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Fayne
2575
Nov 6, 2019
checkVerified Buyer
Finally, I own electrostatic.
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Day 1, 2019.11.05: I've been wanting these cans for over 25 years. Seriously, I just couldn't justify the $999 that KOSS sells em for. Every few years I'd essentially flip a coin and not get them. This time around that $500 at Drop was much more tempting, and that $100 off sale bringing them to $400 was just too hard to pass up. No coin-toss required. As these have just arrived, I'm giving my initial observations.
  • Everything feels super cheap. Plastic everywhere on the cans and energizer.
  • The concentric potentiometer is a nice touch, but I'd love to have a lock on it so I can twist both equally.
  • The 9VDC wall wort is total garbage and should be replaced. Preferably with something that can be turned off without unplugging. Probably find some ChiFi linear.
  • Fuzzy earpads suck almost as bad as pleather and vegan leather. Skin me some dang sheep. Dekoni Fenestrated pads ordered and on the way, hopefully before I melt from the fuzzy.
  • It is incredibly too easy to push the button which makes the cans disassemble. First time taking them off was a very WTF moment.
  • These cans are very compatible with large gauge piercings. The ear cups and pads are huuuge.
For all those mostly negative observations there is one very important thing, and that'd be that these cans sound good. Incredibly good. They've got clarity. They've got punch. It is like a wall of pure sonic bliss. They sound great from all of my audio sources. SDAC-B, DX7s, XR18, and Airist R-2R. All of my sources except the Airist start the signal as XLR and get it brought to single ended. They produce very loud clean sound via the Koss. The Airist needs the volume ramped a bit at the Koss compared to the others, but still sounds wonderful. -1 star for the cheap construction, garbage AD->DC, and fuzzy pads. +4 star for awesome sound, great looks, and extreme comfort. Day 3, 2019.11.07: I'm totally replacing the wall wart. I've the parts for a number of low noise AMB σ25 linear power supplies using the AMB σ78, plus I definitely have a trafo that'll push the voltage I need (both toroid and r-core). Stable 9VDC will not be a problem, and by the gods, having a psu with a fricking power switch will make the energizer not suck. I do not like having to unplug the stupid thing every day when I'm done using it. A short design note for the MassDrop folks. Putting the power switch after the transformer and AC-DC is stupid. Low quality power supplies are the bane of audiophile gear. Just sayin. 1Amp of 9VDC requires a stupid small toroid transformer, we're talking like 9-10VA. Throw in a low noise LDO linear voltage regulator and an IEC socket with fuse, and you can just stuff it in a slightly larger chassis. TI even has some pretty sweet reference designs for this. If y'all are going to do the whole make it better thing... :) So, my initial take still stands. Sounds great, works great, but the power brick is crap. Also, I TOTALLY had to relearn how to take headphones off after I kept hitting the disassembly buttons. Still no regrets in buying it. Day 4, 2019.11.08: My Dekoni Elite Fenestrated Sheepskin Earpads arrived. I missed the most recent Drop for them, so I sourced them direct. They're totally a pain in the butt to apply to the cans, requiring you to stretch the earpad around the ear speaker housing, but oh so worth it. Maximum comfort achieved. If you've got these cans, or are getting them, get the Dekoni pads. Your skin will thank you. Day 9, 2019.11.13: Sill sounds good. No problems there. This is more of just a status update for my PSU replacement project. I've got some 9V 10VA Talema toroid transformers to go with those AMB boards I mentioned previously. I've got most of my circuit board laid out for replacing the power brick with something more or less simple and linear. Fused at the AC input, fused at both of the AC outputs. The ability to run it 115/230VAC in, and the ability to run it with a single or dual power supply modules. Another few days of refinements and I'll hit the order button for a couple of the prototypes. And yes, this stage is pure auto-router. Day 12, 2019.11.16: Ordered some prototype boards from OSHPark. In about two weeks I should have my low noise, and generally better than power brick, power supply. Day 25, 2019.11.29: Prototypes arrived. I didn't screw up on alignments, but there are definitely tweaks I'll be making to the schematic. Now to assemble and test. Prototype boards:
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Renders of Prototype Boards:
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Layout and schematic of replacement 9v PSU for ESP/95x:
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Cans with Dekoni Pads:
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(Edited)
Recommends this product? Yes
gory_glory0209
10
Nov 15, 2019
FayneWow those dac/amps at back. Super
Fayne
2575
Nov 15, 2019
gory_glory0209That picture is missing my latest DAC too. Picked up a SMSL M500. I pretty much regret every DAC on my desk after buying it.
gory_glory0209
10
Nov 15, 2019
FayneI always have the same feeling too buying headsets. I am using Aune X1s for now but looking for a better amp and a dac but cannot decide upon
Fayne
2575
Nov 15, 2019
gory_glory0209If your DAC budget is in the $400 range, I highly recommend checking out the SMSL M500. It crushed it in the ASR tests. It drives all of the MassDrop amps extremely well, and if you're into the MQA streaming thing, it is the cheapest balanced decoder and renderer on the market. Plus, without tearing it down, I'm inferring that it does not use bus powered USB. I hit the soft power-off and it disappears, unlike all of the cheaper DACs I've got. If you're looking for some cheap hybrid tube loving, check out the LOXJIE P20. The company is apparently part of the same umbrella as SMSL, and they do seem to know how to design kick-ass amps. It runs about $100, and is fairly amazing when you swap the tubes out with 5670W or 6N3P-EV. SBAF gave a run-down of the technical details, and it was pretty good. The only caveat, no sensitive/low impedance cans allowed. Minimum of ~45Ω, it works *wonderfully* with the HD58x and HD6xx and in my stack gets more use than my ZDT or CTH. Don't let any of those suggestions sway you from a KOSS ESP/95x if you're lookin at it. For all my complaint over the power brick, and all the hoops I'm throwing myself through, they are great energizers and cans. Like night and day difference between them and any of my other cans.
gory_glory0209
10
Nov 15, 2019
FayneThanks Bud, This is very helpful. I would take a look at the SMSL as I am based in Hong Kong right now its easier to get an SMSL here :)
birusan
7
Nov 19, 2019
FayneHow do the dekoni pads sound? Do they improve the bass but at a cost of less details?
Fayne
2575
Nov 19, 2019
birusanThe Dekoni pads sound fine. I honestly didn't buy them for the sound quality at all, I got em because I can't stand fuzzy or pleather pads. I'm very much in the comfort over sound quality camp, so all my favorite (or expected favorite) cans get the Dekoni Fenestrated Sheepskin treatment. Plus sheepskin lasts longer than cloth or protein leather (for me). I didn't spend enough time with the default pads on to really notice too much of a difference... other than the default pads make my skin itch and were much warmer (temperature wise). These are the most open of all the open-back cans I've got. Even the HD6xx and HD58x dampen background sound somewhat. The HE4xx and HE35x a bit more than the Sennies, The TR-70-250 much much more. With the ESP/95x there is zero dampening, you hear the environment clearly while wearing them. I'm not sure if a tight face seal makes that big of a difference here, especially with the size of the electrostatic drivers in them. You practically could use them as Near Field Monitors.
birusan
7
Nov 19, 2019
FayneIs it cheaper to build your own linear power supply than to buy one?
Fayne
2575
Nov 19, 2019
birusanDepends on how big of a supply you need, how freaky you are about power quality, and how bored you are. Building it... if you don't want good looking it can easily be in the $25, especially if you don't mind inefficiency. Linear circuits are pretty well documented and most of the components are dirt cheap. If you don't mind spending more, you can buy a pcb off of a site like amb.org and source the components yourself. If you have the oscilloscope, multi-meter, and suitable soldering station it can be fun, and you can get something somewhat better than you'd find for the cheaps on ebay. Plus, it is yours. Just expect it to take a while to get one completed. Good enough assembled linear supplies are available on eBay if you don't mind a made in China clone. A very lot of those clones are based on the amb.org designs. If you don't mind supplying your own chassis and trafo, they can be had for super cheap as a bare assembled linear supply board. The largest cost in most of these things is the chassis, especially these days. If I didn't have need for a number of power supplies for other projects I'd likely have gone with eBay. But, I needed a set of PCBs to handle the transformer series I chose to use for most of my sub 25VA projects. If the current design works properly, it is easy enough to scale the transformer location from 10VA to 5/15/25VA. On this current project I'm down $120 for 3 prototype PCB, $20 per Talema 70041K PCB mount transformer, $8 per AMB Sigma25 AC-> DC board, $20 per AMB Sigma78 LDO low noise voltage regulator board, and about $15 in capacitors, resistors, diodes, rectifiers, and connectors. Everything but the prototype board I already had on hand because of earlier projects and my inability to see past the mouser price per item when ordering large lots (why buy the 4 I need when I can buy 100 at 1/10th the price per). :) Mind you, I didn't need the prototype boards if I wasn't using the pcb mount transformer. A standard toroid transformer would work just as well. I probably also should mention that if you don't have experience doing your own boards... dealing with AC power is dangerous. Like, there are many ways you can kill yourself without thinking.
Nottagorilla
65
Nov 20, 2019
FayneI think your preoccupation with the wall-wart is HIGHLY misplaced. There's nothing wrong with it, & you are just wasting your time & money worrying about non-issues. It doesn't need a power switch, NOR SHOULD IT. These are Electrostatic headphones, that little amplifier box is also the energiser for the diaphragms. THEY NEED TO BE CHARGING CONTINUOUSLY FOR OPTIMUM SOUND. The longer they charge, the better they'll sound. Not for a few minutes, nor for a few hours. But: for DAYS & EVEN WEEKS on end! Don't even seriously audition them for at least a full hour after you first power them up! So the lack of power switch is not an omission, it is QUITE deliberate on Koss' part. Whether the amp itself benefits from being on continuously is another story entirely. And you'll have to dig into the amp box & void your GOLDEN LIFETIME WARRANTY to do anything about splitting things up that way. Having had my pair for 6 months now, the amp justs sounds better & better. Power consumption is negligible, the case temperature doesn't even rise 10°F no matter how loud or long I play it. Also, if you look at the specs for this system, you may notice there are voltages being generated here that are a galaxy apart from those that dynamic headphones use. Most dynamic (conventional technology) headphones need just 1 MILLIWATT to deafen you (100db)! The amplifiers in the Koss put out 2,200 AC volts maximum peak per channel, the energiser portion puts a steady 600 volts DC just to charge them up to nominal sensitivity!!! Notice the wall-wart only puts out 9 volts DC?? This is because it isn't really THE power supply; that one is inside the crappy little energiser/amp box. Likely a reasonably sophisticated cluster of DC-DC converters. THAT'S the REAL power supply, & yes, upgrading that to linear supplies likely would make a big improvement. But nobody in their right minds are going to touch that for 2 excellent reasons: 1) This is the ONLY Electrostatic headphone system on the market with a lifetime warranty. Do you REALLY want to void it??? 2) The resulting linear power supply will be MONSTROUS! AND it will cost you hundreds of dollars to build, not $25 for a cute little Talema toroid, excellent transformer that I agree it is. BTW, I do intend to upgrade the energiser/amp in my pair. I am an Audio amplifier designer with 40 years experience, & I like my amplifiers to be all-valve, not misty-MOSFET's like this one (still sounds better than ANY Stax energiser/amp I've heard, including the puerile new 8000!) or the truly blecccchy Stax hybrid abortions like the 007t with its shitty transistor input stages with insufficient gain & feedback trying to push a pair of overstretched 6CG7 duotriodes to their absolute limits. The only amp I've heard that is decisively better is from Woo Audio, who make a nice all-valve push-pull EL34 job for Stax "Pro" (580V) headphones. So if you REALLY want to upgrade your energiser/amp, stop mucking about & send Darrin Fong the $150USD he wants for a Koss-to-Stax adapter cable, and start saving the $3000-odd it will cost you for the Woo amp!!! If that seems a ridiculous amount of money to spend on a $400 set of Electrostatic headphones, consider this: Mr. Speakers "Voce" headphones are $2000USD w/o an energiser/amp & get rave reviews for being about as good as the best Stax's (the 009, which I've also auditioned through custom valve energiser/amps for many an hour). The Stax's are $3800, & they are everything they're claimed to be. The Voce's are marketed as having "an incredibly thin 2.4 micron diaphragm", the inference being that this is state-of-the-art. Your Mass-Plop Kosses? A big, fat 1.5 microns!!! As for Stax, they don't say... What I say, though, is this: As is, the ESP/95X's have THE best bass of ANY headphone I have EVER heard. The combination of lowest distortion, best frequency extension, & best frequency flatness is unsurpassed. The midrange is absolutely on par with the Stax 009's; therefore, the 95X is STILL state-of-the-art, 25 years after it first hit the market!!! Only in the highs are the 95X's a minor disappointment. They are beautiful & ruler-flat right out to about 7000c/s, then there's a little blip of a db or two & then the response falls off a cliff! Only here is the Stax 009 quite noticeably superior. This gives the 95X a slightly "shut in" or "sound stuck in your head" quality. An upgraded 9V transformer will address NONE of this! Leave well enough alone & let (charging!) time work it's magic...
Fayne
2575
Nov 20, 2019
NottagorillaOi. I never said anything about cracking into the energizer, that'd be silly. It'd take wildly more effort than it is worth to modify the internal supply, and yes, lifetime warranty voiding. I'd be better off grokking how to design electrostatic amplifier and making my own, or going full on China-method and reverse engineering the circuit. Nor did I say anything about the cans sounding wrong or bad, because they don't. They're just as good now as they were back when I first heard them in '93 or '94. I just don't like the power brick, it is cheap and made of unknowns, just like all of the power bricks shipped with most entry level audio gear (and some mid). I prefer to turn off my hardware when it is not in use; preferably with a power switch before the transformer and AC->DC. Vampire power draw is real and I'm not terribly keen on it. When a power brick stays warm to the touch even though the hardware it supplies is and has been in the off state for hours, that is a complete waste. Waste heat means power losses which means PG&E charges me extra (you know, the jerks that keep setting California on fire), also means extra ambient heat which means higher power bill due to Air-Conditioning running more often. Plus, once again, it is bad design to put your power switch after the transformer and AC->DC. This is the source of most vampire power draw in most consumer grade equipment (aside from soft power switches and the likes). I highly doubt the internal unit stays energized when the power switch is toggled into the off state, but without cracking the case this is only supposition. I agree that there is a DC->DC going on inside the energizer chassis, likely switch mode. There is no way they'd be hitting the listed voltages otherwise without a class-a, and the heat generated doesn't feel like they went that way. Providing a cleaner DC9v will still make the poor little supply in the chassis happier, and is about the only thing I can do for the unit without breaking warranty. We're talking <=320mA of draw here under normal use, this is stupid simple to provide. From a safety standpoint I'll feel very much the better having fuses at the AC side. Also a real EMI/RFI filter at the input won't be a bad thing as I'm totally not using these in a RF and EM free environment, and while they likely have filters in place just for compliance sake, I can build (or source) better. I'm likely sourcing a medical grade filter at the IEC input, because tighter tolerances for a few more $mackers (and less maths than designing my own common-mode and differential-mode in a second or third order configuration). Replacing the power brick likely won't make a lick of a difference other than making me happy, while reducing my power bill... and lightening my wallet. This is just the first of many, really just a test before the main event, even. The MD LCX, MD CTH, MD 789, MD Airist, and LOXJIE P20 on my desk all need the same treatment. The STAX energizers have always been my planned final upgrade path, energizer wise. And yes, I'm especially interested in their tube units. Best of both worlds? Hell yes, I'll totally take me some tube amplified electrostatic loving. I rather bet that STAX have their main power switch between the input and the trafo, btw. Anyways, first I had to get the cans, which I finally have. As for the adapter, I'll likely make my own even if (for some silly reason) it costs more than buying it. That is part of the fun; it is mine, and I make it mine in my own (totally not) creative ways. Cables are usually the easiest parts, especially when the connectors aren't strange or unique. Wiring diagrams are freely available for the conversion too.
Nottagorilla
65
Nov 21, 2019
FayneOi indeed! I definitely got the sense that a desire to "personalise" your new headphone system was a significant motivator behind your desire to replace that "big", fat'n'juicy wall wart. I too, am not the biggest fan of its form factor. It's prone to sitting awkwardly in the receptacle, particularly horizontally on my power strips. OTOH, I am even more grateful that I got a quieter & cleaner linear adapter than some dinky & noisy SMPS wall-wart... You appear to have gone to a not-insignificant amount of trouble to get a PCB made (?) & sourced for a better transformer than what Koss gives us. But where is the safety improvement in a homemade, non-CE approved power supply project? I highly commend your creative spirit, & I am sure that SOME sort of sonic "difference" will result. I would even grant you that there probably WILL be a sonic improvement, HOWEVER SMALL due to the ACTUAL power supply being the DC-DC converter(s) inside the E90. But ONLY if you don't get too fancy & say, upgrade the amount of filter capacitance (or not!) but DON'T implement an "active" regulator circuit into your "pre"-PSU. That will add its own sound, & the result may not to your liking. Personal experience is against it! There are three issues here: 1) Whilst I am utterly & completely convinced that lowering power supply source impedance is only a good thing ("high current", which is the part non-audio electronic engineers don't understand; the high current capacity is merely a byproduct of the solutions used in LINEAR power supply design to improve sonic & electrical performance), I am rather more skeptical about taking such measures when dealing with switching, regulated psu's "upstream" of a linear one like we have here. Now, without inspecting the insides of the E90 to see how exactly Koss is stepping up the DC input voltage 75-odd times, I could be wrong about the degree of possible sonic improvement. I say this because the E90 is so small & the entire system so..."inexpensive", the implementation of the DC-DC conversion may well be rather basic. There isn't any strict requirement that the high voltages be regulated, especially the 600VDC polarising voltage. OTOH, regulating the polarising voltage is kind of impossible as a high source impedance here is necessary for lowest distortion from a push-pull electrostatic diaphragm. I wouldn't be surprised to see AT LEAST 1,000,000 ohms of added resistance in series with the polarising part of the PSU, as per Stax & others! 2) Because the diaphragms have to charge through such a large amount of series resistance, it takes a long time for Electrostatics to charge optimally. If you keep turning off the E90, your headphones will NEVER sound their best. You won't be getting the sound you paid for, the amazing performance it's capable of. You get lower efficiency (subtle, but noticeable), less treble extension (VERY noticeable), & less detail overall plus a longer wait for the E90 amp section to warm up optimally (QUITE noticeable, too!). Many audiophiles swear by leaving their preamps & power amps on continuously; For example, Bryston recommends it & they offer a mere 20 year warranty as well! So for someone chasing sonic improvements, why modify your system, potentially void your warranty by using an unapproved power supply? Wouldn't THE BEST SONIC UPGRADE be merely to figure out how to set up your E95X system optimally, & just use it accordingly? This is my primary argument! Figure out how to optimise the performance of the "stock" product first, & live with that for a while first. THEN maybe consider safe & thoughtful upgrades instead of just IMMEDIATELY ASSUMING YOU KNOW BETTER! Heck, even a Dekoni or whomever earpad "upgrade" would be a far wiser & more meaningful performance improvement... 2) As for safety, this is a "red herring". When a product has an extremely low maximum power consumption (the supplied wall-wart, as beefy as it is & rated to supply a full ampere, is STILL only rated for 9 watts!), fuses are mostly more trouble than they are worth. The incredibly fine wire on the primary winding of that wall-wart are hardly more tiny than the wire in say, a 1/10th Ampere fuse. Which would burn first? It doesn't matter! Yes, I've seen the rare DC wall-wart develop internal parts failure, like a shorted dinky little electrolytic filter and/or one of 1A 1N4002/3/4 diodes, resulting in enough overheating to partially melt the case. But it is far, far rarer (& has never knowingly happened to me or anyone I personally know in my 55 years on this planet) to have the wall wart catch fire as opposed to merely quitting after that bit of overheating. Most (98%+) of the time wall warts just safely & silently quit. My Stax SRD-7 power supply unit for my SRX-III headphones use only 160VDC polarising voltage. There is no power transformer, just a small 1A diode (half-wave rectifier) feeding a tiny electrolytic (1uF max!) & a 1M resistor straight to the front panel connector. Protection is via an 0.3A fuse mounted in an (unlabeled for amperage) chassis-mounted fuseholder. A foil label affixed to the underside of the unit by the then-Canadian distributor (TAE Electronics of Montreal) shows proof of CSA "special" approval by them (the Canadian version of UL, which was more stringent than Underwriter's Labs as well). Pretty Mickey Mouse, & entirely safe. 40+ years of flawless & near-continuous use! The E95X system meets all relevant CE electrical safety approvals; why are you so unconvinced of its safety?
Fayne
2575
Nov 21, 2019
NottagorillaI never said anything about the stock brick being unsafe. Just that it is the bad design that so many companies have taken. The act of having the brick plugged in generates power waste. If it is warm to the touch when the device is not in use, it is burning the 'lectric juice. I'm not chasing sonic improvements. I'm making a replacement because I can. Because I want a bloody power switch that isn't a master on a power strip, or so far behind the actual AC->DC conversion that even when toggled is wasting juice. If I'm going to make it myself, I'm going to throw in all of the crap that meets local code and emissions requirements. Hell, I even use SAC305 because lead is bad, mmkay. Because I've a habit of wanting to reuse the stuff I make for myself in multiple projects, I'm going to throw all the bells and whistles into it. At worst, I jumper around something that isn't needed. At best I can cookie cutter, and boop boop boop into a chassis they go. I've got seven amps and a handful of DACs and interfaces on my desk which I'm very much so not leaving on 24/7 and I really don't see any reason that their power supplies should be doing anything when the head units are toggled off. I'm quite willing to risk the stresses of powering things off and on as I need them, and I'm patient enough to let something warm up that needs it (I'm lookin at you LCX). The worst case is that I have to pop a chassis and dig around with my multimeter and oscilloscope to identify failed components. Replacement parts are as easy as hitting up mouser or digikey and making use of my reflow station and the aforementioned o-scope and m-meter (bench supply, signal generator, logic analyzer as needed as well) . Tubes are similarly testable and replaceable, which is why I own a TV7B/U and a few hundred of each of the types of tubes I use. If I was going for sonic gains, I'd just slap on some crystal encrusted cables and wooden knobs, yeah? :)
lmwhd650
0
Nov 26, 2019
FayneCan you give a review on the bass, mids, and treble of these. I own Sennheiser HD650 and was wondering if the bass, mids, and treble are the same or better. Also can you use a different better energizer for these Koss.
Fayne
2575
Nov 26, 2019
lmwhd650The sound is better across the board with the ESP/95x vs the HD6xx, I assume it is the same with the HD650. I don't have the 650, just the 6xx. Generally everything is clearer, cleaner, and more precise sounding. Staging wise, if the HD6xx is like sitting in a small dive venue, all close and personal with the musicians. It sounds good, you hear all the detail, but something is lacking... The ESP/95x is like sitting 3rd row center in a concert hall, lighter, airier, and much more precise. There is absolutely nothing I dislike with the sound of these units. The only thing the ESP/95x is missing is heavy sub-bass, and I can live without that. Electrostatic sounds like an ultra refined Planar Magnetic. They have a similar kind of precise sound, just a lot more of it from the electrostatics. You totally can get a better energizer, but you're going to be looking at a pricey purchase, most of the STAX units worth having starting at the orignal ESP/95x MSRP ($1000+).
birusan
7
Dec 20, 2019
NottagorillaDo you think the ifi pro iesl will improve the sound quality of the 95x over the original energiser and power supply?
Nottagorilla
65
Dec 27, 2019
birusanI am not familiar with this particular product from iFi. It may be very good, & I wouldn't rule out it being better. The E90x is a pretty minimalist (as in: Cheap!) effort, it SHOULD be easy to do better. But as I've said here before, this cheapo E90 still sonically MURDERS anything I've heard by Stax, including the SRM-007t & the new (& incredibly disappointing) SRM-8000. The ONLY amp I've heard that is better so far is a big push-pull EL34 amp from Woo Audio ($3000+USD), never paid any attention to the Model# since for that kind of money I'll one day build my own! I'm going to do a bit of research & get back to you with a stronger opinion & better info. But otherwise, you MUST trust your own ears here. Seek out a dealer to do your own auditioning as brand-names mean NOTHING in Audio much of (too much!!) the time. Another option, the one that works for me, is find your closest annual Audio Show & check out the CanJam portion of it!
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