Speaking of linear power supplies
mhardy6647
Posts: 33,787
I went to NEAR-Fest (https://near-fest.com/ ) last weekend with a mission. My mission (which I chose to accept 
) -- to find a decent-quality, fairly robust DC linear power supply, ideally a cheap one.
Well... there was no dearth of power supplies of all shapes and sizes. One vendor had a whole stack of very decent looking ex-lab DC power supplies at what looked like reasonable prices. One slightly homely example caught my eyes. Dual, variable 24 VDC supplies @ 2.5 amps. A little less oompf than I was hoping for, but the price made up for that -- 15 smackers.
The guy who sold it to me said it worked fine -- the only issue was that the mounting bezels for the two meters were... well... not present. I figured a little double-stick tape could provide a simple if not terribly elegant solution... so home with me it came.
Finally got 'round to smoke testing it today. It definitely works -- next step, of course, take a look at the output on a 'scope (or just hook something to it and see how quiet it is -- or isn't).
To paraphrase Crocodile Dundee
DSC_4595 (2) by Mark Hardy, on Flickr
) -- to find a decent-quality, fairly robust DC linear power supply, ideally a cheap one.Well... there was no dearth of power supplies of all shapes and sizes. One vendor had a whole stack of very decent looking ex-lab DC power supplies at what looked like reasonable prices. One slightly homely example caught my eyes. Dual, variable 24 VDC supplies @ 2.5 amps. A little less oompf than I was hoping for, but the price made up for that -- 15 smackers.
The guy who sold it to me said it worked fine -- the only issue was that the mounting bezels for the two meters were... well... not present. I figured a little double-stick tape could provide a simple if not terribly elegant solution... so home with me it came.
Finally got 'round to smoke testing it today. It definitely works -- next step, of course, take a look at the output on a 'scope (or just hook something to it and see how quiet it is -- or isn't).
To paraphrase Crocodile Dundee
That's not a power supply.
This is a power supply.
DSC_4595 (2) by Mark Hardy, on FlickrComments
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That thing is BEEFY!Just a dude doing dude-ly things
"Temptation is the manifestation of desire which equals necessity." - Mikey081057
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"Audiophiles are the male equivalent of cat ladies." - Audiokarma Member -
It is indeed rather hefty.
Just the thing to run, say, one of these
https://www.amazon.com/FX-Audio-TUBE-01-Preamplifier-Black/dp/B01HEQJGPC/ref=sr_1_3?crid=NC8YIRRSZ82U&keywords=fx+audio+preamplifier&qid=1557536458&s=gateway&sprefix=FX+audio+pr,aps,145&sr=8-3
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That would be similar to me using my mc1201's on my khorns.......just a wee bit of overkill
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So Mark I’m wondering if my little PASS mono’s would benefit from the same. Any suggestions? 19v, not sure of the current requirement.Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD. -
I would think so, yes. I am thinking about trying this HP with the ACA that is (still) here, in fact. The one here is running on two Dell laptop bricks -- they're 90 watt P/S, I think. 90 watts at 19 V corresponds to about 4.75 amps, though
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I’ll run upstairs and check em out. See what their rated at. Thanks Mark!Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD. -
I've had great luck with these Chinese R-Core LPS's. I've got 2 exactly like this one, a 5V and a 19V as well as a smaller 9V version without the display. I'm running a NUC with the 19V, an SSD dock with the 5V and a Matrix X-SPDIF 2 with the 9V. Dead quiet and very nice upgrades.
https://www.ebay.com/itm/100VA-Ultra-low-Noise-100W-LPS-R-core-Linear-power-supply-DC-5V-24V-With-display/132529660801?hash=item1edb622381:g:Zz0AAOSwZlZaQHiF2 channel - Willsenton R8 tube integrated, Holo Audio Spring 3 KTE DAC, audio optimized NUC7i5, Windows 10 Pro/JRiver MC29/Fidelizer Plus 8.7 w/LPS and external SSD drive, PS Audio PerfectWave P3 regenerator, KEF R3 speakers, Rythmik F12SE subwoofer, Audioquest Diamond USB cable, Gabriel Gold IC's, Morrow Audio SP5 speaker cables. Computer - Windows 10/JRiver, Schiit Magni 3+/Modi 3+, Fostex PMO.4n monitors, Sennheiser HD600 headphones -
No info or knowledge of, nor affiliation with, but saw this over on Klipsch forum:
https://community.klipsch.com/index.php?/topic/184159-hdplex-200w-linear-power-supply/ -
Little research shows retail of $485, so, not that great a deal. Might take less.
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Dollar for dollar, I'd -- humbly* -- suggest that all y'all be lookin' at laboratory DC power supplies from your favorite surplus dealer (or good ol' eBAY). Obviously, some
rehab might be required, but you'll be looking at extremely high quality, stable, robust and well designed, engineered and built components if you go the Lambda, HP, etc. route. Prices for lowish-voltage supplies are low to cheap, too.
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* of course, humbly
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No info or knowledge of, nor affiliation with, but saw this over on Klipsch forum:
https://community.klipsch.com/index.php?/topic/184159-hdplex-200w-linear-power-supply/
Coincidentally this was just measured at ASR: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-the-hdplex-200w-supply.7713/ -
No info or knowledge of, nor affiliation with, but saw this over on Klipsch forum:
https://community.klipsch.com/index.php?/topic/184159-hdplex-200w-linear-power-supply/
Coincidentally this was just measured at ASR: https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-the-hdplex-200w-supply.7713/
so... in that 'review', the question which was begged -- what does the output of the power supply look like?
To wit:
How clean is the DC output?
How precise are the fixed outputs (or the variable outputs, for that matter)?
How well regulated is the output voltage as a function of load (current)?
I mean, those are meaningful parameters, and not difficult to measure -- and directly and both qualitatively and quantitatively comparable to assess this P/S against others (linear or switching).
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Not sure. You should email Amir those questions and post the response here.
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On the other hand, I guess he's reviewing cables now, too -- that should be interesting.
https://www.audiosciencereview.com/forum/index.php?threads/this-audio-cable-business-is-getting-out-of-hand.7712/
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I'd be more interested in a competent person doing a listening evaluation rather than just measurements. If measurements were all it took to determine the end result then we'd all be saving a lot of cash :^ /2 channel - Willsenton R8 tube integrated, Holo Audio Spring 3 KTE DAC, audio optimized NUC7i5, Windows 10 Pro/JRiver MC29/Fidelizer Plus 8.7 w/LPS and external SSD drive, PS Audio PerfectWave P3 regenerator, KEF R3 speakers, Rythmik F12SE subwoofer, Audioquest Diamond USB cable, Gabriel Gold IC's, Morrow Audio SP5 speaker cables. Computer - Windows 10/JRiver, Schiit Magni 3+/Modi 3+, Fostex PMO.4n monitors, Sennheiser HD600 headphones
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Indeed.dragon1952 wrote: »I'd be more interested in a competent person doing a listening evaluation rather than just measurements. If measurements were all it took to determine the end result then we'd all be saving a lot of cash :^ /
The Seventies (when some, perhaps many, of us, came of hifi age) were rife with a focus on numbers even sometimes at the expense of sound.
And, as in all metrics-based endeavors
it's not hard to game the system if all that matters are the quantitative measurements. E.g., tonnes of negative feedback can yield quantitatively low THD, broad, flat bandwidth and high "damping factor" (i.e., low output impedance). The problem is that large amounts of poorly implemented NFB can do way more harm than good -- sometimes quite literally, as in amplifiers that are driven to
self-destructive ultrasonic oscillation by reactive loads (such as - ahem - Polk Audio's somewhat infamous "Cobra Cables").
The irony of this Onkyo integrated amplifier brochure was completely lost on me when I was amplifier shoppin' in 1977-78.
onkyo by Mark Hardy, on Flickr
Full disclosure - the A-5 and A-7 were actually pretty darned nice amplifiers, silly ad copy notwithstanding
Legendary HH Scott engineer Daniel von Recklingshausen hit the nail on the head with his oft-quoted quip:If it measures good and sounds bad, -- it is bad. If it sounds good and measures bad, -- you've measured the wrong thing.
http://hhscott.com/vonrecklinghausen.htm
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Yes. I remember when I was stationed in Germany in '76-'79 which was right about when the spec wars began. I remember agonizing over the spec sheets of various receivers when I should have just trusted my ears.2 channel - Willsenton R8 tube integrated, Holo Audio Spring 3 KTE DAC, audio optimized NUC7i5, Windows 10 Pro/JRiver MC29/Fidelizer Plus 8.7 w/LPS and external SSD drive, PS Audio PerfectWave P3 regenerator, KEF R3 speakers, Rythmik F12SE subwoofer, Audioquest Diamond USB cable, Gabriel Gold IC's, Morrow Audio SP5 speaker cables. Computer - Windows 10/JRiver, Schiit Magni 3+/Modi 3+, Fostex PMO.4n monitors, Sennheiser HD600 headphones
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dragon1952 wrote: »Yes. I remember when I was stationed in Germany in '76-'79 which was right about when the spec wars began. I remember agonizing over the spec sheets of various receivers when I should have just trusted my ears.
Yeah, I did, too -- fortunately, I also listened a lot, too.
Perhaps even more fortunately, some of the stuff that measured well also sounded good.
As a strictly editorial aside: the more of those "Audio Science Review" things I read, the more I wonder if it's not simply a mammoth put-on; a parody of the objectivists (who are, needless to say, low-hangin' fruit for parody).
E.g., harping on signal to noise ratio -- Folks like me who use truly high-sensitivity loudspeakers might stand to hear a difference between SINAD of, say, 110 and 120 dB -- folks listening through today's fashionable mid-80s dB/watt at 1 meter loudspeakers... not so much.
And THD as a surrogate for sound quality? Typical dynamic loudspeakers (cones, domes, planars, and whatnot) have output THD, particularly in the bass, on the order of several percent. If one hears a difference between an amp with, say, 0.01% and 0.1% THD on a real-world loudspeaker, it's probably not the difference in amplifier THD that one is hearing.
THD is easy to measure but pretty much unrelated to sound quality.
The spectrum of harmonic distortion components produced by an amplifier does have important sonic consequences -- but that ain't what total harmonic distortion measures, of course.
You could look it up, as they say
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mhardy6647 wrote: »Dollar for dollar, I'd -- humbly* -- suggest that all y'all be lookin' at laboratory DC power supplies from your favorite surplus dealer (or good ol' eBAY). Obviously, some rehab might be required, but you'll be looking at extremely high quality, stable, robust and well designed, engineered and built components if you go the Lambda, HP, etc. route. Prices for lowish-voltage supplies are low to cheap, too.
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* of course, humbly
That's great advice, but for right now, I'll vainly* stick with the aesthetically sleek linear power supplies from the audiophile power supply companies.
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*of course looks matter.
https://www.youtube.com/watch?v=Lfmp_kZ0ZfE
Proud and loyal citizen of the Digital Domain and Solid State Country! -
Amir......LOL.......LMAO......LOL.......Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Not for 19V or 5V, but for 3, 4.5, 6, 7.5, 9, and 12V up to 2A, this is said to be regulated and linear. Bought one for my DAC after much research. May start using one on my modem and router too.Expect that there will be bumps in the road. Choose to not let them rattle you.
Polk - Monitor 10As, SDA 2Bs, LSi9s, White RTi4s, S4s, M3s, various centers.
Boston - CR7, CR6s, CR4s.
Subs - M&K V4, M&K VX-7B, JBL SUB150P, Jamo Sub 250, and others.
Thompson Adventures, Inc. -
Amir......LOL.......LMAO......LOL.......
I think he just might be the Andy Kaufman of audio review(ers).
Food for thought.
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DarqueKnight wrote: »mhardy6647 wrote: »Dollar for dollar, I'd -- humbly* -- suggest that all y'all be lookin' at laboratory DC power supplies from your favorite surplus dealer (or good ol' eBAY). Obviously, some rehab might be required, but you'll be looking at extremely high quality, stable, robust and well designed, engineered and built components if you go the Lambda, HP, etc. route. Prices for lowish-voltage supplies are low to cheap, too.
______________
* of course, humbly
That's great advice, but for right now, I'll vainly* stick with the aesthetically sleek linear power supplies from the audiophile power supply companies.
_________
*of course looks matter.
...https://www.youtube.com/watch?v=Lfmp_kZ0ZfE
I do see that point -- but I like the purposeful look of the laboratory.
Maybe something to do with my upbringing.
... oh, and the power switch on the HP P/S did say "on" from the factory; just sayin'. -
mhardy6647 wrote: »DarqueKnight wrote: »mhardy6647 wrote: »Dollar for dollar, I'd -- humbly* -- suggest that all y'all be lookin' at laboratory DC power supplies from your favorite surplus dealer (or good ol' eBAY). Obviously, some rehab might be required, but you'll be looking at extremely high quality, stable, robust and well designed, engineered and built components if you go the Lambda, HP, etc. route. Prices for lowish-voltage supplies are low to cheap, too.
______________
* of course, humbly
That's great advice, but for right now, I'll vainly* stick with the aesthetically sleek linear power supplies from the audiophile power supply companies.
_________
*of course looks matter.
...https://www.youtube.com/watch?v=Lfmp_kZ0ZfE
I do see that point -- but I like the purposeful look of the laboratory.
Maybe something to do with my upbringing.
... oh, and the power switch on the HP P/S did say "on" from the factory; just sayin'.
I'm not sure what Carly Simon's great song "You're So Vain" has to do with linear power supplies (other than DK's reference to his own "vanity" for preferring "aesthetically sleek power supplies"), but I very much appreciate your posting this You Tube video.
It brings back a lot of very fine memories of the day . . . .. -
you hit the nail on the head.
vanity, thy name is power supply.
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Vanity is the power supply of us all.
To quote Thackeray's ending to the great Victorian novel "Vanity Fair":
“Ah! Vanitas Vanitatum! Which of us is happy in this world? Which of us has his desire? or, having it, is satisfied?-Come, children, let us shut up the box and the puppets, for our play is played out.” -
mhardy6647 wrote: »One slightly homely example caught my eyes. Dual, variable 24 VDC supplies @ 2.5 amps.
On second thought, I see a need for me to invest in one of those homely, variable output, lab grade LPSs for test and evaluation purposes.
Proud and loyal citizen of the Digital Domain and Solid State Country! -
DarqueKnight wrote: »mhardy6647 wrote: »One slightly homely example caught my eyes. Dual, variable 24 VDC supplies @ 2.5 amps.
On second thought, I see a need for me to invest in one of those homely, variable output, lab grade LPSs for test and evaluation purposes.
I like your thinking, ol' son...
