[cacatalysis]

Modification of BA is required to accommodate AVVT PX-4M.  A pair of adapters are also required.  Check with Craig if your BA could use these tubes.  Be aware of possible reliability issues with these tubes.  They sound very nice (especially with a Mullard ECC35 as the driver).  My pair became useless when one of them burned out after less than a year of moderate usage, although this could just be my bad luck.     

 

[rosgr63]

No need to modify the BA, in fact it's not recommended.
 
Jac can either rebase the AVVT PX4M or get Glenn to build you a pair pf B4 to UX4 adapters.
 
Some BA's use a Yamamoto combo B4/UX4 socket in which case no problem at all.
 
I have used  the AVVT PX4M in mine, Craig has mentioned they are the "Holy Grail" of PX4's. 

 

[Feuergeist76]

Thank you guys so much for your quick reply and help, it's a bliss for me as a quite newbie to tubes to get a step into this topic with your help.

I'll consider using an adapter and get the AVVT PX4 Mesh tubes as they seem to be quite good.

Thanks again!

 

[cacatalysis]

My BA is modified by Craig himself to accommodate both PX25 and PX4.  Craig also made a pair of B4 to UX4 adapters for me at the same time.  I trust Rosgr's words, who is a real expert on tubes in general.  The modification of my BA could be just to accommodate the use of PX25 tubes.  Osram PX25s are my personal favorite power tubes in BA, usually with either a Raytheon or National 6F8G as the driver for HD800.  6SL7/ECC35 are preferred driver tubes when using PX4 or EML 300 mesh (set the BA at 4V) as power tubes, among those the combination of 7F7(with an adapter)/EML 300 mesh sounds the best to me.  I think it is a good idea to roll driver tubes first, which has a bigger impact on the overall sound to my ears.           

 

[rosgr63]

The AVVT PX4M have the same speck as the original PX4 so they can be used as they are
The PX25 are different so a mod is necessary
I am not an expert thanks for the kind words I am still learning

 

[rgs9200m]

So is EML (emission labs) going to make a PX4 tube? Thanks.

 

[CEE TEE]

Thanks for your good remarks, CEE TEE.

Just one question, I'm about to go for a AVVT PX-4M and im wondering about if the B4 socket is matching the Balancing Act? Because I've read from CEE TEEs post that I should look for a UX-4 socket?

Maybe someone can help me out with that.

Thanks in advance!

Feuergeist

Hello Feuergeist and Everyone,
 
Sorry, I realized that I did not completely explain and illustrate my thoughts correctly/properly.  

 
I have updated my post with additional information and pictures to try to be accurate and help explain:  
http://www.head-fi.org/t/497049/balancing-act-tube-rolling/330#post_11114148

 

[CEE TEE]

Here is purrin's thread on modifying the BA to be able to take PX-25 tubes:
http://www.head-fi.org/t/598460/eddie-current-balancing-act-mod-for-px25
 
And here is purrin's B4 to UX-4 adapters, mine were made (as rosgr63's were) by glenn2359.

 

[CEE TEE]

  So is EML (emission labs) going to make a PX4 tube? Thanks.

Hi rgs9200m, yes...Tari said that EML will be making a PX4 tube, which is great news.  Probably expensive, but great to have another option plus a more reliable option than the KR PX4 has had lately after the death of the founder.
 
I purchased my BA from Tari and he still has Moth amps, etc. So I would be excited to hear his thoughts on the tubes. I don't think that he is running HD800 though, so my headphones and DAC will have an impact on which tubes I ultimately prefer.  I can say that I would love to try AVVT PX4 sometime and the EML PX4 when they come out.  I purposely have not tried Osram PX25 as I am afraid of liking them and not being able to find/afford them!

 

[rgs9200m]

Thanks. Actually I have a Pinnacle, but I latched onto this thread since it needs PX4s. 

 

[Radio_head]

I am running a Pinnacle as well.  Info on the EML is from Jac himself.  I originally inquired with him about the AVVT PX4M, but he convinced me to just wait for the EML as they are supposed to be superb and have a good warranty to boot.
 
The PX4 is a special tube no doubt, the only one that maybe edges it out for me is the 2A3's on my Moth.

 

[Feuergeist76]

Hello Feuergeist and Everyone,

Sorry, I realized that I did not completely explain and illustrate my thoughts correctly/properly.  

I have updated my post with additional information and pictures to try to be accurate and help explain:  
http://www.head-fi.org/t/497049/balancing-act-tube-rolling/330#post_11114148

CEE TEE and Ros, Thanks a lot for your help, with your and Ros support I finally figured out this socket issue. I also found an adapter which is coming from HK:

http://www.ebay.com/itm/1x-British-B4-1561-tube-to-UX4-80-tube-adapter-teflon-socket-converter/291009116714?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3D80ba60a5e78247e790e764b199369bdf%26pid%3D100033%26prg%3D20131017132637%26rk%3D1%26rkt%3D4%26sd%3D291009116714

Finally I got everything together, I'll use today if I'll go for the EML 300B XLS and the AVVT PX4M together or if I'll take only one of them. Anyway either of them will be an upgrade of my EH 300B.

Cheers,

Feuergeist

 

[CEE TEE]

^Wow, Feuergeist...great find!  Have not seen anyone offering that adapter yet.  Thanks for sharing.  May help others too!  Looking forward to hearing which ones you end up with and how they sound.

 

[rosgr63]

I am pleased I could be of some help.
 
18 months ago I asked this particular seller to make me a pair privately which they did, now they offer them as part of their range.

 

[rgs9200m]

 
^ Very nice review of the KR and EML output tubes for the BA.  I've been using the EML 300b Mesh and love them but I'm also tempted to get a pair of KR PX-4.   Does anyone know if the current production KR tubes are the same quality they were a few years ago?  I'd heard the quality may have changed following the death of the founder, but it could just be a nasty rumor . . 

I also have this question. Is there an issue with the KR PX4 reliability? Does anyone have experience about how long they last? Thanks.