Power supplies and cables - observations, considerations & commentary

[vortecjr]

Just wanted to report that I switched from the Regen supply to an iFi iPower 9V. Sound seems slightly improved. Nothing dramatic.

As far as heat: I live in a very warm environment, the mR gets warm to very warm - definitely not too hot to touch comfortably - which is what JS warned about. My DAC doesn't pull any power over the USB, acc'd to the mfg.

Just remove the USB connection and keep power on and that will give you an indication of what your DAC is / isn't doing with the USB power.

[sbank]

In case anyone is thinking that they need to wait until they can afford an expensive PS before its worth investing in a microRendu, let me tell you that there is no need to wait. I am working on getting a nice custom LPS soon, but instead of waiting in silence have been listening with an $11 Hosa adjustable PS from Amazon (set at 7.5V) that I grabbed just to hold me over for a couple of weeks. The sound quality is excellent even with this inexpensive supply. It clearly crushes the stock 2009 MacMini/Audirvana+ setup that I had been using.

I'm using in DLNA mode with Lumin as primary control point and mimimserver running from my Synology NAS.

[Dev]

In case anyone is thinking that they need to wait until they can afford an expensive PS before its worth investing in a microRendu, let me tell you that there is no need to wait. I am working on getting a nice custom LPS soon,

 

Mind sharing some details :-)

[barrows]

Hi Barrows, my understanding is that the Supercaps in the Uptone LPS -1 are essentially batteries with lower capacity. They are disconnected from the charger during use (discharge). What is the benefit of charging batteries with batteries?

 

Because the charge cycle of the Super capacitors is short, the charger (actually just another power supply) needs to be connected and powered up at all times. So the charger becomes the problem, typically most will use a wall wart SMPS based charger for this, and hence one will have all the problems associated with placing an affordable (read cheap as *hit) SMPS in close proximity to the audio system: it will broadcast a fair amount of interference into the air, and spray a bunch of nasty harmonics back on to the AC line to be shared with one's precious music signal via DAC and amp power supplies. By powering the LPS-1 with batteries, one eliminates any possibility of the supply causing problems with the rest of the audio system and the AC line. Or, one could build a nice linear based charger, either way, a good linear power supply, or a big LiFePO4 battery pack with regulator and charger, there is going to be some additional expense.

[lmitche]

Because the charge cycle of the Super capacitors is short, the charger (actually just another power supply) needs to be connected and powered up at all times. So the charger becomes the problem, typically most will use a wall wart SMPS based charger for this, and hence one will have all the problems associated with placing an affordable (read cheap as *hit) SMPS in close proximity to the audio system: it will broadcast a fair amount of interference into the air, and spray a bunch of nasty harmonics back on to the AC line to be shared with one's precious music signal via DAC and amp power supplies. By powering the LPS-1 with batteries, one eliminates any possibility of the supply causing problems with the rest of the audio system and the AC line. Or, one could build a nice linear based charger, either way, a good linear power supply, or a big LiFePO4 battery pack with regulator and charger, there is going to be some additional expense.

Thanks Barrows, so a good LPS that minimizes the backwash into the AC side should do the trick? And the output of the LPS1 will be the same regardless?

 

Did I get it right?

[firedog]

Just remove the USB connection and keep power on and that will give you an indication of what your DAC is / isn't doing with the USB power.

 

Thanks. mR didn't get more than quite warm to the touch (not what I'd call hot) without the DAC - same as with the DAC attached and working. So good indicator my DAC isn't drawing current.

[Pepsican]

In case anyone is thinking that they need to wait until they can afford an expensive PS before its worth investing in a microRendu, let me tell you that there is no need to wait. I am working on getting a nice custom LPS soon, but instead of waiting in silence have been listening with an $11 Hosa adjustable PS from Amazon (set at 7.5V) that I grabbed just to hold me over for a couple of weeks. The sound quality is excellent even with this inexpensive supply. It clearly crushes the stock 2009 MacMini/Audirvana+ setup that I had been using.

I'm using in DLNA mode with Lumin as primary control point and mimimserver running from my Synology NAS.

 

I agree. I have the exact same set up, except that I use the iFi power supply. It sound better than what I had before (an Odroid as a streamer) and it outclasses my Denon transport.

[vortecjr]

Here is an interesting approach that John S also approved of for the microRendu:

http://www.computeraudiophile.com/f27-uptone-audio-sponsored/battery-power-supplies-regen-28718/#post548110

[feelingears]

Thanks Barrows, so a good LPS that minimizes the backwash into the AC side should do the trick? And the output of the LPS1 will be the same regardless?

 

Did I get it right?

 

While I want a nice LPS like everyone else, I'm wondering if plugging the iFi iPower into a filter like the AC-7A would eliminate/mitigate the kick-back-into-the-AC/system noise issue?

 

This filter was recommended by Jim Smith, author of Good Sound:

http://www.arraysolutions.com/ac-7a

 

So in theory to stop the contaminating "backwash" noise you'd plug the iPower into this and plug this into AC.

 

Is this conceptually accurate/effective? Would it in theory help sound quality?

[lmitche]

Yes, stopping the backwash is one of the benefits claimed for the ac-7a.

[theppd]

Any comparisons of any LPS to the SOtM battery PS? Curious because I'm gonna use the uRendu with it (when it finally ships to my direction).

[Pepsican]

While I want a nice LPS like everyone else, I'm wondering if plugging the iFi iPower into a filter like the AC-7A would eliminate/mitigate the kick-back-into-the-AC/system noise issue?

 

This filter was recommended by Jim Smith, author of Good Sound:

AC-7A - AC line filter with 1 ft cord with 120 V AC NEMA standard plug and receptacle for Wall-Warts or other AC mains devices.

 

So in theory to stop the contaminating "backwash" noise you'd plug the iPower into this and plug this into AC.

 

Is this conceptually accurate/effective? Would it in theory help sound quality?

 

One of the main design goals of the iFi was to minimize the noise kicked back into the power grid. you shouldn't need a filter.

[One and a half]

One of the main design goals of the iFi was to minimize the noise kicked back into the power grid. you shouldn't need a filter.

 

Ifi don't specify what frequencies are transmitted back to the mains. The Ifi wall wart is no angel when it comes to being quiet, if so their aircraft technology should equally work on the AC as well as the output, but there's no mention of this on the Ifi Web pages, so no need to extrapolate into imagination.

[Liam]

Ifi don't specify what frequencies are transmitted back to the mains. The Ifi wall wart is no angel when it comes to being quiet, if so their aircraft technology should equally work on the AC as well as the output, but there's no mention of this on the Ifi Web pages, so no need to extrapolate into imagination.

 

This is what iFi have said on their iPower thread. I'm sure if more specific info is required they would respond. They are pretty good that way.

 

" Originally Posted by Abee_V

Does the iPower throw switching noise back into the AC main?"

 

"Hi,

Normally yes. But the iPower has a 6-Element Input Array which pretty much stops noise in its tracks from going back into the mains.

 

At shows we run with +20 iPOWERs off the same spur!"

 

Cheers."

[Superdad]

" Originally Posted by Abee_V

Does the iPower throw switching noise back into the AC main?"

 

"Hi,

Normally yes. But the iPower has a 6-Element Input Array which pretty much stops noise in its tracks from going back into the mains.

 

At shows we run with +20 iPOWERs off the same spur!"

 

Cheers."

 

Then again, John did some measurement of the iPower and say some very strange things on the scope along with extremely high leakage voltage. He described them here, though he went into a bit more detail with me on the phone. Not to say that the iPower does not "sound" decent. I have one, and it is a modest improvement over the Mean Well 7.5V/2.93A/22W unit we supply with the REGEN.

But the iPower is still a switcher and there is no way they are removing all AC-side noise from it. If they were--and in that tiny case--they could have a patent, exit the hi-fi business and make tens of millions selling it for power supplies all over the world.

[orgel]

If they were--and in that tiny case--they could have a patent, exit the hi-fi business and make tens of millions selling it for power supplies all over the world.

 

Huh! No one could ever do that, could they?

 

--David

[MikeyFresh]

While I want a nice LPS like everyone else, I'm wondering if plugging the iFi iPower into a filter like the AC-7A would eliminate/mitigate the kick-back-into-the-AC/system noise issue?

 

This filter was recommended by Jim Smith, author of Good Sound:

AC-7A - AC line filter with 1 ft cord with 120 V AC NEMA standard plug and receptacle for Wall-Warts or other AC mains devices.

 

So in theory to stop the contaminating "backwash" noise you'd plug the iPower into this and plug this into AC.

 

Is this conceptually accurate/effective? Would it in theory help sound quality?

 

 

In my particular system, powering the mRendu with an iFi iPower, the AC-7A made a very positive improvement to the sound when added to filter any SMPS backwash into the AC mains.

[feelingears]

In my particular system, powering the mRendu with an iFi iPower, the AC-7A made a very positive improvement to the sound when added to filter any SMPS backwash into the AC mains.

 

@MikeyFresh Thank you. (So great that everyone is so helpful here.) I'm trying to eek out some more high freq. transparency and attack from my system. I swapped an interconnect and wow got a ton of it plus prat, but the bass receded (not just balance tipping)...sigh. Y'all know the drill.

 

Anyway, between these filters and LPSes there is plenty to play with. Cheers!

[sbank]

Mind sharing some details :-)

 

http://www.computeraudiophile.com/f10-music-servers/d-i-h-built-linear-power-supply-project-sonore-microrendu-28825/#post550377

 

Dev, Here is the story on my LPS. Put it on the other board to try not go to far off topic.

[Dev]

http://www.computeraudiophile.com/f10-music-servers/d-i-h-built-linear-power-supply-project-sonore-microrendu-28825/#post550377

 

Dev, Here is the story on my LPS. Put it on the other board to try not go to far off topic.

 

Perfect and Thanks.

[MikeyFresh]

If I use 6 Panasonic Eneloop Pro Ni-MH AA batteries wired in series for approximately 7.2 volt output, what kind of run time would I expect from the microRendu given this battery's 2550 mAh rating with 2450 mAh as the stated minimum?

 

I said approximately 7.2v output because these batteries are rated at 1.2v each, but when I put my voltmeter on the 6 pack it measures 8.48v, any ideas as to why?

[JohnSwenson]

If I use 6 Panasonic Eneloop Pro Ni-MH AA batteries wired in series for approximately 7.2 volt output, what kind of run time would I expect from the microRendu given this battery's 2550 mAh rating with 2450 mAh as the stated minimum?

 

I said approximately 7.2v output because these batteries are rated at 1.2v each, but when I put my voltmeter on the 6 pack it measures 8.48v, any ideas as to why?

 

The microRendu by itself (DAC does not draw power from the bus) uses about 200mA at 7V. That comes out to 12.5 hours at the rated capacity. The current draw will increase slightly as the voltage goes down. A safe conservative number is probably 10H.

 

If the DAC is pulling current from the bus, those numbers will go down.

 

John S.

[MikeyFresh]

The microRendu by itself (DAC does not draw power from the bus) uses about 200mA at 7V. That comes out to 12.5 hours at the rated capacity. The current draw will increase slightly as the voltage goes down. A safe conservative number is probably 10H.

 

If the DAC is pulling current from the bus, those numbers will go down.

 

John S.

 

Thank you very much John, I had forgotten to take into consideration the DAC's draw, spec'd at "<300mA".

 

So thats why last night I ran out of juice somewhere between the 5 and 6 hour mark.

 

When the UpTone LPS-1 becomes available, I could put 8 of these same batteries in series for about 11.2 volts (I tested them fully charged they are actually about 1.4v each not the 1.2v in their spec) and 19,600mAh.

 

But some of that added capacity would be offset by the LPS-1 having a 1.5 amp draw as opposed to 1 amp (+ the 300mA DAC draw) right now directly connected to the mRendu?

 

I am still a bit stumped as to why the battery quit when it did last night, the pack still measured 6.5v after I disconnected it, and each of the 6 cells were between 1.04 and 1.12v. At that voltage I guess the pack couldn't provide the needed current anymore?

[charlesphoto]

Received my microrendu yesterday; so glad to have squeezed in on this run. I've been like a four year old the week before Xmas. Replaced my Unitiqute that was under utilized performing streaming only functions to a Naim DAC V1 (UQ now moved to the office where I can truly use it). Streaming in upnp mode from minimserver on a Small Green microVortexbox using Kazoo.

 

Wow. Still burning in, but wow. It's night and day out of the box (and the Naim was no slouch) and I can tell it's settling in nicely (USB out on DAC V1 also never used before). Running the iPower though a dedicated circuit and I can see how an lps might bring a bit more weight and gravitas but the "inky blackness" is almost a bit disturbing at times its so clean already! This unit, at this price, its a "game changer" - for me it's game over. My ears are screwed after a life time of being a rock and roll photographer, so the ability to have more come through better defined at a lesser volume without being overly "hifi" is key to taming my roaring tinnitus.

 

I love the simplicity of the design - much smaller than I expected, but feels really nicely built. Runs warm but not hot at all with the ifi (you could fry an egg on the Naim, even just in streaming out mode - will heat my basement office nicely!). I'd say I gained a good few decibels on volume which doesn't hurt my sweet but slightly underpowered amp (NAP 110). It does show off the pros and cons of my amp - amazing with Coltrane; not enough guts for The Doors. The speakers, Kef LS50's are closer to the wall and together than recommended, so the bass needs real taming and focus, and the rendu scores on that account. Still full, but a lot more detailed. Overall, I'm really impressed with the balance. Everything seems to be in the right place. GUI is super easy and everything worked. Tried so far with Kazoo, Kinsky, and Lumin. Prefer simplicity of Kazoo layout and speed of Lumin. Any other open home control software I should consider?

 

If the microrendu is a solution that works for you then I wouldn't hesitate for a second to get one. I'm absolutely over the moon with mine and how its transformed my system. Thank you, and thank you for not putting it in an oversized case with fancy front and charging four times as much for it.

[charlesphoto]

Oh, and insanely good with my Sennheiser HD700's too!