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

Showing 5 responses by samhar

Exchange the tubes one at a time to the other amp, this should show which tube is making noise or if the noise is something else.

Ask CJ if it's possible to have a tec modify the bias in the amps to work with the Siemans. I know with my amp I have to re-bias my 6DJ8 or 6922 even when using another set of the same model tubes.

I hear your frustration I also dislike the EH sound!!! I also don't care much for the 6H30 so you might be carful as you also may not like this tube!!!
Just curious what speakers are you using?
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.
Great news!!!!

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

Not really!! They set the amps up to run tubes they knew would be readily available. I also dislike the lack of harmonics in the current Russian 6922's, they just don't have a good quality sound.

If you decide to try another tube give the Amperex 7308 a try, warm with detail another great tube!! Don't forget 6DJ8's can't always be substituted for 6922 because of higher heater current.

Enjoy,
Sam