[stuck limo]

That's strange. Mine hums no matter what source is used. Even battery powered Pono Player and Shanling M0 hum. Not a little hum either. Tried different interconnects. Only thing not tried is different ac wall receptacle. Since the ifi is a switcher it should be polarity agnostic so I doubt using another receptacle will matter. Will try it when I get a chance.

So @stuck limo does the ifi improve things sonically?

I've tried the 9v/3a and the iFi vs the stock but only very briefly. I may this weekend when I get more time. The only thing I *thought* I heard was there was more body to the sound signature with the 3A and iFi 2A vs the stock. But don't quote me on that yet.

At home I have the iFi plugged into a Furman power conditioner with an iFi AC iPurifier in that same wall outlet. No hum. I also have it plugged in at work right now into a regular cheapo power strip and there's no hum. Can you describe more about the hum you're hearing?

 

[barondla]

I've tried the 9v/3a and the iFi vs the stock but only very briefly. I may this weekend when I get more time. The only thing I *thought* I heard was there was more body to the sound signature with the 3A and iFi 2A vs the stock. But don't quote me on that yet.

At home I have the iFi plugged into a Furman power conditioner with an iFi AC iPurifier in that same wall outlet. No hum. I also have it plugged in at work right now into a regular cheapo power strip and there's no hum. Can you describe more about the hum you're hearing?

@stuck limo it sounds like 60hz hum and it is loud. Close to as loud as the loudest music. Sounds identical to a turntable that doesn't have the ground wire connected. Weirdness for sure.

 

[stuck limo]

Who even lives like this?? This is disgusting.......ly good sounding.

(iFi iSilencer > AQ Carbon > LH Revive > AQ Carbon into Micro USB adaper > LH GO2Pro SEX (upgraded SE) > AQ Victoria w/ upgraded Carbon DBS > Koss) >>>> Powered by iFi iPower

It also sounds excellent running off my Valhalla 2 tube amp. (AQ Water cables feeding it)

I'll post some impressions later but essentially it sounds like a tweaked Senn 600.

 

[greenhornet4]

Cross Post from the less active ESP950 thread:

Hey friends,

This morning I sat down to find my ESP950s have a slight buzzing coming from the left ear piece. This occurs even when it isn't plugged into a source, just the electrifier. I received these back from KOSS only two months ago, while having bought them about four months ago and am not eager to relive that experience, especially given that I just put after market earcups on them. Wondering if this type of problem is usually from the electrifier, or from the phones themselves. Thanks!

Had a similar problem, turns out I was sitting on a heating pad (pulled muscle in back). Heating pad off, buzz gone. The buzz was audible with everything disconnected, power off. Go figure.

 

[barondla]

The Koss seem fairly sensitive to their electrical environment. Reminds me of moving coil phono step up devices. Rerouting a power or signal wire, locating the energizer box differently or turning other components off can reduce noise. The Koss are like hotrod cars and sometimes need a little tlc to perform at their highest levels.

 

[stuck limo]

@stuck limo it sounds like 60hz hum and it is loud. Close to as loud as the loudest music. Sounds identical to a turntable that doesn't have the ground wire connected. Weirdness for sure.

So last night I got the hum! It didn't matter what power source I used, it was there. The whole week it was fine where it was using the outlet it was using. Then out of nowhere, it decided to happen. I moved across the room to another outlet (another Furman) and the issue went away for all power sources. So now I ordered yet ANOTHER Furman to plug into that side of the room. Previously, I was using an extremely cheap LG power strip in that particular area.

 

[stuck limo]

So I needed a carry bag for the Koss, and since I don't feel like spending 150 bucks on the official leather bag from Koss, I ended up buying this for 18 bucks with tax:

https://www.amazon.com/AmazonBasics...0&pf_rd_r=QR2PEWKZT09BNP282REY&qid=1572120459

I think it'll work and I'll report back when it arrives on Monday.

Basically, if anyone wants to know how the Koss compares to the Senn 600, here's my impressions with Vesper Elite Hybrid pads:

Koss is smoother and about 25 to 50% "faster" sounding (not as fast as something like a Stax L700)
Senn 600 has more forward mids and sounds more exciting.
Koss is darker sounding by a tad but retains amazing detail retrieval, probably moreso than the 600 (not drastically, but noticeable)
Koss has wider and deeper soundstage, better bass and doesn't sound as trebly.
Koss is "cleaner" and thinner sounding, whereas the 600 sounds lush in comparison, yet the Koss sounds more "present"
Senn 600 sounds a bit more romantic and doesn't grab my attention as much as the more technically capable Koss. It's easier to passively listen to the 600 but not drastically so.
Compared to a Stax L700 off a heavily modified/beefed up 252s Stax amp, the Koss and Senn 600 have "soul" and a musicality that the Stax doesn't.

Basically, IMO, the Koss ESP950 sounds like a Senn 600 on steroids. It's like they took all the aspects of the Senn 600 and tweaked them juuuust a bit in different directions. They are noticeably different but still share the same type of sound signature that would easily allow a listener to transition back and forth without a shock to the system. I actually prefer the mids presentation and the brightness of the 600, but on all other aspects, I tend to prefer the Koss. The Koss is certainly not a replacement for the 600, but it is definitely a complimentary upgrade.

 

[PolloLoco]

I've bought 2 more amps (yes, I have a problem) and can say with absolute certainty - the Koss ESP950 or in my case, the ESP95X, scale A LOT with more power. The modded Stax L300 I have don't scale up anywhere near so much.

First - I got a Stax energizer, the Stax SRD 7 MK 2. I connected it to my Sabaj D5 Dac using a cheap mini speaker amp that I had used with a chromecast audio. It claims to be 200W, but I'd be shocked if it put out more than 50W. Wow. On Stax threads, the argument is that by getting an energizer instead of a stax amp, you trade improved dynamics and lose a little detail. I can honestly say the Koss improve in BOTH dynamics and detail. I have to admit, I used the bass and treble knobs on my amp to color the sound slightly, but wow, it was the best sound I'd ever heard from headphones. By comparison the Koss E90 energizer seemed veiled . . . I overpaid for the SRD7 MK 2 ($250) due to a bidding war, but this may be the best bang for the buck option for Koss ESP950 owners. If you have a speaker amp you're happy with, you might be all set.

I started shopping for a better speaker amp, or an IESL (a far more advanced, but expensive energizer) - when I came across a stax SRM 717 on a Japanese auction site. I thought it was a steal, until the auction site and middle men charged me $100 more in fees than I'd previously paid . . . Still I'd buy it again in a heartbeat. I was intrigued by the switch that disables the volume control in the SRM 717 and make it a power amp. Perhaps foolishly, that had me more interested than buying an SRM 727. Also with a voltage swing of 450V - it matches Stax's most powerful amps, so probably the best dynamics I was likely to get outside of getting one of the aftermarket amps like the KGSS or Carbon.

The first day of listening, for 2 hours, I wasn't sure it was an improvement honestly. Day 2, I was just smiling - I think I've hit my endgame. The reason being that the bass is so much stronger, and the treble to a lesser extent, that the mids take a slight step back. It took me while to realize the mids were just as detailed as before, if not moreso - but the soundstage was dramatically improved. No joke, these sound like completely new headphones to me . . . There's so much detail, and the soundstage has had me reacting to 3D effects I'd never noticed. I've also connected a cheap tube pre-amp via RCA inputs, and really enjoyed the sound. The only negative pairing I've found was that I tried to connect my Loxjie P20 as a pre-amp via XLR, but had a steadily growing buzzing? Perhaps I have a bad 4 pin XLR to 3 pin XLR Y cable.

Since day 1 I've had a love hate relationship with these headphones. It took me months, but now I'm beyond thrilled with my purchase. The first time I heard the coil whine - I wanted to throw these across the room. But now, they're super comfortable, effortless, detailed and sweetly musical. I'm using the cheap Chinese pads which work surprisingly well, but just ordered the Dekoni fenestrated lambskin pads from Drop. I don't like the velour pads these came with, and am skeptical of fenestrated pads though I've never tried them.

Until recently I thought I'd eventually get Stax SRM L700 headphones, but now I don't think I'll bother?

 

[Amish]

@PolloLoco I'm glad you are happy. I agree that the ESP95x (in my case) does scale better with a good amp. The Koss energizer is not a bad little unit but it doesn't have the power of some better Stax amps or energizer. That said, the Stax L700 is a bigger step up. I purchased the L700mkII and the difference was large. As of now, I use the Koss headphones for gaming and general PC duties while I use the L700 for music. IMO there is no comparison. The Stax L700mkII stomps the Koss ESP 95x into the ground, but the cost difference is big. Worth every penny to me though.

 

[adeadcrab]

I have noticed a linear power supply help a bit with soundstage, or perhaps the perception of soundstage.. switching from 95X to Elex, the Elex is much, much more dynamic and filled with microdetail. Would be interesting to see if a stax amp, or another electrostatic amp can improve dynamics and microdetail on the 95x..

 

[robo24]

Got the ESP 95X used on here a couple weeks ago, and the Stax 323a on here a couple days ago. They were pretty good with the stock energizer, but just WOW with the 323a. The phones themselves are just crazy light and very comfortable. Ordered some Alcantara Vesper pads too. Nice to get the 95X and the 323a & cable for what the standard price has been for the Koss version. I'm terrible as describing sound, but the soundstage improvements were obvious.

 

[PolloLoco]

@PolloLoco I'm glad you are happy. I agree that the ESP95x (in my case) does scale better with a good amp. The Koss energizer is not a bad little unit but it doesn't have the power of some better Stax amps or energizer. That said, the Stax L700 is a bigger step up. I purchased the L700mkII and the difference was large. As of now, I use the Koss headphones for gaming and general PC duties while I use the L700 for music. IMO there is no comparison. The Stax L700mkII stomps the Koss ESP 95x into the ground, but the cost difference is big. Worth every penny to me though.

Thank you very much for that feedback. Next time I get an urge to experiment, I'll consider the L700 again. What amp are you using for both? With my SRM 300 I preferred my modded L300 slightly. With the SRM 717, the Koss is a clear winner.

I'll have to judge whether my hearing can pick up any improvement between the ESP950 and L700. I wish I could try them locally but this rarer stuff seems to require commitment and risk. Ill also have to research if there are sonic differences between an L700 mk 1 and 2. I know build quality improved.

 

[llcook51]

Has anyone compared the ESP 95X or 950 with the Stax SRS-3100 Ear speaker system?

 

[PolloLoco]

Has anyone compared the ESP 95X or 950 with the Stax SRS-3100 Ear speaker system?

Sort of. The L300 I have are modded with the L500 pads, L700 band and blue tack to increase bass. I also have an SRM 252A amp that I've been playing around with.

If I were to compare the 2 base systems, I prefer the Stax setup more. Better clarity, more bass and treble (but not more extension). But theres little soundstage, everything is super intimate.

If you were interested in upgrading to a more powerful amp, I enjoy my Koss ESP95X more. The Stax L300 improved somewhat with the better amp, but the Koss improved a ton. The Koss are also much more comfortable for me, though they may look cheap.

Hope that helps answer your question.

 

[llcook51]

Sort of. The L300 I have are modded with the L500 pads, L700 band and blue tack to increase bass. I also have an SRM 252A amp that I've been playing around with.

If I were to compare the 2 base systems, I prefer the Stax setup more. Better clarity, more bass and treble (but not more extension). But theres little soundstage, everything is super intimate.

If you were interested in upgrading to a more powerful amp, I enjoy my Koss ESP95X more. The Stax L300 improved somewhat with the better amp, but the Koss improved a ton. The Koss are also much more comfortable for me, though they may look cheap.

Hope that helps answer your question.

Thanks. That is exactly what I needed to know.