Ampeg svt-cl standby/power/fault light flashes

pottymonster · #1 06-10-2010, 07:05 PM

so im still pretty new to all this stuff, still trying to find my way. ive been reading up and havent found anything exactly like what im dealing with online, but from the various things ive read it sounds like either a power fluctuation or a resistor problem. heres whats going on...

ive had my stv-cl for about a year now. today when i turned it on before practice, the standby/power fault light was flashing red to green. this was while the amp was still in standby mode, just after i had flicked the power on. after about 15-20 seconds it stopped flashing and went red. i flicked the standby and few seconds later it lit up green like normal. turned the whole thing off and started over again, same deal.

so i played for about 25 minutes, the light stayed green the whole time, nothing cut out and the amp sounded fine. After practicing i turned it off for a bit and then turned it back on, the light on the front didnt flash or anything, it just behaved normally. played a bit a looked at the bias lights in back, while not playing one of the lights was green the other was very dim green, when playing the red and green lights were on for both. from what ive read, this sounds like normal behavior (?).

any thoughts on why it would be flashing after a period of being dormant? could it be there was a power surge after turning it on? something busted inside? should i have it checked out?

thanks for the help!

waleross · #2 06-10-2010, 08:22 PM

I have the CL, mine is only 6 months old. I would take it in for a checkup just to make sure nothing is wrong. I would rather spend the $bench fee than poke around mysefl. I'm sure the other members will give you more information.......good luck

Bubba Ghanoosh · #3 06-10-2010, 08:32 PM

Acccording to the manual, the red-green flashing indicates "a fault in the power tube circuit." You may want to stop playing it until you get it looked at, or get more experienced/specific answers from this forum.

Jerrold Tiers · #4 06-10-2010, 08:55 PM

IF it did the light deal without the high voltage (in standby), it was NOT sensing a real problem..... because without +V, there can BE no problem......, and the standby removes ALL power except filaments and the -180V for the drivers.

So we can figure there was some problem with the sensing circuit. It might be well worth getting that fixed, since otherwise you won't know if a later "light show" is real or just the messed-up sensor circuit.

pottymonster · #5 06-24-2010, 06:02 PM

Hey again! Thank for all the thoughts and suggestions. I left it alone for about a week and it was fine the next time I used it. But then the next week it did it again!

What happened this time was the same thing: turned it on in standby mode and the light was flashing. This time it didn't stop though... it just kept flashing. We did a few tests in our studio and it turned out that if the amp was sharing an outlet with any other appliance be it an amp, a pa speaker, or the computer, the light would flash when you turned it on. If we unplugged the other stuff from the outlet the amp was fine.

I guess its a 50/50 thing. Part amp part outlets? The other amps are all fine including a marshall 6100lm which draws as much or more than my svtcl. I guess I should take it in for a checkup cause we're gonna have to share outlets with crappy power at most venues anyway. Don't want the problem popping up then.

If anybody else has any thoughts, i'd really appreciate it!

RickenBoogie · #6 06-24-2010, 06:35 PM

Yes, take it in to a qualified amp tech. Be SURE.

adunham1 · #7 06-24-2010, 06:42 PM

Same exact thing happened to me about 2 weeks after I bought my SVT-CL from Guitar Center. Luckily I still had warranty time, so I took it to the local repair shop and they said it was a problem with the tubes and replaced them all for free! I'd absolutely 100% recommend taking it to the repair shop... especially if you've still got any warranty time. Research how expensive it is to buy tubes for that head and you'll understand why the warranty is such a fantastic deal on these.

MotorVenom · #8 07-14-2011, 10:25 AM

I have had the same problem with my Ampeg SVT/CL, I have found the problem only happens when I am plugged into a outlet with other equipment - when I isolated my amp the problem went away. I just experienced this happening at a club for the first time and have played all over with no problems - we tried every outlet in the place and my amp wouldn't work, luckily a bass player in another band saved my night and let me use his amp, got home plugged my amp into an outlet in my garage, no problem.... I don't know if I can trust this thing anymore......

MN_Bass · #9 07-14-2011, 10:29 AM

I had a mid nineties CL that did that, but shortly after it wouldn't power up at all. I would also recommend taking it to a tech, just to be safe.

JimmyM · #10 07-14-2011, 05:39 PM

Quote:

Originally Posted by MotorVenom

I have had the same problem with my Ampeg SVT/CL, I have found the problem only happens when I am plugged into a outlet with other equipment - when I isolated my amp the problem went away. I just experienced this happening at a club for the first time and have played all over with no problems - we tried every outlet in the place and my amp wouldn't work, luckily a bass player in another band saved my night and let me use his amp, got home plugged my amp into an outlet in my garage, no problem.... I don't know if I can trust this thing anymore......

Nonsense! Just take it in and have it looked at. All broken tube amps can be fixed.

Real Ska · #11 07-15-2011, 08:59 AM

Same thing happened to me at my first band rehearsal with my new heritage svt! Except my experience happened mid song! in the middle of a song, all sound disappeared. When I looked at the amp, the green/red light was flashing! I put it back in standby for a bit to check things out. All the tubes seemed to be working, but I noticed one of the bias adjusters was barely over biased. I adjusted it back and took it back out of standby. The amp worked fine for the rest of practice. I did notice that a lamp was plugged into the same outlet. Coincidence???
I dunno, this is my first tube amp. But my previous hybrid amp never failed me once. If my new svt gives me problems at my gig tonight, I'm returning it. Gorgeous tone is pointless if the amp is unreliable.

Real Ska · #12 07-16-2011, 04:34 PM

Took my heritage svt-cl on it's maiden voyage last night, for a gig in Santa Cruz. When it was our turn to take the stage the first thing I see is a stage outlet loaded to the MAX! & there was no alternative....
Guess what happened?
My new svt performed flawlessly! Having a chance to see what it could do in a gig setting was rewarding too! (not being restricted to considerate volume levels at home for my neighbors)
It sounded great! This thing is going nowhere! The only thing that comes to mind that may have caused the flashing light is maybe a short power surge? Maybe an action of the tube protection feature? I'll probably get a good surge protector in my gig bag for the future just to be safe.

MotorVenom · #13 07-20-2011, 01:24 PM

Quote:

Originally Posted by JimmyM

Nonsense! Just take it in and have it looked at. All broken tube amps can be fixed.

I don't think there is anything wrong with my amp, in fact this weekend I took it to a show and it worked fine. I believe the problem was with the power at the club, unfortunately my amp was the only one adversely affected. I am going to take it in to have it looked over and see if there is in fact a problem, I picked up an extra head (GK Backline) so I can rest easy about running into insufficient power sources in the future.

(I've played through an SVT for 28 years)

4StringShooter · #14 07-20-2011, 05:32 PM

ive had my stv-cl for about a year now. today when i turned it on before practice, the standby/power fault light was flashing red to green. this was while the amp was still in standby mode, just after i had flicked the power on. after about 15-20 seconds it stopped flashing and went red. i flicked the standby and few seconds later it lit up green like normal. turned the whole thing off and started over again, same deal.

Here's what happened to me.... Replaced my Pre-Amp Tube. Turned on the Amp, played for about 30 seconds, then BOOM. Took the Amp in. Tech said he checked every solder joint, and found PROBLEMS with the POWER TUBE GROUNDS. Ended up replacing ALL Power Tubes, AND the " bad " pre-amp tube I had put in. Amp worked like new till recently when it just cut out at a Gig. Shut off the Standby, waited a few seconds, clicked it on and it worked fine. Did it AGAIN the next set. Do like the others have said...TAKE IT IN .

Mines going in shortly.

MotorVenom · #15 07-21-2011, 09:43 AM

Thanks everyone, I will be taking it in to see what is up, not surprised to get such good intelligent input from bass players

I'll post what I learn hopefully next week. Cheers!!

MotorVenom · #16 08-03-2011, 02:53 PM

Yup, as you all suggested, 3 of 6 Power Tubes were bad and the other 3 marginal. Usually when my stuff breaks it's broke, it doesn't work just sometimes, that is why I was so confused. I appreciate all the input. The GK got me through a couple shows and I'm gonna carry that back and forth to practice now, save my Tubes and my back for shows. Have a great week.

Real Ska · #17 08-03-2011, 04:19 PM

Before it was determined that 3 of the tubes were bad, did they all still illuminate or glow when the amp was turned on? Or were 3 of them noticeably dimmer or not glowing?

MotorVenom · #18 08-03-2011, 04:37 PM

I did not look, I was convinced when the front power light was flashing that it was an electrical problem, first time it happened I was sharing a power source with some other items and when I isolated my amp the problem was fixed and didn't reappear for several weeks. I was at a club when it happened the second time and when I got home and plugged it in it was fine, which further led me to believe it was a problem with the source of the power not the amp itself. I was wrong. I'll definitely be paying more attention and trying to educate myself a bit in the future.

Real Ska · #19 08-03-2011, 11:53 PM

Quote:

Originally Posted by MotorVenom

I did not look, I was convinced when the front power light was flashing that it was an electrical problem, first time it happened I was sharing a power source with some other items and when I isolated my amp the problem was fixed and didn't reappear for several weeks. I was at a club when it happened the second time and when I got home and plugged it in it was fine, which further led me to believe it was a problem with the source of the power not the amp itself. I was wrong. I'll definitely be paying more attention and trying to educate myself a bit in the future.

Thanks. I'm new to tube amps myself & am just trying to figure out to diagnose potential problems. I haven't had the fault light blink once since it first happened, all the power tubes appear to glow when the amp is on. Sort of a mystery to me. I do hear what I can only describe as a 'metallic tingling' when the tubes are first warming up or cooling down. The tubes are new. I think I read somewhere that this is normal, right?

JimmyM · #20 08-04-2011, 12:22 AM

Ya, it's the filaments heating and cooling. If it doesn't stop after it warms up, then you have to worry. But that's normal.

Anyway, tube amps are easy to diagnose. It's either tubes, capacitors, transformers, pots, switches, jacks, or those little parts all soldered together.