01-23-2013 09:03 PM - edited 01-23-2013 11:44 PM
Hi all, I have this problem with my little Kustom V5.
It's absolutely fine with the stock Chinese el84 valve, but when I change to a JJ EL84 it distorts really badly. I sent the JJ back thinking it was faulty, got 2 more (this time low plate voltage) still no luck.
Funny thing is that the tone control really effects how much it distorts with the JJ, but acts like a normal tone circuit should when the stock Chinese valve is used.
Can anyone please advise? Here's a little clip showing what's happening...
01-24-2013 12:00 AM - edited 01-24-2013 12:04 AM
My bad for not reading ! lol blame it on jet lag!
So you bought a JJ, thought it was bad and got a new one. same prob. Now that I think about it IIRC there a couple guys modding those at TPDRI and experienced the same problem with JJ tubes in that amp.
If it works fine with the orig EL84 and not a JJ you could try an EH Ruby, or other version. Some amps aren't fits for certain tube brands. Seems kind of strange though becasue I use a lot of JJ 84's in other amps I have, or others I've fixed.
FWIW some of those Chinese tubes are not half bad. Sino's are getting popular and going up retail price.
01-24-2013 02:08 AM
lol no worries, jet lag can do that
I've ordered Schuguang, I think that's what the stock valve is? Not sure, but we'll se how that goes when it arrives. Fingers crossed!
01-27-2013 10:16 PM - edited 01-27-2013 10:17 PM
Cool! I think its like I read in other tech threads about 6V6, 6V6 GT versions. For some reason slight mfg variations can cause issues among tube brands. For some its the internal element formation and for others its other internal differences or additional elements (even though not in use or in circuit) that somehow create unforseen problems.
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