[Sonic Defender]

I am so bummed. My Schiit Valhalla arrived today after being delayed by a postal strike here in Canada. I hook it up and I get that lovely 60hz hum. Maybe somebody should write a song called 60hz Hum, kind of catchy don't you think? Anyway, I digress.
 
I hooked the Valhalla up with my Rega Apollo CD player, so nothing else in the link. I unplugged the source, still a hum. Took the Valhalla into another room and with no source, there is the hum. Took it upstairs in my house, no source, yet again the hum. The hum builds from total silence when the amp is first turned on to reaching it's full hum within about a minute. This makes me suspect the amp as it seems to coincide with the tubes warming up.
 
I am sure the tubes are sitting in their pins properly and I have pushed down on all of them several times to be sure. When the music is on the hum is not a factor, but of course during quiet sections in songs the hum will be a factor. I even tried a different headphone from my Grado HF2, instead using a cheapo Sony with a 1/4" adapter to allow it to be fed by the Valhalla, still a hum and interestingly (at least to me) the hum I think is slightly louder with the Sony/1/4 adapter combo.
 
So am I sending the unit back to Schiit or what would you advise? I am going to take the amp to another location and test it there to see if there is still a hum, but I am fairly confident there will be. Any thoughts comments welcomed. Cheers.
 
 

 

[Koolpep]

Hey,

I have the Valhalla, there should be no hum, only dead silence. That's really a bummer for you and I'm sorry about that.

Unfortunately these things can happen, something can be damaged during transport or may have slipped through quality check. I am sure if you contact Schiit, they will find a fast solution for you. Crossing fingers about the strike though...

I am sure you will enjoy e new Valhalla even more once youget it.
Cheers,
K

 

[Impulsive]

i would firstly contact them, maybe they can just send you set of new tubes.

 

[Sonic Defender]

Thanks for your replies, much appreciated. The hum has now virtually dissapeared. I can only assume that this was the tubes getting broken in? Seems plausible, to me. Is that sometimes the case that the tubes emit a hum until a minimal run in state has occured? The hum was very clear so no chance it was my imagination that is for sure. Any thoughts on this situation seeming to resolve itself? Cheers.

 

[flaming_june]

Yes, sometimes humming in tube amps can last up to 20 minutes from when you turn it on.  

 

[Koolpep]

Oh, that is interesting. 
 
Only with new tubes I guess until they have melted away whatevertheymeltaway or "burn-in"...
 
So once this happens you have no humming anymore, is that right? I got my Valhalla used and already broken in, so I don't had this experience yet.
 
Thanks a lot!!

 

[Sonic Defender]

Hi Koolpep. Yes, there is no hum at all now, or so little that I can't detect it. So far I am really enjoying the Valhalla. My Creek integrated still provides overall better sound, but for jazz and ambient music I really like the Valhalla. I think for rock the Creek is superior as it controls the very aggressive passages better and is less voiced toward midranges where the Valhalla seems to shine.
 
Because most rock music is so very, very, very poorly recorded with screaming guitars showing up in the mid range the Valhalla seems to emphasis what to me is the worst elements of rock music. I am also using the Valhalla with Grado HF2s so perhaps if I may buy some DT 880/990 for their higher impedence.
 
Overall the Valhalla is delivering what I wanted from it, a different sound signature from my Creek with a strength in vocal and string reproduction. I am very pleased so far and expect to stay that way. Cheers.

 

[Vma5]

I got my valhalla earlier this week and I can hear a hum through the headphones. I tried to lift the ground loop, but it didn't help at all to getting rid of the hum, also I noticed when I turn on the amp the amp is silent, but when the tubes kick in the hum starts. I wouldn't mind the hum if I heard it only when I'm not listening music, but I can hear it when I'm listening quiet music or when there's not many instruments playing on the song.
 
This is my first headphone amp, so I don't yet know much about these things. Any suggestions what I should do to get rid of the hum?
 
This is my first post here, but I've been reading these forums a while.

 

[Sonic Defender]

Hi Vma5, don't worry about this, at least not yet. After a few sessions my tubes became quite silent, but it did take at least 4 hours of play time on them. I have heard others say it can take longer. Love my Valhalla. I ended up purchasing some DT 880/600ohm cans and this combo is fantastic, even with rock. Hope your tubes calmn down soon. Cheers.

 

[Vma5]

Thanks for the info! I got my amp on wednesday and I've listened approximately 15h to it already. Let's hope the hum goes away soon.

 

[NinjaSquirt]

When I had my Schiit Valhalla, I never noticed a hum with a Beyer DT880 or even the AKG K702 ever.

 

[Vma5]

I sent message to the Schiit support and they said that it's probably a normal tube hum and to run the amp very low level for 8 hours. I did that and the hum is still there. Does the normal tube hum really sound like 60hz hum with little distortion/buzz in it, even if I turn the volume knob the level of the hum stays the same. I can hear the same sound coming from the power supply of valhalla.
I just want to make sure if this is normal or not, because I've read that Valhalla is pretty much silent.

 

[Zombie_X]

I know a lot of NOS tubes, if they have never been used, hum to beat all hell when first used. Some of my Tung-Sol tubes hummed for a long while so I put the amp in my attic (darned cold in there) and I left the amp on for a day and the hum/buzzing subsided. The most irritating thing with tubes with when you hear the metal in side the tube expanding. That usually sounds like a "ping" or "pop" noise.
 
In your case it could be a ground loop issue. I am not sure for certain. I know some Little-Dot amps have that hum and it's a ground loop problem.
 
If you can get spare tubes I would try those. Even using cheater plugs can eliminate it but those aren't entirely safe either.

 

[Vma5]

Quote:

I know a lot of NOS tubes, if they have never been used, hum to beat all hell when first used. Some of my Tung-Sol tubes hummed for a long while so I put the amp in my attic (darned cold in there) and I left the amp on for a day and the hum/buzzing subsided. The most irritating thing with tubes with when you hear the metal in side the tube expanding. That usually sounds like a "ping" or "pop" noise.
 
In your case it could be a ground loop issue. I am not sure for certain. I know some Little-Dot amps have that hum and it's a ground loop problem.
 
If you can get spare tubes I would try those. Even using cheater plugs can eliminate it but those aren't entirely safe either.

I tried those cheater plugs and it didn't do anything. I also tried the amp in different rooms without any source and still the amp had the hum. I don't really know if I can get any spare tubes in here where I live (well, I could order from schiit, but if those doesn't work either). So, could this be the standard tube hum as the schiit support said? And if it's, is there any way to get rid of it? (Changing tubes?)

 

[Zombie_X]

You could try cleaning the pins off with rubbing alcohol. Also lightly sanding the pins with an emery board helps as well. A small brass brush can be used to remove the oxidation as well. Oxidation looks like a blue or black splotch on the pins. Sometimes the entire pin is blue or black and that must be removed by said means. Oxidation will only be found on non gold plated pins as gold plating is resistant to oxidation.
 
I would say 70% of the time hum/noises in a tube is from oxidation on the pins and that can be remedied by cleaning the pins off. I had a noisy 6080W tube and the noise was generated from oxidation on the pins. Once cleaned off, the tube had no more issues. Also some tubes are just noisy by nature. This can be from many things such as manufacturing variances, usage, damage, and oxidation and so forth. Try cleaning the pins off and see if that helps.
 
The hum could also be microphonics in the tubes themselves. This is very common and most of my tubes have them to a varying degree. Microphonics can be cured by adding dampers to the tube but them again this isn't a 100% fix. Microphonics can not always be remedied as sometimes they are too great. In these situations replacing the tubes is the best bet.
 
Quote:

I tried those cheater plugs and it didn't do anything. I also tried the amp in different rooms without any source and still the amp had the hum. I don't really know if I can get any spare tubes in here where I live (well, I could order from schiit, but if those doesn't work either). So, could this be the standard tube hum as the schiit support said? And if it's, is there any way to get rid of it? (Changing tubes?)