Need help C-J monoblock LP-140M with Siemens CCa


I am new to the tubes world and this is the first time ever I have tubes power amp in my audio gear.

I have been used 3 different sets of NOS/NIB Siemens CCa tubes in my Conrad Johnson LP-140M amplifier, and all have started to fizzle, crackle and/or pop within a few days.

Just curious if others have had this problem? My dilemma is that I like the sound of these CCa tubes, and don't like any junk tubes (Electro-Harmonix was supply with the Amp from C-J factory) in this amp. I don't believed they sound nearly as good as Western European make tubes.

I have hear about Ediswan CV2492 from UpscaleAudio.com, is it really equivalent or better than (Siemens, Telefunken or Valvo) CCa?

Thank you so much for all your feedback and/or suggestions for alternative tubes.
vinhusc
If there is something sticky on the tube or I just want to clean them up I use lighter fluid it doesn't damage the lettering.
Thank you so much for all of you guy info.

Personally I do NOT like anything make in Russia or China. However, CJ designer do believed: There is NO better tubes available to improve the sonic performance for the CJ LP140M !!!????!!! I do NOT agreed with them about this and I have to switch the others gear.

My system: Sonus Faber Guarneri Memento spk with REL B2 Sub, MBL 5011 PreAmp, Weiss Medea DAC, Esoteric P-05 CD Transport.
Thank you so much for all of you guy info.

Personally I do NOT like anything make in Russia or China. However, CJ designer do believed: There is NO better tubes available to improve the sonic performance for the CJ LP140M !!!????!!! I do NOT agreed with them about this and I have to switch the others gear.

My system: Sonus Faber Guarneri Memento spk with REL B2 Sub, MBL 5011 PreAmp, Weiss Medea DAC, Esoteric P-05 CD Transport. and IsoTek Sigma GII Power Conditioner.

Believe me, I've already spend so much money on my stereo system and I can NOT let any junk stuffs degrade the system.
Good news! Conrad Johnson just call me and ask the sent my LP-140M for them to update the circuitry for the driver input... so I be able to run any kind of 6922 tubes in my PowerAmp.

They claim that their design was optimized for the used of Electro-Harmonix! ... sound silly to me.