UpTone JS-2 Power Supply Listening Impressions

[nbpf]

4 hours ago, Superdad said:

 

JS-2:

Choke-filtered

Power-factor corrected (virtually no harmonics kicked back into the wall)

Shotkky diodes

Shielded R-core transformer

Low output impedance

Pre- and post-regulator capacitance balanced for best dynamic recovery 

Two independently adjustable outputs (5, 7, 9, 12 volts)

5 amps at 5V, 6 amps at 7V, 8 amps at 9V, 7.2 amps at 12V (with 120/240V AC input; 12V capability drops to 6.3A with 115/230V and 5.95A with 110/220V AC)

Includes one 1.5m Oyaide/Belden 15AWG star-quad DC cable

Fine anodized Japanese enclosure with integrated heat-sinks

Weight: 11.2 pounds

Built, tested, and burn-in in the US.

3-year warranty

$925 plus shipping ($95 via insured FedEx Priority to most countries; $30-50 via insured 2-day Priority Mail within the USA)

In stock for immediate shipment.

 

All in all a great value and a good long term investment.  I think we have just passed the 400 units built milestone.  Only ever had one person return one--and that was because he had a phobia about "radiated emmisiins" from phones and power supplies (so why did he buy it in the fist place? )

 

Sonically most people say it creams every other LPS they have tried, save the Paul Haynes--where some say it is a toss up where others prefer Paul's fine unit (which they may have paid a good deal more for and had to wait an eternity to receive.).

Thanks, I have sent you a message through the "Contact Us" web form!

[nbpf]

Is the hot pin of the JS-2 plug the lower one or the upper one? Thanks, nbpf 

[nbpf]

1 minute ago, Superdad said:

 

Lower pin.  Standard IEC60320-C14 wiring.

Thanks!

[nbpf]

9 minutes ago, Superdad said:

 

Lower pin.  Standard IEC60320-C14 wiring.

Thus, that's the opposite of what depicted in http://www.hifi-advice.com/blog/audiophile-insights/cables-info/iec-connector-standards/, right?

[nbpf]

5 minutes ago, Superdad said:

 

No.  They are looking at the cable plug.  I am looking at the inlet itself.  It's the same.  Think about it. 

What shall I think about? If the phase is to be connected to the lower pin than it is not to be connected to the upper pin which is what one would expect from http://www.hifi-advice.com/blog/audiophile-insights/cables-info/iec-connector-standards/!

[nbpf]

10 minutes ago, mansr said:

A device that requires a specific orientation is faulty. In some cases, mixed orientations can cause hum, nothing more. If that happens, it's generally easy to find the culprit and flip it around.

As said, it is impossible to "flip it around" without also flipping around other devices if one used a hydra or a distribution block. In this case, all the IEC connectors will have the phase on the same pin. In this setup, flipping around individual connections would only be possible if the IEC connector was symmetric which is not the case. Of course, if one used a power strip with Schuko plugs instead of an hydra or distribution block, one can easily flip around individual connections. This is not the case with an hydra. Hence my question.

[nbpf]

9 hours ago, Superdad said:

 

You asked which pin of the JS-2's inlet is connected to the line (hot) side of the cord.  Our unit is wired according to standards.  If you look at an IEC65320-C14 inlet with the ground pin at the bottom, the HOT pin is always on the right.  But if you look face-on (as if it is a snake about to bite you) to the cord that will plug into that inlet, the HOT will be on the left.  

The page you are linking to is showing line-hot from the perspective of the end of the cord.

So they and I are saying the same thing! 

 

You are right and the two pictures are perfectly consistent with the hot pin being the one below. Thanks! 

[nbpf]

What is the recommended way of powering a DigiOne Signature using UpTone Audio devices?

 

1. Power both the dirty and the clean side of the Signature with the two outputs of a JS-2? Would this defeat galvanic isolation?

 

2) Power the clean side with a LPS-1.2 and the dirty side with no matter what PSU?

 

and finally:

 

3) The LPS-1.2 comes with a 36w PSU. I understand this is a standard SMPS. Is it advisable to connect it to the same hydra that powers the DAC or should it better be powered by another mains spur? Can in principle the JS-2 power a LPS-1.2 (I understand that this would be a rather meaningless waste of resources)? 

 

Sorry if these questions have already been raised in different forms and thanks for the attention! 

[nbpf]

2 hours ago, Superdad said:

 

For the benefit of all, I am going to give the long answer to this common question.

Rather uniquely among linear power supplies, we go to great lengths (hand-cutting/punching the electrically insulating high thermal coefficient pads we use for the regulators) to "float" the DC output "grounds" (-ve) of the JS-2. Why go to all the trouble of building a high-current, low-noise, low-output impedance power supply only to invite grunge back in from the AC mains ground of your house--especially since a lot of "power conditioners" dump noise into the ground connection.  (Of course we do ground the chassis and transformer to AC mains ground for safety.)

However, because the JS-2 uses just one set of Schottky diodes, and one large DC choke/inductor (one of the keys to our design), its two completely separately regulated outputs do share a common DC output -ve ("ground").

So yes, if you are powering two devices which are truly galvanically isolated from one another (e.g. a computer and the downstream side of an ISO REGEN, or the two sections of the DigiOne Signature in your case), using the two outputs of a JS-2 for both will defeat the galvanic isolation.

 

 

That will work very nicely, though I would still suggest avoiding an SMPS for the "dirty" computer module side of the Allo system.

 

 

I won't venture too deep into the misunderstandings of the evils of SMPS units (its the AC leakage to DC lines--blocked by our UltraCap supplies--and not the minor amount of very high frequency, spread-spectrum, extremely low amplitude noise they kick back into the AC mains; your wall is already much noisier that what a small SMPS contributes).  But it is general decent practice to plug the UltraCap "energizer"/charger brick directly into the wall and not into the output of whatever AC "power conditioner", filter, or isolation transformer you may have.

 

 

Not just in principle--in practice!  A JS-2 can (with AC mains of 120 or 240V) produce up to 7.2 amps at 12V, so it can easily charge at least a couple of UltraCap LPS-1.2 units (3 if one of the LPS-1.2s is always in low-charge-current mode, i.e. output load less that 0.5A). When given a choice, always use at least 12V to charge an UltraCap LPS-1.2 as less current will be drawn from the charger.

 

As for it being a waste of a lovely JS-2 output:  Yeah, there is that.  But if the second output is not otherwise being used it is reasonable use.  A number of people do that.

 

 

No problem at all!  Good info gets buried in old posts (I really should gather some of them together and update our FAQ pages), and you gave me an opportunity to expound a little on a few often asked about topics.  

Thanks for the clarifications. I guess a LPS-1.2 is probably the most straightforward way to get the best out of a DigiOne Signature and JS-2 + LPS-1.2 would be the deluxe solution!

[nbpf]

Today I received the JS-2 that I had ordered about two weeks ago. It was delivered in a perfect packaging. The build quality of the JS-2 is fantastic. It is now warming up powering a DigiOne Signature and a LPS-1.2. Thanks to Alex and the UpTone Audio crew!

[nbpf]

What are the tolerances in the output voltages of the JS-2 for 5V, 7V, 9V and 12V when the outputs are not under load? I measure 5.00V on the output of my ifi 5V/2.5A PSU but only 4.91V on the output of my JS-2. Is this normal? Thanks, nbpf  

[nbpf]

2 minutes ago, Superdad said:

 

Typically about 1-2%.

 

 

There is a good chance that your meter is a little off since most iFi iPower SMPS warts measure high under no-load (I just checked the 9V iPower I have here and with no load it outputs 9.3V). As I personally Q.C./test/burn-in every JS-2 we build, with a short cable I generally see 4.95-4.99V.

It does also depend upon where you are measuring it.  At the end of our supplied 1.5m 15awg there will have been a little drop.

 

More importantly than voltage under no-load is how well a PS holds up under not just typical loads but fast transient loads.  And the JS-2 excels there since the choke-filtered design (which feeds the regulators with a half-sine-wave and not a harmonics-ladden sawtooth as in conventional trans>diode>caps>regs>caps design) allows us to use rather small, low ESR caps after the regulators, keeping impedance low.

Thanks for the clarifications, I very much appreciated! 

 

I came to the idea of measuring the JS-2 voltage under no-load (and at the end of the supplied 1.5m 15awg) because I was experiencing under-voltage exceptions when powering a DigiOne Signature (DS). 

 

The exceptions were thrown no matter whether I was powering the DS with the JS-2 or with the 5V iPower and eventually turned out to be due to a poor assembly of the DS. Blame on me, they completely disappeared after I reassembled the DS.

 

It is a bit difficult to say who is the main culprit, but the DS sounds now gorgeous when powered by the JS-2 (dirty side) and by the LPS-1.2 (clean side). I guess I am settled with power supplies but I am going to try the JS-2 also on an old M2Tech hiFace Evo. Will it sound better than the DS? I do not think so but ... who knows?

 

Best,

nbpf

[nbpf]

I have been using a JS-2 to power the dirty side of an Allo DigiOne Signature and a LPS-1.2 (that in turn powers the clean side of the same Signature) since about one month. I am very pleased with the results. However, there is an issue that is puzzling me.

 

Last weekend I did some re-cabling and realized that the phase of the JS-2 is just the opposite than the phase of all my other components: the Naim DAC, the Supernait 2, the Oppo 203 all have the phase at the lower socket pin. On Naim cables, this is marked with L. The JS-2 phase is just on the opposite pin, the one marked with N on Naim cables.

 

If one has a power strip this is not a problem: one can turn the Schuko plug around and have all components connected consistently. But with a power distribution block or hydra, there is no way to adjust for one load with inverted phase.

 

Is there a special reason why the JS-2 has a different phase than all my other components?  I have measured the phase of nDAC, SN2, JS-2, etc. using an Oehlbach phaser: http://www.oehlbach.com/en/power/phaser.

 

Thanks, nbpf

[nbpf]

49 minutes ago, wanta911 said:

I'll let Alex answer but as far as I know the standard is to have the bottom pin (red arrow) live in the case of the JS-2 plug orientation. I would assume that's what it is?

 

 

 

 

Yes, that is what I would have expected but a phase detector clearly indicates the phase to be at the other (upper) pin, hence my surprise. For the SN2 and the Naim DAC, the same detector indicates the phase to be at the lower pin. The plug orientation is the same in these devices. 

[nbpf]

4 minutes ago, JohnSwenson said:

What do you mean by phase in this respect? There is a switch, a fuse then the two sides connect to the primary winding of the transformer. What does "phase" mean in this arrangement? Neither side is connected to anything else other than the primary of the transformer.

 

How does it matter which pin gets connected to which side of the primary winding? Neither side of the jack gets connected to safety ground.

 

Can you provide a schematic of what you mean by phase? That link provided gives no indication what it is actually measuring.

 

John S.

Thanks for replying! Unfortunately I cannot provide you a schematic of the Oehlbach device or a precise specification of what it measures.

 

The purpose of the device is to indicate which pin of an audio device should ideally be connected to the live pin of a Schuko female socket of a power strip. The idea is that, for optimal sound quality, all devices connected to a power strip should be connected consistently.

 

As reported, the device indicates the lower pin (the one marked with L on Naim cables) for SN2, nDAC and Teddy Pardo power supplies and the upper pin for the JS-2. Hence my question.

 

No matter what the Oehlbach device does measure or indicate: what is your advice? Shall one connect the lower pin of the JS-2 to the phase (live), the upper pin or it just doesn't matter?

 

Thanks, nbpf

 

[nbpf]

1 hour ago, Superdad said:

 

We did go over all this with you back in June (this and the 8 posts that follow it: https://www.computeraudiophile.com/forums/topic/20528-js-2-power-supply-installed/?do=findComment&comment=829340).

 

The JS-2 is wired to the IEC60320-C14 standard.

 

Not that any of this matters since the R-core transformer in the JS-2 is wired balanced on both the primary and secondary sides, and its DC outputs are “floated.”

(The chassis and the transformer are grounded for safety of course.)

 

So other than the fact that the fuse and switch are in-line only on one side of the AC mains line, the JS-2 is entirely symmetrical.

 

Thanks Alex! 

 

In June I had no JS-2 and thus my interest was pretty much theoretical. Now I have a JS-2 and I am planning to buy a distribution block. For this reason I have checked the polarity of all my components, included the JS-2.

 

With a distribution block, I will obviously not be able to ensure that each device is connected to the mains live through the pin indicated by the phase detector unless the detector indicates the same pin for all devices.

 

The JS-2 is currently the only device in my system for which the phase detector indicates that the upper pin should be connected to the mains live. For all other devices, it indicates the lower pin. Hence my question. 

 

I'm taking from your answer that it does not actually matter which pin of the JS-2 is connected to the mains live.  

[nbpf]

Just now, look&listen said:

No information on what magic tester try to detect.

No differences in JS-2 internal circuit, but switch & fuse.

So what to worry about ?

Maybe retry phase detector test with JS-2 power switch in On position, see if change  

I do not think there is anything magic with the Oehlbach device. It is just a device that attempts at detecting which pin of a device should be connected to the mains live, the idea being that in an audio system it could be beneficial if all devices were connected consistently.

   

I have tried the phase detector with the JS-2 power switch off and on and, in the latter case with and without connected loads. In all these three configurations the phase detector indicates the upper pin of the JS-2 as the one that should be connected to the live. As reported, the same detector indicates the lower pin for all my other devices. Hence my surprise.

 

I am not worried but considering the cost of a distribution block, I want to be sure that it does not actually matter which pin of the JS-2 is connected to the mains live.  

[nbpf]

I have just realized that it is about one year since I have bought a JS-2 and I feel it's time to say again thanks to the UpTone Audio team for making available such a great product! During the last year, I have used the JS-2 mainly to power an LPS-1.2 and an Allo DigiOne Signature and it has worked flawlessly. Meanwhile, the JS-2 has become an integral part of our living room. It has taken hold of a shelf below the Naim DAC and the SuperNait 2 and I enjoy its design and build quality every day.