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

[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

[gstew]

Thanks.

 

Can you tell the difference between energizing LPS-1 with stock smps and ifi 9V power?

 

Because according to designers' purpose, it will make no difference.

 

I have run LPS-1s with 3 supplies so far... the stock Meanwell, a cheapo 12v supply, and a DIY 12v supply. I could not tell a difference in the sound of the gear powered by the LPS-1s with any of the energizing supplies. I DID have some noise bleed-through with the Meanwell, discussing it with Alex we suspect it was radiated noise picked up through my transformer volume controls. But it only happened in certain configurations while not playing and when setup for playing, no noise and no difference.

 

I'm currently building two pretty massive DIY supplies designed to each power up to 4 LPS-1s... I have plans....

 

 

I think what you power the LPS-1 will matter, not because it will have any effect on the output of the LPS-1 itself, but because the supply will have an effect on the AC power feeding the entire system. I prefer to have no cheap a** noisy power supplies anywhere near my audio system.

 

@barrows is absolutely correct in what he says about some extant noise potentially still affecting other gear through the mains.

 

While my current amps DO have SMPSs, I do not use any other SMPSs with my audio gear, including source computers and networking gear. And where I have changed SMPSs out for DIY'd linear supplies, when they are directly powering a piece of gear, I have generally heard improvements. I do have a friend swearing his R-Pi-based player using a modified HiFiBerry DAC+ Pro sounds better with a specific SMPS powering the Pi, I'll be trying that in my setup soon.

 

But I'm with Barrows and YashN and generally keep generic consumer SMPSs out of my setups.

 

 

 

Cheers, man. Duly noted.

 

The funny thing is: I emailed MCRU regarding their regulated LPS for LPS-1 this morning, want to know whether it is truly effective.

 

You know what they replied? They emailed me back: there is no need to use LPS-1 for your uptone regen or microrendu, our LPS is the best.

 

I did an interesting test a few days back. I powered an SDTrans384 feeding a somewhat modified Soekris DAM DAC with the following:

 

1. A DIY linear supply based on the K&K Audio Low Voltage Supply here: http://www.kandkaudio.com/other-kits/ . It was the 12 watt version with larger caps before and after the regulator.

 

2. A single LPS-1 set to 5v

 

3. A single LPS-1 set to 7v feeding a Belleson 5V/2A regulator.

 

4. 2 LPS-1s set to 5v in parallel.

 

#1 was good all around, but did not beat any of the other options in any parameter.

 

#2 was the cleanest and most focused and detailed, but not as dynamic as any of the others. That doesn't mean it is not dynamic, just not as much as the others in direct comparison.

 

#3 was about as dynamic as #1 & #4. Also it was more focused and detailed than #1, but not as good as #2 or #4

 

#4 was more focused and detailed than any of the others EXCEPT #2, where it lost out a bit, though decisively. It was up in the same realm of dynamics as #1 & #3.

 

I stuck with the single LPS-1, #2, as my preferred power source for this, my best digital source.

 

My next try will be a dual paralleled LT3042 regulator board from OPC on DIYAudio, powered by 2 LPS-1s set to 7V, and paralleled at the output of the two paralleled LT3042 sections (each has 4 of the regs giving about a 1A output capacity). I'm hoping this will give me the benefits of the additional current capacity of 2 LPS-1s while retaining the detail and focus I get with a single one direct.

 

 

 

I have a second question now:

 

On the website, it is mentioned that "the adventurous could even purchase two units and hook their outputs up in series, perhaps with one set to 7V and the other to 5V to obtain 12V"

 

Since I have an exasound e12 need a 12V linear power supply, at the moment I'm using Sbooster 12V, how am I going to hook two units of LPS-1 and output 12V? Any connector I should purchase in order to do that?

 

Any help would be appreciated,

Wei

 

See this post from Alex where he described a quick and dirty series adapter:

 

http://www.computeraudiophile.com/f27-uptone-audio-sponsored/ultracap%99-linear-power-supply-1-operation-and-pre-purchase-thread-30173/index5.html#post615780

 

While I haven't done this myself, I did make up a quick DIY adapter for a friend who used it with two LPS-1s in series to power his Aries Mini to good effect:

 

http://www.computeraudiophile.com/f22-networking-networked-audio-and-streaming/overall-isolation-network-universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-and-power-29916/index21.html#post618874

 

Greg in Mississippi

[gstew]

I MAY be the heaviest user of LPS-1’s around, with 8 in various positions in my 2 setups.

 

Of course, energizing that many means a bunch of separate power boxes & a lot of AC outlets.

 

I did repurpose an early computer music player linear supply with dual outputs as an LPS-1 energizer… but it was not enough.

 

Earlier this year I started to build 2 quad-output power supplies just to energize my LPS-1s. They started with:

 

1.       A hefty toroid with 2 10V/10A secondaries (surplus buys, so surprisingly inexpensive)

2.       Diode bridges using good fast-recovery diodes (same family as the often-used MSR860) with John Swenson transformer ringing suppression snubbers

3.       47,000uf post-diode filter caps (also surplus from Ebay and inexpensive)

4.       2 LT1083 7.5A  regulators per side (sadly obsolete, but I had a sufficient stock in my parts boxes) for 4 outputs per supply

5.       Another 47,000uf filter cap on the output of each regulator

6.       Hefty wire all the way to the output connectors

7.       All in a good cost-effective EBay case with good heatsinks

 

These should EASILY put 3-4  amps into each output all-day/all-night.

 

Done, right?

 

Wrong!!!!

 

On the plus side they worked VERY well as LPS-1 energizers. On the negative side, the SQ of my systems went subtly south with these units installed. Of course, what you feed an LPS-1 with DOES NOT IMPACT THE OUTPUT AT ALL! No questions on that. So they must be feeding noise back into my AC circuits.

 

First, you have to understand I am a FANATIC about AC power… so much I’m looking at a solar power setup so I can take my audio systems off the grid! To get the best AC power I can, I have the following:

 

-          A PS Audio P10 in each system powering the main audio gear only, with at least a couple stages of parallel AC filters ahead of each P10.

 

-          ALL audio-related, but not core audio gear are on a separate AC circuit, again with multiple parallel AC filters. This includes my music servers and associated networking gear.

 

-          The music servers and associated network gear are all chosen for fairly low-power usage to help keep their electrical noise low AND all are powered from linear supplies (mostly DIY’d).

 

-          There’s a LOT of noise filtering in the house… clamp-on chokes on every household item that produces noise and a large number of parallel filters around the house on the circuits powering those noisy items.

 

-          An Entech AC noise analyzer used to determine where to place these filters AND confirm effectiveness.

 

These LPS-1 energizing supplies were of course plugged into the non-core audio gear separate circuits. AND still I got a subtle, but noticeable drop in SQ.

 

Back to the bench… replace the fast-recovery diodes with some higher-current Schottkys and an dual-snubber setup. 47,000uf caps at the output of each regulator come out and after some experimentation, get replaced with much smaller 1,800uf caps. Add more filtering on the AC input. Try some series resistance on the secondaries to lower the filter capacitor charging peaks… these quickly came out as they caused too much drop in available output current.

 

Testing this all on my bench, the final setups seemed to function almost good AC filters too… just plugging in the energizing supplies almost eliminated AC line noise as indicated on the Entech... and the magnitude of drop helped me confirm some of these changes.

 

Put them back in the system for a trial yesterday (as before, I’m just plugging them into the separate AC power circuit to assess SQ impact, they weren’t powering LPS-1s at that point)… And DANG, not only did the SQ not drop, but it subtly improved ,with a small drop in background noise (to my ear). It was even more improvement (again to my ear) than SQ drop before!

 

HOT DANG!

 

And it got a little better when I pulled out the various LPS-1 energizing supplies I’d been using (none of which had ANY optimization, but all were much lower power supplies and less likely to cause significant AC line pollution) and used these supplies  to power my LPS-1s.

 

Gotta love progress!

 

Attached is a poor picture of one of the units on my bench… and a couple shots of my output checking setup showing no-load versus a 6 ohm test load (which should cause about a 1.9 amp draw). They handled that nicely with only a small voltage drop, which stays about the same when all 4 outputs are loaded simultaneously. 

 

And in the systems, each energizing 3 LPS-1s right now, they are at room temp, no heat at all (which was not true of the variety of supplies I used earlier).

 

Gotta love DIY!!!!

 

Greg in Mississippi

[gstew]

9 minutes ago, JohnSwenson said:

Hi Greg,

yep the huge spikes caused by large caps on a standard bridge to cap supply generate a lot of noise. Going to smaller caps helps a lot but doesn't completely eliminate the problem. But then you don't have a lot of cap to handle short term large current changes.

 

This is why I have the circuit that is in the JS-2 which uses a small initial cap, feeding a high current choke, then a large cap. The circuit is carefully tuned such that the load on the diode bridge is almost resistive, thus no big spikes, but there ARE large caps on the output which can supply a large amount of short term current. The whole thing is tuned so the output will respond very quickly.

 

Of course all that is useless for a LPS-1 feeder. So just going with a small cap is fine.

 

John S.

 

Hey John!

 

Yup, I even considered adding a couple of chokes to resolve the issue, but no space in the enclosure. Your configuration (as used in your JS-2) is IMHO the gold-standard solution for an AC-connected power supply.

 

On my standard DIY'd AC supplies with fairly large filter capacitors I generally use 4-pole capacitors. Their construction puts the cap's inherent inductance in series, which seems to help lower the noise fed back into the AC lines. BUT 4x ~$80/cap was a bit too rich for these supplies.

 

I'm just happy I was able to quiet them down with some fairly minor adjustments.

 

AND of course, best to you in getting settled in the new house!

 

Later!

 

Greg