UpTone JS-2 Power Supply Listening Impressions

[jtwrace]

Alex, OK, I stole the above quote from a different thread (Regen PSU Add-on), and couldn't find a UTA MMK thread, so here it goes...

 

Is that MeanWell PSU an option for a MMK, or just a one-off. And do you have any other options/recommendations for an inexpensive Mac Mini external PSU ??

 

Of course, I would love to order a JS-2, but it is just too expensive for me now But, I have been thinking about a MMK kit w/ some kind of affordable PSU. Others might be interested as well. Oh, and what kind of lead time do you have on MMK's, what with all the Regens, JS-2's, development work, home life, goofing off, and such ?

 

Thanks,

Just save for the JS-2. It really is that good.

[Jiffi32]

Just save for the JS-2. It really is that good.

 

+1

[sdube]

+1

 

+2

[Superdad]

Is that MeanWell PSU an option for a MMK, or just a one-off.

 

Hi Dave:

No, it was just that Wayne is overseas, wanted to use a cheap supply for a while yet still get the benefit of the Linear Fan Controller circuit of the MMK (which does away with the 12V/0.5A(!) 25Khz pulses of the stock PWM fan speed control).

So I ordered hime up this 88W Mean Well switcher--it even has the right 5.5mm x 2.5mm plug size:

GS90A12-P1M: MEAN WELL: Power Supplies & Wall Adapters

 

 

And do you have any other options/recommendations for an inexpensive Mac Mini external PSU ??

 

Well you really need a solid 5A supply, and while 12V/5A LPS units are out there, I'm not sure what qualifies as "inexpensive" to you, and even some of them for a few hundred dollars are not all that special technically. Admittedly I'm biased, but standard trans>diodes>cap>regulator supplies just don't get me excited (especially if they use 75-cent bridge rectifiers).

 

 

Oh, and what kind of lead time do you have on MMK's, what with all the Regens, JS-2's, development work, home life, goofing off, and such?

 

Our Mac mini DC-conversion/Linear Fan Controller Kit is in stock at all times. Just got in another 50 toolkits for them.

Sadly, home life and goofing off are but a distant memory at present. But that's okay, I have you guys!

[Superdad]

Is that MeanWell PSU an option for a MMK, or just a one-off.

 

Hi Dave:

No, it was just that Wayne is overseas, wanted to use a cheap supply for a while yet still get the benefit of the Linear Fan Controller circuit of the MMK (which does away with the 12V/0.5A(!) 25Khz pulses of the stock PWM fan speed control).

So I ordered him up this 88W Mean Well switcher--it even has the right 5.5mm x 2.5mm plug size:

GS90A12-P1M: MEAN WELL: Power Supplies & Wall Adapters

 

 

And do you have any other options/recommendations for an inexpensive Mac Mini external PSU ??

 

Well you really need a solid 5A supply, and while 12V/5A LPS units are out there, I'm not sure what qualifies as "inexpensive" to you, and even some of them for a few hundred dollars are not all that special technically. Admittedly I'm biased, but standard trans>diodes>cap>regulator supplies just don't get me excited (especially if they use 75-cent bridge rectifiers).

 

 

Oh, and what kind of lead time do you have on MMK's, what with all the Regens, JS-2's, development work, home life, goofing off, and such?

 

Our Mac mini DC-conversion/Linear Fan Controller Kit is in stock at all times. Just got in another 50 toolkits for them.

Sadly, home life and goofing off are but a distant memory at present. But that's okay, I have you guys!

[Elescher]

Although there has already been plenty of praise posted here on the JS-2/REGEN, I don't think that enough can be said for the man behind the scenes. Alex is a "Superdude". I honestly don't know how he does it. The man is on a mission and is so focused on achieving his goals that he cannot be stopped. Alex, I mean this in a good way. For those fortunate enough to have one of his products and had the opportunity to speak with him, you know what I am referring to. For those that haven't yet, you will soon see. Thanks Alex.

[Superdad]

Elescher: Thank you for those VERY kind words.

 

My situation is a really striking example of the old adage "Careful what you wish for." As an audio entrepreneur since my teens (that's when I first joined the quartet of what became Hovland Company), I have been chasing and breathing audio and music for a long time (I'm in my early 50s now).

 

But having my 10-year association with my friend, the brilliant John Swenson, bear such commercial success in a short period has been rather overwhelming (can you say REGEN mania?!). While it is exciting and rewarding on many levels, it is also very challenging as I wear so many different hats each day. It is one thing to know all of what needs to be done to ride the wave, handle all the logistics, grow the business, and deliver great customer service--it is another thing to find all the hours in a day/night to do that by myself with one assistant/assembler.

 

You mentioned focus. While that is indeed what it takes (sometimes to the point of exhaustion), I try to remind myself to have fun. My wife gives me a hard time if I complain, asking rhetorically "Well this is what you wanted, isn't it?"

Yes it is (though I would be much happier with fewer e-mails--just telephone if you have a lot of questions ).

 

The most fun of all is brainstorming and working with John on new designs for the near and far future. And things we have talked about, some of them for a long time, will now be fiscally possible to bring to market. THAT is really exciting to both of us.

 

So onward.

 

And have a GREAT weekend everyone,

 

--Alex C.

[Daudio]

So I ordered hime up this 88W Mean Well switcher--it even has the right 5.5mm x 2.5mm plug size:

GS90A12-P1M: MEAN WELL: Power Supplies & Wall Adapters

 

...you really need a solid 5A supply, and while 12V/5A LPS units are out there, I'm not sure what qualifies as "inexpensive" to you, and even some of them for a few hundred dollars are not all that special technically. Admittedly I'm biased, but standard trans>diodes>cap>regulator supplies just don't get me excited (especially if they use 75-cent bridge rectifiers).

 

Alex,

 

Got it ! I understand your concerns about the tech in power supplies. I built a lot of LM317/337 supplies back in the 70's, and recall the Shokty diode fad a little later, plus what you and John have written about the JS-2. I do not deny the quality and value, but almost $1000 is just too much for my meager budget no matter what. So if I can find a good compromise PSU, around $200-300, I may just go that route, even through I don't have a good place to put external power boxes at the moment. Probably do something in the fall, after recovering from an expense 'storm' the past couple of months

 

 

Our Mac mini DC-conversion/Linear Fan Controller Kit is in stock at all times. Just got in another 50 toolkits for them.

Sadly, home life and goofing off are but a distant memory at present. But that's okay, I have you guys!

 

The MMK stock situation sounds great. But I am beginning to wonder about you, if the impatient, irrationally exuberant, and otherwise weird, CA members could even be considered as a replacement for wife and kids

[Daudio]

Just save for the JS-2. It really is that good.

 

+1

 

+2

 

Sorry gents, but just not going to happen, without something like winning a lottery (unlikely since I don't buy tickets).

 

I spend too much on audio hardware as it is, living on just SS, with an occasional used gear sale. I know you all meant well, but it doesn't go down so well, when I have had to replace a subwoofer, water heater, car exhaust system, eyeglasses, and miscellany in the last month or so, in addition to annual property taxes, and the regular monthly bills !! Whew...

 

While I recover from that expense 'storm', I entertain myself by thinking about spending some (small) money on this hobby (not even my #1 !).

[satfrat]

Sorry gents, but just not going to happen, without something like winning a lottery (unlikely since I don't buy tickets).

 

I spend too much on audio hardware as it is, living on just SS, with an occasional used gear sale. I know you all meant well, but it doesn't go down so well, when I have had to replace a subwoofer, water heater, car exhaust system, eyeglasses, and miscellany in the last month or so, in addition to annual property taxes, and the regular monthly bills !! Whew...

 

While I recover from that expense 'storm', I entertain myself by thinking about spending some (small) money on this hobby (not even my #1 !).

 

+1

 

My recent retirement sucks financially tho I do love having more time to enjoy my system.

[sdube]

Any more inputs/responses on this question concerning improvements in JS-2 after break-in/stabilization of capacitors and stuff?

Randy

It will be interesting to see if you notice a further improvement after at least 72 hours on the PSU, as most large value electrolytic capacitors take a while to fully stabilise.

 

Regards

Alex

[Jud]

Any more inputs/responses on this question concerning improvements in JS-2 after break-in/stabilization of capacitors and stuff?

 

You could always just wait a couple of days and see for yourself.

[jtwrace]

You could always just wait a couple of days and see for yourself.

 

Nah, speculation is much more desirable in this hobby.

[sdube]

"Exactly, approximately", as was said in a film.

Nah, speculation is much more desirable in this hobby.

[sdube]

Of course, you are right, Jud-the-not-so-obscure, but the cretin I am, I want to match my humble impressions with theory at large.

You could always just wait a couple of days and see for yourself.

[Jud]

Of course, you are right, Jud-the-not-so-obscure, but the cretin I am, I want to match my humble impressions with theory at large.

 

Always liked Hardy.

 

No JS-2, so I can't help there. I personally think the Regen might keep improving for a good 100 hours or so, though I like it plenty right at the start. (And that's a very informal opinion, nothing rigorous at all.)

 

Will look forward to your impressions.

[JohnSwenson]

Any more inputs/responses on this question concerning improvements in JS-2 after break-in/stabilization of capacitors and stuff?

 

Large scale macro behavior will not change significantly with breakin. There are ALWAYS some macro effects due to temperature. When the unit is cold you can always get more short term current out of it than when it is hot. When it is hot you have less margin before internal components reach their thermal limits. The JS-2 is quite thermally robust so you really have to pull hard on it to notice this, but it is there. For example if you have a computer that at its normal condition is pulling so much current that the JS-2 gets HOT but is not yet in thermal limiting, something that causes the computer to draw significantly more current could cause it to go into thermal limiting. Doing that while it is cold you probably wouldn't notice anything.

 

Small transient behavior WILL change overtime during the first couple of days. For example when driving a computer the highly transient load will cause some voltage noise on the output (the JS-2 is very good at minimizing this, but it isn't perfect). The exact details of this noise will change during the first few days of use. I have not done any studies on exactly how it changes, I just have one production JS-2 and I have been using it for a long time, so it is LONG past any burn-in.

 

Due to how these things change in other equipment that I HAVE looked at, my guess is that it will be pretty good at first, then over the first day get much worse, then over the next couple days get much better than it was at first.

 

John S.

[Superdad]

At John's suggestion I got a new piece of test gear last month--an adjustable DC load with 2 inputs and digital display (at the same time I bought him a more elaborate, programmable one that create all sorts of interesting load events--he told me he wonders how he ever got along without it).

 

Previously I was only able to test the JS-2 one output at a time and in fixed load increments above and below what its limits are. With this new unit I can run both outputs at the same time and dial the load amperage to the limits of the JS-2 in any combination of voltages and balance that I want.

 

The other night I had fun doing just that. Boy was I surprised at what it really can do! 7 amps at 12V? Yes! 3A at 5V on one output while 4.8A at 12V on the other? Yep. This thing rocks! And of course nobody has gear with a continuous draw like I was testing at. (And I run every unit in for over an hour at full load--5A at 5V being the thermal torture test since the voltage drop is large).

John will have to estimate what sort of peak current it can deliver--probably 10+ amps.

Guess I need to update the specs on the JS-2 web page.

 

It is a heck of a supply. Only wish the labor and parts coordination time was not so intense. Really limits how many of them we can build and ship each month (about 25 max. and people are waiting).

[sdube]

Thanks. Soon, then.

Always liked Hardy.

 

No JS-2, so I can't help there. I personally think the Regen might keep improving for a good 100 hours or so, though I like it plenty right at the start. (And that's a very informal opinion, nothing rigorous at all.)

 

Will look forward to your impressions.

[sdube]

Thanks a bunch, John. Your guess about the sound of JS-2 kind of corresponds with what I have been hearing. Just wasn't sure since there is a new Regen going through its paces, too. May I now bother you, Alex, and the denizens of this forum with a few more queries?

 

1. Is it okay to leave the JS-2 on all the time, when not travelling? I do power down the Mac Mini but leave the Regen and JS-2 on: Is this an okay practice?

 

2. Why do many folks power the Regen at 9 v from the JS-2?

 

3. I have the impression that two Regens daisy-chained can be powered by a single dc output of the JS-2, the second one powering the Mac Mini. Am I right? How is this to be done?

 

4. Ask because I have two more Regens on order, one for daisy-chaining in the main system, and the other for my study system. Is the magical mystery machine to power the Regen due out in October? I would like to carry it back with me in later October to avoid postage delays and customs perversions. Might this be possible?

 

5. Is to okay to have the JS-2 (with MM and Regen) connected to the (quite nice) power conditioner that has my other equipment, on a dedicated 20 amp line? Or should the JS-2 be shifted to a second dedicated 20 amp line with another conditioner? Of course, I could try but space and time are at a premium, and I do not want to obsess.

Thanks in advance,

 

Saurabh

 

Large scale macro behavior will not change significantly with breakin. There are ALWAYS some macro effects due to temperature. When the unit is cold you can always get more short term current out of it than when it is hot. When it is hot you have less margin before internal components reach their thermal limits. The JS-2 is quite thermally robust so you really have to pull hard on it to notice this, but it is there. For example if you have a computer that at its normal condition is pulling so much current that the JS-2 gets HOT but is not yet in thermal limiting, something that causes the computer to draw significantly more current could cause it to go into thermal limiting. Doing that while it is cold you probably wouldn't notice anything.

 

Small transient behavior WILL change overtime during the first couple of days. For example when driving a computer the highly transient load will cause some voltage noise on the output (the JS-2 is very good at minimizing this, but it isn't perfect). The exact details of this noise will change during the first few days of use. I have not done any studies on exactly how it changes, I just have one production JS-2 and I have been using it for a long time, so it is LONG past any burn-in.

 

Due to how these things change in other equipment that I HAVE looked at, my guess is that it will be pretty good at first, then over the first day get much worse, then over the next couple days get much better than it was at first.

 

John S.

[sandyk]

The other night I had fun doing just that. Boy was I surprised at what it really can do! 7 amps at 12V? Yes! 3A at 5V on one output while 4.8A at 12V on the other? Yep. This thing rocks! And of course nobody has gear with a continuous draw like I was testing at. (And I run every unit in for over an hour at full load--5A at 5V being the thermal torture test since the voltage drop is large).

John will have to estimate what sort of peak current it can deliver--probably 10+ amps.

Guess I need to update the specs on the JS-2 web page.

 

 

 

Most impressive !

[Superdad]

1. Is it okay to leave the JS-2 on all the time, when not travelling? I do power down the Mac Mini but leave the Regen and JS-2 on: Is this an okay practice?

 

2. Why do many folks power the Regen at 9 v from the JS-2?

 

3. I have the impression that two Regens daisy-chained can be powered by a single dc output of the JS-2, the second one powering the Mac Mini. Am I right? How is this to be done?

 

4. Ask because I have two more Regens on order, one for daisy-chaining in the main system, and the other for my study system. Is the magical mystery machine to power the Regen due out in October? I would like to carry it back with me in later October to avoid postage delays and customs perversions. Might this be possible?

 

5. Is to okay to have the JS-2 (with MM and Regen) connected to the (quite nice) power conditioner that has my other equipment, on a dedicated 20 amp line? Or should the JS-2 be shifted to a second dedicated 20 amp line with another conditioner? Of course, I could try but space and time are at a premium, and I do not want to obsess.

 

 

Hi Saurabh: That's a lot of questions, but you are part of the UpTone Frequent-Buyer Club so I'll give it a go :

 

1) I leave my JS-2 on all the time, but I also leave my computer on all the time. Due to the nature of the revised "no-load" load circuit in this year's JS-2s (done primarily to increase current capability at 12V in countries where the mains supply is low; 100V Japan, or 220V Asia which is like having just 110V here), the JS-2 actually runs warmer without a load on it than it does when a 0.8A or greater load is on. So don't be surprised if the heatsink on the left side feels warmer when your computer is off than when it is on. Does not matter to anything for longevity, SQ, etc., but I figured I'd mention it.

 

2) The only reason we know of for some preferring the REGEN powered by 9V (versus the also available 7V setting of a JS-2, or the 7.5V SMPS that comes with a REGEN) is that it gets the chips, clock and PCB board a little warmer, and John tells that warmer chips generate less noise (at some infinitesimally low level of course). The 2 ultra-low-noise regulators in the REGEN are dropping whatever voltage you feed it down to 5V and 3.3V so the difference between that and the feed is dissipated as heat (depending upon current drawn from those 2 regs--almost noting for the 3.3V, and something between 0 and 0.5A for the 5V generated for the USB VBUS).

 

3) Yes, you can power 2 REGENs from one output of a JS-2 no problem. You will need to get a 'Y' cord splitter like this one: http://www.amazon.com/gp/product/B007Q8IKRE

All ends of the 'Y' cord I linked to are 5.5mm x 2.1mm. The second custom Oyaide/Belden 15AWG shielded, star-quad DC cable you bought at the time of your JS-2 purchase has a 5.5mm x 2.1mm plug at one end and you would plug that into the 'Y' cable and the male plugs into the REGENs.

 

4) The mystery supply will not be shipping in October. Even November looks iffy at this point as it is a complicated design going through the usual process (see my and John's posts in the other thread about it). It will be able to power 2 REGENs BTW.

 

5) The JS-2, being a choke-filtered design (and also having an R-C snubber on the transformer secondary) is possibly the most "line quiet" LPS out there in that it is kicking almost nothing in the way of harmonics back into the mains. Far less than your power amp, preamp, or DAC I can assure you. And since its DC output grounds are not common to the AC mains ground or chassis (though for safety the JS-2's chassis and R-core trans ARE connected to the IEC socket mains ground pin), any ground noise from your Mac mini is not going back through the supply. So yes, go ahead and let the JS-2 share your power conditioner with the rest of your gear. Or just plug it directly into the wall. I doubt you will hear a difference either way.

 

Hope that helps.

 

Best,

 

ALEX C.

[sdube]

Does that help? More than anyone can know, said he/I, a Luddite music lover tinkering with technical stuff. I love this view from the frequent buyers lounge. Clearly, membership has its rewards, the benefits that accrue. (Enough corporate clap-trap to take the mickey out of it.) Thanks a ton, Alex; I am all sussed out. Oh, and you are a good man, Alex C.

 

Hi Saurabh: That's a lot of questions, but you are part of the UpTone Frequent-Buyer Club so I'll give it a go :

 

1) I leave my JS-2 on all the time, but I also leave my computer on all the time. Due to the nature of the revised "no-load" load circuit in this year's JS-2s (done primarily to increase current capability at 12V in countries where the mains supply is low; 100V Japan, or 220V Asia which is like having just 110V here), the JS-2 actually runs warmer without a load on it than it does when a 0.8A or greater load is on. So don't be surprised if the heatsink on the left side feels warmer when your computer is off than when it is on. Does not matter to anything for longevity, SQ, etc., but I figured I'd mention it.

 

2) The only reason we know of for some preferring the REGEN powered by 9V (versus the also available 7V setting of a JS-2, or the 7.5V SMPS that comes with a REGEN) is that it gets the chips, clock and PCB board a little warmer, and John tells that warmer chips generate less noise (at some infinitesimally low level of course). The 2 ultra-low-noise regulators in the REGEN are dropping whatever voltage you feed it down to 5V and 3.3V so the difference between that and the feed is dissipated as heat (depending upon current drawn from those 2 regs--almost noting for the 3.3V, and something between 0 and 0.5A for the 5V generated for the USB VBUS).

 

3) Yes, you can power 2 REGENs from one output of a JS-2 no problem. You will need to get a 'Y' cord splitter like this one: Amazon.com: 5.5x2.1mm 1 to 2 M/F DC Power Splitter Cable for Security CCTV Camera: Electronics

All ends of the 'Y' cord I linked to are 5.5mm x 2.1mm. The second custom Oyaide/Belden 15AWG shielded, star-quad DC cable you bought at the time of your JS-2 purchase has a 5.5mm x 2.1mm plug at one end and you would plug that into the 'Y' cable and the male plugs into the REGENs.

 

4) The mystery supply will not be shipping in October. Even November looks iffy at this point as it is a complicated design going through the usual process (see my and John's posts in the other thread about it). It will be able to power 2 REGENs BTW.

 

5) The JS-2, being a choke-filtered design (and also having an R-C snubber on the transformer secondary) is possibly the most "line quiet" LPS out there in that it is kicking almost nothing in the way of harmonics back into the mains. Far less than your power amp, preamp, or DAC I can assure you. And since its DC output grounds are not common to the AC mains ground or chassis (though for safety the JS-2's chassis and R-core trans ARE connected to the IEC socket mains ground pin), any ground noise from your Mac mini is not going back through the supply. So yes, go ahead and let the JS-2 share your power conditioner with the rest of your gear. Or just plug it directly into the wall. I doubt you will hear a difference either way.

 

Hope that helps.

 

Best,

 

ALEX C.

[pompon]

Got JS-2 and Regen today.

My dac is Exasound E28 femto clock mini xlr

 

JS-2 is very nice looking.

Can't use the hard adaptor with the regen because usb port is too close other connectors. I have curious on way btw to solve this problem.

[sdube]

So, another question, can I power an ifi USB 3 along with two Regens at 9v with an appropriate three way adapter cable? Read here (or somewhere) that it is possible. The cable is on way to me. Ta, Saurabh

Hi Saurabh: That's a lot of questions, but you are part of the UpTone Frequent-Buyer Club so I'll give it a go :

 

1) I leave my JS-2 on all the time, but I also leave my computer on all the time. Due to the nature of the revised "no-load" load circuit in this year's JS-2s (done primarily to increase current capability at 12V in countries where the mains supply is low; 100V Japan, or 220V Asia which is like having just 110V here), the JS-2 actually runs warmer without a load on it than it does when a 0.8A or greater load is on. So don't be surprised if the heatsink on the left side feels warmer when your computer is off than when it is on. Does not matter to anything for longevity, SQ, etc., but I figured I'd mention it.

 

2) The only reason we know of for some preferring the REGEN powered by 9V (versus the also available 7V setting of a JS-2, or the 7.5V SMPS that comes with a REGEN) is that it gets the chips, clock and PCB board a little warmer, and John tells that warmer chips generate less noise (at some infinitesimally low level of course). The 2 ultra-low-noise regulators in the REGEN are dropping whatever voltage you feed it down to 5V and 3.3V so the difference between that and the feed is dissipated as heat (depending upon current drawn from those 2 regs--almost noting for the 3.3V, and something between 0 and 0.5A for the 5V generated for the USB VBUS).

 

3) Yes, you can power 2 REGENs from one output of a JS-2 no problem. You will need to get a 'Y' cord splitter like this one: http://www.amazon.com/gp/product/B007Q8IKRE

All ends of the 'Y' cord I linked to are 5.5mm x 2.1mm. The second custom Oyaide/Belden 15AWG shielded, star-quad DC cable you bought at the time of your JS-2 purchase has a 5.5mm x 2.1mm plug at one end and you would plug that into the 'Y' cable and the male plugs into the REGENs.

 

4) The mystery supply will not be shipping in October. Even November looks iffy at this point as it is a complicated design going through the usual process (see my and John's posts in the other thread about it). It will be able to power 2 REGENs BTW.

 

5) The JS-2, being a choke-filtered design (and also having an R-C snubber on the transformer secondary) is possibly the most "line quiet" LPS out there in that it is kicking almost nothing in the way of harmonics back into the mains. Far less than your power amp, preamp, or DAC I can assure you. And since its DC output grounds are not common to the AC mains ground or chassis (though for safety the JS-2's chassis and R-core trans ARE connected to the IEC socket mains ground pin), any ground noise from your Mac mini is not going back through the supply. So yes, go ahead and let the JS-2 share your power conditioner with the rest of your gear. Or just plug it directly into the wall. I doubt you will hear a difference either way.

 

Hope that helps.

 

Best,

 

ALEX C.