AC Filtering, Grounding Boxes, Linear PSU and Balanced Power.

[YashN]

Great project! 

 

Thanks. I finished my ultracapacitor prototype today. Was checking out its initial charge and discharge behaviour with a multi-meter next to me while watching Sherlock's Episode 2 for this year's season - great episode, far better than last week's.

 

It have been some discussions regarding improved SQ with short DC to DC hard adapters.This would also apply to USB to USB power cable. A hard USB to USB DC adapter might just improve that SQ further.

 

Yes, that works: the nearer the load (i.e. the device being powered) to the regulator's (or your other means of powering if you don't like regs) output, the better.

 

This can be mitigated to a large extent with the implementation of true remote or Kelvin sensing though, so that then you're not at the mercy of the length of the connector (hard or wire) that much.

 

However, I have come to the conclusion that the very USB connector design itself is damaging to SQ for async USB real-time audio streaming, this even more so as we use higher-frequencies of data transfer.

 

Ideally, I would have liked the DAC manufacturer not to include or allow the power lines connections or pins within the connector which takes the Data lines, and have a separate, ideally orthogonal power-only port. I don't know how much of that is possible while keeping impedance requirements standard, but that's globally how it should be IMO.

 

So, for all DACs with a single USB power jack, we're still putting patches on pimples without curing the inner disease though...

 

If you've got any pictures it would be very interesting to see them as well!

 

I had some and some more planned, my Macbook Pro's power supply has been misbehaving. I tried repairing it, and it would have been rather easy to do if only the +ve and GND/return wires were disconnected. But in my case, it's worse than that: the 5 small pins soldered to the tiny PCB in the computer-side plug broke off. I tried re-soldering them with various techniques, but this is much too small in terms of scale a job to do with my soldering iron. These are tiny connections, so soldering one wire can easily bridge to the adjacent one. The sense pin for the 1-wire protocol communication is really, really tiny and gets bridged all the time. So, I've had to order a whole new jack with wire. It's coming from Asia, but it supposedly going to be slow to reach here in Canada. After this I'll be able to post pics more easily.

[Middy]

a soldering cheat with 2 big an iron for fine work is flood the pins and bridge but then carefully wick off with solder wick and a tiny amount of flux..Don't linger to long with the iron.

wrap the wick around the tip.. Use needle pliers to keep the wick taught...

hope that helps mate..

 

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[Cornan]

Clearly, you have misunderstood, so let me clarify:

 

We were talking about your recommendation about never using a regulator after a battery.

 

I said that you can make mistakes when using a battery followed by a regulator and this can give you the wrong impression about this configuration.

 

Here is a more detailed example:

 

Your DAC needs 5V. So you want to power it with a battery and a regulator.

 

Imagine you choose the LM317 as regulator, as I did for my DIY Linear Regulated PSU.

 

If you put a 5V battery in front of the regulator, and think you can get good, stable, regulated, in short bettter sound from the battery + regulator to the DAC, you won't.

 

What you need to know here is the that the regulator will drop out some voltage for it to be able to work on the regulated output in a stable manner.

 

For the LM317, it is said to work best when there's at least 2.5V - 3.5V to drop.

 

This means, that if you want the regulator to be able to supply a low-ripple, stable, you actually need to feed the regulator a rather stable (5V + 2.5V) or up to a (5V + 3.5V).

 

That is, the supply to the regulator, or in this case, the battery, must be from 7.5V - 8.5V for this configuration to work well and get better, regulated sound.

 

So, in case you have tried a battery with a regulator, and haven't paid attention to the drop-out and necessary buffer to consider powering the regulator, you may have been powering the device out-of-regulation.

 

What that means is that the device can still work (as it may be receiving around 5V but with ripple and noise), but the SQ will not be as good as expected, it can actually be bad if you compare it straight to the 5V battery.

 

So, if you made the mistake of voltage starving the regulator itself because the initial battery voltage was too low, then you could also make the mistake of thinking batteries can't be followed by regulators to get better SQ...

 

This should help make things clearer.

 

I did understand you in the first post, but thanks for a more detailed description how the voltage regulator works.

 

I can only speak from my own experiance and according to it a unregulated battery is usually the best option since you remove one voltage regulator. Voltage regulators (even linear ones) makes noises and two of them makes even more noise. However, this highly depends on choosing the correct voltage and mAh rating for the unregulated battery.

 

In my experiences a unregulated battery sound best when its voltage range is above the nominal voltage. It should actually never come down to the nominal voltage during a listening session which requires that you select the battery pack wisely.

To give an example I power my Aries Mini with a 14,8v/12000mAh/6A Li-ion battery pack. The Mini requires 14v (1,2A) - 18v (1A). Not more. Not less. My battery pack is 16,8v fully charged and outputs 6A. With 12000mAh it will take roughly 6-7 hours of active listening for the voltage to come down to 15,4v. I never want to come down to 14,8v for the best result IME.

 

Now, I am not saying that unregulated battery is always the answer. It highly depends on how you choose the specs and in some cases it is absolutely necessary to keep the voltage constant by using linear voltage regulators which AFAIK should be high quality and close to the powered source (ie. external) to sound best.

 

As always it is best to try both. With my coming FMCs (MC100CM) I will try both unregulated (7,4-8,4v) and regulated (5v) battery supplies. I suspect that the FMCs will sound better with a low voltage than with a higher voltage...but I intend to find out the truth in my own setup.

 

YMMV ofcourse.

 

 

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[Cornan]

Here again, no! There is not 'something to it' - not in the usual charging a battery with an SMPS vs charging a battery with an LRP. You shouldn't have any difference at all. I would be very surprised if you did.

 

If somehow there are still effects related to Leakage Currents in your setup and if you're keeping the chargers connected at all times (which you said you aren't doing), then there could be some differences, but it won't have to do with the battery power itself (assuming the same battery in both cases), but more with the Leakage Current interactions of each charger power supply and other power supplies in the chain.

 

Let's leave it at that.

Ok, we leave it. I am not expecting a revolution...but I intend to experiment if a clean charging power could change the SQ of a battery disconnected from AC mains.

 

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[Cornan]

a soldering cheat with 2 big an iron for fine work is flood the pins and bridge but then carefully wick off with solder wick and a tiny amount of flux..Don't linger to long with the iron.

wrap the wick around the tip.. Use needle pliers to keep the wick taught...

hope that helps mate..

 

Sent from my SM-G900F using Computer Audiophile mobile app

Thanks Middy! ?

 

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[YashN]

I can only speak from my own experiance and according to it a unregulated battery is usually the best option since you remove one voltage regulator. Voltage regulators (even linear ones) makes noises and two of them makes even more noise.

 

Not true in all cases:

 

- If you build the circuit properly, two regulators can give you a new, much better circuit in terms of ripple rejection.

 

- Some batteries under load can have their noise profile raised a lot more than one or two regulators

 

However, this highly depends on choosing the correct voltage and mAh rating for the unregulated battery.

I'd say it doesn't depend on that: that is something you always do, no matter if battery or mains, or LRP - rather it depends on the noise profile under load and also whether you're using a proper cap with it, not a proper cap with it, or in a no-cap config.

It highly depends on how you choose the specs and in some cases it is absolutely necessary to keep the voltage constant by using linear voltage regulators which AFAIK should be high quality and close to the powered source (ie. external) to sound best.

 

Bears repeating here: proper use of the regulator necessitates you feed it with your final load's operating voltage but also, the additional drop-out buffer voltage to the regulator itself so that it remains in the optimal regulation mode.

 

If you're not doing that in a battery + Reg config, you're probably getting bad SQ and concluding the wrong thing.

As always it is best to try both. With my coming FMCs (MC100CM) I will try both unregulated (7,4-8,4v) and regulated (5v) battery supplies. I suspect that the FMCs will sound better with a low voltage than with a higher voltage...but I intend to find out the truth in my own setup.

 

Worth experimenting. I believe I gave some thoughts in another thread: it will depend a lot of how you do it, whether the FMC has internal regulators or switching circuits, etc...

 

Low-power to the FMC may create less noise/EMI/RFI, but too low a power may put it in out-of-regulation mode (we're considering the internal regulators here, not anything external), creating more non-linearities and damaging SQ. So, must be checked on a case by case basis, maybe the manufacturer can help with optimal values. You generally do not want a device operating out-of-regulation though despite it probably working even at the lower voltage.

 

The best thing would probably replace all internal regulators by battery or really good linear regulated PSU rails.

[YashN]

Ok, we leave it. I am not expecting a revolution...but I intend to experiment if a clean charging power could change the SQ of a battery disconnected from AC mains.

 

Indeed, never let anyone stop you from investigating yourself.

I don't expect any with our usual means of power though (we're assuming here that the charger itself is disconnected from mains after having charged, otherwise other noises through the AC mains and RFI/EMI would also come into play).

[YashN]

I have been experimenting a lot with the LM317 and concomitant circuits around it.

 

It has a variety of behaviours when it comes to output impedance in these circuits (simulated, not measured unless you count the first few listening session in between layout and sense line changes as valuable too), many of which show peaks and troughs and sometimes, depending on what elements you had in the circuit and where, more chaotic lines reminiscent of Picasso's sketches than what you would expect.

 

For a line-level audiophile PSU, it becomes quite convoluted to simultaneously reach great-sounding targets of PSSR, low noise floor, low output impedance for a wide-bandwidth, etc...

 

This internal schematic should give you an idea of what we're dealing with:

 

 

This, coupled with some sim + build experiments, should bring to mind a few things simultaneously:

 

- Complexity, Non-Linearity, Chaotic behaviour

 

- An off-the-shelf chip may have been designed with other uses in mind rather than our purpose (audiophilia), as such, some foibles may never be completely cleared out in practice

 

- Taking the datasheet recommendations for our purposes doesn't even begin to bring you close to solving the issues with some of these chips (not all fortunately).

 

- Building a discrete, low-part circuit to reach our goals is probably the better option here - as simple as needed to get the job done (regulation, low-output impedance over the important bandwidth, rapidity of transients, recovery, noise floor, ...) but no simpler, and never at the detriment of overall SQ

 

 

I wouldn't recommend the LM317 for audio, but as mentioned earlier, as a learning platform, it's good, probably one of the best things you could do: here, the weaknesses are a path to learn some deeper things in Electronic Design and audiophilia.

 

My LM317 will probably be relegated in the end to Lab PSU duties where it belongs more than in an audiophile LRP...

[Cornan]

Just finished one of my 100Base-TX (pin 1/2 & 3/6 on a distance) Ethernet cable with silver wires.

 

 

Now I just have to make another one between the router and uphill FMC. TP-Link 6800mAh 5v regulated battery packs have arrived. Just waiting for the unregulated battery pack and a delayed DIGITUS OM4 fiber cable to get this experiment going! Bummer, I'll need to keep calm! ?

 

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[YashN]

Just finished one of my 100Base-TX (pin 1/2 & 3/6 on a distance) Ethernet cable with silver wires.

[ATTACH]32303[/ATTACH]

Cool, looking forward to your listening impressions and A/B comparison with a normal off-the-shelf Ethernet cable.

[Cornan]

Cool, looking forward to your listening impressions and A/B comparison with a normal off-the-shelf Ethernet cable.

I will report back with impressions regarding several comparisons:

 

1. FMCs vs great AC Wireless

2. MC100CM powered by two regulated battery packs (uphill & downhill) vs downhill powered by unregulated battery & uphill powered by regulated battery.

3. DIY 100Base-TX Ethernet cable vs Cat7 Ethernet cables with plugs covered with electrical tape.

4. Router external grounding impressions.

 

I am also planning to get a linear regulated lab PSU (Peaktech) for my router...but that plan is postponed due to other more important things.

 

Here is a couple of pictures with the DIY cable installed...just missing that darn 10m DIGITUS fiber cable. It is still early morning here in Sweden so the mobile pictures is'nt all that great, but hopefully enough to get a picture! ?

 

 

 

 

 

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[Solid-State]

This is the best regulator on the market now

great for DAC

 

0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK

[YashN]

2. MC100CM powered by two regulated battery packs (uphill & downhill) vs downhill powered by unregulated battery & uphill powered by regulated battery.

 

If it's not too much, could you also please add:

 

2(b) Upstream MC100CM powered by battery, Downstream by Linear Regulated PSU?

 

What is the regulator in your 'regulated battery' device?

[YashN]

The end of Tinker, Tailor, Soldier, Spy has a great song from a young Julio:

 

[Middy]

Best film I have seen for years.

put a 'smiley ' on my face ?

 

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[YashN]

This is the best regulator on the market now

great for DAC

 

0.8uV Ultralow noise DAC power supply regulator 3.3/5/7V 1.5A*x2 - DIYINHK

 

Quite good as a drop-in for a test, but without knowing the actual output impedance plot, there's a fair chance one could build a better circuit with the chip.

 

This is also not the optimal way for audiophile purposes:

 

4)The PCB follows the official demo circuit for ultimate performance.

 

The ultimate performance parameters in the datasheet rarely have to do with audiophile playback.

 

They do mention these cousins in the applications section of the datasheet though:

 

- VCOs

 

- Mixers

[YashN]

Best film I have seen for years.

put a 'smiley ' on my face 

 

Did you know that the real life events the story was based on included someone who blew "Le Carré's" cover, thereby forcing him into retirement prematurely?

[Solid-State]

HIFI LT3042 Voltage regulation external Power Supply 5V for USB in DAC Low-noise | eBay

 

 

http://cds.linear.com/docs/en/datasheet/3042fa.pdf

[Middy]

Did you know that the real life events the story was based on included someone who blew "Le Carré's" cover, thereby forcing him into retirement prematurely?

Lucky for us he did ? I didn't know that. Even the wife like the film. Some heavy hitting actors in the film I am glad they did a good job redoing it from the Alec Guinness version.

 

 

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[Cornan]

If it's not too much, could you also please add:

 

2(b) Upstream MC100CM powered by battery, Downstream by Linear Regulated PSU?

 

What is the regulator in your 'regulated battery' device?

 

The TP-Link 6700 mAh http://www.tp-link.se/products/details/cat-5689_TL-PBG6700.html have most likely a cheap voltage regulator...but I will try with my Kingrex uPower as well which have a linear regulated 5v output.

 

 

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[Cornan]

I just made a simple grounding cable between my Entreq Minimus to my router using the thin 22 awg silver wire and screw terminal RJ45 plug. Both pin 4 &5 is GND...but I just added the wire to pin 4 in my initial experiment.

 

 

Wow! Yippie! That was by far the best place for my Minimus since I went the isolated & unshielded path. Just about everything became more dynamic and alive. The whole frequency range actually. More "omph" and "presence"!

Conclution. I will add another wire to pin 5 on my RJ45, twist the wires and leave it there for good! ?

 

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[Cornan]

HIFI LT3042 Voltage regulation external Power Supply 5V for USB in DAC Low-noise | eBay

 

 

http://cds.linear.com/docs/en/datasheet/3042fa.pdf

Thanks TubeMan!

Saved this one as a plausible candidate. Otherwise, I have almost descided to give this linear voltage regulator a try which looks very good and valuable to these eyes http://www.ebay.com.au/itm/Ultra-low-Noise-40-V-Adjustable-Voltage-Regulator-Module-1-25-20V-1-5-Amp-/371189087840?hash=item566c97fe60 ?

 

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[lmitche]

I have three of these. They are very good, not great, but good. Voltage adjustment is a bit wobbly. They are low drop devices which is nice.

[Cornan]

I have three of these. They are very good, not great, but good. Voltage adjustment is a bit wobbly. They are low drop devices which is nice.

Thanks Imitche! ?

Do you have a recommendation of a really great linear voltage regulator suitable for unregulated batteries? I am thinking of adding two great regulators in small aluminium boxes with two DC2.1 sockets (input & output) to add close to the uphill/downhill FMCs (with DC output close enough for a DC to DC coupler)

 

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[Cornan]

I just finished off my other 100Base-TX cable plus a twisted silver wire for my router (pin 4&5) with a slightly better screwless RJ45 plug which gave another great SQ bump.

Just got word that my DIGITUS OM4 cable have been shipped...so not too far until I can evaluate it all! ?

 

Listening to Justice album "Woman" and enjoying myself!

 

 

 

A really great album! ?

 

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