[sclamb]

Quick question. I have the WA6 SE maxxed out version (with the Sophia 274B tube), and the power component makes a low humming sound. It is audible from a few feet away in a quiet room but not audible once the headphones are playing.

I was looking at power cords/conditioners etc, and noticed this on the IsoTek site:

______________________________

If actual pieces of equipment are buzzing this is generally one or more of the following:

Poor transformer design or construction.

Poor mechanical mounting.

Over voltage supply.

Significant distortion of the supply.

DC present on the supply.

______________________________

Do any of you other WA6 or WA6 SE owners have this low humming sound from the transformer? Could it be that I need to get a power conditioner and better power cords? In the back of my mind I am sure Jack at WooAudio said it was normal, but now I have a bee in my bonnet about it

Thanks.

 

[breakfastchef]

My WA6 SE is running the Sophia and two Sylvania 6DE7s, and I have not noticed a buzzing in the amp or PSU amp. I would contact Jack before throwing money at power conditioners and cords. Let us know how this plays out.

 

[sclamb]

To clarify, this is a low volume humming rather than a buzzing.

In answer to this question that I asked:

'I hear a low volume humming from the transformer side of the amp when I get close to it. Is it normal for it to make a humming sound?'.

Jack responded:

'The slight hum of the transformer is normal. This will not affect the amp to work properly and will not degrade sound quality.'

However, I am more worried now that one owner has said there is no sound at all from their amp.

 

[takezo]

low level "drone" humming, or more specifically mechanical humming,
is normal from tube amps... only solid states seem free of this...

now, if you hear humming from the headphone while music is playing
or paused, then you've got some concern since it will affect your
enjoyment of the music... in this case, you'd have to figure
out if it's coming from the amp, source, interconnects, home ac,
rf interference from adjacent components, tubes or internal
grounding issue...

 

[sclamb]

Thanks takezo. I do not hear the "drone" humming through the headphones at all - just externally when I do not have the phones on. Not a major problem, just interested in the cause (and interesting that breakfastchef has no hum at all).

 

[takezo]

i'm pretty sure all tube amps have some level of mechanical humming...
some more audible than others...
maybe breakfastchef's amp is an exception...

 

[sclamb]

I have been reading up on transformer hum. I wonder if perhaps I need to clean my mains voltage of DC which can worsen the humming. Seems that this type of hum is a well known phenomena, and can be related to the internal quality of any individual transformer.

 

[Golden Monkey]

Yeah, it's most likely the transformer, nothing to worry about. I used to use some PowerVar power conditioners, and they are basically a transformer that decouples the incoming power. It would hum when it was just sitting there with everything off, but would get louder the longer my equipment was in use. With open phones it was really distracting, and I tried all kinds of things to quiet them (nothing worked). Since they were sitting on the floor, the hum would resonate through the floor boards, and drive me completely nuts. Final solution was to just get rid of them completely.

In your case, I'm sure it is just the transformer doing what it does. If it gets louder or worse, or begins to sound like its oscillating/wavering, you've got problems...

 

[atbglenn]

My WA6 (not SE) is completely free from any (USA) 60 hz mechanical transformer hum, and no hiss or hum through the headphones. Maybe it's noticeable with Europe's 50 hz mains power?

 

[sclamb]

Hmmm. Could it be the Sophia tube that is making the humming sound? It is hard to tell if it is coming from the transformer block at the back or not.

Could it be the tube and, if so, what type of cheap tube could I replace it with to see if it makes a difference?

 

[sclamb]

Quote:

Originally Posted by atbglenn /img/forum/go_quote.gif My WA6 (not SE) is completely free from any (USA) 60 hz mechanical transformer hum, and no hiss or hum through the headphones. Maybe it's noticeable with Europe's 50 hz mains power?

Interesting theory. I also wonder if there is DC current dirtying the UK mains that I have read can also cause transformer humming.

 

[sclamb]

I also just noticed this. When I turn on the power, I see a white flash go up the mesh plate on the Sophia tube before it start to glow orange. Is this normal?

 

[atbglenn]

That doesn't sound normal to me, but I'd ask Jamato. He's the expert.

 

[sclamb]

Good idea. I just sent jamato8 a PM with a link to this thread.

 

[sclamb]

I just switched the amp back on again and there was the white flash in the 274B tube and a spark or two fell down to the base. Sounds like I may have to call on the 30-day warranty on the tube and get a replacement from Jack. Could this be causing the hum, and more importantly, could it be damaging the internals of the amp?