[TakashiMiike]

Hey Everyone I bought a HiFiman Ef2a about a month ago, and have been really enjoying it. But for the past 2 days I will listening to music and randomly it will break out into loud heavy static. After turning it off and letting it sit overnight it is fine again. Also If I try turning it off and on while the static happens, it still continues, but If I turn it off and take out the tubes, and then put them back in it is gone for a while.
 
My question is, is this a sign that I need to replace the tubes? I didn't ask the seller how many hours he had on the amp and I can't find much information about this. Thanks.

 

[jamato8]

Quote:

Hey Everyone I bought a HiFiman Ef2a about a month ago, and have been really enjoying it. But for the past 2 days I will listening to music and randomly it will break out into loud heavy static. After turning it off and letting it sit overnight it is fine again. Also If I try turning it off and on while the static happens, it still continues, but If I turn it off and take out the tubes, and then put them back in it is gone for a while.
 
My question is, is this a sign that I need to replace the tubes? I didn't ask the seller how many hours he had on the amp and I can't find much information about this. Thanks.

Does the sound follow the tube if you reverse the position?
 
 

 

[Equus]

Ditto on jamato8's suggestion of swapping tube positions, unless the static is coming through both channels.  Seems odd though if you simply reseat the tubes that the static goes away, unless you're allowing a lot of cooling time before trying it again.

 

[TakashiMiike]

If I reverse the tubes, it fixes the problem for a while but then it starts up again. The sound doesn't "reverse" in any way, it comes from both channels, and all sounds go away, it just becomes static, very loud static. The loudness of it is related to volume wheel, not to the music loudness.
 
P.S Turning it on today, there is an audible about half as loud as the music hiss not as loud as the static but consistent in the background. This was not happening before.

 

[Equus]

Anyone in your area that does DIY or something that can take a listen for you?  May be a connection gone loose or the pot going.

 

[TakashiMiike]

Unfortunately I don't know anyone near me, do you not think this would be fixed by just replacing the tubes?

 

[mrarroyo]

I would try something simple like tightening the tube sockets and cleaning the tube pins using a brass brush and alcohol. Do make sure the amp is off and the power cord disconnected from the outlet. Next make sure all your cables are properly seated. Are you feeding it via rca or the usb input?

 

[jamato8]

It is doubtful both tubes would be bad. It appears to be a problem with the power supply. Possibly a bad capacitor. 

 

[TakashiMiike]

Quote:

I would try something simple like tightening the tube sockets and cleaning the tube pins using a brass brush and alcohol. Do make sure the amp is off and the power cord disconnected from the outlet. Next make sure all your cables are properly seated. Are you feeding it via rca or the usb input?

Feeding it via usb, I will try it next time it messes up again, It seems very intermittent, could  be fine for a long time then just randomly mess up.

 

[TakashiMiike]

Quote:

It is doubtful both tubes would be bad. It appears to be a problem with the power supply. Possibly a bad capacitor. 

If this is the case why would switching the tubes places with each other fix the problem?

 

[jamato8]

You said it only fixed the problem for a short while. As a cap sees more time in the circuit it heats back up and if bad can start leaking, which can cause noise. If it doesn't follow the tube or is in both R and L then it most likely is always before the tube, which is the power supply. 

 

[TakashiMiike]

The strange thing is the noise totally overpowers everything, the music no longer plays, it's not like grain, it's like complete LOUD static. If this is the power supply what can I do about it? Are there any cost effective ways of dealing with it? I still suspect it's the tubes, because sometimes switching them fixes it for a long time, sometimes short, it seems related to the tubes.

 

[mulveling]

I vaguely remember something like this happening to me with a Berning Micro ZOTL, years ago. I was trying out a pair of NOS Sylvania 6sn7WGT that had cost a pretty penny from a dealer. The music was fine for a while, and then the loud static/noise happened all at once like a switch was flipped - as in your case, it was overpowering, and most definitely in both channels. I immediately turned off the amp and put back in the stock Sovteks - and never had the problem again. One of those 6sn7WGT ended up being bad, and had to be marked with the "=(" of death via masking tape & sharpie.
 
Still baffles me - never heard a tube fail quite like that - but I figured it was a combination of a single tube failure (perhaps a severe mismatch) interacting with the ZOTL's unique topology. Try new tubes, preferably non-chinese if possible.

 

[TakashiMiike]

 
Quote:

I vaguely remember something like this happening to me with a Berning Micro ZOTL, years ago. I was trying out a pair of NOS Sylvania 6sn7WGT that had cost a pretty penny from a dealer. The music was fine for a while, and then the loud static/noise happened all at once like a switch was flipped - as in your case, it was overpowering, and most definitely in both channels. I immediately turned off the amp and put back in the stock Sovteks - and never had the problem again. One of those 6sn7WGT ended up being bad, and had to be marked with the "=(" of death via masking tape & sharpie.
 
Still baffles me - never heard a tube fail quite like that - but I figured it was a combination of a single tube failure (perhaps a severe mismatch) interacting with the ZOTL's unique topology. Try new tubes, preferably non-chinese if possible.

That is exactly the problem I'm having, I will try to grab some new tubes asap, thanks for the sound advice. It scares me every time it happens, just happened for the first time today. Odd thing is I have yet for it to happen on Linux, or when just listening to music, it always happens when I'm playing a video game in windows, maybe it's coincidence, I don't know, still testing different things when it happens, but I will grab some new tubes.

 

[jamato8]

Quote:

That is exactly the problem I'm having, I will try to grab some new tubes asap, thanks for the sound advice. It scares me every time it happens, just happened for the first time today. Odd thing is I have yet for it to happen on Linux, or when just listening to music, it always happens when I'm playing a video game in windows, maybe it's coincidence, I don't know, still testing different things when it happens, but I will grab some new tubes.

I wonder if both tubes are powered by a common B+. If so and not divided in any way, it could be the tube but that is a poor way to supply the voltage.