[Red Jacket Mike]

I just got my WA6SE back from Woo Audio today; I had sent it in to get the modifications done in order to use 6FD7s and other tubes.  My amp was built and purchased earlier this year, before that change had been made.
 
I connected everything, and fired up the amp, only to hear an extremely loud hum in both channels (louder in the left, though).  This is not a faint background hum as mentioned in some threads I found while searching for this problem; it's really loud, almost drowning out the audio.  I'm afraid to keep the amp on for more than a few seconds after it starts.
 
I have a Marantz CD5003 connected via optical to a DAC Magic, and then RCA outputs to the WA6SE.  I've tried switching tubes, switching RCA interconnects, checked all my other connections, checked the power umbilical cord, etc., and the hum persists.  I've just emailed Jack explaining the problem, but I thought I'd post here, in case it's something simple I haven't thought of.  Basically, I have everything connected the same as before.  I had been using an EML 5U4G and a pair of Sylvania 6EW7s.
 
I've also removed the bottom plates on both the amp and power supply to check if any caps are blown, or anything else looks amiss; everything seems fine on the inside.
 
Does anyone have any suggestions for what I might try?  This is frustrating, after being without the amp for a couple of weeks, I may have to send it right back there for repair again.  Thanks in advance for any help anyone can give.

 

[flaming_june]

If you keep it on after a few seconds it disappears.  Hum can be normal up to two to five minutes after an amp is turned on.  Jack also explains it on the FAQ section on the website.

 

[Silent One]

Quote:

I just got my WA6SE back from Woo Audio today; I had sent it in to get the modifications done in order to use 6FD7s and other tubes.  My amp was built and purchased earlier this year, before that change had been made.
 
I connected everything, and fired up the amp, only to hear an extremely loud hum in both channels (louder in the left, though).  This is not a faint background hum as mentioned in some threads I found while searching for this problem; it's really loud, almost drowning out the audio.  I'm afraid to keep the amp on for more than a few seconds after it starts.
 
I have a Marantz CD5003 connected via optical to a DAC Magic, and then RCA outputs to the WA6SE.  I've tried switching tubes, switching RCA interconnects, checked all my other connections, checked the power umbilical cord, etc., and the hum persists.  I've just emailed Jack explaining the problem, but I thought I'd post here, in case it's something simple I haven't thought of.  Basically, I have everything connected the same as before.  I had been using an EML 5U4G and a pair of Sylvania 6EW7s.
 
I've also removed the bottom plates on both the amp and power supply to check if any caps are blown, or anything else looks amiss; everything seems fine on the inside.
 
Does anyone have any suggestions for what I might try?  This is frustrating, after being without the amp for a couple of weeks, I may have to send it right back there for repair again.  Thanks in advance for any help anyone can give.

Disconnect all components from your amp (except headphones), then power it up. If no hum is presence, your hum is being transferred by the other electronics in your system. Allowing you to narrow your focus.

 

[Xcalibur255]

Quote:

I have to say that for sure it is the 6fd7s , but your rectifier creating all that heat. As I write this post I have been listening to my wa6 for 3 hours and without 0 exaggeration my amp feels like it is not even on . I am using EML 274B and I have to add this amp never sounded so good.

My EML 274B runs much cooler as well.  I think that 5AS4G might have pulled 3 amps, which would help explain the added heat, but I'm not certain of that.  The 5R4GY only pulls 2 amps and it ran warmer than the EML as well, so it would seem that whatever the drive tubes are pulling from the rectifier makes a difference in that regard too.  All I know is the whole thing runs cool now.  Heck my SS VHP2's chassis gets warmer than the Woo does now.

 

[Xcalibur255]

Quote:

Does anyone have any suggestions for what I might try?  This is frustrating, after being without the amp for a couple of weeks, I may have to send it right back there for repair again.  Thanks in advance for any help anyone can give.

If the hum is that loud it could be a grounding issue, or possibly a contact issue with one of the tube sockets.  A hum that is louder than the music means something is amiss for certain.

 

[OutdoorXplorer]

I am done with the 6SN7 options for my maxxed WA6SE. All the tubes were sold and switched by to the stock 6EW7. Anyone who needs the Glenn's adapters which contact me.

 

[Red Jacket Mike]

Quote:

Disconnect all components from your amp (except headphones), then power it up. If no hum is presence, your hum is being transferred by the other electronics in your system. Allowing you to narrow your focus.

Thanks for this and the other replies; I haven't heard back from Jack yet.  I've disconnected all other gear, just connecting the power cord and the umbilical, and my headphones.  Extremely loud hum is still present.  It starts out silent when I turn on the amp's power; after about 5 seconds, the hum fades in.  There's a crackle or two, then nothing but steady hum.  Very loud, not affected by the volume control at all.  It's about 80% in the left channel, 20% in the right.  
 
And, as suggested above, I let it go for nearly 5 minutes; no change.  Steady loud hum just continues.

 

[Clayton SF]

Quote:

Thanks for this and the other replies; I haven't heard back from Jack yet.  I've disconnected all other gear, just connecting the power cord and the umbilical, and my headphones.  Extremely loud hum is still present.  It starts out silent when I turn on the amp's power; after about 5 seconds, the hum fades in.  There's a crackle or two, then nothing but steady hum.  Very loud, not affected by the volume control at all.  It's about 80% in the left channel, 205 in the right.  
 
And, as suggested above, I let it go for nearly 5 minutes; no change.  Steady loud hum just continues.

Try rolling a different pair of tubes to see if one or both of the current tubes are shot.

 

[Silent One]

Quote:

I am done with the 6SN7 options for my maxxed WA6SE. All the tubes were sold and switched by to the stock 6EW7. Anyone who needs the Glenn's adapters which contact me.

Would you kindly speak to your experience with 6SN7 tubes (liked/disliked)? And the purging of them? Thanks.

 

[sillysally]

Quote:

I am done with the 6SN7 options for my maxxed WA6SE. All the tubes were sold and switched by to the stock 6EW7. Anyone who needs the Glenn's adapters which contact me.

Smart move.

 

[OutdoorXplorer]

It may suits many but not too my likings after all. It was kind of weird experience with 6SN7s or VT231. I find it too much distortions with those tubes.

 

[Xcalibur255]

Quote:

It may suits many but not too my likings after all. It was kind of weird experience with 6SN7s or VT231. I find it too much distortions with those tubes.

Could you elaborate on this a bit?  I hear less distortion (none actually unless the volume is insane) with the 6SN7, not more.

 

[sillysally]

He has a WA6SE not a WA6. The WA6Se where not meant to use 6SN7's and imo even with Glenn's adapter.

 

[wind016]

Sorry that I can't read the whole thread but it's way too big. So are the stock tubes and the Sophia Princess considered the best for the WA 6SE? Are the other upgrade options worth the hassle?
 
Quote:

Smart move.

 

[Groundzero]

Quote:

It may suits many but not too my likings after all. It was kind of weird experience with 6SN7s or VT231. I find it too much distortions with those tubes.

I'm curious about this too. I use 6SN7 with Glenn's adapters and find much less distortion than 6DE7/6EW7. Could the 6SN7 be revealing distortion in the rest of your setup?
 
Quote:

Sorry that I can't read the whole thread but it's way too big. So are the stock tubes and the Sophia Princess considered the best for the WA 6SE? Are the other upgrade options worth the hassle?
 

 

The other upgrades are really subjective. They are worth the hassle if you end up liking them more and vice-versa.