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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
myles_b_astor's avatar
myles_b_astor
134 posts
 
Vinhusc is right. Got the same dirt straight from the top. For some reason, the 140M amplifier is more sensitive to the choice of driver/input tube than is the 275M. In fact, Lew said use of other tubes could damage the 140M. And in fact, they carefully match all three tubes and tell you to only use them in the positions indicated.

So caveat emptor.
samhar
1,048 posts
 

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.

vinhusc OP
11 posts
 
Noh, it's impossible because CJ is very conservative and my dealer told me that they will NOT going to do any modification on my amp.
Well, I'm giving up and looking for the other PowerAmp!
rleff
1,065 posts
 
Vinhuse if you really like those amps I would give bob bracket of rhb designs a call to see if he can modify them to use the tube you reaaly want to roll into those amps;here is his website address,also he gets very positive customer comments on his work.

http://www.rhbsounddezign.com.
Give it a shot might work out well for you
cmalak
681 posts
 
Vinhusc...have you heard the amps with the stock CJ 6922s? If not, I would at the very least do that before deciding to switch your amps and see whether you like them or not.
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