77 SVT dropped

[anonymous02282011]

So, I dropped my beloved 77 SVT on the sidewalk last week.

It fell top down, so it was upside down on the pavement. It fell from a height of about 3 feet.

I took it to the gig, but it wasn't working, so I drove it to my tech. He checked all the tubes, and miraculously only one needed replacing -- the 6C4.

When I got it home it started off sounding pretty good, perhaps a bit noisier than it had been, but soon thereafter every time I played an 'A' it made this weird noise, like a glassy, shaking noise. It would make the same noise, but to a lesser degree if I knocked my fist along the front-top of the amp, just above the control panel or when I plugged in/pulled out of the jack. Both channels were affected.

The more I played it, the noise started to happen on Bb's and Bs too.

The amp is back with the technician (who is VERY reputable) but I was wondering if anyone here might be able to make some helpful suggestions.

Jerrold? JohnK?

[adamrobertt]

Reverb tank?

[anonymous02282011]

Old SVTs don't have reverb. I don't think new ones do either.

[uaudio]

That sucks...I live in fear of that with some volunteer roadies. And my gear isn't 30+ years old. Good tech will hopefully sort it out. Good luck!

[anonymous02282011]

Thanks bud. Fortunately nobody was hurt when it fell. That's the most important thing.

[jarrod cunningham]

sounds like a microphonic tube or loose tube socket . mine made noises when you tap on the top or faceplate ... lol these things are quirky , but well worth the effort .

[chicago_mike]

cracked solder joints, lifted traces, such things can happen when you drop and 80+lbs amp. lucky the chassis didnt warp..happened to me with a very eary 70's chassis.

[hrgiger]

Originally Posted by adbass

Fortunately nobody was hurt when it fell. That's the most important thing.

It is? Are you kidding me? If I had one of those and I dropped it I would immediately stick my head (or more likely some nearby unsuspecting person's) between it and the sidewalk to soften the blow!

[Destructobot]

Sounds like a microphonic tube. With the amp on and the volume up, gently tap on each tube with a chop stick or pencil. They'll all make noise through the speakers to some degree, but if any one of them is particularly unruly when tapped, that's the culprit.

[B-string]

It is probably the replacement 6C4, they are noisy little basterds. Takes some time to find a good one.

[anonymous02282011]

Originally Posted by hrgiger

It is? Are you kidding me? If I had one of those and I dropped it I would immediately stick my head between it and the sidewalk to soften the blow!

Yea I felt like bonehead for sure.I'm just pleased the power tubes didn't all go dead. Now that's pricey.

When I got to the gig the guitar player told me a story about how he once tried to save a falling SVT.

He instinctively stuck his leg out to try to 'soften the blow'

. . . he ended up with a broken knee cap.

So it was probably a good thing that I didn't try to break the fall.

Needless to say, I learned my lesson about hauling this beast of an amp. If it had fallen on someone else, or perhaps a pet or something, I'd have a lawsuit on my hands for sure.

[anonymous02282011]

B-string, Destructobot; thanks for the helpful suggestions

[dangorange]

I had something very similar happen to one of my old tube amps, it turned out to be a loose/cracked solder joint on one of the electrolytic power capacitors. Ask your tech to check those out, I was getting an almost ring modulator tone out of my amp once. A buddy and me tested all the tubes, no issues there. We then went through the whole inside with chopsticks, poking around while playing a bass through the amp - DO NOT DO THIS if you do not work on tube amps, very dangerous.

We opened the compartment that housed the big power caps and voila, one of the connections was loose, soldered it up and everything was good. This was an old Fender Studio Bass, wish I still had it.

[johnk_10]

Originally Posted by B-string

It is probably the replacement 6C4, they are noisy little basterds. Takes some time to find a good one.

+1!

[anonymous02282011]

Thanks guys.

Just hearing you all chime in is making me feel better.

I'm such a klutz! argh.

[goldenglory18]

May I suggest a case for your beloved?

[Lo-E]

I'm arriving late to this post, but my first thought when I read the heading was "When do you get the cast off?" I just assumed you tried to break it's fall....

[johnk_10]

Originally Posted by goldenglory18

May I suggest a case for your beloved?

+1

on my second gig with it, at load-in, my brand new (at the time) SVT-VR fell off a dolly (about 3 feet) but fortunately it was in an ATA case. when opened her up, there was NO damage whatsoever and has always worked perfectly.

[B-string]

Originally Posted by adbass

Thanks guys.

Just hearing you all chime in is making me feel better.

I'm such a klutz! argh.

Stuff occurs, only the depth varies. [Staying away from the potty mouth sensors!]

[JimmyM]

hey, who hasn't dropped an svt? most of the time they're fine, though. they're actually built like tanks and can take their fair share of abuse. a $12 tube is nothing to fix it in the long run. too bad 6c4's are so problematic.