[maheeinfy]

 
It's no good and they still want a 10% handling fee. Nice

Just to clarify, I didn't yet talk to WA about return. Their reasoning is that amp doesn't hum when no input is connected, so amp has no issues. So, i thought if i return it, i will be charged handling fee.

 

[pippen99]

Need some help please.  Just took delivery of a six month old WA5.  This is my  first tube amp so if this question is stupid please be kind.  Both of the Sophia Royla Princes 300b tubes have loose shards of glass and/or black material inside the tube.  Is this normal and safe to use?  The stock tubes are not like this. Also the Woo website is not really clear about second owner warranty rights.  Do I have any?  Thanks for your forbearance and help.

 

[maheeinfy]

You have to take into account headphone sensitivity. Is the humming noticeable on any headphone at a volume setting where you would normally be listening to music?

Hum is not noticeable for lot of music i listen to. However on silent passages, i tend to turn up the volume and hum gets noticeable
 

Wow! My first impression is that doesn't say much for the 3 dacs you used with your woo amp. All 3 of those manufacturers (or your interconnects) are making these faulty/hummy dacs. You need to choose your dacs better and bring up these faults on the appropriate threads.

Are you able to try someone else's/local stores woo amp with you're dacs and interconnects? You seem to have eliminated all other possibilities unless you haven't yet tried a second set of interconnects.

Here is my gear
DAC - Schiit Modi Gen1, Emotiva DC1, Fiio X3ii. 
Interconnect: Schiit PYST, Emotiva X RCA
USB: Belkin Gold series 10foot, Emotiva MUSB (this wont matter as i am not connecting the DACs to laptop). DACs are powered off in all my testing.
 
What i don't understand is all these work fine in my solid state setup. No hum even at max volume. I have ordered some Bluejeans LC1 RCA cables, so that is my next step in testing.
Unfortunately i don't know anyone with a Woo amp, none of my friends are into audio.
 

I'm no expert but that's a good question - what HPs are you using

Beyer T1, Shure SRH1540, AKG K240

 

[maheeinfy]

  Try the amp with nothing plugged into it.
120Hz is from the power supply not interconnects that would give 60Hz hum.
And if it is the power supply in the amp the 120Hz will be more like a buzz.

When nothing is connected(except power), there is no hum.
 
Amp does hum even when used as preamp. So i connected its output to my emotiva speaker amp and made a little video capturing the hum Its with my phone, so not the best mic was used, but it seems to capture the hum.
 
https://www.youtube.com/watch?v=tLwxn6veb6g

 

[GrindingThud]

That sounds like power supply noise. I had to do a lot of work on my WA3 to suppress the noise low enough for my satisfaction.
Short the amp input and verify no noise at all volume positions.

 

[2359glenn]

No hum with nothing connected even with the volume turned up ???

 

[maheeinfy]

  No hum with nothing connected even with the volume turned up ???

That's right.
Out of the four inputs, I connected only input1. Switching inputs using the knob, on input1 there is hum, and switching to other inputs, its silent.
 
Just making the connection with a device is causing the hum.

 

[maheeinfy]

That sounds like power supply noise. I had to do a lot of work on my WA3 to suppress the noise low enough for my satisfaction.
Short the amp input and verify no noise at all volume positions.

'Short the amp input' - You mean connect left and right input with a single RCA cable? If yes, I did that and there is no hum.
 
Can you tell me how you were able to reduce noise on WA3? Did u have that noise problem with your solid state gear(if you own)

 

[2359glenn]

With the volume turned down should be the same as a shorted input.
If you have no hum with  no input the amp is OK.
You are ether having a ground loop or is coming from your DAC

 

[GrindingThud]

No, I meant the center pin of the rca to the outer ring (signal short to signal signal common).....
The WA3 mods are in the thread in my signature line.

'Short the amp input' - You mean connect left and right input with a single RCA cable? If yes, I did that and there is no hum.

Can you tell me how you were able to reduce noise on WA3? Did u have that noise problem with your solid state gear(if you own)

 

[GrindingThud]

Totally agree with this!

With the volume turned down should be the same as a shorted input.
If you have no hum with  no input the amp is OK.
You are ether having a ground loop or is coming from your DAC

 

[maheeinfy]

  With the volume turned down should be the same as a shorted input.
If you have no hum with  no input the amp is OK.
You are ether having a ground loop or is coming from your DAC

Thanks. 
 
Since all my DAC's are turned off in my testing, out of those two, it's possible that it is ground loop problem. However all my other gear doesn't seem to have this problem. 
 
I tested WA2 with many wall sockets in my apartment; even took the amp to a friend's apartment for testing, and the hum was there every time.

 

[RomRom]

  it's possible that it is ground loop problem.

 
Please disconnect earth line on your power cord (or try a two-prong AC power cord - no ground) to see if the hum goes away. This is purely for testing and is NOT a permanent solution!

 

[redcat2]

  Need some help please.  Just took delivery of a six month old WA5.  This is my  first tube amp so if this question is stupid please be kind.  Both of the Sophia Royla Princes 300b tubes have loose shards of glass and/or black material inside the tube.  Is this normal and safe to use?  The stock tubes are not like this. Also the Woo website is not really clear about second owner warranty rights.  Do I have any?  Thanks for your forbearance and help.

Hi, The answer is yes and no, it is quite normal to see older tubes with little bit of glass in them not ideal but normal, as to the sound it does not make any relay difference in my opinion to the sound. I have had one or two tubes turn up like this over the years just happens sometimes in transport. Safe to use yes.

 

[FredrikT92]

For those who got WA6-SE with HD600/HD650, how much is the clock at the pot arrow? 
My phone shows 92dB peaks at 9 a clock! Holy cow