any users reviews of Uptone Power Supply and mac kit?

[Solstice380]

OK, being the engineer type I made some temperature measurements on the JS-2, the Mac Mini, the Oppo and the rack. I'll try to tabulate the results here. (sorry for any formatting issues) I used a Raytek IR thermometer. I measured the the JS-2 on all 4 sides (bad access to the Right Rear so no measurements) and these are the averages of 3 measurements. Operation was in the order listed; after ~60 Mins of iTunes/BitPerfect 44/16 AIFF followed by ~30 mins of HQP 3.6.1 upconverting 44/16 AIFF to 2XDSD (5.6 MHz) full poly-sinc / DSD7 followed by 30 mins at idle (no player playing). Late 2012 Mac Mini i7 Quad Core 512 GB SSD 16GB RAM using USB to Oppo 105D.

 

Here goes: Deg. C

 

Operating Rear Left Left Front Front Right Mac Mac Oppo CPU

Condition Left Rear Front Left Right Front Front Top Front %

 

60 mins.

iTunes/ 24.0 27.5 24.4 22.8 22.6 23.6 22.0 23,8 24.6 4-5%

Bitperfect

 

~30 mins.

HQPlayer 24.5 29.4 24.8 23.8 24.0 24.8 23.6 27.2 24.8 15-16%

upconvert

to 2XDSD

 

~30 mins. 23.6 26.5 24.2 22.6 22.3 23.2 21.2 22.2 23.6 1-1.5%

at Idle

 

Rack Support 19.7 Sides measured at the root of the heat sink fins 4-5 fins in from each end

 

I think this is a great thermal design based on the delta T values. On a percentage basis the Mac Mini heats up more than the JS-2! I suspect that the regulators inside the JS-2 is near the left rear. I didn't look for a pic of the insides, but I think Alex posted one somewhere here before.

 

That's all I had time to do and write up tonight. Bob, I'll get some time over the next few days to do some listening / comparing and get beck to you. I agree that my wording could be misconstrued. Right now I'm messing with players and HQP has a myriad of settings to try. I can say that the Oppo does an outstanding job with DVD-A and SACD discs, and I've heard more than glimpses of that with HQP 3.6.1 into the Oppo.

 

p.s No using this for marketing unless there are royalties involved! Unless of course Mr. Crespi's first name really is Amex as someone's autocorrect (probably) made it up above, then I want my 5% cash back. ;-)

[Superdad]

Hi Jay:

Thanks for the pics and for thermally probing the JS-2. Glad you are enjoying the sound too!

 

21-26 decrees C? You guys don't want to know what I cook these things at on the bench! I use an accurate, wired thermal probe attached to my multimeter and hold it against the chassis in between the heat sink fins right next to where the screw comes through for the regulator of the rail I am testing. And then I pot the probe on the metal tab of the regulator itself. The difference between the two measurements allows me to calculate the effectiveness of the dissipation by the copper bar, high performing electrically isolating thermal pads, and the heatsink of the chassis. Of course the lower the differential the better. Running for an hour at 5V/5A is the big torture test (12V/5A is no big deal), and with the 24C differentials I get, that's about 33 watts. Darn good heat sinking--especially with electrically insulating thermal pads (to keep the output ground 100% isolated from house ground--one of the small secrets to the great sonic performance).

But the actual temp in that test? Heatsink around 68C! And the tab of the regulator inside the chassis?: 24-degrees more, so 92C! For use Americans that's about 154 and 198 Fahrenheit….

 

But again, don't worry, Jay's 21-26C (70-79 F) is all most of you will ever get--at any voltage. But it should be comforting to know that the beast can take the heat.

[BobL]

Jay,

I look forward to any reports on SQ differences with the Oppo, but no hurry. I used to like SACD from my vintage Oppo 980H (used as a transport, with HDMI digital audio extractor giving 88.1kHz PCM output to my DAC) until the LPSU arrived, and from then on I preferred CD layer rips on the Mini to playing the SACDs. I guess Oppo have improved since then, but on mine CD was poor and I needed a separate transport for those.

 

Sorry to be a nuisance on yet another topic, but are your temperatures direct readings from the IR thermometer, or have calibration corrections been applied? I don't doubt the JS2 stays pretty cool, but one problem with metals is that they reflect IR as well as visible, so the instrument is mainly measuring what is reflected from the room, and there is an underestimate of temperature compared to the accurate way Alex is using. Aluminium/aluminum surfaces are particularly tricky because they can vary in emissivity (x10) according to what treatments have been applied previously, so it can be very difficult to calibrate.

 

When I have done this sort of IR test I have stuck bits of black insulating tape (emissivity about 0.95) on the spots I am measuring, but it can be difficult to clean off the adhesive afterwards, so I don't try it on front panels!

[Solstice380]

Hi Bob,

 

Yeah, IR has it's issues and black body is the only way to get true readings. But, this ain't my first rodeo! I've been measuring temps from LN2 to 3000 deg C for 35 years and we even patented a voltage based 2 wire contact method. (We did work with LANL that this was a part of, looking at temp coefficient of frequency of materials and first order phase transformations in superconductors with the High Field Magnetics Lab). IR also isn't that accurate near room temp. Glossy black electrical tape isn't much better than metal. I wanted to get at the root of the heat sink fins so it was really the only way. I use this thing pretty regularly and have compared its readings to my Omega Thermocouple Calibrator with a flat foil Type K contact probe. It's within a half degree agreement. (No DBT or GR&R, sorry LOL)

 

So, the readings are close on an absolute basis but the readings are all good on a relative basis. And, I was more interested in delta T under the different conditions. There wasn't a big range - usually +/- 0.3 deg - for the 3 individual readings. TIFWIW (free!). If you want do a Kickstarter for me I'll fabricate a tiny Type K probe to measure the root of the fins. :-)

 

I'd have to say there is no comparison between the older and current Oppo gear. I moved my 83 up next to my Pio Elite BDP in the HT setup so I am familiar with that, and the 105D just blows it away. Instrument separation and localization, body of tone (I have a s___load of test tone sources on test CDs from XLO to Hi-Fi to Stereophile, etc. as well as my fave reference recordings in different media) and most important to me - timing and pace. "It doesn't mean a thing if it doesn't have the ability to swing! The 105d even has a "Pure Audio" mode that shuts down the video processing. I snagged it as a cheap way to start messing around with DSD - I'm loving the resurgence after SACDs almost went the way of the DoDo bird, commercially!

 

What gear have you been playing around with recently? Sounds like you are well down the path on the CA front! Thanks for the learned discussions.

[Solstice380]

Now I see that the guy with a real lab in his house has better measurements! Thanks for that info, Alex!

[jtwrace]

Very cool temp info. I got curious and did a test on my old amps too. How long does it take for your amp to heat up?

[sandyk]

Alex C

 

Do you have ripple specifications for the various rails of your JS2 power supply ?

 

Kind Regards

Alex K.

[Superdad]

Do you have ripple specifications for the various rails of your JS2 power supply ?

 

It's been a busy week and today went long with finishing up another 6 units for Monday shipment. No matter how efficient I try to be, these things take time to build. Hoping to get the sales rate up enough this spring to bring a worker on.

 

I'll give you the short answer to your question: Ripple? Essentially none! Its a linear supply, and with John's choke filter design, after the diodes there is only DC with a nice sine wave riding on top as oppose to typical cap only filters which produce a sawtooth containing a ton of high frequencies (something that standard regulators don't handle well).

 

You can see a ripple waveform with switchers (at multiples of their rate), but with an LPS all there is is residual noise. And measuring that noise is a very tricky business unless you have a specially isolated test box. Boiling it down to a single number for valid comparison to someone else's numbers is not possible since it depends greatly on what frequency range you are measuring. Much better to look at such things on a wideband scope (and in a shielded box with the florescent lights and everything else off!).

Even a good true-RMS AC meter (like the Aligent 34401A that Teredak shows in the pictures posted in that thread) is only good out to 300kHz, and the best LPS will be the one that has low residual noise across a MUCH wider bandwidth--at least up to 1Mhz.

 

So specifying LPS residual noise is a bit like just quoting a single number for jitter, when what matters is the spectrum.

 

In the end, noise specs and plots for an LPS really won't tell you how it is going to perform with a demanding, dynamic load. A lot of the sonic/performance difference between power supplies of any type have much more to do with transient load response.

 

 

Allow me to quote my more eloquent mentor regarding the technical design of the JS-2 in comparison to other approaches:

 

 

John Swenson 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 (lets 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."

[BobL]

Hi Bob,

 

Yeah, IR has it's issues and black body is the only way to get true readings. But, this ain't my first rodeo! I've been measuring temps from LN2 to 3000 deg C for 35 years and we even patented a voltage based 2 wire contact method. (We did work with LANL that this was a part of, looking at temp coefficient of frequency of materials and first order phase transformations in superconductors with the High Field Magnetics Lab). IR also isn't that accurate near room temp. Glossy black electrical tape isn't much better than metal. I wanted to get at the root of the heat sink fins so it was really the only way. I use this thing pretty regularly and have compared its readings to my Omega Thermocouple Calibrator with a flat foil Type K contact probe. It's within a half degree agreement. (No DBT or GR&R, sorry LOL)

 

So, the readings are close on an absolute basis but the readings are all good on a relative basis. And, I was more interested in delta T under the different conditions. There wasn't a big range - usually +/- 0.3 deg - for the 3 individual readings. TIFWIW (free!). If you want do a Kickstarter for me I'll fabricate a tiny Type K probe to measure the root of the fins. :-)

 

I'd have to say there is no comparison between the older and current Oppo gear. I moved my 83 up next to my Pio Elite BDP in the HT setup so I am familiar with that, and the 105D just blows it away. Instrument separation and localization, body of tone (I have a s___load of test tone sources on test CDs from XLO to Hi-Fi to Stereophile, etc. as well as my fave reference recordings in different media) and most important to me - timing and pace. "It doesn't mean a thing if it doesn't have the ability to swing! The 105d even has a "Pure Audio" mode that shuts down the video processing. I snagged it as a cheap way to start messing around with DSD - I'm loving the resurgence after SACDs almost went the way of the DoDo bird, commercially!

 

What gear have you been playing around with recently? Sounds like you are well down the path on the CA front! Thanks for the learned discussions.

 

Hi Jay,

 

Sorry if I have been teaching grandmother to...

 

I'll PM you on the IR when I've done a few more checks of my own, but thanks for the Oppo information, which is very encouraging, and will probably mean a trip to a dealer before long, if I can find a space in our very small house. Where I can, I work with less than rack-width boxes

 

Nothing significant to report on gear; most of mine is both obscure and obsolete, of a similar vintage to the 980H. After a lot of playing around with Mini tweaks it was time to do more music playing, while waiting somewhat impatiently for John Westlake's MDAC2 to be completed. Maybe the Regen will appear soon and give me something else to play with....

[sandyk]

Alex C

Please check your PMs.

Kind Regards

Alex K.

[jtwrace]

Is it possible to get a JS-2 with a higher output voltage but same amperage rating for one output? Say 16Vdc.

[sandyk]

Is it possible to get a JS-2 with a higher output voltage but same amperage rating for one output? Say 16Vdc.

 

Perhaps using the little Kelvin Sense PCB, which can use different resistor values for other voltage outputs?

PM Alex C.

[gsquared]

A few months ago, I ordered the Uptone Audio MMK board and I opted to hire Alex to do the installation on my new 2014 Mac Mini Core i7. I'm sure I could have installed it myself, but due to my time constraints at the time, I felt it would be faster to just send the Mini to Alex and let him do it for me. I did not order the JS-2 from Uptone because I have a Paul Hynes SR5 LPS.

 

I'm just getting around to writing this review because the new home my family moved into does not have a good room for my system, so I'm temporarily using some small bookshelf speakers in a room that is sub-optimal for listening. (I'm hoping to find a more suitable room in the home soon).

 

This listening session was from last Thursday at my good friend Brad's home on his system. His system consists of a PS Audio DirectStream DAC, a BAT VK-52SE pre-amp, a McIntosh 275 power amp, and Harbeth 30.1 monitors. His listening room is a bit lively, but overall it sounds very good.

 

A few notes about the OS and playback software. Brad and I both use identical OS and playback software. Following Alex's advice, I optimized/slimmed a clean version of OS X and installed it on to an SD card and created an identical one for Brad to use. The playback software we use is Audirvana Plus 1.5.10. For all of our tests, the machines were booted from the SD card that held the OS and the playback software. Then we un-mounted the internal HDs. Music files were accessed from an external Thunderbolt HD.

 

Our overall objective was to compare my MMK outfitted Mac Mini powered by the Paul Hynes SR5 LPS to Brad's stock Mac Mini. Brad's Mac Mini is a 2011 (I believe) server version. But before we did our comparison, Brad wanted to listen to my Light Harmonic 2G USB cable. Brad uses the iFi Micro USB and he had been using the iFi Gemini cable. So the first thing we did was listen to his system using his Macbook Pro as a frontend, booted from the optimized/slimmed OS X on the SD Card.

 

It was clear the Light Harmonic 2G was superior to his Gemini cable, so we left it in for the main listening. We also switched out his balanced analog cables with a pair of DNM cables that I had because they also sounded better than what he was using.

 

We gave his system some time to settle in with the cable changes, now it was time to do some comparisons between my MMK outfitted Mac Mini to his stock Mini. Out of curiosity, we did a quick comparison of his Macbook Pro to his stock Mac Mini. Overall, the Mac Mini seemed to be better sonically, but I would have to do more listening to get a better grasp of the differences.

 

Uptone Audio MMK Upgraded Mac Mini Comparison

 

We started our main listening with Brad's stock Mac Mini. Everything was dialed in, booted from the SD card, internal HDs were un-mounted, settings all checked in Audirvana Plus. We began listening to 5 tracks: "Bridge Over Troubled Water" by Eva Cassidy (a Redbook track off of Best of Audiophile Voices V XRCD disc), "New Favorite (live)" by Alison Krauss + Union Station (a DSD track off their Live disc), "Fields of Gold" by Eva Cassidy, another Redbook track, "The Trawlerman's Song" by Mark Knopfler, a DSD track off his Shangri-La disc, "Little Wing" by Stevie Ray Vaughn (the DSD version off the MOFI disc The Sky Is Crying), and finally "Let It Be Me" by Inger Marie Gundersen (a DSD track off the disc Female Audiophile).

 

For me, listening to these tracks and a few others before doing any comparisons was a good thing since his system is still relatively new to me. Brad has made some changes to his system and this was the first time I'd heard it in it's current form.

 

The last track we listened to befor switching in my Mac Mini was the "Let It Be Me" track. When we switched over to my Mac Mini and played the track, it was literally like listening to a completely different and far superior recording of the same track. As I sat there (trying to keep a poker face so I didn't influence Brad's impression), I could not believe how much better the MMK/LPS powered Mac Mini was compared to the stock version. What I heard was much better dynamics, black backgrounds, much more clarity and detail to both vocals and the instruments. At the beginning of that track, there symbols and drums struck softly and then Marie Gundersen begins singing. Then the bass and piano follow. As I listend to my Mac Mini, I was struck with how much more detailed and nuanced the music was. Notes seemed to come out of a much black background than before. As instruments were played, the notes were much more vivid, almost like you could visualize the musicians playing the instruments.

 

When I finally looked over at Brad, the first thing out of his mouth was "It's really incredible, isn't it!" and then a huge grin came across my face.

 

We went on to re-listen to the tracks we listened to before, and in every case the result was the same... my Mac Mini outfitted with the Uptone MMK board powered by my Paul Hynes LPS clearly sounded superior in every way to his stock Mac Mini. I told Brad, that in order for me to really get a good handle on the differences, I would have to live with both machines for a week or so. He agreed that this brief listening session, while enough to clearly hear the improvements of my Mini vs his, it's certainly not long enough to get a complete feel for the differences.

 

As we ended our session, I told Brad that I would have loved to hear this comparison using the Uptone JS-2 vs the Paul Hynes LPS. Since the MMK board was designed using the JS-2, I would assume it would outperform my Paul Hynes, but it would be an interesting comparison nonetheless.

 

I came away from that listening session convinced that if you are happy with your DAC and speakers, the biggest improvement you can make to your computer audio front-end is adding an excellent linear power supply unit. And if you use a Mac Mini, the MMK is a no-brainer! Kudos to Alex and John for their brilliant engineering of the MMK.

 

Gary