[jhljhl]

No, has to be a 12au7 type!

OK thanks.  Too bad have lots of them.

 

[frankrondaniel]

  I moved to a pair of cryo'd NOS Mullard CV4003's a little over a week or so ago as well. I don't get any flashing/arcing with mine thankfully. Overall, very yummy. 
 
I agree with the previous comments - a very resolving, detailed tube, that's tonally balanced with richly textured bass and superb impact. They've become my favorite WA7tp tube, and play well with all of my headphones. Both my LCD-2 and my HD800 sound tonally "right", which is saying something. The only "gripe" I have is that sibilance is very obvious if it's on the recording (particularly with the HD800, to no ones surprise). This is not a tube that glosses over recording flaws in the slightest. If you're looking for gooey "tube warmth", look elsewhere. However, if you want microdetail, resolution, texture, soundstaging & separation, and excellent timbre, this is the best I've heard. As l've spent time listening with these tubes, I keep picking up nuances and details that I hadn't heard before, oftentimes in the lower registers of the spectrum. The low end punch these tubes can exhibit still catches me off guard, with zero bass bloat. Quite impressive - and the end of the WA7tp tube-rolling journey for me. 

 
Hi Joel,
 
Turns out that I've been using the CV4003's in the PSU for a while now.  I agree with your evaluation - especially with regard to driving the HD800's.  Trouble is that I find when using the EH 6C45 Gold Plated tubes in the amp the highs remain somewhat uncomfortable.  Switching to Cryo Treated 6C45Pi tubes in the amp, I think that I get as close as possible to having the "gooey tube warmth" on the WA7. Very smooth, weighty though still detailed sound.  Only problem is I lose the wide sound stage that I prefer.  It seems to collapse to the middle.  More of an inside-the-head experience.  I'd love to find a tube for the amp that gives me the same sound but with an improved sound stage.6It's too bad that the rolling options for the amp are limited.GC456C45

 

[groovyd]

got a second set of 4 Cryo-treated Mullards from Upscale Audio still in original boxes from great britain and very obviously never used, still with full clear printing on the tubes and shiney copper pins and they do not exhibit the same white strobe on power-up as the others I got from company b.  The construction of the cans inside the tube look slightly different too, they don't have holes in them like the others.

 

[JoelT]

 
Turns out that I've been using the CV4003's in the PSU for a while now.  I agree with your evaluation - especially with regard to driving the HD800's.  Trouble is that I find when using the EH 6C45 Gold Plated tubes in the amp the highs remain somewhat uncomfortable.  Switching to Cryo Treated 6C45Pi tubes in the amp, I think that I get as close as possible to having the "gooey tube warmth" on the WA7. 

 
I'm usually not finding the HD800's highs to be uncomfortable when using the Gungnir/Wyrd combo as a source, with the exception of recording specific sibilance that occasionally rears it's ugly head. I've been experimenting with a subtle application of EQ to cut the sibilance/glare. 1.5db-2db in the 10k range is doing the trick for me at the moment. I tend not to listen to the HD800 very loud though - it is a bright leaning can, for better or worse. I'll probably try the Anax 2.0 mod sometime in the near future, and possibly a good copper cable rather than the SPC stock cable. Over smoothing or masking of the HD800's treble region with mushy sounding tubes obviously isn't ideal either, as the headphones technical prowess can be lost (as you pointed). 
 
I agree that the lack of driver tube options for the WA7 is unfortunate, though I suspect it was by design (i.e. simpler for first time users). That said, I've had a lot of fun and enjoyment with the addition of the WA7tp tube rolling, so I'm thankful for that. Looking back at what the stock WA7 sounded like with the solid state PSU, I've come a very long ways in terms of sound quality. It has been a learning experience.

 

[JoelT]

  got a second set of 4 Cryo-treated Mullards from Upscale Audio still in original boxes from great britain and very obviously never used, still with full clear printing on the tubes and shiney copper pins and they do not exhibit the same white strobe on power-up as the others I got from company b.  The construction of the cans inside the tube look slightly different too, they don't have holes in them like the others.

That's where I bought mine as well. I like their grading, testing and labeling - knowing what you're getting is worth it IMO. Enjoy.
 
Just out of curiosity, what were your test rating #'s?

 

[groovyd]

  That's where I bought mine as well. I like their grading, testing and labeling - knowing what you're getting is worth it IMO. Enjoy.
 
Just out of curiosity, what were your test rating #'s?

all 4 are T1=29000 T2=28000... is that any good ?  I know nothing about those numbers.

 

[JoelT]

I don't know specifically what the test scores correlate to - I should call them and find out, as it'd be interesting. Mine were sold as "platinum" grade and are listed as 27000/29000 respectively. The cryo'd Cifte's I have are rated 30000/30000, and the the JAN Sylvania's I used to run were tested at 20000/20000 (by TCtubes). 

 

[jhljhl]

I noticed that when the power supply is right next to the main unit there is a buzzing sound but if there is 2-3 inches apart there is no buzzing.  Any one else notice this?

 

[JoelT]

  I noticed that when the power supply is right next to the main unit there is a buzzing sound but if there is 2-3 inches apart there is no buzzing.  Any one else notice this?

Strange. Mine sit about 1" apart and there is no buzzing/noise whatsoever.

 

[desertblues]

Strange. Mine sit about 1" apart and there is no buzzing/noise whatsoever.

Same here, 1" apart and no noise of any kind.

 

[jhljhl]

Same here, 1" apart and no noise of any kind.

I changed powercords and now the buzzing stopped thanks.

 

[HiFiGuy528]

 
I changed powercords and now the buzzing stopped thanks.

 
Glad it was a simple fix.  

 

[smellyfungus]

got a second set of 4 Cryo-treated Mullards from Upscale Audio still in original boxes from great britain and very obviously never used, still with full clear printing on the tubes and shiney copper pins and they do not exhibit the same white strobe on power-up as the others I got from company b.  The construction of the cans inside the tube look slightly different too, they don't have holes in them like the others.

just curious do you have a pic of your tube collection? I swear you must have at least 20 pairs or so with all the backup pairs you order.

 

[groovyd]

just curious do you have a pic of your tube collection? I swear you must have at least 20 pairs or so with all the backup pairs you order.

I have more then that haha, prefer to be well prepared for the tube-pocalyse 

 
 
I have 2 units, home and work and each has the WA7tp.  I bought 4 pair of cleartops, 4 pair of JANs, 4 pair of mullards, and the original 2 pair of stock.  For the WA7's i have the 2 pair of stock, another 10 pair of golds cryo, 6 pair of NOS, and 4 pair of the hybrids. 

 

[jhljhl]

   
Glad it was a simple fix.  

I highly recommend a good power cord.