The Woo Audio 2
Dec 8, 2015 at 5:51 PM Post #1,321 of 1,750
 
  A pair of 6922 pinch waist: $1800+
   
  http://www.ebay.com/itm/2-x-CCa-E88CC-Valvo-D-getter-pinched-waist-yello-label-same-7L0-code-Box-/141821047786

 


These are for many the Holy Grail of all Holy Grails. Here's what Brent Jessee has to say about the Holland made Valvo Cca Pinched Waists...starting about half way down. These are also the first year production of the pinched waists which had the added caveat of having gold internal wiring (supposedly) for reportedly a richer sound. Read it and weep.


Cca:
Whew, these babies are so scarce there isn't even much info out there about them! Mentioned by audiophiles, usually in a reverent whisper, these gold pinned gems are about as good is it gets in 6DJ8-land. Matched triode sections, low noise screening, 10,000 hr. heater life expectancy, carefully controlled frame grid winding, low microphonics......the list goes on and on. This is regarded as one of the most detailed and three-dimensional sounding tube ever made in this family of tubes. Most of what is available is Siemens or Telefunken made, although there are a few very rare examples of Philips or Amperex Holland made out there. Since this was a tube made specifically for the German goverment and military, all that I have seen carry a German brand label, even those made in Holland. Even rarer are the Holland made Cca tubes with the pinched waist indented glass midsections, said to be the most sonically "3D" tube ever made, of any type. Finding these is akin to finding a 1795 gold piece in your attic! I don't believe there were any of these Cca tubes made in the USA. Awesome audiophile tubes! Yes, they are costly, but like most top flight NOS audio tubes, you get what you pay for. These Cca tubes will give you more improvement in sound than upgrades like expensive speaker cables that can cost 5 times as much as a pair of Cca tubes!


There must be diminishing returns.  I think it is mostly the rarity as well as supply and demand for collectors.  Probably more for investing then use.
 
Dec 9, 2015 at 9:43 PM Post #1,322 of 1,750
 
There must be diminishing returns.  I think it is mostly the rarity as well as supply and demand for collectors.  Probably more for investing then use.


I have some Siemens CCa tubes and they are nice, but not my favorites. What I am learning about tubes is the manufacturing quality and condition of the particular tubes are really important.
 
Dec 15, 2015 at 3:53 AM Post #1,323 of 1,750
With the hifiman range if HPs are there regular users here of the wa2 with say the he560, he500 or 400i that works really well. I have enjoyed the warmth and timbre if the he560 before.

I bought my wa2 for the hd800s I have but wondering how (un)limited my limitations are - ie just high impedance headphones.

Also I've heard the hd650s in the past, eg with my soloist amp,but they never impressed me much for my personal prefs (compared to my hd800s of course) but do they do anything phenomenal with the wa2 fir me to reconsider these? And u enjoyed the hd600 but more as an easy listening HP but u assume that's what they will be with the wa2 too.
 
Dec 23, 2015 at 1:08 AM Post #1,325 of 1,750
WA2 doing double duties, headphone amp + preamp. 
smily_headphones1.gif

 

 
Jan 9, 2016 at 3:51 PM Post #1,326 of 1,750
I can't see to find the answer but I just want to ask the obvious.

Looking at the front of the amp, left set of tubes is left channel and right set is right?

FYI, I get a hum on the left channel that comes and go if I moving or more precisely the amp jiggles from moving the cable. Amp is silent when I sit still,

When I tap the amp, I can hear the tapping on just the left channel.

I am going to clean the pins with detox as I swap pairs. I rarely role my tubes in the WA2.

I just wanted to know which tube is faulty if cleaning does not help.

Thanks,
 
Jan 9, 2016 at 5:27 PM Post #1,327 of 1,750
I can't see to find the answer but I just want to ask the obvious.

Looking at the front of the amp, left set of tubes is left channel and right set is right?

FYI, I get a hum on the left channel that comes and go if I moving or more precisely the amp jiggles from moving the cable. Amp is silent when I sit still,

When I tap the amp, I can hear the tapping on just the left channel.

I am going to clean the pins with detox as I swap pairs. I rarely role my tubes in the WA2.

I just wanted to know which tube is faulty if cleaning does not help.

Thanks,
Yes
 
Jan 9, 2016 at 6:10 PM Post #1,328 of 1,750

 
Thanks.  I just finished cleaning all the tube pins.  I swapped the driver tubes.  I dried the pins with a cotton swab but will wait another hour before I power it.
 
Feb 18, 2016 at 11:03 PM Post #1,329 of 1,750
Hi guys. I'm probably about 30hrs in the break in stage of my WA2 and also started to hear a slight hum on the left channel. The hum is intermittent and comes and goes randomly. Contacted Woo Audio and was informed this could be due to the new tubes being broken in and that the hum will disappear overrime. Wanted to know if you guys had the same experience. Thanks!
 
Feb 18, 2016 at 11:39 PM Post #1,330 of 1,750
Hi guys. I'm probably about 30hrs in the break in stage of my WA2 and also started to hear a slight hum on the left channel. The hum is intermittent and comes and goes randomly. Contacted Woo Audio and was informed this could be due to the new tubes being broken in and that the hum will disappear overrime. Wanted to know if you guys had the same experience. Thanks!

 
Switch the driver tubes & see if the right side starts humming.
 
If not, then switch the power tubes & test that too.
 
 
If that doesn't work & there is still humming on the left side then it's probably the amp, but I doubt it.
 
Tubes, especially the cheap ones, are very finicky.
 
Feb 19, 2016 at 12:33 AM Post #1,331 of 1,750
Hi guys. I'm probably about 30hrs in the break in stage of my WA2 and also started to hear a slight hum on the left channel. The hum is intermittent and comes and goes randomly. Contacted Woo Audio and was informed this could be due to the new tubes being broken in and that the hum will disappear overrime. Wanted to know if you guys had the same experience. Thanks!

I have this exact problem on my WA2, but its on the right channel. First i thought it was the power tubes. Right one started hissing and when i switched them, hiss also switches to left.

Later I acquired two other pairs of power tubes and the right channel tube hisses on these two pairs as well. At this point i started thinking something is wrong on the right channel on the amp.
Also if i tap the right tube, tapping sound thru headphones is different/loud than when i does the same to the left tube. May be you can try this and see if your left one sounds louder than right.

Since this hiss is random, i can't say for sure if it goes away after some time. I atleast have 70+ hrs on my current tubes and they hiss sometimes. Still waiting for logging more hours with these and hopefully hiss goes away

edit: i assumed you are calling hiss as hum. In my case hum(another problem) gets audible when vol at 11o clock and from both channels
 
Feb 19, 2016 at 11:57 AM Post #1,332 of 1,750
Thanks for the tip. The audible sound coming out of my left channel is more a hum (not a hiss). It sounded more like a ground loop. Will try switching tubes tonight to see if the hum moves to the right channel.

Yes, same thing with my unit on the hum. I can hear an audible hum when vol is past 1 o clock. I am thinking this is normal as the gain is maxed out. Besides with my HD800, a vol past 12 o clock is already very loud. But I did check with Woo Audio and they said you will definitely hear a hum if you max out the volume. Im still iffy on this so I will monitor to see if the hum gets worse - taking into account your case where the hum is audible at 11 o clock.
 
Feb 19, 2016 at 11:09 PM Post #1,334 of 1,750
Hi guys, so I tested tonight.  Plugged in directly into the outlet.  Gosh... worse!  The hum was more audible! 
 
I then switch the driver tubes - no change. Still hum on the left channel. 
 
But when I switch the power tubes, the hum moved to the right channel.  Now the problem is the hum is extremely audible on the right channel and I can hear it even as I play music!  Terrible!  I think I have a bad power tube.  These are the stock power tubes that came with the amp so I guess this will need to be replaced.    
 
Feb 19, 2016 at 11:10 PM Post #1,335 of 1,750
  Hi guys, so I tested tonight.  Plugged in directly into the outlet.  Gosh... worse!  The hum was more audible! 
 
I then switch the driver tubes - no change. Still hum on the left channel. 
 
But when I switch the power tubes, the hum moved to the right channel.  Now the problem is the hum is extremely audible on the right channel and I can hear it even as I play music!  Terrible!  I think I have a bad power tube.  These are the stock power tubes that came with the amp so I guess this will need to be replaced.    

If the hum follows the tube, then the tube is shot...no doubts there.
 

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