[heyguyslol]

Despite what the HA-3A power chart says the 4.4mm has quite a bit of power. All of my can's are easy to mildly difficult to drive.

To my understanding unless you are pushing into Susvara territory, the 3A can generally drive it.

 

[TheAbyss2022]

Anyone get hissing with dynamic driver headphones? My HD700 and HD800S connected to 1/4 input have a lot of hissing in the background. I mostly listen to my LCD 4 but it is annoying.

 

[Louisiana]

Anyone get hissing with dynamic driver headphones?

No hiss with Meze 109 Pro, no matter which input.
I forgot:
Also no hiss with ZMF Atrium & Auteur Classic.

 

[betula]

Anyone get hissing with dynamic driver headphones? My HD700 and HD800S connected to 1/4 input have a lot of hissing in the background. I mostly listen to my LCD 4 but it is annoying.

Could be your tubes being more sensitive with high impedance headphones. Is it the same if you change the impedance switch? Perhaps try them with a different set of tubes.

 

[TheAbyss2022]

Could be your tubes being more sensitive with high impedance headphones. Is it the same if you change the impedance switch? Perhaps try them with a different set of tubes.

Its always been on the lowest impedance as the noise gets worse going to medium and high. I swapped out the nos tubes and put the stock ones and and I noticed the noise was reduced but it was still there.

Do you reckon this should fix the issue? https://ifi-audio.com/products/iematch4-4/

 

[godmax]

Anyone get hissing with dynamic driver headphones? My HD700 and HD800S connected to 1/4 input have a lot of hissing in the background. I mostly listen to my LCD 4 but it is annoying.

Both of my dynamic Kennerton headphones(116dB/mW sensitivity) and also the Denon D9200 (to a lesser extend) tend to hiss on my HA-3A, where as my Emu Teak, Klipsch HP-3 and Fostex TH-909 are free from hissing.
Interestingly both of your Sennheisers are high impedance and not overly high sensitivity (100ish dB/mW), I would have assumed you will not get any hissing on the Cayin with these.
Have you connected your DAC through RCA or XLR to the HA-3A? (little different signal path, see post)

 

[TheAbyss2022]

Both of my dynamic Kennerton headphones(116dB/mW sensitivity) and also the Denon D9200 (to a lesser extend) tend to hiss on my HA-3A, where as my Emu Teak, Klipsch HP-3 and Fostex TH-909 are free from hissing.
Interestingly both of your Sennheisers are high impedance and not overly high sensitivity (100ish dB/mW), I would have assumed you will not get any hissing on the Cayin with these.
Have you connected your DAC through RCA or XLR to the HA-3A? (little different signal path, see post)

I tried both RCA and XLR to the DAC with the same result.

Even lightly tapping on the amp gives me some feedback bumping noises in the headphones.

Update: I bought the Ifi Audio DC Blocker because I believe its transformer hum as I can hear it humming without any RCA or XLR cables connected so it has to be the transformer.

 

[Guacamolly]

I tried both RCA and XLR to the DAC with the same result.

Even lightly tapping on the amp gives me some feedback bumping noises in the headphones.

Update: I bought the Ifi Audio DC Blocker because I believe its transformer hum as I can hear it humming without any RCA or XLR cables connected so it has to be the transformer.

How old is your electrical panel and the wiring is the house ?

 

[heyguyslol]

I tried both RCA and XLR to the DAC with the same result.

Even lightly tapping on the amp gives me some feedback bumping noises in the headphones.

Update: I bought the Ifi Audio DC Blocker because I believe its transformer hum as I can hear it humming without any RCA or XLR cables connected so it has to be the transformer.

If you haven't already try moving the amp to other outlets and/or rooms. I did this when I was trying to troubleshoot my noise issue which it ended up being dirty power in my main room setup, my studio room is much cleaner to a near black bkg.

While this may not solve your issue it may help narrow down what the problem is. gluck

 

[TheAbyss2022]

If you haven't already try moving the amp to other outlets and/or rooms. I did this when I was trying to troubleshoot my noise issue which it ended up being dirty power in my main room setup, my studio room is much cleaner to a near black bkg.

While this may not solve your issue it may help narrow down what the problem is. gluck

I moved the amp down to the kitchen from my room and had the same result so hopefully the Ifi DC Blocker solves the issue.

How old is your electrical panel and the wiring is the house ?

I live in a newly built house (5 years old).

 

[Guacamolly]

I moved the amp down to the kitchen from my room and had the same result so hopefully the Ifi DC Blocker solves the issue.

I live in a newly built house (5 years old).

If It's not Working then you should call the electrician and make a new line for the audio equipment only. My rig is right near the electrical panel and i have no noise.
( 2017 house )

 

[TheAbyss2022]

If It's not Working then you should call the electrician and make a new line for the audio equipment only. My rig is right near the electrical panel and i have no noise.
( 2017 house )

Not sure if changing anything on the switchboard will help.

 

[heyguyslol]

Not sure if changing anything on the switchboard will help.

I've heard some audiophiles going the route of having a dedicated isolated ground installed so that may be something to consider depending on how far down the wabbit hifi hole you want to go.

11 min, you can jump to about the mid point to skip the power condition talk.

 

[Andykong]

I tried both RCA and XLR to the DAC with the same result.

Even lightly tapping on the amp gives me some feedback bumping noises in the headphones.

Update: I bought the Ifi Audio DC Blocker because I believe its transformer hum as I can hear it humming without any RCA or XLR cables connected so it has to be the transformer.

Not necessarily. Vacuum tubes are high-impedance circuits while Solid State amplifiers are low-impedance circuits, in general. That's why vacuum tube amplifiers are more prone to interference. The vacuum tube is only part of the problem, the biggest devil is hidden in the circuitry. For this reason, you should not listen to the tube amplifier when nothing is connected to the input. I'll describe this as open-loop situation and I have discussed this topic repeatedly in other tube headphone amplifier thread such as HERE, HERE and HERE.

 

[TheAbyss2022]

Not necessarily. Vacuum tubes are high-impedance circuits while Solid State amplifiers are low-impedance circuits, in general. That's why vacuum tube amplifiers are more prone to interference. The vacuum tube is only part of the problem, the biggest devil is hidden in the circuitry. For this reason, you should not listen to the tube amplifier when nothing is connected to the input. I'll describe this as open-loop situation and I have discussed this topic repeatedly in other tube headphone amplifier thread such as HERE, HERE and HERE.

I forgot that I had a laptop, I always connect to my gaming PC via USB. I connected my DAC to the laptop and still had the same result. Looking back, I recall my ifi Zen Can creating electrical interference noise everytime I changed volume so I think it's dirty power and a DC blocker should eliminate the hissing.