[roadster-s]

Is it normal for the power transformer of my WA6SE to be generating noise one can hear when standing a few feet away? nothing that's interfering with the sound, but it does make the rectifier tube "rattle" a little.

 

[obzilla]

Quote:

 
That's why I haven't pulled the trigger on the WA2 or 22... waiting a minimum of 4 weeks isn't going to happen.

 
Patience pays off in this hobby. Just think, had you pulled the trigger 4 or 5 weeks ago, you'd have it by now.

 

[Csericks]

That's why I haven't pulled the trigger on the WA2 or 22... waiting a minimum of 4 weeks isn't going to happen.

I bought a WA6 in 2009 which I replaced with a WA2 about 4 months ago. In both cases it was well worth the wait!

 

[driver 8]

I emailed Woo Audio about expedited service 2 days ago and they told me my amp would be ready to ship on Monday regardless, making my time from order to ship 13 days -- not too bad.
 
They're out of stands again, though.

 

[Xcalibur255]

Quote:

 
I was looking in to another amp the other day using Fullmusic 2A3s and I was immediately reminded of sophia's. I'd totally believe that an OEM arrangement could exist. I'd imagine getting into the manufacturing side of an niche technology would be costly if you weren't already in on it. I figure the machinery used to make valves probably doesn't exist as 'off the shelf' box solutions (as it were). If someone wanted new gear, you'd probably have to have a engineering firm scratch build you the equipment. Even Sophia's site emphasises a   'research orientated' company. So they're using someone somewhere for the legwork.
 
If it helps anyone, Fullmusic have some pics.
http://www.tube-fullmusic.com/products/en-product.htm
If you're cynical, OEMing is just rebadging. In the short time I've been using tubes, I've read a lot about how some will chase down a particularly type with the knowledge it's brand X by any other name. ODMs are interesting too http://en.wikipedia.org/wiki/Original_design_manufacturer

Fullmusic and Shuguang OEM for a number of smaller boutique brands actually.  The brand can request specific material usage, design variations, or assert that only more experienced workers be on their line to improve consistency but in the end it will still have the same look as the tube its based on because of the tooling and raw components availability.
 
The one I've always been curious about is KR Audio.  They are Czech just like EML and there are signs of a connection there but the KR Glass looks very different.  I then noticed that the glass envelope for their 2A3 is just like the ones used in the Shuguang 2A3B and the new Psvane 2A3, but there are clear indications that KR has an actual production facility in the Czech Republic so this wouldn't make sense either.
 
Modern tube manufacturing seems to have adapted to the global economy to some degree.

 

[Xcalibur255]

Quote:

guys need help here..
 
choose one of these tubes with more mids and lows to it..
 
RCA 6EW7 small bottle or Sylvania 6EW7 big bottle??
 
my stock tubes are the Sylvania 6EW7 i dont know if its the big or small bottle (its the Big/Fat bottle imo) you guys can help me see in the above picture and tell me..THX
 
and has anyone tried the Philco 6FD7 ??? how are they?? i heard that 6FD7 are good for LCDs and HE series headphone??
 
im getting them from Wiwi Tubes.

I think you'd like the Japanese made Raytheon 6EW7.  Good body to the music and strong low end for a 6EW7.  They have a mellow sound that emphasizes the mids somewhat.  6FD7 tubes have a thicker sounding lower midrange and upper bass region but the transparency isn't as good IMO.  The 6EW7 reminds me of a 6SN7 in a lot of ways, which is why Woo originally chose it for the amp I'm sure.
 
You can find the Rays easily enough on eBay if you are patient.  They will have Made in Japan stamped right on the glass if they're the right ones.

 

[rosgr63]

Quote:

 
The one I've always been curious about is KR Audio.  They are Czech just like EML and there are signs of a connection there but the KR Glass looks very different. 

 
Alesha Vaic (AVVT), and Dr Kron (KR) were the pioneers of modern tubes.
Alesha worked with Jac van de Walle (EML) and Dieter Ennemoser (C37 Project) on certain projects.
 
Alesha had a contract with Audio Note.

 

[Silent One]

Quote:

Is it normal for the power transformer of my WA6SE to be generating noise one can hear when standing a few feet away? nothing that's interfering with the sound, but it does make the rectifier tube "rattle" a little.

 
This is not normal. And will require further observation. Also, if your rectifier rattles a little, your sound is being affected. Once the matter is resolved, you will know...

 

[roadster-s]

^^^^ tried different outlets (I have 4 dedicated outlets for my complete AV system) switched power cords, etc... no change. Will email Jack to see what he has to say.

 

[Silent One]

Hopefully, it turns out to be something simple... in need of correcting but simple. I absolutely adore WooAudio amps! Their build quality, aesthetics and enjoyment. Their business model - low entry point with lower priced parts is brilliant! If I thought saving up a year was a long time to bring home a 6 Special Edition, imagine if the entire line was offered with premium parts only? I'd only be receiving it right about now.

 

[Xcalibur255]

Quote:

Is it normal for the power transformer of my WA6SE to be generating noise one can hear when standing a few feet away? nothing that's interfering with the sound, but it does make the rectifier tube "rattle" a little.

Is it a hum?  Slight hum can be normal, but it shouldn't be audible from a few feet away.  Are you leaving your amp on without a headphone plugged in?  That could cause this, and it is very bad for the transformers too.
 
Alternatively if the transformer isn't potted correctly it could be causing enough vibration to produce this.

 

[Ahzari]

Is it a hum?  Slight hum can be normal, but it shouldn't be audible from a few feet away.  Are you leaving your amp on without a headphone plugged in?  That could cause this, and it is very bad for the transformers too.

Alternatively if the transformer isn't potted correctly it could be causing enough vibration to produce this.

I also hear a light hum when I'm rather close to the SE, from my normal sitting area 6 ft away I don't hear anything.

 

[roadster-s]

Quote:

Is it a hum?  Slight hum can be normal, but it shouldn't be audible from a few feet away.  Are you leaving your amp on without a headphone plugged in?  That could cause this, and it is very bad for the transformers too.
 
Alternatively if the transformer isn't potted correctly it could be causing enough vibration to produce this.

Yes it's a slight hum, but I can't hear any out of my three 1,000 watt power amps, unless my ear is stuck right against them. Headphones always plugged-in when on. What I hear from the rectifier is a slight "shimmering" rattle hat comes from within and I hear that one standing a foot away (that has me quite concerned). If I'm arm's lenght away from the amp and power it off, I can tell right away that that hum is shutting off with it.

 

[Ahzari]

Quote:

Yes it's a slight hum, but I can't hear any out of my three 1,000 watt power amps, unless my ear is stuck right against them. Headphones always plugged-in when on. What I hear from the rectifier is a slight "shimmering" rattle hat comes from within and I hear that one standing a foot away (that has me quite concerned). If I'm arm's lenght away from the amp and power it off, I can tell right away that that hum is shutting off with it.

I think I know what you mean, I get that slight shimmer vibration right when the rectifier starts up but then it smooths out in a second. I never noticed anything outside of that initial startup. I do have tube dampers on though (maybe they help)..

 

[roadster-s]

Quote:

I think I know what you mean, I get that slight shimmer vibration right when the rectifier starts up but then it smooths out in a second. I never noticed anything outside of that initial startup. I do have tube dampers on though (maybe they help)..

No dampers and mine actually gets noisier as it warms up.....

 I did intend to buy some dampers but wish to resolve this problem 1st since it's not a normal operational condition.