Installed the UpTone JS-2 LPS Today WOW!

[Superdad]

What are the specs? How many rails?

Price?

 

UPTONE AUDIO JS-2 DUAL-OUTPUT, CHOKE-FILTERED LINEAR POWER SUPPLY

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* Dimensions--9.0 inches wide x 9.1 inches deep x 3.3" tall (with feet).

 

* Weight--10.5 pounds; 14 pounds in its full double-box shipping cartons (shipping dimensions 14"x14"x9").

 

* Line operating voltage--100V to 240V, user selectable from the outside (you flip over the fuse holder and change the fuse amperage; it ships set, and with the right fuse, for whatever country you reside in).

 

* Included AC power cord--Volex 2 meter, 16AWG, shielded cord (USA mains plug, but you can cut and attached an appropriate local plug; it is a good heavy and shielded cord, so adapting it is worthwhile).

 

* Included DC power cable--

5-foot, shielded, star-quad; 4 conductors of tinned, stranded 18AWG; paired at the connector that makes it about a heavy 15AWG. Gold/copper/brass Oyaide 5.5mm x 2.5mm DC barrel plugs at both ends (Upon request I can terminate one end with a 2.1mm version of the Oyaide connector in case you need that size at the device end). The difference this cable makes (mostly in the bass)--versus a 2m 18AWG shielded sample I had on hand--was a minor surprise.

Although the JS-2 has two separate DC output jacks, I can only afford to include one of these custom cables in the base price of the supply (plus each one takes time to make--and I dislike soldering cables). I also sell this unique cable separately for $45--only to JS-2 buyers.

(I also offer for $10, a nice factory-made, 1-meter, 16AWG shielded cable with DC 5.5mm x 2.5mm jacks, so I think only the first 100 JS-2 units will come with my custom cable. After that we will include two of these pre-made cables and just offer the fancy one as an upgrade.

(Here is a link to a site that sells a nice assortment of adaptors to go from 5.5mm x 2.5mm plugs to other sizes: C Series Connector)

 

* Construction--

All stainless steel hardware; High quality, carefully specified circuit parts and electromechanical items. Low intensity amber front panel power-on LED. Individually assembled and tested. Four-year, no questions asked warranty (excludes shipping costs after 90 days).

 

* JS-2 supply specs--

Two independently adjustable, separately regulated outputs; Voltage choices are user set from the back panel: 5V, 7V, 9V, or 12V.

Guaranteed current capability is 5 amps continuous at any voltage setting.

 

The unit has ample reserves and can deliver instantaneous current of about 10 amps. Even a variety of attached devices won't draw much continuous amperage (my i7 Mac mini idles at 0.8A and peaks at start up and during heavy processing at barely 3A). The JS-2 outputs are thermally protected, and each one has a "fault" light next to it (all that happens if you exceed the continuous current capability of the supply is the light comes on and the output voltage sags a little until the regulator cools a bit).

 

Since the supply has two outputs, people ask how much total load they can put on it. In other words, since either output can deliver 5A continuous, does that mean you could in theory plug a full 5A into both outputs and get 10 amps out of the supply? No, it does not, because the power transformer and inductor are not rated for that. So the guideline is: any voltage combination, and any amperage combination that does not draw much more than 5-6 amps total between the two (We have run a steady 5V/3.4A from both outputs simultaneously for one hour, so that's 6.8 amps--yes the unit got hot! And at the 7V or 9V setting the JS-2 can run continuous at over 7 amps! But at 5V or 12V the max will be 5A). In real world usage you really won't have to worry about any of this. A music server computer on one output at 12V and whatever variety of DAC, headphone amp, or hard drives, etc. you want to load up on a single voltage on the other output will work fine. Just use common sense. (But don't go by the ratings of the wall warts and SMPS bricks you are replacing as those are often over-speced to stay cool.)

 

* Unique features--

Large DC choke (inductor) filtering is really the heart of the design, so I'll let John Swenson explain its benefits succinctly:

"The traditional cap only filter (transformer, diode bridge, big cap) produces raw DC with a sawtooth riding on top. That sawtooth produces lots of high frequency components that the regulator has to deal with. Traditional regulators do very well at low frequencies, but have lousy characteristics at high frequencies which means a fair amount of those high frequency components from the cap-only filter get through to the regulator. Fancy discrete regulators do well at blocking the high frequency components, but add cost and complexity to a PS. My approach is to use a properly designed choke-based supply whose ripple is a perfect sine wave, no high frequency components, thus a traditional regulator works very well. The discrete regulator is not needed to deal with the high frequency components, since there aren't any."

 

One output has what we are calling a pseudo-Kelvin-sense line. Basically, when the little slide switch is set towards the SENSE line's SMA connector jack, the JS-2 ignores what voltage that jack's blue rotary switch is set for, and it gets the voltage set by a pair of resistors at the far end of the SMA cable (A 5-foot thin coax cable made with male-to-male SMA plugs comes with the JS-2). What this feedback circuit does is not only compensate for the resistance and voltage drop in the DC power cable, but also assures that the voltage at the device responds instantaneously to sharp current demands. This really works, and I can hear the effect with the Mac mini DC board with sense resistors on it (The mini takes 12V, same as one of the regular switch settings; so if I flick the sense switch quickly, the computer does not hiccup and we can compare the effect of the Kelvin sense circuit.) Is the beneficial effect as big as our choice to use an R-core transformer or what you hear from good computer OS optimizations? No, not really. But we built it in anyway, and I bet if someone wanted to put the JS-2 10 feet away from the computer, then the sense line would really shine.

Besides, this circuit also allows for an infinite choice of voltage setting from DC Output #2--well any voltage from 1.25V up to about 14V. The intention, aside from including the sense jack and resistors on the optional Mac mini DC-conversion/Linear Fan Controller Kit, is to offer little 1-inch 'Sense Cubes' to be used with other computers, small DACs, headphone amps, etc. These will have a female DC jack and female SMA jack on the side, and either a DC plug or jack (undecided) on the other side as output. Inside will be a tiny board with resistors to set the voltage.

 

* Custom, electrostatically shielded 100VA R-core transformer--

This was a costly design choice, but a really good one. Just powering the computer, the difference--between the R-core and a toroidal transformer in the bass was shocking. And in comparisons powering a DAC or other audio-signal-handling component, the sonic benefits ranged top-to-bottom, cymbals and piano to deep bass. Plus R-core transformers, due to the gapless construction of the core, are dead quiet.

 

* Price--

JS-2 with power cord, 1 custom DC cable, 1 SMA coax cable, US$925 plus insured shipping anywhere in the world (US Postal Priority Mail or custom quoted FedEx "Great Rates"--to some countries a cheap as postal service, but faster).

[Superdad]

Would you supply the end user with the parts list? I love soldering whenever I can to pay for my Metcal solder station I had to have. :-)

 

Well my cable is just a pair of Oyaide DC2.5G plugs (nicely made and the only ones possbible to use for the large gauge wire I use), and the Belden 9418 shielded, star-quad cable I chose.

What makes it tricky is that pairing up the 18awg conductors (red/black, green/white is proper for this one) results in about a 14.7awg conductor. And for the ground side, I tie the shield at one end (left side of the printing, connect to the PS for those that have my cable already), so that is even bigger. Add in how closely stripped these all have to be to use the strain relief band and fit into the plug shell, and the fact that the wire insulation is not high-temp rated, and I can promise that first attempts will not be pretty.

 

I buy the Belden cable a few hundred feet at a time, and I import the Oyaide plugs from Japan. Buy that stuff by the foot or the piece and you will pay more than I am charging for the complete cable. Then again, I am not presently offering the cable to anyone but JS-2 buyers, nor am I reselling the raw wire or plugs (the latter would be a violation of my agreement with Oyaide as they have a USA importer for retail channels).

[Superdad]

I have a single JS2 setup with the following equipment:

- from a single jack on 12v I power a Nuforce Icon HDP and an Alix board running voyage Mpd

- from a single jack on 5v I power both a Raspberry Pi and an SSD. The Pi acts as my NAS (just activated samba on Raspbian)

I have a Schitt Wyred between the Alix board and the Nuforce. Found it improves the SQ.

 

Now I am just waiting for the Regen, which I also plan to power from the JS2

 

Am very happy with that setup. Sounds pretty damn good.

 

Wow Stephane, you are certainly making good use of the JS-2 powering all those devices! That's great as it is exactly what we intended.

Thanks and regards,

--Alex C.

 

P.S. Our "USB Regen" device is heading into production very soon. Now just a matter of getting the PCBs and the customized enclosures delivered from the vendors. Hopefully less than a month. Discussion of that product is ongoing over in this thread: http://www.computeraudiophile.com/f10-music-servers/uptone-audio-regen-22803/

[Superdad]

if used with a sb touch, does it come with the appropriate plug for the touch?

thanks,

drmike

 

Indeed it does. I just verified that the SB3 and SB Touch both use a 5.5mm x 2.5mm DC barrel connector, and that is the exact size of the plugs on the custom cable we ship with the JS-2. (Though I also stock the 5.5mm x 2.1mm size of the Oyaide barrel plug for those that need it, and I occasionally will make a custom configured cable for a JS-2 owner.)

[Superdad]

How would I connect a JS-2 to my DAC using a dual-headed USB cable?

 

Using this $9 adapter: USB A Female to 5.5x2.5mm Male DC Power Cable

[Superdad]

If I may ask, why would one prefer this over, let's say, for example, an HDPlex LPS at three times the cost? I assume very few have tried both, so I guess I'm looking for a specs comparison at this point.

 

Hi:

Sorry to be slow in reply to your question. There is no doubt that the HDPlex is a fine unit and a fantastic bargain at its price. It is astounding what they can build things for over in China. The truth is, my total parts cost (including the cables and packing) for the JS-2 is a few dollars more than the retail price of the HQPlex. That does not include any of my 5 hours labor and testing, the $50 per I give John Swenson as royalty on his design, or the 3-4% PayPal charge I absorb.

 

As for the performance and features of the JS-2 itself, there are some significant differences--aside from the flexibility of user-adjustable output voltages and 5A capability at all voltages. While I will avoid criticizing the bargain HDPlex, I can't say positive things about their choice to use $1 bridge rectifiers, but I applaud their use of an R-core transformer (just as we do; through we have ours shielded, and 25% of my R-core cost is in shipping the darn things over from China).

 

Maximum and peak current ratings are no problem, and our units are rather close in that regard. But when one talks about measurements (as I think SandyK was bugging me for over in the other JS-2 review thread), that becomes VERY problematic because a single figure for noise/ripple is a pretty meaningless measurement.

 

First off, unlike an SMPS, a properly designed linear power supply should have basically zero ripple--certainly not at line frequency and not at any particular frequency. All that should be measurable is residual noise. But over what bandwidth? From 0Hz to 100KHz? Or up to 500KHz or several megahertz? And is that under a continuos or varying load?

So not only is comparing a single number between manufacturers meaningless because it depends on the the range and the nature of the load, but actually performing the measurements is difficult simply because the ambient environment (fluorescent lights, other gear, etc.) will creep into sensitive test equipment. Heck, take you cheap multimeter and wave its leads around any gear and you will get a dozen millivolts reading.

 

So the only way to fairly compare noise measurements between two power supplies is to have them side by side and use the exact gear, the exact bandwidth, load etc. And still, I'd rather look at the noise spectrum on an analyzer than distill it down to one pointless number.

 

All that said, what really makes for a great LPS in audio are several things other than noise/ripple. Response to transient loads being number one; rejection of line noise and not putting crap back into the line being two next factors.

 

 

Here are some clear explanations from John Swenson regarding the technical design of the JS-2 in comparison to other approaches:

JS on choke (DC inductor) PS:

"The traditional cap only filter (transformer, diode bridge, big cap) produces raw DC with a sawtooth riding on top. That sawtooth produces lots of high frequency components that the regulator has to deal with. Traditional regulators do very well at low frequencies, but have lousy characteristics at high frequencies which means a fair amount of those high frequency components from the cap-only filter get through to the regulator. Fancy discrete regulators do well at blocking the high frequency components, but add cost and complexity to a PS. My approach is to use a properly designed choke-based supply whose ripple is a perfect sine wave, no high frequency components, thus a traditional regulator works very well. The discrete regulator is not needed to deal with the high frequency components, since there aren't any."

 

JS on diodes:

"All diode types except Schottkys emit a burst of ultrasonic noise as they turn off. This noise can go forward into the load circuit AND it can go back into the AC line, and it can also excite the transformer resonance.

The "slow" diodes still have this ultrasonic noise. Schottkys are the only type which do not have this noise.

Schottkys also usually have about half the voltage drop of other diode types and are usually faster.

Which type to use depends a lot on what your supply looks like and what you are trying to optimize for.

With a traditional low voltage design with a large cap right after a bridge you get large current spikes, these produce a large amount of high frequency noise which needs to be filtered by what comes after the cap. In this type of circuit the slow diodes can help cut down on the extent of the high frequencies generated by the sharp high current pulse. BUT they still generate the ultrasonic noise.

 

This is another reason why I like to use the choke-based design. With the choke there is no steep high current pulse, so no disadvantage to Schottky diodes. You get the advantage of no ultrasonic noise, lower voltage drop (so lower power consumption in the diode) and no big massive current pulses."

 

And finally, JS on speed:

"The filters I design also have very fast recovery time. A traditional C-only filter has a fairly slow recovery time. With the C-only if the load presents a large current change (let's say your computer starts taking 3A instead of 1A, then goes back to 1A after a short time). With the C-only filter the voltage across the cap goes down quickly and takes a long time to get back up to the original level. With the choke based supply charge can come from both the cap AND the magnetic field stored in the choke. The result is that the voltage drop is less AND it recovers to the original level 10-20 times faster than the C-only filter. In my designs I carefully tune the filter to provide a considerably lower drop and the much faster recovery time.

 

The result is that the raw voltage presented to the regulator is much easier to work with for the regulator. But shouldn't the regulator make that irrelevant? The problem with the slow response time is that frequently that 2A current spike is not a lone event, there might be a bunch of them in a row. With the slow response the cap can get into a situation where it doesn't recover in time for the next event, and the raw voltage descends rapidly to the point that the regulator temporarily goes out of regulation. With the fast recovery time that is much less likely to happen.

 

This is actually very important for low voltage high current supplies. With any regulated supply the higher the raw voltage is above the regulated voltage the more heat you have to dissipate in the heatsinks. So the tendency is to run the raw voltage fairly close to the output voltage, which means margin for these sorts of short term current spikes is fairly small."

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[Superdad]

Hi everyone. JS-2 continue to move as fast as we can build them (which admittedly isn't very fast, about 15 every three weeks), and sometimes a batch has so many going to one country that I scratch my head and wonder what is going on.

Last month it was France, but this month 7 of the 10 international bound units (see below pic of international; the 5 domestic units of the batch left yesterday) are heading down under--6 to Australia and 1 to New Zealand.

 

Another popular destination is Singapore. And one of these today is headed to the Czech Republic (even the heavily discounted FedEx "Great Rate" program we use could not keep the freight on that one from breaking $200; Most every other country we just charge $95 for super-fast, insured FedEx Priority).

 

Hard work but good times. Thanks all…

 

--Alex C.

 

[Superdad]

Would it be possible to ask where the JS-2 would stand in comparison to the new 'mystery' PSU if say I was looking to power 2 low power devices (DAC and MicroRendu)? I know that details are forthcoming about the 'mystery' PSU but is the JS-2 still meant to be king of the hill? Sorry if I'm jumping ahead with this question (again, in regards to info about the mystery unit).

 

Well the new supply will be just 1A at 3.3v, 5V, or 7V (user switch-selectable of course), so while it will be wonderful with the microRendu, the REGEN, Squeezebox Touch, SSDs, and small DACs, you would likely need one for each device. What DAC are you looking to power?

 

The JS-2 can output continuous 5A @5V and 7A @12V--or combinations in between when using both of its outputs, so it really is a different and more powerful beast.

 

My partner John Swenson shared--at the bottom of the JS-2 web page--some details regarding the technical design of the JS-2 in comparison to other approaches. (JS-2 Linear Power Supply – UpTone Audio)

 

In addition to those, and aside from the feature differences such as user-selectable output and mains voltages, quiet R-core transformer, and beautiful casework and highest quality cable and packing system, I would like to point out a couple of VERY important and entirely unique aspects to the design which I often forget to mention and which prove that there are NO linear power supplies on the market which are similar in circuit function to the JS-2.

 

Our choke-filtered design has many advantages--and the results are measurable and audible.

1) The JS-2's DC output ground is entirely isolated from the AC mains and chassis ground (though our transformer and chassis are grounded to the AC mains for safety). With any other LPS, if you put a continuity meter to the DC output ground and the mains wall ground you will get a "beep." So other supplies are giving a path for noise--and for ground loops. We go to a lot of trouble to isolate the output ground.

 

2) All other power supplies in this market--both SMPS and LPS--kick noise spikes back into the AC mains. Yes, LPS units do it to as their diode bridges are not conducting over the entire AC waveform (only about 50% of time), so they put harmonics back into the line. With the JS-2's choke-filtered design, we are drawing current from the entire waveform (98%). Thus we are the ONLY POWER FACTOR CORRECTED LINEAR POWER SUPPLY ON THE MARKET. Thus we do not kick ANY harmonics back into the AC mains. This is a very big deal.

 

 

Coming back to your question about the JS-2 versus our small but radical forthcoming new supply: If you meant which one will sound better with a microRendu or a small DAC, then I'll have to get back to you on that as we have neither finished measurement benchmarks nor done a fair comparison between them under real world conditions.

[Superdad]

I have always been tempted to take the plunge on the JS-2 but it really isn't worth it unless I can power my Aries with it. I know jtwrace uses the JS-2 for his Aries but I was wondering if there were other impressions using the 12V in lieu of the 15/16V spec.

 

We have lots of Aries owners using a JS-2. Mr. Wang of Auralic himself blessed the use of a 12V supply. As is typical, he said that at 12V you just need a little more current capability from the supply.

That's why lots of laptops and other devices specify higher voltages: So the outboard PS units don't have to be as beefy or costly. There is no chips in any of this gear that uses even 12V. It all gets dropped down with regulators (linear ones if you are lucky) to 5V, 3.3V, 1.2V.

 

The robust JS-2 just laughs at the sort of loads most people throw at it with streamers and DACs. It is only when you get into full blown CAPS (computer audio music servers) with a bunch of drives do you then need to more carefully assess current demand. I routinely test JS-2 units on the bench at 7.4 amps(!)/12V. Barely gets warm as not much is dissipated/wasted. The cooker is continuos 5 amps at 5 volts--an hour at that is the burn-in routine!

[Superdad]

Hello. I have an Aries Mini these days so it is not a suitable candidate for the JS-2 which is unfortunate as I would love to try it with it. Jason is as far as I know the only one using it with the higher end Aries, though perhaps there are others. Given Jason replaced the linear power supply that came with the Aries with the JS-2 that is telling. Though perhaps he had other reasons as well.

 

Hi Barr:

 

Your JS-2 will power your Aries Mini just fine. Try it and see!

 

Best,

 

ALEX

[Superdad]

Alex - where are you guys on the JS2 production schedule? Is the lead time currently long for new orders?

 

Saw your e-mail from this morning about this. Just doing too many things at once today (I hate tax time!).

 

As you saw above, we just shipped a batch of 15 this week. But my assistant is already well into the next batch. Have not set an official date yet, but March 30th should be easy. Maybe sooner. Only about half of this reduced-size batch of 11 (all I have left of boards and chassis for the next 5-6 weeks) are already spoken for.

 

So jump on in, production is fine and so are these sweet power supplies.

 

[Superdad]

That's not true. It will power it but the MINI needs a minimum of 14vdc IIRC. The ARIES and ARIES LE is ok on 12Vdc but NOT the MINI. It will power it and it will work but the regulator will burn itself over time.

 

Hi Jason:

 

Thanks for that info. I'll certainly accept that as Mr. Wang is always forthcoming. But what you say about regulator burn-out is a bit odd since the voltages used in the device are much lower, and stepping down from 12V creates less heat than dropping from 14V. Then again, the Aries mini uses at least 4 switching regulators and things can get weird with those. They might be both buck and boost regs.

 

That said, it would be just one tiny resistor change next to one of the JS-2 switch settings to give you a 14V output. Max current at that voltage would probably drop to about 3.5 to 4 amps, but that is plenty for the Aries mini requirement of 1.2A at 14V.

 

Ciao,

 

--Alex C.

[Superdad]

I seem to remember Alex mentioning that the JS-2 has this multi-output ground issue covered. I certain hope so since mine is being shipped next week! I also have an HD Plex so I'm curious about the performance difference between the two.

 

The choke-filtered JS-2 is a very different kind of LPS. Very much built for speed. The big choke and Schottky diodes allows us to use one pair of big caps before the regulators and just a small cap after the regulators. Transient current capability is great.

 

And unlike any other LPS on the market, our output ground is 100% isolated from mains ground.

 

I promise that versus the HD Plex you will be in for a treat. Especially if you are powering a DAC or other audio component.

 

I am still puzzling over Mytek's recommending a crazy high amperage supply when the Brooklyn draws barely 12 watts. Draw 5 times that before the 88W (@12V) JS-2 even notices it's there...

[Superdad]

Alex, after owning the JS-2 for over a year now powering my C.A.P.S. it still performs EXCELLENT!

 

I certainly hope so! A quality LPS should perform well for decades…

 

Thanks for your kind words. So should I expect to be hearing from your friend soon?

 

Have a great weekend,

 

--Alex C.

[Superdad]

Do you have all the required certification for the european market?

 

You mean, do I have declarations of conformity on file for ALL of the following EU/IEC directives?:

 

--Low Voltage Directive 2014/35/EU (To current versions of EN60950)

 

--EMC Directive 2004/108/EC (Including test standards to current versions of EN55022, EN55024, EN61000)

 

--IEC 61558-1 (IEC:2005+A1:2009; SAFETY OF POWER TRANSFORMERS, POWER SUPPLIES, REACTORS AND SIMILAR PRODUCTS)

 

--Directive 2005/32/EC (Ecodesign requirements for standby and off mode electric power consumption of electrical and electronic household and office equipment)

 

--WEEE Directive 2002/96/EC (Waste of electrical and electronic equipment)

 

--RoHS Directive 2011/65/EU (Restriction of the use of certain hazardous substances in electrical and electronic equipment)

 

Sure, but we charge $1,800 for the version of the JS-2 that comes with all of those certificates.

 

Just kidding, but no, while the product is quite carefully and safely designed--and I have reviewed most of those directives in mind numbing detail--other than having RoHS compliance docs and CE compliance on the TE/Corcom voltage inlet/fuse/switch/voltage selector, the R-core transformer, and the Hammond choke--we have not drawn up self-certification documents or paid an outside firm for testing.

 

Since we do not use dealers/importers, each end-user assumes responsibility--and risk--for purchasing this power supply. People must judge the design, quality, and workmanship themselves. Compare the JS-2--which after assembly by my assistant I personally test, burn in, and retest every unit--with any LPS from China, and then decide. I'd be far mode afraid of any toaster or hair dryer.

 

After building and shipping over 250 JS-2s worldwide--and having just one single output failure in the field (not a safety hazard, just an inconvenience), I think people can have a lot of confidence.

 

And we have yet to have any problems with JS-2s going through customs. That's more than I can say for USB REGENs going into some places where the Mean Well SMPS--plastered with a dozen safety logos that are backed by certificates right on their web site--have been rejected a few times (because of the SMPS, not due to the REGEN itself).

 

Hope that helps.

 

Have a great weekend,

 

--Alex C.

[Superdad]

Hi Alex,

If I buy and import in Europe goods without the certification:

 

Hi Silvio:

Well let's go ahead and look at what you worry about a bit more closely...

 

1) The customs can stop the delivery and destroy the goods: I lose the goods and money;

 

This is not true.

All JS-2s shipped internationally go via FedEx Priority door-to-door service ($95 for 2-4 day service anywhere in western Europe). FedEx has their own "customs cage" in each country, and the packages are shipped with instructions for "return-to-sender" in case of not being deliverable.

But more to the point:

a) Over half of the more than 250 JS-2s sold were shipped overseas (virtually all the European and Asian countries, plus Australia, S.America and elsewhere)--and we have not had a single rejection by customs in any country;

b) The goods are covered by transit insurance, and I personally back them. No one will ever loose both goods and money when purchasing a product from UpTone.

c) Despite the myth, seizure and destruction of goods is not something that regularly happens with shipments of quality goods from the USA to Europe (and as above, FedEx covers this and either returns or pays for loss).

 

 

2) If I have a fire due to an electrical problem caused by goods without certification the insurance does not pay me: I lose my house and money.

 

Well here is where each person must use their judgement and common sense to make their decision, but I will offer these points:

 

a) The only points of attachment to the AC mains supply (almost the only place in a DC power supply where there is enough current to cause any hazard) is via the certified mains power module--containing IEC inlet, switch, voltage selection, and fuse--and power cord to your wall. The fuse we install in JS-2 units going to 220/230/240V countries is just 0.5 amp. In ANY over current situation or mains short, that fuse will blow and nothing more will happen.

 

b) The JS-2 enclosure is virtually sealed (the holes seen along the left and right edges of the top panel are above the exterior of the heatsinks and do not open into the unit). Let us imagine an extreme situation, where an electronic component on one of the circuit boards in such a way as to get some part hot enough to flame (such things can and do happen in audio components, though we have never seen it in ours). The circuit boards themselves are of an ISO-rated flameproof variety, and aside from the fact that there is not much else that a single flamed part can ignite, there is not enough air inside the JS-2 chassis to feed a fire (to prove this, I took an old JS-2 enclosure, put flammable fluid on a rag, lit the rag, tossed it into the chassis, and put the cover plate on; the flame went out in less than 20 seconds--before the top panel even got particularly hot).

 

c) The outside of the JS-2 chassis does not get hot in normal use. At 12V output setting driving a continuous 7(!) amp load the chassis and heat-sinks stay at 25 Celsius (77 Fahrenheit). And even at the much more challenging 5V at 5 amp continuos load (who would ever have that voltage/load to put on it)--which is what I run-in EVERY unit at--the top cover gets to 38C (100F) and the left side heatsink where the regulators are attached gets to 50C (122F).

(I once wrapped the entire chassis in tissue paper and ran the JS-2 at 5V/5A(!) for an hour. No fire.)

 

 

Given all the above, I'd be much more concerned about leaving your house with a coffee maker, toaster, or phone charger left plugged in. We take safety quite seriously, and having carefully read both the USA and EU safety standards, it is clear that the JS-2 exceeds them in all areas. (That's much more than can be said about some of the Chinese LPS units we have seen where they do not even attach the mains ground pin to anything.)

 

The EU permits self-certification by firms, or I can cough up a few thousand dollars to pay some outside company to write up the paperwork (very little actual testing is required--it is mostly just a document racket), but given that we sell direct, there is no importer requirement to go to the trouble just yet. And there are other product alternatives out there for those who are worried and need the paperwork to allow them to sleep.

 

Thanks and regards,

 

--Alex C.

 

P.S. There are still about 4 JS-2 spots left in the batch we are building now for May 6th shipment. Contact us to make a reservation.

[Superdad]

1 hour ago, Padawan38 said:

A friend loaned me Uptone JS2 DC cable that work very weel, do you know whether we can buy this cable , seems Uptone does not sell it as standalone.

 

Hi:

We do offer our grey Oyaide/Belden star-quad (4*18awg) shielded cable separately, it just does not have a web page as it is mostly included/sold with our JS-2 power supply.

 

We offer it in only 3 configurations:

1.5 meter with 5.5mm x 2.5mm plug both ends ($75)

1.5 meter with 5.5mm x 2.5mm one end and 5.5mm x 2.1mm other end ($75);

0.5 meter with 5.5mm x 2.1mm plug both ends ($70).

 

All three are in stock for quick shipment.  First Class Mail postage is $3 in USA, $9 to Canada, and $13 to rest-of-world.  Priority Mail and fast FedEx shipping are also available (we have a special contract with FedEx, so the cable, which can fit in a FedEx envelope can often be sent overseas this way for about $20, depending upon country).

 

To purchase, just sent a short note to us via https://uptoneaudio.com/pages/contact-us.  If you include your delivery address, phone number, and choice of cable termination we can respond promptly with a web invoice.

 

THANKS,

—Alex C.