KOSS ESP-950 Thread
Sep 17, 2020 at 5:08 PM Post #3,811 of 3,923

adeadcrab

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That bottlehead amp looks nice. I've been looking for a good tube amp to drive my STAX and was leaning towards Mjolnir Audio but it's nice to have another option.
You should test drive it for us :D
 
Sep 21, 2020 at 5:29 AM Post #3,812 of 3,923

PolloLoco

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I figure I'll post this here and on the Kaldas RR1 thread. This weekend, for fun I made a Stax to Koss adapter, so that I could use my Stax terminated headphones with the Koss E90 amp. I've attached the picture below.

A friend had used the female end of my Koss extension to make me a Koss-to-Stax adapter. I saved the male end, and this adapter was a lot easier to make. I used Spritzer's advice and added a 4M7 resistor to the bias line - but otherwise, the female socket I was able to find online was much easier to solder to than the common male plugs. Without the resistor, I believe the problem is that Stax headphones are more likely to arc, thereby damaging your diaphragms.

The Stax cable I bought from Spritzer for the Kaldas RR1 fit flush as shown in the image. The pins on my Kaldas RR1 cable are longer and end up being exposed. In any case, both cables work just fine. I may add a cylinder or backshell to make sure pins aren't exposed in any case.

This might be useful for people wanting to dip their toes in the Stax or Kaldas headphones, without having to invest in an amp right away. The E90 did a decent job of driving my Kaldas RR1. The signature was brighter than I expected, and I used a tone generator to see if the E90 gave me more extension on the high end. It did not - I could hear a slightly lower max frequency with the E90 than with my SRM 717 (14.5KHz vs 15KHz). But the overall tonality was brighter, driving the Kaldas closer to neutral. The bass was still great, far better than my Koss ESP95X - but nowhere near as good as with my Stax SRM 717 amp.

The Stax SRM 717 provides better soundstage, a little more clarity, and deeper bass. Would I use the E90 as my primary amp? No. Would I use it at work as a secondary amp? Absolutely, if I'm eventually allowed to return to the office after this crisis.
 

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Sep 24, 2020 at 7:23 AM Post #3,813 of 3,923

Timoteew

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Sep 24, 2020 at 11:18 PM Post #3,814 of 3,923

barondla

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Oct 4, 2020 at 8:01 PM Post #3,816 of 3,923

Brahmsian

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I've written up some of my thoughts on the Koss ESP95X, please feel free to take a look over on my website: https://www.modioaudio.co.uk/blog/koss-esp95x-artisan-sound-in-a-thoroughly-mediocre-package. If you can look past the obvious quirks such as poor construction and occasional whining/popping sounds then you are left with the most natural sounding headphone I've ever heard.

Interesting that the energizer measured 15v. I and another headfier both experienced hum with the iFi 9v power supply. Apparently you didn't. How is that linear power working out?
6D8E4AFC-B622-4358-8D19-DF98D103B1EE.jpeg

3A812D2A-E9F7-47F6-BE36-1EF9FBD27922.jpeg


I’m not sure the noise issues are due to the stock power supply though.The noise I had went away on its own after about two weeks.
 
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Oct 5, 2020 at 4:21 AM Post #3,817 of 3,923

Timoteew

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Interesting that the energizer measured 15v. I and another headfier both experienced hum with the iFi 9v power supply. Apparently you didn't. How is that linear power working out?
6D8E4AFC-B622-4358-8D19-DF98D103B1EE.jpeg

3A812D2A-E9F7-47F6-BE36-1EF9FBD27922.jpeg


I’m not sure the noise issues are due to the stock power supply though.The noise I had went away on its own after about two weeks.
Cheers for getting in touch - the hum hasn't been eliminated completely by the iFi power supply, but it occurs considerably less frequently and not as severely as it did for me with the stock wall-wart. The linear psu in the image is only powering the DX3pro DAC/amp unfortunately as it only has 5v and 15v outputs - would have been ideal if it could supply the E90x energiser too!
 
Oct 8, 2020 at 2:41 PM Post #3,818 of 3,923

sling5s

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How do these (Koss ESP 95X) compare to ath-msr7: detail, mids and soundstage?
I used to own the esp 950 but it's been too long to remember.
 
Oct 9, 2020 at 2:27 AM Post #3,819 of 3,923

dagothur

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How do these (Koss ESP 95X) compare to ath-msr7: detail, mids and soundstage?
I used to own the esp 950 but it's been too long to remember.
I haven't heard the ATH-MSR7, but the ESP/95X has a slightly dark, polite, fast signature. From memory it reminds me a lot of the HD6X0 series.
 
Oct 10, 2020 at 2:18 AM Post #3,820 of 3,923

Makiah S

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That bottlehead amp looks nice. I've been looking for a good tube amp to drive my STAX and was leaning towards Mjolnir Audio but it's nice to have another option.

I'm a very biased and happy Mjolnir owner, the second hand one off's that pop up are a complete steal! Quite stunning imo and hopefully I can upgrade to a Carbon quality amp one day, but @spritzer is the "Don" for a reason imo and I do know enjoy my 95X on a CCS modded Mjolnir amp

Cheers for getting in touch - the hum hasn't been eliminated completely by the iFi power supply, but it occurs considerably less frequently and not as severely as it did for me with the stock wall-wart. The linear psu in the image is only powering the DX3pro DAC/amp unfortunately as it only has 5v and 15v outputs - would have been ideal if it could supply the E90x energiser too!

In my home I did notice a touch less "noise" with the iFi Power X adapters.

I haven't heard the ATH-MSR7, but the ESP/95X has a slightly dark, polite, fast signature. From memory it reminds me a lot of the HD6X0 series.

I've never known an ATH can to be dark... having a 95X now tho I can attest that despite being "dark" the top end doesn't come across as obviously rolled off as it does/can with the HD 6XX
 
Oct 10, 2020 at 2:45 AM Post #3,821 of 3,923

dagothur

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I've never known an ATH can to be dark... having a 95X now tho I can attest that despite being "dark" the top end doesn't come across as obviously rolled off as it does/can with the HD 6XX
True, but in fairness I'm remembering a pair of HD650s I heard 10 years ago running on a Audio-GD Compass. The Koss Esp/95X are as closed to balanced as a dark headphone gets and it's hard to find a very similar dynamic can. I'm also using my Audio-GD D27 as the source which is in another league compared to the Compass.
 
Oct 10, 2020 at 3:03 AM Post #3,822 of 3,923

Makiah S

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The Koss Esp/95X are as closed to balanced as a dark headphone gets and it's hard to find a very similar dynamic can.

mmmhm, I'm always impressed with 95X. I can go from listening with 009 to 95X and I don't hate it... yea there's a LOT missing but enough to still appreciate the music and overall transparency of the system I'm listening with

It's like the perfect "musical" headphone imo, it won't destroy older poorly mastered music and doesn't mask all of the nuance in well mic'd, mix'd and mastered tracks either
 
Oct 11, 2020 at 11:11 AM Post #3,823 of 3,923

PolloLoco

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How do these (Koss ESP 95X) compare to ath-msr7: detail, mids and soundstage?
I used to own the esp 950 but it's been too long to remember.


I own the ath-msr7B and the ESP95X - and I've read that most people believe they're identical to the MSR7 except for the balanced connections.

The ESP95X are faster and more detailed despite being ethereal and polite by comparison. The ESP95X have a bigger soundstage. My MSR7B is a bit shouty in the upper mids, and despite originally agreeing with a pro review about their timbre being super accurate - compared to the ESP95X it falls short. There's a lot more treble in the MSR7B, but it's not necessarily better since I find it a bit piercing. I think I will sell my MSR7B soon. The MSR7B has punchier bass, but I don't think it's as detailed or good at layering percussion instruments in the mix. Overall - the ESP95X are more natural and easier to listen to. The MSR7B are agressive and solid closed portables. The MSR7B were a great option for work - since they didn't leak sound at all and had decent isolation in the office.

On a similar note - I'd like to ammend my comment about the L700 being absolutely better than my ESP95X. I still think it's true, but the L700 have an element of warmth that I enjoy - but was surprised by despite reading reviews about it. I expected the brightness and thin forward detail of the L300/L500's I used to own. But listening to mids on the L700 vs the ESP95X isn't just better on the L700 - it's different. I love the pleasant warmth the L700 brings to vocals, making them more intimate and nuanced. But the Koss ESP95X mids are more natural in my opinion - and there are times I can see myself preferring that sound. Though I'd probably prefer the L700 90% of the time.
 
Oct 11, 2020 at 11:24 AM Post #3,824 of 3,923

PolloLoco

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This won't be a 100% hijack post - I'll post comparisons to my ESP95X, and add comments that might benefit ESP950 owners.

I'm attaching pictures of my finished open Koss ESP6 Pro Bias conversion. It's the most rewarding project I've had since I jumped back into the audiophile hobby. It was technically quite easy since I taught myself to solder during the COVID crisis, and I'm still bad at it. In short, I removed nearly 2 pounds of guts from a Koss ESP6, all the damping and added pro bias cables from Kaldas. The open grills are laser cut wood that I then drilled and ground, though I may still try to get more accurate grills 3D printed. I've done quite a bit of pad rolling - but in the end, the cheap generic Koss ESP950 pads from EBAY ($12) fit best. If the pads are too thick, they lose too much detail with no noticeable gain in bass. Unlike with my Koss ESP950 - the generic pad fit is such that I get no wrinkles where they contact my face and I get a really good seal.

KossESP6Pro.jpg

The sound is surprisingly good for 50 year old drivers . . . some people say they weren't meant for pro bias, others say they're identical to the ESP9 drivers and as such would be OK with pro bias. If they eventually die on my Stax SRM 717 - I'm OK with that, but I'd do it again. Overall they don't sound as good as the ESP95X but they're in the same ballpark. The treble and bass are both slightly rolled off by comparison, I tend to equalize by 3DB below 60 hz and occasionally above 12.5KHz. The mids are more forward and impactful, not ethereal - they're more like my Kaldas RR1. The Koss ESP95X have a bigger soundstage and are easier to listen to.

One lesson I learned while playing with these for the last couple months - is that the damping Koss put in - really smothered the sound. I was really disappointed with my closed and open builds - until I removed all the felt and the plastic grills on the pad side. After that, these really came alive with detail and speed. I've read that the Koss ESP95X have damping on the grill side - and I'm pretty sure I'll eventually try to take it out. I've removed the felt under the pads previously, and the treble came alive - removing a bit of veil I didn't realize was there.

Kosses.jpg
 
Oct 15, 2020 at 11:12 PM Post #3,825 of 3,923

Amish

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I'm a very biased and happy Mjolnir owner, the second hand one off's that pop up are a complete steal! Quite stunning imo and hopefully I can upgrade to a Carbon quality amp one day, but @spritzer is the "Don" for a reason imo and I do know enjoy my 95X on a CCS modded Mjolnir amp

I too am a Mjolnir owner. It is the only amp I use with my STAX and KOSS electrostats and I was thinking about buying a tube amp from him but like I said, I've been on the fence for a while now. I really do not need another amp. God knows I have too many.
 

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