[ratboi]

Same here, except that I am in Australia and using a US->AUS plug adaptor results in a ground loop hum. I've emailed koss to ask whether another 9V 1A adaptor would fix this, if anyone else has some tips to deal with ground loop hum I'm all ears So far I've found the hum stops when I ground myself by making physical contact with chassis of my preamp, or my keyboard.

I was prepared to be underwhelmed but the ESP 95/X is su-perb. Truly.

Yes, these are in a special league, have loved mine since end of 2016 - original Koss version, but (except for the pads) they are the same. Massdrop were selling a 220V adapter early on, might have helped you out, but the selection shows 'sold out' right now.

As barondla states, folks were buying a high amperage medical grade adapter and using it to improve performance. The grounding would be excellent, don't know about international availability. I kept the link, didn't buy - now I see it is discontinued. It was from SL, model number MENB1030A0903F01. Found through Mouser Electronics. Looks like they sell to Australia, so I suggest you check their site. ME20A0903N01 might work for you, only 2A but that should be more of a high end power supply. Others may feel free to correct me, or make better suggestions. $23.43 AUD.

 

[ratboi]

Has anyone tried a linear power supply instead of the stock adaptor? I was thinking of something to solve ground loop and found this:

https://www.aliexpress.com/item/15V...1c-4061-af8e-9086f4d51f1a&transAbTest=ae803_5

It does 9V / 1.25A apparently, while the stock adaptor does 9V/1A. Would this linear power supply work? Is that close enough in line with stock specs?

Maybe a bit overkill, friend! Maybe you've got a better deal with them, but I'm seeing $82.69 AUD for that. Yikes!

 

[adeadcrab]

Thanks for the mouser electronics link - I'll get that one instead

The options on massdrop were for a 110 or 220v unit - it seems both options still use the US style plug.

 

[Allanmarcus]

If you are hearing a hum, something else is going on. I would try a different circuit, or better, a whole different building. I doubt that is the the issue. I would not waste time chasing a power supply; I would return it as defective.

 

[adeadcrab]

If you are hearing a hum, something else is going on. I would try a different circuit, or better, a whole different building. I doubt that is the the issue. I would not waste time chasing a power supply; I would return it as defective.

I'll try that first, though wouldn't a US->AUS adaptor introduce hum?

 

[ratboi]

I'll try that first, though wouldn't a US->AUS adaptor introduce hum?

Does it have a transformer? is it three wire or two?

Not knowing the words to Basket Case by Green Day _might_ introduce a hum. Past that, I can't be sure what your issue is; sorry...

 

[barondla]

Ok, so >= 1A, and 9V only? I'd better get one.

@adeadcrab no idea if a different power adapter will fix the ground loop hum. My original Koss has no hum and the ifi adapter causes it.

 

[adeadcrab]

Australia plugs always have 3 pins, one of them being earth. Both the stock plug and the US->AUS adaptor only have 2 pins..

The only adaptors that I see with the earth pin are those linear power supplies with massive toroidal transformers.. :S

 

[IBJamon]

Hey guys! I finally got my Koss back last night and man they are excellent. I brought them in to work because my boss wanted to see them (he's an audio nut also) and I showed a few other coworkers. I may have sold 2-3 more sets unintentionally.

When I was at Koss HQ a couple of weeks ago, they said there were no extension cables for sale. I didn't think to ask again last night when I picked up my repairs, but it seems they are not easily obtainable anymore. I did pick up 2 sets of the pleather pads for dirt cheap to test/play around with. They sound really good; not sure which is better. They are (physically) warmer though, so I went back to the cloth ones for now. It sure would be nice if someone could make custom pads that cost less than $90.

While at work I noticed that they hum if the source is not connected or doesn't have a lifted ground. I unplugged my cable from my phone and it started humming, and went away when I plugged it back in. (I have a LG G7 ThinQ, which has an excellent Quad DAC). I hope that helps!

 

[barondla]

Hey guys! I finally got my Koss back last night and man they are excellent. I brought them in to work because my boss wanted to see them (he's an audio nut also) and I showed a few other coworkers. I may have sold 2-3 more sets unintentionally.

When I was at Koss HQ a couple of weeks ago, they said there were no extension cables for sale. I didn't think to ask again last night when I picked up my repairs, but it seems they are not easily obtainable anymore. I did pick up 2 sets of the pleather pads for dirt cheap to test/play around with. They sound really good; not sure which is better. They are (physically) warmer though, so I went back to the cloth ones for now. It sure would be nice if someone could make custom pads that cost less than $90.

While at work I noticed that they hum if the source is not connected or doesn't have a lifted ground. I unplugged my cable from my phone and it started humming, and went away when I plugged it back in. (I have a LG G7 ThinQ, which has an excellent Quad DAC). I hope that helps!

@IBJamon glad Koss got your headphones sounding great again. Would hate to do without mine. Think the sound quality is still improving as they play.

Not surprised by the lack of extension cables. Koss has supplied 700 more than they thought they would. That's a lot of extra cables. Thought about ordering the Fong adapter cable for a Stax amp. Don't see many used Stax SRM amps for sale now. Will probably await the new Koss amp.

 

[IBJamon]

Where did you hear Koss was developing a new amp?

 

[barondla]

Where did you hear Koss was developing a new amp?

Where did you hear Koss was developing a new amp?

In the Question & Answer with Michael Koss Jr. He was asked if they were working on an upgraded E90 and he said "stay tuned".

Makes sense. There isn't a lot more that can be done to improve the headphones. The E90 has lots of room for improvement.

 

[fjf]

It sure would be nice if someone could make custom pads that cost less than $90.

https://vesperaudio.com/earpads?brand=178

 

[IBJamon]

https://vesperaudio.com/earpads?brand=178

Those are the ones that cost $90.

 

[IBJamon]

So, a funny story. I have been an audio nut for quite some time (I built my home theater almost 15 years ago). I have had several pairs of headphones come and go through here, with my favorites being planars (T50RP Mk3, M1060). I have always felt like estats is where I wanted to end up, so I got the massdrop when I got a nice unexpected bonus at work.

Well, when I got them back, I let my wife listen to them. In all of my years of doing cool audio things, my wife has never had 'that look' and said I want one before. Well, she did with these Koss ESP/95X. So now, I have a pair ordered that should hopefully arrive by Mother's Day...