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View Full Version : Scratchy Sounding Jubilee.....Help Please!

smunched
10-31-2007, 06:14 PM
OK, so as the subject says, my Jubilee 25/50 is producing a not so wonderful scratchy "white noise" kind of sound. It had done this very little on 1 or 2 occasions in the past, but right now it is producing a constant scratching noise. Anyone have any idea what my problem might be? I'm thinking I'll have to bring it to a tech to have a look either way, but it's really bothering me right now. Thanks in advance.
Blue Strat
10-31-2007, 07:01 PM
Probably one of the preamp tubes. See if any of the volume or gain controls affects the noise level. If the 12AX7s are more than a few years old it's time to change them, but even brand new preamp tubes can be noisy.
GearHeadFred
10-31-2007, 09:14 PM
If you give up and decide to sell it, I'll take it off your hands!
Just kidding - but a Jubilee 25/50 is on my "gotta have" list! Good luck.
ChickenLover
11-01-2007, 05:57 AM
That sounds a lot like the oh-so-common bad FX loop jack internal connection. To do a quick test...plug a known good short instrument cable into the FX Send and Return...if that cures it then it's just a dirty/faulty connection inside one of the FX jacks (I think its the Return jack but not sure). The jack can be cleaned but ask a more experienced tech...they might say replacing it is a better long term solution. But you can always just plug a jumper cable into the FX loop jacks to alleviate this problem in a pinch.
ChickenLover
11-01-2007, 06:00 AM
And if Mike is right about the preamp tubes...I think the stock RFT tubes are a really good match for that amp. Well...at least some of them came with RFTs stock (my black 100W 2555 did).
smunched
11-01-2007, 04:01 PM
That sounds a lot like the oh-so-common bad FX loop jack internal connection.

Thanks for the tip.......I didn't realize that is a common problem with these amps. Oddly enough, I turned it off and then came back to it a few hours later and the amount of scratching had cleaned up significantly, but still made some noise on occasion. Either way, I'll likely still bring it to a tech and have eveything looked at properly rather than me fumbling around.
mmorse
11-01-2007, 04:10 PM
And if Mike is right about the preamp tubes...I think the stock RFT tubes are a really good match for that amp. Well...at least some of them came with RFTs stock (my black 100W 2555 did).

I have Raytheon blackplates in my 2550. Another nice tube for that amp.
mcdes
11-03-2007, 10:38 PM
wow, i have/had the same problem! and it was the return effects loop jack!

awesome cheers guys!
mcdes
11-03-2007, 10:41 PM
i should state it was on a fender ultimate chorus, not my ac30 if someone does happen to check my signiture.
Structo
11-06-2007, 08:59 AM
Sometimes on FX loops all that is needed is to insert a plug a few times.
They are switching jacks that can corrode over time.
You also can spray some deoxit on the plug and plug it is a few times to clean it.
If it is a sealed jack (marshall type) then if the plug trick doesn't work you will have to have the jacks replaced.