Discussions of alternate "energizing"/charging PS units for use with UltraCap LPS-1 (not that any will make ANY difference to output)

[Jud]

 

I do not fully understand (or like) the iDSD's USB-bus/battery scheme--I wish the thing had a separate DC jack to power/charge it. But at least it does not seem to go over the USB spec max of 0.5A.

 

You mention "running the iDSD off its battery": I guess I do not know how you do that since anytime a USB cable (or REGEN output) is hooked up to it then you are providing it bus power (quite clean in the case of the REGEN's VBUS) and charging/running-off the battery.

 

Hey, I just know what i read in the papers - or in this case, what I've read in the micro-iDSD's instruction pamphlet. It says if one turns on the DAC before the bus is powered it will run from its battery and continue to do so even when the bus is connected to current; while if one turns on the DAC only after the bus is powered, the DAC will run from bus power. At least that's what I think I recall reading.

 

Unless of course you are getting into interrupted USB Pin 1 cable games and running off of--and later recharging--the iDSD's battery that way.

 

Nope.

[sandyk]

Jud

Please check your PMs

Alex

[Superdad]

Hey, I just know what i read in the papers - or in this case, what I've read in the micro-iDSD's instruction pamphlet. It says if one turns on the DAC before the bus is powered it will run from its battery and continue to do so even when the bus is connected to current; while if one turns on the DAC only after the bus is powered, the DAC will run from bus power. At least that's what I think I recall reading.

 

Ah yes! May I should have RtFM.

Thanks,

--Alex C.

 

P.S. Jud--call me this weekend if you want to catch up. I'll just be whacking away at my e-mail box and testing LPS-1 circuit boards. Taught my son how to run the FPGA stand-alone programming system for flashing in the code. That will give my regular staff more time to assemble, etc.

[Superdad]

So far about 25% of the people who have ordered an UltraCap LPS-1 chose the "Omit the energizing supply" option (which saves $15 off the $395 complete package price).

 

That option was presented primarily for the great many USB REGEN owners out there, since that product came with the same 7.5V/2.93A Mean Well supply, and if the LPS-1 is going to be used to power a REGEN, they already have the correct AC>DC unit to "energize"/charge the LPS-1. We are for saving the planet and saving you a little money.

 

However, we have seen some requests (both here on the forum and via e-mail) from people who now wish to add the Mean Well back to their UltraCap LPS-1 order.[/i]

 

Maybe they either realized that what they have on hand for the task does not meet our stated requirement range of 7.5V/2.5A, 9.0V/2.0A, or 12V/1.5A.

 

Or maybe some are starting to believe what I have been posting about the unimportance of the ultimate quality of the energizing unit to the output of the LPS-1 and that blocking SMPS AC leakage current will render it benign.

 

In any case, I have come up with an easy way to handle your requests, one that won't be a logistical nightmare for us, and which won't affect your place in the order queue--so you will receive your full UltraCap LPS-1 product when originally promised.

 

Just go to this special product/order page on our web site, click "Add to Cart" and check out:

Add a Mean Well AC>DC 7.5V SMPS back to your UltraCap LPS-1 order

 

The above is not a page you can navigate to from menus on our web site. This is a semi-private link, as it is just for those who have an existing advance order for an LPS-1. We will not be shipping this item separately, and anyone who orders this SMPS & cord without already having an LPS-1 on order will see us cancel it and refund your $15.

 

Please be sure to type you first and last name exactly the same as on your original LPS-1 order. It will make it much easier for us to combine them.

 

THANK YOU.

 

--Alex C.

[flkin]

Whoever's interested in this thread is a true audiophile ?

 

Worried about a power supply to power a power supply to power a device.

 

?

[Superdad]

I received and replied to the below question over at the Add-back-the-Mean Well thread, then figured the info in my response might be of interest here.

 

 

 

Alex, you have talked about Level V and VI SMPS in another post. What level is the iPower 9V/2A sold with the micro rendu?

 

Well that would be a question for iFi Audio as they make no indication on the product, packaging, or web site.

 

To be clear though, Level V and VI are just efficiency standards for external, AC-connected power supplies (Level VI became required by the USA & Canada this past February, Level V is still good for all of Europe). But as they are newer standards, the units that comply with them typically also comply with the newest radiated and conducted emissions standards.

 

So while technically I am wrong to refer to Level V/VI SMPS units as all being the sort that suppress and spread their noise across a high and wide bandwidth, it is a reasonable correlation and easier than citing all the other IEC regulations that apply to such units.

Compared to "warts" and "tabletops" of just a few years ago, current SMPS products from China (where virtually ALL these things are built) spew far less into the mains than the used to.

Also, thanks to the proliferation of low voltage supplies for LED lighting--and the new standards associated with them--there are now a few companies (Mean Well near the lead) producing power-factor-corrected (PFC) units which, by virtue of circuits in them that force them to draw power more evenly during the entire AC wave cycle, cause less distortion of the AC mains overall.

 

[Not to claim these are better "sounding" than a good LPS, but the fact is that all traditional linear power supplies--with standard trans>diode>cap arrangement--are only drawing from about 50% of the wave, a PF of .5, and are putting harmonics back into the AC. The exception is our JS-2, whose choke-filter topology makes it, as far as I know, the only power-factor-correct LPS on the market. I think John said its PF is about .97]

 

Of course, as I have been saying, the worry with modern SMPS units is not the noise put back into the line (your house power is already FAR more polluted by other things--like dimmers, etc.), it is the large AC leakage current and the creation of extra "leakage loops" in your hi-fi system. You WILL have other leakage loops (between all your regular components with power supplies), but it is best not to add to them with funky leakage patterns from cheap SMPS warts.

 

And that is one of the great things about our UltraCap LPS-1:

In addition to delivering very fast, very low impedance, very low noise DC output, the LPS-1 100% blocks the leakage current from whatever supply (SMPS or LPS) that is feeding/charging it. That feeder does no more harm than if it was charging your toothbrush or phone in the other side of your house.

[cat6man]

Whoever's interested in this thread is a true audiophile

 

Worried about a power supply to power a power supply to power a device.

 

 

an excellent observation!

[cat6man]

 

Compared to "warts" and "tabletops" of just a few years ago, current SMPS products from China (where virtually ALL these things are built) spew far less into the mains than the used to.

 

a bit tangential, but it would then be beneficial to replace the older cheap smps wallwarts around the house?

[Superdad]

a bit tangential, but it would then be beneficial to replace the older cheap smps wallwarts around the house?

 

If you want to reduce pollution of your house AC a bit, I'd cast an eye to all those old cheap triac/SCR light dimmers. The crap from them is likely much worse than from some small answering machine wart.

 

Actually, if you have some really old, heavy, bulky warts, they are likely to just be unregulated transformer supplies and not switchers. Keep those!

 

When I built my listening studio, I custom made a plate and box for two good sized VARIAC transformers like these (can't find my now pics of the inside with fuses, etc.):

 

 

[jamesg11]

My solution has been to just not have the dimmer lights on! ... is this actually a solution, apart from it being impractical for many situations?

[Astralark]

I received iFi 9V, it looks really like a very normal non-audiograde product. Well, it make no difference to SQ when charging LPS1. At least it is smaller than mean we'll power unit.

 

 

Sent from my iPhone using Computer Audiophile

[zilch0md]

I received and replied to the below question over at the Add-back-the-Mean Well thread, then figured the info in my response might be of interest here.

 

 

 

 

 

Well that would be a question for iFi Audio as they make no indication on the product, packaging, or web site.

 

To be clear though, Level V and VI are just efficiency standards for external, AC-connected power supplies (Level VI became required by the USA & Canada this past February, Level V is still good for all of Europe). But as they are newer standards, the units that comply with them typically also comply with the newest radiated and conducted emissions standards.

 

[snip]

 

 

I very much enjoyed reading this edifying post, Alex. Thank you for taking the time to educate us. :-)

[gstew]

John, a quick question on alternate power supplies.

 

Since I have a philosophical adversion to SMPS's in my source equipment, I'm planning to DIY a set of linear supplies to energize my LPS-1's (currently have 2 with 2 more on order and maybe more in the future).

 

Short term I plan to re-purpose a pair of supplies that I used to use for running a music player computer via a PicoPSU unit with a 2nd 12v supply just for the P12 CPU connection. This supply uses 2 Hammond 166N24 transformers with 24Vct/4A secondaries in a 2-diode (8A MSR860) full-wave rectifier circuit feeding 15,000uf caps for aout 17VDC which I regulate down to 12v using a pair of LT1083 7.5A regulators on reasonably large heatsinks. Of course, I'll check heatsink temps under load and swap in larger ones if needed. Does this sound like it'll work short-term?

 

Longer term, I have some no-name surplus 346VA toriods that each have 2 10Vct/8A secondaries. Here I'll use a 4-diode (again 8A MSR860) full-wave bridge on each into a 47,000uf cap and then a 2nd in a CRC configuration and expect about 14VDC out. Then again I'll feed LT1083 regulators, but here 2 regulators per rail. I've got a case with some significant heatsinking that will fit two of these, so I'd have 2 transformers, four 14VDC supplies, with 8 regulated outputs. I will need to check, the full load dropout is specified as 1.5v for these regulators, but I may have sufficient rail sag that I might need to use the variable output version and set them for 10v-11v to keep them in regulation.

 

Does this sound like it will work as a good long, multiple rail source for my LPS-1's?

 

TIA!

 

Greg in Mississippi

[scan80269]

Not sure if this is the right thread...

 

I just discovered by accident that my Teradak 30W LPS when used as energizing supply for LPS-1 can indicate the extent of current draw by the LPS-1. How? By the varying intensity of AC hum/buzz that the Teradak generates!

 

I didn't notice the AC hum when the Teradak powered my microRendu directly, but after adding in the LPS-1, the Teradak hum became much more discernible! When the LPS-1 goes into high current draw mode, the Teradak hum is detectable even from a few feet away. The hum is essentially an audible indicator of LPS-1 current consumption! I was able to correlate the hum loudness with the Teradak AC-side power consumption as read with a Kill-a-Watt meter.

 

What I noticed is that the periods of high current draw by the LPS-1 appears non-deterministic, but certainly dependent on the load the LPS-1 is driving. There is some degree of randomness in the periods of high current draw for charging a supercap bank inside. I find this rather fascinating.

 

Because of this hum, I will most likely disqualify this Teradak from being an energizing supply for the LPS-1. I may try something like HDPlex 100W LPS next.

[Superdad]

What I noticed is that the periods of high current draw by the LPS-1 appears non-deterministic, but certainly dependent on the load the LPS-1 is driving. There is some degree of randomness in the periods of high current draw for charging a supercap bank inside. I find this rather fascinating.

 

Because of this hum, I will most likely disqualify this Teradak from being an energizing supply for the LPS-1. I may try something like HDPlex 100W LPS next.

 

Hi:

 

John explains about the charging cycles in this post in another thread.

 

If you don't want to hear acoustic complaints of an "energizing"/charging supply for your LPS-1, why not just use the 22W/2.93A/7.5V Mean Well we supply with the kit?

As explained elsewhere, the LPS-1 blocks the leakage current from the SMPS, the output of the LPS-1 is not affected by the feeder supply at all, and the amount of ultra-high-frequency switching noise (low amplitude and spread over wide bandwidth) that comes from an SMPS is likely less than the other noise that is on your line. Plus the 50/60Hz harmonics kicked in by the bridge rectifiers in the other LPS, or the leakage currents elsewhere in your system are likely more harmful than what a blocked-SMPS will contribute.

 

Just sayin'...

[scan80269]

Hi:

 

John explains about the charging cycles in this post in another thread.

 

If you don't want to hear acoustic complaints of an "energizing"/charging supply for your LPS-1, why not just use the 22W/2.93A/7.5V Mean Well we supply with the kit?

As explained elsewhere, the LPS-1 blocks the leakage current from the SMPS, the output of the LPS-1 is not affected by the feeder supply at all, and the amount of ultra-high-frequency switching noise (low amplitude and spread over wide bandwidth) that comes from an SMPS is likely less than the other noise that is on your line. Plus the 50/60Hz harmonics kicked in by the bridge rectifiers in the other LPS, or the leakage currents elsewhere in your system are likely more harmful than what a blocked-SMPS will contribute.

 

Just sayin'...

Hi Alex,

 

Thanks. I'm fully aware the Mean Well should be more than good enough as the energizing supply for the LPS-1.

 

My Teradak is merely a reflection of the occasional DIY'er in me (I suffer from periodic soldering iron withdrawal...) I had replaced the silicon rectifiers with Schottky rectifiers and all the aluminum electrolytic caps were replaced with Panasonic FM of larger values, as I could not identify the brand of the originals. The small R-core transformer surprised me with that much hum, but perhaps it has more to do with the mounting than the transformer itself.

 

In a few days I'll have another microRendu listening session with the LPS-1 being energized by a few different power supplies, which should provide convincing proof that the choice of energizing supply won't affect the sound, as long as the input power requirements of the LPS-1 are met.

[Superdad]

The small R-core transformer surprised me with that much hum, but perhaps it has more to do with the mounting than the transformer itself.

 

Hmm... an R-core trans that hums? Weird since big R-core we use in the JS-2 is dead silent. Maybe yours is getting stressed by the load. Don't know.

[scan80269]

Hmm... an R-core trans that hums? Weird since big R-core we use in the JS-2 is dead silent. Maybe yours is getting stressed by the load. Don't know.

 

That R-core in the Teradak is rather smallish, with a 30VA rating. You're probably right about it getting stressed by the load, as it is nearly silent without a load. That LPS design doesn't have much power headroom to speak of, and its output impedance is likely rather high. I guess I get what I paid for...

 

Will definitely use the Mean Well units to power the LPS-1s for this upcoming microRendu listening session.

 

BTW, I think the pseudo-randomness of the LPS-1 current draw is actually good behavior. Lack of periodicity (for other than reference clocks) is usually a good thing for SQ in digital audio.

[JohnSwenson]

What I noticed is that the periods of high current draw by the LPS-1 appears non-deterministic, but certainly dependent on the load the LPS-1 is driving. There is some degree of randomness in the periods of high current draw for charging a supercap bank inside. I find this rather fascinating.

 

 

There is another process going on, when the system switches banks it starts charging a string, it charges to full voltage (determined by the output voltage), then stops charging. If the output current is low, such that it takes a long time to discharge the string connected to the output, the freshly charged string drops in voltage a little bit (there is always some current draw on a string, primarily running the logic circuits that control the bank regulator). There is a "topping off" process that turns the charger back on for a very brief time if the voltage on the "charging string" gets a little too low.

 

If the output current is high this topping off process will never happen, but for a low output current the topping off will happen every few seconds to keep the string near the upper voltage so it has a full charge when IT gets connected to the output.

 

You could very well be hearing the topping off in addition to the main charging. The exact timing of the topping off can vary a little due to noise on the ADC measuring the string voltage.

 

John S.

[scan80269]

There is another process going on, when the system switches banks it starts charging a string, it charges to full voltage (determined by the output voltage), then stops charging. If the output current is low, such that it takes a long time to discharge the string connected to the output, the freshly charged string drops in voltage a little bit (there is always some current draw on a string, primarily running the logic circuits that control the bank regulator). There is a "topping off" process that turns the charger back on for a very brief time if the voltage on the "charging string" gets a little too low.

 

If the output current is high this topping off process will never happen, but for a low output current the topping off will happen every few seconds to keep the string near the upper voltage so it has a full charge when IT gets connected to the output.

 

You could very well be hearing the topping off in addition to the main charging. The exact timing of the topping off can vary a little due to noise on the ADC measuring the string voltage.

 

John S.

John, thanks for the explanation!

 

I'm most likely hearing the topping off action, as their durations are noticeably shorter than the full charging cycles.

 

One thing I realized may apply to feeding an LPS-1 with a linear power supply only: the 12V/1.5A setting is better than 9V/2A or 7.5V/2.5A. Given the same amount of power (V * I) delivered into the LPS-1, a linear PS set to a higher voltage output with less current drawn from it should dissipate less power and therefore run cooler. While playing around with my el-cheapo Teradak as energizing supply, I originally set it to 7.5V, and it got quite warm after a while with the LPS-1 powering my microRendu. After I adjusted its output to 9V, it started running just a bit cooler. I don't think this Teradak can be adjusted all the way up to 12V, but I suppose I can rotate that multi-turn pot to one extreme to see what voltage I get. I assume the LPS-1 can handle being fed something like 10 or 11V as long the appropriate current level is also maintained?

[Superdad]

Given the same amount of power (V * I) delivered into the LPS-1, a linear PS set to a higher voltage output with less current drawn from it should dissipate less power and therefore run cooler. While playing around with my el-cheapo Teradak as energizing supply, I originally set it to 7.5V, and it got quite warm after a while with the LPS-1 powering my microRendu. After I adjusted its output to 9V, it started running just a bit cooler. I don't think this Teradak can be adjusted all the way up to 12V, but I suppose I can rotate that multi-turn pot to one extreme to see what voltage I get. I assume the LPS-1 can handle being fed something like 10 or 11V as long the appropriate current level is also maintained?

 

The reason your Teradak runs cooler at 9V is not entirely because the LPS-1 requires less charging current than at 7.5V. More than half of it is because the voltage drop--from whatever the raw, under-load DC coming off the transformer and diodes is--is greater to at 7.5V than at 9V.

 

For example: let's pretend that the LPS-1 draws 2.0 amps continuous (which it does not) from both 7.5V and 9V. And since the Teradak can be adjusted to 12V, let's assume that the raw voltage from the trans/diodes under load never gets below about 13V (if it did the regulator would not have enough drop to regulate).

 

At 9V output the drop from 13V is 4V. 4V times 2.0 amps = 8 watts of heat that must be dissipated through the regulators into the heatsink. At 7.5V out, the drop 5.5V and at 2A that would be 11 watts. So that's 3 watts difference right there.

 

However, since the LPS-1 draws (intermittently) 2.5A at 7.5V and 2.0A at 9V, it would be a bit more accurate (but not very because it is not a continuous draw--and in many cases is much less if in low-current mode) to say 5.5V*2.5=13.75W versus 4V*2A=8W. So of that 5.75W difference, 3W of it is just due to the PS design and not the difference in draw.

 

A more extreme example is our own wide-range, high-current JS-2: It runs MUCH, MUCH cooler delivering 7 amps at 12V than it does 4.5A at 5V. That's because with just one choke, one transformer secondary, and one set of didoes, it has to make its 5/7/9/12V span with just carefully chosen transformer output voltage and heroic efforts of heatsinking (all while electrically isolating the regulators' metal tabs from the chassis so we can offer a "floating DC" output design.

 

More than you wanted to know, but what the heck.

[scan80269]

The reason your Teradak runs cooler at 9V is not entirely because the LPS-1 requires less charging current than at 7.5V. More than half of it is because the voltage drop--from whatever the raw, under-load DC coming off the transformer and diodes is--is greater to at 7.5V than at 9V.

 

For example: let's pretend that the LPS-1 draws 2.0 amps continuous (which it does not) from both 7.5V and 9V. And since the Teradak can be adjusted to 12V, let's assume that the raw voltage from the trans/diodes under load never gets below about 13V (if it did the regulator would not have enough drop to regulate).

 

At 9V output the drop from 13V is 4V. 4V times 2.0 amps = 8 watts of heat that must be dissipated through the regulators into the heatsink. At 7.5V out, the drop 5.5V and at 2A that would be 11 watts. So that's 3 watts difference right there.

 

However, since the LPS-1 draws (intermittently) 2.5A at 7.5V and 2.0A at 9V, it would be a bit more accurate (but not very because it is not a continuous draw--and in many cases is much less if in low-current mode) to say 5.5V*2.5=13.75W versus 4V*2A=8W. So of that 5.75W difference, 3W of it is just due to the PS design and not the difference in draw.

 

A more extreme example is our own wide-range, high-current JS-2: It runs MUCH, MUCH cooler delivering 7 amps at 12V than it does 4.5A at 5V. That's because with just one choke, one transformer secondary, and one set of didoes, it has to make its 5/7/9/12V span with just carefully chosen transformer output voltage and heroic efforts of heatsinking (all while electrically isolating the regulators' metal tabs from the chassis so we can offer a "floating DC" output design.

 

More than you wanted to know, but what the heck.

 

Thanks for the detailed explanation, Alex!

 

It's also my understanding that the power wasted as heat in a linear PS is a heavy function of the voltage difference between its DC output and the unregulated DC at the rectifier/smoothing caps as well as the load current. My Teradak uses the bottom face of its aluminum chassis as heatsink for the 3-terminal regulator, which is better than some other LPS designs where the regulator or power transistor are given only smallish heatsinks sitting on the PCB. I would never buy such LPS designs. Since I prefer a cooler running LPS if it's all the same to the LPS-1, I'm going to see how high the Teradak output voltage can be adjusted before the regulation fails.

 

BTW, my JS-2 is VERY happy driving 12V into my Aries Femto. There is very little heat to speak of.

 

Can you tell I've been having too much fun?

[Albrecht]

Not sure if this is the right thread...

 

I just discovered by accident that my Teradak 30W LPS when used as energizing supply for LPS-1 can indicate the extent of current draw by the LPS-1. How? By the varying intensity of AC hum/buzz that the Teradak generates!

 

I didn't notice the AC hum when the Teradak powered my microRendu directly, but after adding in the LPS-1, the Teradak hum became much more discernible! When the LPS-1 goes into high current draw mode, the Teradak hum is detectable even from a few feet away. The hum is essentially an audible indicator of LPS-1 current consumption! I was able to correlate the hum loudness with the Teradak AC-side power consumption as read with a Kill-a-Watt meter.

 

What I noticed is that the periods of high current draw by the LPS-1 appears non-deterministic, but certainly dependent on the load the LPS-1 is driving. There is some degree of randomness in the periods of high current draw for charging a supercap bank inside. I find this rather fascinating.

 

Because of this hum, I will most likely disqualify this Teradak from being an energizing supply for the LPS-1. I may try something like HDPlex 100W LPS next.

Hi,

 

I run the TeraDak 30w 9v 2AMP and have not experienced any hum, warming, noise, etc. at all. This is running it with the microRendu directly, and with the LPS-1 and microRendu combo. IMO, the microRendu sounded awesome with the TeraDak before the LPS-1. But after, with the LPS-1, the SQ went up a very significant notch. Before the LPS-1, - the microRendu was also significantly warmer, (now it's cool to the touch). The LPS-1 is now a little warm, but significantly cooler than the microRendu was.

 

Cheers,

[Jud]

Moved from another thread to this one, where it is on topic:

 

The Mean Well SMPS. I have not yet tried substituting the El Cheap-O for the Mean Well, but I suppose I should try that just for giggles.

 

Thanks. I currently have the El Cheapo powering the LPS-1 and like the results. I have the El Cheapo plugged into one of the little B&K iso transformers; something I will likely fiddle with in the next little while is plugging the El Cheapo directly into the power strip, and moving my router's SMPS from the power strip to the B&K, to see whether that makes any difference.

[zilch0md]

Moved from another thread to this one, where it is on topic:

 

 

 

Thanks. I currently have the El Cheapo powering the LPS-1 and like the results. I have the El Cheapo plugged into one of the little B&K iso transformers; something I will likely fiddle with in the next little while is plugging the El Cheapo directly into the power strip, and moving my router's SMPS from the power strip to the B&K, to see whether that makes any difference.

 

https://www.amazon.com/gp/product/B000LDLF3M

 

Yeah, that B&K Precision 1604A has a floating secondary - the neutral is not connected to ground (but the safety ground is still intact, all the way from the three-prong wall outlet to this unit's three-prong outlet). As I understand it, you've got the right idea - using it to reduce backwash to the mains.

 

Isolation transformers with floating secondaries can also attenuate incoming normal-mode noise from the mains to your equipment, where isolation transformers with grounded secondaries attenuate common-mode noise from the mains to your equipment.