It would be good to see some detail, specs, pictures(internal/external) of both Nirvana and LPS. This question of suitable power supplies for Pi based transports and DAC's has been ongoing for some time, hopefully a successful conclusion is close.
Agreed, it would be interesting to try out the new Allo power supplies. Always a lot of work to put out a quality product though, and it can take more time than everyone involved would prefer. Meanwhile, if time is of the essence there are some diy power supply options that can make Katana sound quite good.
It's probably time for a Katana 1.2 revision where we can supply the 5V's and +/- 15V from high quality external psu's.
It can be done now, although bypassing the +-14v LDOs was not planned for. I haven't LDO bypassing myself yet, but I have suspected there might be something a bit less than fully optimal about the analog audio side of things (aside from filtering). Haven't tried to figure out if possible issues due to the LDOs, using Sparkos instead of OPA1612, AVCC regulation circuitry, a little RF getting into output stage, etc.
What I think would probably help the most (in addition to good linear power supplies) would be to connect it to a good galvanically-isolated synchronous-mode-capable USB card and then use a PC to send it high sample rate native DSD512 from HQplayer. Can't do that from RPi, so it would mean bypassing the stock Katana MCU and using something else to control it. Dimdim's ESS controller could be one possible option. A USB card that could probably work would be: I2SoverUSB - I2S over USB Audio
The only reason I would consider something that radical is because I think Katana is a very good dac, and to some extent it is probably held back from the best possible sound quality it could likely produce by being tied to RPi.
Sorry for getting a bit off-topic re power supplies. I will stop here.
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Tz been a while.
What's the status about our best 5V SPMS project?
In my case it's still an iPower with buffercap.
Allo obviously got a bit off track with Nirvana.
OK. Allo squeezed a linear PS - Shanti in between.
Do I want to replace my iPowers with it?
Nope.
Shanti, despite it's undeniable qualities, just comes with IMO too many so-and-so's and hmmhs.
One of the IMO key issues to me is the cap-sucker issue at turn-on.
Not sure how a part is supposed to survive such a torture over a longer period of time. (Allo actually confirmed that behavior.)
At turn-off it's the fade-out-forever issue. Basically the supercap gets
discharged over the load. Which of course can push this or that load into
critical situations.
Allo IMO simply missed to build-in proper relays on the DC outputs to avoid any power-up/power-down issues to properly cope with the supercap buffer.
And then even though we've been discussing the long iPower DC cables over here and elsewhere, Allo had the great idea to copy that long-DC-cable idea. And that idea included the introduction of el-cheapo cable adapters. Yeah. I know. Compromises have to be made.
But. It's not that we havn't been discussing a potential solution earlier. Sbooster e.g. has shown how to cope with the DC cable challenges.
Sbooster simply added another buffer and filter at the tip of the DC cable.
Some less critical issues are the size. It's huge. It's at least 8 times the iPower.
And then the 2nd output is just 1A. I'd preferred at least a 2A output.
The recommended PS for the new PI4 is 3A !?!?
And hooking up Katana to the 1A output. Hmmh.
If Nirvana should ever hit the market I hope Allo somehow addresses and avoids these hmmhs and so-and-so's.
Enjoy.
What's the status about our best 5V SPMS project?
In my case it's still an iPower with buffercap.
Allo obviously got a bit off track with Nirvana.
OK. Allo squeezed a linear PS - Shanti in between.
Do I want to replace my iPowers with it?
Nope.
Shanti, despite it's undeniable qualities, just comes with IMO too many so-and-so's and hmmhs.
One of the IMO key issues to me is the cap-sucker issue at turn-on.
Not sure how a part is supposed to survive such a torture over a longer period of time. (Allo actually confirmed that behavior.)
At turn-off it's the fade-out-forever issue. Basically the supercap gets
discharged over the load. Which of course can push this or that load into
critical situations.
Allo IMO simply missed to build-in proper relays on the DC outputs to avoid any power-up/power-down issues to properly cope with the supercap buffer.
And then even though we've been discussing the long iPower DC cables over here and elsewhere, Allo had the great idea to copy that long-DC-cable idea. And that idea included the introduction of el-cheapo cable adapters. Yeah. I know. Compromises have to be made.
But. It's not that we havn't been discussing a potential solution earlier. Sbooster e.g. has shown how to cope with the DC cable challenges.
Sbooster simply added another buffer and filter at the tip of the DC cable.
Some less critical issues are the size. It's huge. It's at least 8 times the iPower.
And then the 2nd output is just 1A. I'd preferred at least a 2A output.
The recommended PS for the new PI4 is 3A !?!?
And hooking up Katana to the 1A output. Hmmh.
If Nirvana should ever hit the market I hope Allo somehow addresses and avoids these hmmhs and so-and-so's.
Enjoy.
Just to mention it.
A Shanti >> Pi4 >> Katana combo and a properly set up pCP,
all in all - a pretty much plug'n play complete audio solution @ around $/€ 450,
sounds IMO really good - and that not just for the money.
IMO Allo really pushed the limits over the last couple of years...
...and there'll always be space for improvement.
Enjoy.
@Allo: Since PI4 a 2nd USB-C power adapter is required for Shanti (and the PSs to come)!
A Shanti >> Pi4 >> Katana combo and a properly set up pCP,
all in all - a pretty much plug'n play complete audio solution @ around $/€ 450,
sounds IMO really good - and that not just for the money.
IMO Allo really pushed the limits over the last couple of years...
...and there'll always be space for improvement.
Enjoy.
@Allo: Since PI4 a 2nd USB-C power adapter is required for Shanti (and the PSs to come)!
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Still interested myself in the smps.
In my project I'm using a higher voltage smps off-the-shelf version and using multiple stage choke and voltage regulator reduction. I anticipate more than satisfactory performance. As well, my units will have a UPS fit between the smps and the pie for file safe shutdown and power switch control. All aspects of the UPS are bypassed under normal operation and the clean power supply is let through. Should be a solves all foremost situations. I'll unleash the details and results when I get everything out of beta. One of the main features is a new standard size format for the hat and how it is attached, it is larger and the entire setup is designed to fit into a DIY audio chassis.
S
In my project I'm using a higher voltage smps off-the-shelf version and using multiple stage choke and voltage regulator reduction. I anticipate more than satisfactory performance. As well, my units will have a UPS fit between the smps and the pie for file safe shutdown and power switch control. All aspects of the UPS are bypassed under normal operation and the clean power supply is let through. Should be a solves all foremost situations. I'll unleash the details and results when I get everything out of beta. One of the main features is a new standard size format for the hat and how it is attached, it is larger and the entire setup is designed to fit into a DIY audio chassis.
S
Last mention was in the Shanti thread, post #568. Prototype was completed and performance looked good, however the transformer was producing too much heat. Wurth had provided an out of spec transformer, a new one was received and we are still awaiting news. I would guess with launch of USBridge sig and upcoming revolution DAC its not a urgent task. I hope the new transformer does not cause other problems or require extensive modifications of the design. If it does I'm not sure Allo will persevere. There is a demand for a better SMPS, so all we can do is keep asking.Tz been a while.
What's the status about our best 5V SPMS project?
In my case it's still an iPower with buffercap.
Allo obviously got a bit off track with Nirvana.
OK. Allo squeezed a linear PS - Shanti in between.
Do I want to replace my iPowers with it?
Nope.
Shanti, despite it's undeniable qualities, just comes with IMO too many so-and-so's and hmmhs.
One of the IMO key issues to me is the cap-sucker issue at turn-on.
Not sure how a part is supposed to survive such a torture over a longer period of time. (Allo actually confirmed that behavior.)
At turn-off it's the fade-out-forever issue. Basically the supercap gets
discharged over the load. Which of course can push this or that load into
critical situations.
Allo IMO simply missed to build-in proper relays on the DC outputs to avoid any power-up/power-down issues to properly cope with the supercap buffer.
And then even though we've been discussing the long iPower DC cables over here and elsewhere, Allo had the great idea to copy that long-DC-cable idea. And that idea included the introduction of el-cheapo cable adapters. Yeah. I know. Compromises have to be made.
But. It's not that we havn't been discussing a potential solution earlier. Sbooster e.g. has shown how to cope with the DC cable challenges.
Sbooster simply added another buffer and filter at the tip of the DC cable.
Some less critical issues are the size. It's huge. It's at least 8 times the iPower.
And then the 2nd output is just 1A. I'd preferred at least a 2A output.
The recommended PS for the new PI4 is 3A !?!?
And hooking up Katana to the 1A output. Hmmh.
If Nirvana should ever hit the market I hope Allo somehow addresses and avoids these hmmhs and so-and-so's.
Enjoy.
Yeah. I do also have the feeling that Allo got its priorities shuffled. Not sure if that Würth transformer was the only thing.
On the other hand that's a great chance that all the ""learnings"" from and feedback about Shanti find their way into a
slightly redesigned Nirvana.
And not to forget. Shanti wasn't and IMO still isn't free of quality issues.
I hope Allo is going to put even more focus on this.
Let's not talk about the total lack of documentation (except some FCC test results). But that also belongs to my section of "quality issues".
Enjoy.
On the other hand that's a great chance that all the ""learnings"" from and feedback about Shanti find their way into a
slightly redesigned Nirvana.
And not to forget. Shanti wasn't and IMO still isn't free of quality issues.
I hope Allo is going to put even more focus on this.
Let's not talk about the total lack of documentation (except some FCC test results). But that also belongs to my section of "quality issues".
Enjoy.
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Try to follow @Soundcheck's advice in Post #1... building a linear PSU with R-core transformer will cost a lot more money if you want to better iFi Power SMPS. That is if you don't want to get an Allo Shanti...
So.
I opened this thread in 02/2017. Time flies!
What happend in between? Not much. At least on the SMPS front.
Ah wait. iFi launched a new iPower X at IMO insane 99$ recently.
IMO pretty much nothing I read about the device justifies such a hefty
100% increase on the price tag compared to the original iPower.
I doubt that I ever gonna buy one of these iPower Xs. ( I do own 4 or 5 iPowers)
What else?
Allo finally made it. The SMPS called ""Nirvana"" is up for sale now.
As usual documentation is scarce to pretty-much-non-existent on the Allo side.
59$ for 2*5V with 2.85A each (??) is a very interesting starting point though.
One output cabled. One with USB-power-port which allows for very short
connections. Nice.
Not sure why they didn't go for USB-C. They use USB-C on all recent devices.
I'm also not sure about the current limitations of USB as power port. I hope Allo
clarified that a permanent 2.85A would do.
Differential noise at 0.4uV to 1.2 uV is kind of a wide and vague range. However.
Even at 1.2uV it's not too bad. Though Allo is not telling us under which load
conditions this can be accomplished.
And then we need to keep in mind that's just the audio frequency range 0-20kHz
we're looking at.
It seems Allo considers higher noise frequencies irrelevant.
All the potential SMPS switching noise and other HF noise area simply gets not listed.
Please Allo, attach a HF plot to the device spec. Just looking at 0-20kHz makes no sense.
Real nice to see are the Allo claims to have the annoying 50/60Hz junk noise under control.
Still no word about slew rates though. Slew rates are one of the most important characteristics
in power supply design. Poor filters, caps, cabling and connectors can have a huge impact on that parameter.
The RPI4 comes with a 3A power demand (if maxed out).
Nirvana comes with 2.85A. Not nice.
Though I think that'll do for basic RPI operation.
It would be nice to see how the voltage drop looks like under load.
And if that could be adjusted internally.
If I'm not mistaken, both outputs can not be switched separately. That's not nice.
For many applications this could have an advantage. We've been discussing this
also on the Shanti thread.
I added 2 remote controlled relays to the Shanti outputs to accomplish this.
It also solved issues (thumps/discharge-over-load) around the turn-on/off behavior of Shanti.
I guessed most issues were related to the supercap buffer on the output.
Early Allo comments on the Nirvana design suggested the lack of a supercap buffer. They kept word.
They now ended up with 8k2 uf. Let see how that output behaves on the turn on/off part.
Bottom line.
If it's true that "Nirvana" comes close to Shanti (according to Allo) it should be
a very interesting device. It's much smaller than Shanti and costs just 59$.
On the first glance Allo seems to have done a nice overall job.
Though. Calling it "Nirvana"...
Enjoy.
PS: Let's all hope that the Y caps show decent longevity.
I opened this thread in 02/2017. Time flies!
What happend in between? Not much. At least on the SMPS front.
Ah wait. iFi launched a new iPower X at IMO insane 99$ recently.
IMO pretty much nothing I read about the device justifies such a hefty
100% increase on the price tag compared to the original iPower.
I doubt that I ever gonna buy one of these iPower Xs. ( I do own 4 or 5 iPowers)
What else?
Allo finally made it. The SMPS called ""Nirvana"" is up for sale now.
As usual documentation is scarce to pretty-much-non-existent on the Allo side.
59$ for 2*5V with 2.85A each (??) is a very interesting starting point though.
One output cabled. One with USB-power-port which allows for very short
connections. Nice.
Not sure why they didn't go for USB-C. They use USB-C on all recent devices.
I'm also not sure about the current limitations of USB as power port. I hope Allo
clarified that a permanent 2.85A would do.
Differential noise at 0.4uV to 1.2 uV is kind of a wide and vague range. However.
Even at 1.2uV it's not too bad. Though Allo is not telling us under which load
conditions this can be accomplished.
And then we need to keep in mind that's just the audio frequency range 0-20kHz
we're looking at.
It seems Allo considers higher noise frequencies irrelevant.
All the potential SMPS switching noise and other HF noise area simply gets not listed.
Please Allo, attach a HF plot to the device spec. Just looking at 0-20kHz makes no sense.
Real nice to see are the Allo claims to have the annoying 50/60Hz junk noise under control.
Still no word about slew rates though. Slew rates are one of the most important characteristics
in power supply design. Poor filters, caps, cabling and connectors can have a huge impact on that parameter.
The RPI4 comes with a 3A power demand (if maxed out).
Nirvana comes with 2.85A. Not nice.
Though I think that'll do for basic RPI operation.
It would be nice to see how the voltage drop looks like under load.
And if that could be adjusted internally.
If I'm not mistaken, both outputs can not be switched separately. That's not nice.
For many applications this could have an advantage. We've been discussing this
also on the Shanti thread.
I added 2 remote controlled relays to the Shanti outputs to accomplish this.
It also solved issues (thumps/discharge-over-load) around the turn-on/off behavior of Shanti.
I guessed most issues were related to the supercap buffer on the output.
Early Allo comments on the Nirvana design suggested the lack of a supercap buffer. They kept word.
They now ended up with 8k2 uf. Let see how that output behaves on the turn on/off part.
Bottom line.
If it's true that "Nirvana" comes close to Shanti (according to Allo) it should be
a very interesting device. It's much smaller than Shanti and costs just 59$.
On the first glance Allo seems to have done a nice overall job.
Though. Calling it "Nirvana"...
Enjoy.
PS: Let's all hope that the Y caps show decent longevity.
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Received my Nirvana this morning, and replaced the ipower(DC gnd connected to PE) which was powering my Digione player. No load was 5.25V, and now only utilizes one ac outlet, so much easier to accommodate. Has fixed the underpower warning on the Pi, no more flashing red LED. Hints of improvement, especially female vocals, but it's going to take much more listening time to tell. Unlike the ipower it does not radiate EMF, so much improved. I would like to see someone post objective measurements, but congrats to Allo for a well designed and executed SMPS.
Thx for the feedback Chris. It pretty much confirms what we've been expecting.
I doubt that we'll see much of (sophisticated) real world measurements. I can't recall to have seen any
PS measurements on any PS over here.
Did you measure the voltage drop under load?
I did not measure voltage under load, but no under voltage warning from the Pi 3B which I used to get regularly with the ipower. At some point I will swap out the Pi with a 3B+ which has a greater current draw and see how that behaves. Been concentrating on listening, and my general impression is that there is a difference for the better. Seems crisper and more detailed, and vocals (M/F) more natural. Overall I like what I'm hearing, Allo has done a great job on this, I would encourage them to offer other voltages.
I have a couple of iFi iPowers in my system and was looking at the Allo Nirvana, but the shipping cost to U.S. is almost 50% of the price.
Is the iPower EMF radiation issue measured/documented someplace?
Plenty of discussions about the ipower if you run a google search. One here that may be useful Mains Leakage Currents | Audio Science Review (ASR) Forum
You can remove the leakage current from the ipower by grounding DC outer barrel to PE. I used an EMF meter on the ipower, high levels iclose to the body of the wall wart and it follows through the cable at similar levels. Applying the grounding using iFi's groundhog connector this disappears, EMF levels along the cable fall back to background levels (still high at wall wart). The groundhog connector is available from iFi for ~$12, I emailed tech support and they sold me the connector, so are fully aware of the leakage current issues. Opening it up connection to PE is via a self recovery fuse (~160 mA trip) and a ceramic 100pF low esr capacitor plus another polypropylene capacitor (?), overall resistance to ground is ~16 ohms (see picture).
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