[Shane D]

Has anybody had any hum in the headphones and managed to beat it?
I got a replacement set from Drop after my first set failed. I only used them for about ten hours and thought were fine with the odd whisper of noise. I thought maybe it was interference from where I had it set up.

I notice now when I turn it on, especially at high volume, with nothing playing, it has a nasty hum. It is much harder to hear at my normal listening level. And it non-existant when music is playing or between songs. When I hit pause on my music source it is quiet for about 10 to 20 seconds and then the hum is noticeable.

 

[fjf]

Yes, it happened. Put them on and push gently the cup against your ear. That will move the membrane slightly and (for me) solve the issue.

 

[Shane D]

Yes, it happened. Put them on and push gently the cup against your ear. That will move the membrane slightly and (for me) solve the issue.

That worked for me with crackling headphones. Don't think that will affect the hum. It seems like when the music stops, within a very short time, the amp switches modes (stand by maybe?) And then it gets noisy.

 

[fjf]

Does it disappear if you switch it off and then on?

 

[Shane D]

Does it disappear if you switch it off and then on?

Nope.

 

[fjf]

You may have a ground loop: https://web.mit.edu/jhawk/tmp/p/EST016_Ground_Loops_handout.pdf

 

[Shane D]

You may have a ground loop: https://web.mit.edu/jhawk/tmp/p/EST016_Ground_Loops_handout.pdf

But if that was the case, wouldn't all my amps be having problems?

 

[silent-circuit]

But if that was the case, wouldn't all my amps be having problems?

No, a ground loop is an issue with the power / ground isolation at your location / in your home or business.

 

[Shane D]

No, a ground loop is an issue with the power / ground isolation at your location / in your home or business.

So, by definition it would affect all my amps right?

 

[silent-circuit]

So, by definition it would affect all my amps right?

No, some are more susceptible than others, though I would expect you to have run in to a similar issue with other gear before.

 

[Shane D]

No, some are more susceptible than others, though I would expect you to have run in to a similar issue with other gear before.

I don't think it is a ground loop problem. I have gone through about 10 amps in the last two years and this is a first. And I have had multiple SS amps, multiple hybrid amps and one full tube amp. None have had any problems, including my last E95X (this unit is a warranty replacement).

 

[Shane D]

No, some are more susceptible than others, though I would expect you to have run in to a similar issue with other gear before.

I don't think it is a ground loop problem. I have gone through about 10 amps in the last two years and this is a first. And I have had multiple SS amps, multiple hybrid amps and one full tube amp. None have had any problems, including my last E95X (this unit is a warranty replacement).

 

[barondla]

I don't think it is a ground loop problem. I have gone through about 10 amps in the last two years and this is a first. And I have had multiple SS amps, multiple hybrid amps and one full tube amp. None have had any problems, including my last E95X (this unit is a warranty replacement).

The Koss energizer is much more susceptible to hum than a mere headphone amp. It is like comparing a moving magnet phono stage to a moving coil head amp. The Koss might be amplifing considerably more than a normal headphone amp.

I hear a very very slight hum when using the PonoPlayer plugged into USB power. There's none on battery power. I've never heard hum from the PonoPlayer when using any of my high efficiency IEMs. That gives an idea how sensitive the Koss is.

Make sure nothing electrical is near the Koss, the interconnects or power supply. If using RCA cables make sure the connectors fit tightly. Try different cables - some are shielded better than others. I had better luck with 3.5mm to RCA vs. aux cable. which is good because the PonoPlayer is now running into a Schiit Loki EQ. That has an extra ~ 6db of boost added in the low end.

Good luck,
barondla

 

[Shane D]

The Koss energizer is much more susceptible to hum than a mere headphone amp. It is like comparing a moving magnet phono stage to a moving coil head amp. The Koss might be amplifing considerably more than a normal headphone amp.

I hear a very very slight hum when using the PonoPlayer plugged into USB power. There's none on battery power. I've never heard hum from the PonoPlayer when using any of my high efficiency IEMs. That gives an idea how sensitive the Koss is.

Make sure nothing electrical is near the Koss, the interconnects or power supply. If using RCA cables make sure the connectors fit tightly. Try different cables - some are shielded better than others. I had better luck with 3.5mm to RCA vs. aux cable. which is good because the PonoPlayer is now running into a Schiit Loki EQ. That has an extra ~ 6db of boost added in the low end.

Good luck,
barondla

Thanks for the advice but Drop was kind enough to offer me a full refund. They received them today and issued my refund. I will put the money towards something different.

 

[Pharmaboy]

To all on this thread--I'm sad to report that someone who occasionally posted here, @Geezer Rock 001, recently passed away (heard this from his wife today).

Randy and I had become good PM buddies for some time. I learned from him and valued his perspective on just about everything.

R.I.P. @Geezer Rock 001.