bridge rectifier. The picture series features continuous magnification.


123


456


7



There is a spike, each time the diode shuts off. Pic #4 shows, that the spike is really a longer ringing.

Pic #5 and #6 measure the frequency of the shut-off ringing. It's about 40kHz. But you see that this is not all. There are spikes within the ringing. Pic #7 shows am even greater stretch. You see that much higher frequencies are involved, the spike is a second ringing at around 600kHz. These measurements are made with no signal applied to the amplifier and thus with low forward current. With the amplifier being loaded, the amplitude of the spikes and ringing is higher.

Do you think I'm counting peas ? This is the reason you eventually hear a mains hum from your speakers. Normally the feedback of the amplifier would zero out the switching spikes, but the frequency of the ringing is so high, that the amplifier is not able to eliminate it.

The distortion mechanism of switching diodes is very low in numbers. It is part of the total-harmonic-distortion figure of your amplifier, but even if your amp's distortion is 0,0001%, this kind of high-frequency burst distortion is not at all correlated to the music and thus you may well be able to hear it.

There are ways to lessen or change the effect of diode switching (i.e. placing a capacitor over the rectifier diodes, chosing fast recovery diodes, etc.) but in practice I have not encountered any AC powered amplifier without a certain level of mains hum.

Even if the mains hum is very low, it changes the sound character of the musical performance. It throws some kind of grain and aggression into the picture. This deteriorating effect is smaller with vacuum tube amplifiers that employ a rectifier-tube which does not generate high-frequency bursts.

However, there is a very effective way, we can completely eliminate the negative effects of AC induced noise and switching bursts:


Battery Power

If we were able to power our hifi-system with a battery, we would not only avoid the mains- and diode-switching-noise, we would also have a fast power source with a very low impedance. No need to employ large (and slow) electrolytic capacitors. No need for expensive power cords, no filters, purifiers or AC-conditioners required.

What makes a high-quality audio amplifier expensive ? It is the power supply.

In order to lessen the effects of AC noise and switching HF bursts while maintaining a low output impedance, sophisticated circuitry and expensive components are needed. And even then, the performance of an expensive hi-end amplifier may still be improved by certain power cords or expensive AC-conditioners.

Does that make sense ?

In any case, AC power may be convenient, but it makes our hifi-gear very expensive as soon as a - higher than standard - qualitiy is desired.

Even if we were willing to spend larger sums of money to buy expensive equipment, power cords, purifiers and power conditioners, the performance even of your average car battery in terms of current capacity, noise and speed is very difficult to match.

In other words, with the use of - just your old car battery -, audio equipment of high sound quality could be achieved with moderate cost.

BYOB - Bring Your Own Battery