SVP issue???

ledyard · #1 03-16-2011, 12:36 AM

I just got a SVP pro. Love the sound. Played it for an hour or so at home then racked it and took it to rehearsal. Running with a QSC PLX 1602 in bridged mono.

I played it at rehearsal last night and it was killer for about a hour of real loud practice. Then as I'm in the middle of a song i hear this ungodly loud crackling popping sound coming from my speakers. I back off the attack and it happened again a few seconds later. I looked in the back and found that the 1/4" cable plugged into the pre was pulled out partially. I dont know why.....but anyways I popped it back in and played another song. halfway through it did it again (the noise). So I changed the cable from the amp to the pre and I played through everything really loud for about 2 minutes. I even turned it up more. No problems. I thought it was the cord. I was playing a passive P bass and also noticed the clip/limit light was barely coming on once in a while when i would play heavy on the E string around the 5th -7th fret area.

Tonight, I went to my other bands rehearsal and all was the same except I had a MIA Cirrus (18 v active). Still had that slight clip/limit light on lower notes. Soon as we started a song there was that loud awful popping noise. Like unplugging your instrument cable and touching it on your bridge a bunch of times.
So I plugged straight into the power amp. No issues. Plugged the pre back in.....and the noise was back when i played hard.
Note: I was not running the pad engaged with either bass on either night. Should I have been? Ran pre master volume at noon and gain at like 11:00.

I'm obviously taking it to my tech unless someone tells me i'm missing something stupid here. I had a similar problem with a SS guitar head years ago when it had some faulty solder joints.

Anyone have any ideas? Its almost as if the volume causing vibration was causing it. thats the vibe I got. but I'm probably wrong. Played it at home for at least an hour straight with no issues though. (low volume)

JimmyM · #2 03-16-2011, 01:04 AM

bad tube, faulty solder joint, faulty jack...probably nothing too serious, at least let's hope. but with gear that has tubes in it, it's only natural to check the tubes first.

ledyard · #3 03-16-2011, 07:24 AM

I'm thinking solder joint or jack maybe. doesnt feel like a tube. But hey...thats why i'm not a tech. Just waiting for my tech to txt me back on when I can take it to him. Hopefully he can diagnose it while I'm there.

Irritating, cause it sounds absolutely awsome with my P bass.

12bass · #4 03-16-2011, 07:52 AM

Might be worth re-seating all of the tubes, and possibly moving them around to see if that changes anything (remember that V4 is a 12AU7). Also, try pushing the buttons in-and-out a few times as well as plugging/unplugging the input and output. Might be a faulty connection from lack of use. Sounds like it may be a bad solder joint though....

ledyard · #5 03-16-2011, 10:07 AM

I got ahold of my tech. I'm going to take it up monday and play it for him. its doesnt bother me to take it to him. We're aquaintences and I havent been up in a long time so he'll look it over while i'm there and we'll B.S. for a while. Plus he wont charge me an arm and a leg.

ledyard · #6 03-21-2011, 01:38 PM

Problem soved. The ground leg on the master volume pot had a jacked up solder joint. So my tech took both boards out and went over every joint with a fine tooth comb. Touched up alot of other joints as well. Glued that green wire coil thing(have no idea what it is) in place also. He said since it is suspended in air by a few wires that they have been known to snap off if dropped or traumatized. So thats a non issue now. Should be like new now. We'll see tonight when I give it a thorough pounding at rehearsal.