noob question about my new ampeg

gordabega · #1 04-18-2011, 12:39 PM

hey guys. i just bought an svt4 pro last week, and it is my first (and hopefully only) amp for quite a while.

i brought it to rehearsal last saturday and the signal cut out intermittently, throughout the day.

i have a schecter california custom (jass bass clone) with EMGs and i ran my bass driver DI in front of the amp. i am using my friend's Eden XLT 410 cab. i ran through one side of the amp and had a 3630 compressor through the effects loop.

i had good sound for a while, but i'd say about an hour or two into rehearsal it would cut out. i assume it's a limiter or something so it wouldn't damage the amp. i stopped using it and went through the di for the rest of the time.

i did try a 1x15 sonic pa cab for a few songs, but it cut out there too.

my buddy (cab owner) told me to bridge it mono and run the cab that way, since it's an 8ohm, 600W cab. does that sound right?

thanks!

Muckaluck · #2 04-18-2011, 12:54 PM

Bridged or unbridged shouldn't impact the amp going into protection. Sounds like you need to bring it to a tec.

I don't know if you bought it used, but through my experience, most of the stuff I've bought used I had to put a bit of money into to get it up to playing specs, especially amps.

RickenBoogie · #3 04-18-2011, 05:23 PM

+1 see an amp tech, be sure.

TomB · #4 04-18-2011, 06:43 PM

You may need professional help, but before you decide the problem is inside the amp, try simplifying your signal chain and see if the problems recur. You mentioned at least 2 devices that could have this kind of problem, not to mention the cabling hooking it all together. Try a rehearsal or other lengthy session that's just bass into amp and see if the problem recurs. If so, then seek help. If not, then you'll need to look elsewhere in your signal chain.

Ric5 · #5 04-18-2011, 06:47 PM

I have 3 ampeg heads. I love the tone. But one of them has the cut out problem. The other 2 are rock solid.

selftitled907 · #6 04-18-2011, 06:54 PM

Quote:

Originally Posted by TomB

You may need professional help, but before you decide the problem is inside the amp, try simplifying your signal chain and see if the problems recur. You mentioned at least 2 devices that could have this kind of problem, not to mention the cabling hooking it all together. Try a rehearsal or other lengthy session that's just bass into amp and see if the problem recurs. If so, then seek help. If not, then you'll need to look elsewhere in your signal chain.

+1
remove everything from the equation besides the amp and guitar first, then decide to spend the money for a tech to check it out. but from the sound of it....ric5 seems to have an ampeg with a similar problem. might be a hit or miss thing with ampeg.

gordabega · #7 04-19-2011, 12:48 AM

well i did buy it used, and the owner said he thought he had a problem with it cutting out at one time, so he brought it in to one of the most well known repair shops around (Savage Audio for those of us Minnesotans here) and they went through it and beefed up all the solder joints and everything, and they found no problems after that. i am asking for the receipt from that repair so i can call them and refer to that repair. maybe they have some sort of warranty period, and maybe i'm still in it.

i will do everything you all are suggesting, and i appreciate all the help. i am new to bass stuff, and it's all coming at me rather quick.

gordabega · #8 04-19-2011, 02:18 AM

hey all, i did a little googling and found this thread here from a little while back:

Ampeg svt4 cuts out....Overheating?

i did put it in an SKB rack (the one with a handle only on one side) with a 2 space vented blank above it. i think i'll yank it out of the rack, and try it with just the bass first off, and add the sans amp next if things go well.

another suggestion from another thread was to check the mute footswitch jack. i guess those are known to go bad too.

either way, this website has already proven to be a wealth of knowledge, and i have many avenue to try before going to a tech. thanks everyone!

gordabega · #9 04-19-2011, 12:26 PM

i have a copy of the repair receipt dated last July 2. they replaced all 3 preamp tubes, repaired all circuit board connections, cleaned and tightened all controls, jacks, transformer(s) and circuit board, and tested it. the previous owner told me they played with it in the store (like jammed with it) for hours before giving it back to him.

i'm starting to think it could be overheating, but i won't know until i get in to jam with it, and that won't be until at least the weekend. ;(

gordabega · #10 10-21-2011, 11:53 PM

This summer has been one trial after another, since my wife was in and out of the hospital. I sold a few things on Craigslist and was able to afford to get it to a tech. It turns out, the previous tech work neglected to fix solders between the circuit board and the back panel of the amp. One look at this amp and the tech I brought it to figured it out and fixed it. Tomorrow I will try it out, and I am hoping to be blown away.

gordabega · #11 10-25-2011, 12:31 PM

well dudes, if any of you is from the Mpls area, take your repairs to Casey Gooby. Music Electronic Tech. he fixed what Savage Audio missed and only charged me $100 for it. Savage's labor rate is higher and obviously they missed this problem. my amp kicks a lot of Bass. looking fwd to getting a decent cab or two to go with it now.

Slackerprince · #12 10-25-2011, 12:35 PM

Victory!
Too bad it always takes $.
Good luck and enjoy.

S

father of fires · #13 10-25-2011, 12:49 PM

Quote:

Originally Posted by gordabega

well dudes, if any of you is from the Mpls area, take your repairs to Casey Gooby. Music Electronic Tech. he fixed what Savage Audio missed and only charged me $100 for it. Savage's labor rate is higher and obviously they missed this problem. my amp kicks a lot of Bass. looking fwd to getting a decent cab or two to go with it now.

Yeah!!! Good for you and I hope the misses is doing better!

gordabega · #14 05-21-2012, 05:56 PM

OK dudes, sorry to resurrect an old thread, but I have a question for youse all:

So the amp has worked swimmingly over the past few months. Since I had it fixed really. My usual setup is the amp and 2 XLT 410 clones, daisy chained to create a 4 ohm load. then of course the BDDI pedal in front and the 3630 in the effects loop.

i brought it to rehearsal (only one cab though) for a hair metal tribute band (i'm subbing for my buddy whose waiting on baby number 7?) and it was really farty. would that be because ther amp is used to pushing 8 speakers, so now i have the volume too high? i thought that the amp took care of that.

i daisy chained an available Peavey 1820 cab into my 410 and it helped but i think it continued. i'm not sure, i was too worried about playing the parts right.

and F.O.F., it has been a hell of a ride, but we think she's finally in the clear. she had another surgery in March. they placed a SHUNT (catheter) in her brain and a drain tube from it to her stomach to get rid of the spinal fluid causing the pain. no idea how it came to be, but VERY THANKFUL that it's all over. she's back to work and we're hoping back to normal life.

Dan55 · #15 05-21-2012, 07:11 PM

Good to hear your wife is better.

As for the single cab farting out, that's likely if you're going for the volume level you usually get with 2 cabs. Sometimes it takes 2 cabs (or more) to reach certain volume levels. Otherwise, the amp can overpower a single cab. All that is dependent on the amp and cabs used, of course.

Dan

JimmyM · #16 05-22-2012, 12:01 AM

Glad your wife is doing better. Farty sound makes me think maybe a tube is out. Also, I don't know if the power section needs occasional biasing like the SVT 3 Pro, but that might also be a problem. But I'd check the tubes first. If you have a couple known good tubes, try swapping them out one by one.

walterw · #17 05-22-2012, 12:12 AM

frankly, i suggest losing the POS alesis comp in the effects loop.

you might find the amp suddenly jumps out in the mix, to where you can actually turn it down a little and reduce stress on all the components.

Jerrold Tiers · #18 05-22-2012, 06:12 AM

The 4PRO WILL definitely over-power some speakers in the low end, and may cause farty sound, or even loud bangs as the voice coils hit the magnets.

Typically that can happen when in bridge mode, and usually when the lows are boosted, which it seems might be the case for your sub gig..

The amp has a limiter, but doesn't "know" when the speakers have had enough.

Koog · #19 05-22-2012, 06:19 AM

If your bass is active, it will overdrive the Ampeg unless you press the Db cut button to the on position while playing. Unless you do this the amp will overheat and cut out or shut down.

The only time you should have the Db cut off is when you play passive basses.

Hope this helps.

Koog.

Immigrant · #20 05-22-2012, 08:48 AM

And if the pedal between the bass and the input is louder ON than on bypass, turn the output down until volume is equal in both positions.

The 3630 is a POS. I had fart issues with one and replaced it with a dbx, which later got replaced with a pedal type Compressore.