Blowin SVT3pro,! Help on situation

Discussion in 'Amps and Cabs [BG]' started by StoutXXX, Feb 1, 2003.

  1. I have a SVT3 pro with a musicman and 6x10 cab. The first head i bought just did not even turn on when I took it home. The second one has seen gigs and practices constantly and is notover run. today it popped and went dead again. Nopower. Advice needed. had recieved the second one for free after returning first to guitar center. I dont wanna own this head if its gonna have reliability problems. FRustrated and slumpedover. please help.
  2. Good old Ampeg quality control. Get something else. I had an SVT-3 Pro and was never happy with it. And it worked.
  3. My Ampeg's screwey too. They really need to do something about quality control. I've suggested it here, but it didn't seem to fly, but I see non stop complaints about Ampegs not working how they were designed to on this very board.
  4. I had mine for almost 5 years of heavy playing. Never had a problem.
  5. Ampegs are just as reliable as any other mass produced amps (and, no I don't work for them or own an SLM ampeg:D). I've seen problems with just about every amp you could name. There are just as many threads on here complaining about SWR, Hartke, GK, etc as there are about Ampeg.

    StoutXXX: Bring it back and get a tech to open it up and tell you what's wrong with it. 9 chances out of 10 it's something simple. At any rate keep bringing them back if they don't work and are still under warranty. If you get fed up, just get something else. That's about all I can offer you in the line of advice ;). Good Luck.
  6. rok51


    Sep 2, 2002
    Crawfordville, FL
    Been using my SVTIII Pro steadily since 1994. Absolutely no problems. Still diggin' the tone (and features).

  7. bass616


    Mar 1, 2003
    I've had my svt 3 pro for 3 years now and have had absolutely zeo problems with it..and i dont baby it either...heavy road use...usually full open sugesst looking at the ohm matching between the head and the cabinet..i lost a good G-K head that way...just a sugesstion..
  8. cb56


    Jul 2, 2000
    Central Illinois
    good thing you have that Ampeg 5 year warranty, better than some lesser warranties. Let's name some amp makers that have lesser warranties.
  9. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Better because it's needed more often?
  10. I've had my SVT-3 Pro for about 2 years, and it has done nothing but work perfectly for me. I normally run it wide open, and get some distortion out of the Preamp tubes. If there is something wrong with it, take it back to get fixed. If it takes more than one trip to the store to fix it, that seems more indicative of the store working on it than Ampeg, IMHO.

  11. SVT 3 Pro's run OK on 8 ohm loads. 4 ohm loads make them freak out and once they start acting up, they don't stop, even after a complete rebuild. Do a search on the SVT3 Pro and see how many people have had problems with theirs, myself included. I recommend you take the amp back to GC and swap it for a completely different amp before you're out of your 30 day exchange/refund period. New amps should work. PERIOD.
  12. rok51


    Sep 2, 2002
    Crawfordville, FL
    Can't really agree with the 'freakin' into 4 ohm thing. I know YMMV, but other than a very few 'quiet'(??) gigs, My III pro has seen nothing but a 4 ohm load in a loud band context, and has never even burped. I will agree that it has 450 of the 'small' watts, which is one of the complaints that I frequently hear about the amp as well as the noise floor being relatively high.
    PBG, as a 'bench wiz', do you know if anything other than the cosmetics and Speakon vs binding posts changed between the III Pro and the 3 Pro? Most of the 'reliability' issues I have seen posted seem to deal with the latter.

  13. cb56


    Jul 2, 2000
    Central Illinois
    Better 'cause it's there if and when it's needed.
    My point is, it wouldn't make sense to put a 5 year warranty on something if it's a POS. The company would go under in no time. Or be bought out by Yorkville or somebdy :D
  14. I don't have the amp anymore but I've still got the factory skits and tech revisions for the first five generations of the 3Pro. I can't compare it to the old SVT III because I've never seen one. The III Pro and the 3Pro are the same amp, and I can tell you that there is absolutely NO way that a Speakon connection vs binding posts will make ANY difference in how the amp runs. Even if the binding posts made intermittant contact, the effect would be an overall average rise in impedance which would make the amp work LESS hard.

    All of the tech revisions from SLM themselves deal with driver circuitry and relays which have proven to be VERY faulty. The amp is also VERY overrated and without explicitly admitting it, Ampeg recommends biasing the output transistors colder on any SVT3Pro that is having trouble. The result is a net power reduction, so much so that I could not even get mine to push over 280 watts into a 4 ohm dummy load at 1 kHz. Bass frequencies were even worse! I got tired of replacing driver and output transistors trying to get the amp up to its advertised output. SLM's own notes spec a stable bias point for 320 watts @ 4 ohms.

    The amp is a VERY unstable design and runs at the limit of its parts tolerances. If you lower voltages and put the amp into a more stable operating range, it's too weak to be useful. Ampeg bascially gambled with a poor design that it will not break down and if it does, warranty service will offset customer greivances. I'm sure that decision was made a by a bean counter who weighed percentage costs of warranty service against redesign and reparting and decided to risk it rather than take the extra time for quality.
  15. Psyco,

    That was awesome,

    that amp was the worst amp i ever owned, and i'm gald i bought it for cost, when i was working at a SLM dealer.
  16. I know this is old but I started it. After the final soldering was done on loose connections I have never had a problem running wide open at a 4 ohm load all day long. I blew a fuse not to long ago but jsut pooped in a new one and away we went. And when the engineer was working on it he showed me his calculations on the power capability and it was right at the 450 watt level. I figured I had to put this in after all the ampeg bashing including myself. This amp is more than solid for loud applications witht eh right cab.:D
  17. Scott D

    Scott D

    Apr 21, 2003
    Minneapolis, MN
    Yeah, i hear all these probelms about the new ones. Like Rok51, Mine is a 1994. It's perfect for anything I do. It's really loud, Like all it needs to be for me is @ 9 oclcok w/ a 4 ohm load w/ cabs in the 100DB range. It sounds great. I don't think i'd ever replace it unless it broke.
  18. Slot


    Oct 17, 2003
    Sydney - The Shire
    I prefer playing out of my crappy 50 watt samick combo, than my svt3.

    That says plenty !!!
  19. Scott D

    Scott D

    Apr 21, 2003
    Minneapolis, MN
    Ha, and you know whats sucks? You guys paid about $900 for a crappy working one, and i paid $350 for a flawless ol used one.
  20. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    I am going to disagree with PBG on this deal.

    Well, I think you may be confusing the SVT-3PRO amp with some totally different one somewhere.

    The SVT-3PRO is COMPLETELY DIFFERENT from the SVT-III. The SVT-3PRO is the "tube driven mosfet" design, which we have made almost unchanged since 1993. The SVT-III has an all-solid-state power amp and less power.

    I checked with Service. Per Service, we sell a lot of SVT-3PRO units, and get very few service/warranty issues with them.

    This is "news" to the Service Dept, as well as the engineering folks here. I asked, and nobody has any idea what this "reducing the bias" deal could be.

    I checked the change record for the unit, and found TWO changes of values in power amp. One was in a DC offset corrector, and one was in the drive from the overtemp sensor to the relay circuit. The rest of the "changes" in the power amp were pretty much correcting paperwork, or in one case changing to a different resistor style.

    Way back when the unit first came out around 10 years ago, there were some over-biased and under-biased units that got out. Production had messed up, and maybe you are remembering that.

    Underbiasing will NOT reduce power, but it will cause crossover distortion.

    Nothing that "has proven to be VERY faulty" in the driver or relay circuit is known about by anyone in service or engineering.

    For sure there has not been the sort of "flurry of changes" that are typical of problem units.

    Since the amp has been made for 10 years, with only minor changes needed, and a good service record, I think the charge of being "unstable" is unjustified. Very early units did have some problems, as noted, but that was a long time ago. A lot of the problems were due to solder issues on jacks, and were not limited to this unit.

    Limit of part tolerances? No, the unit is pretty conservative actually, there are a plenty of output devices. Each pair only needs to supply around 3 amps to make power, and they are rated for 12+.

    In fact, the unit has spawned a few competitive units that "borrowed" some ideas and technology from it. Imitation being the sincerest form of flattery.................


    Frankly, with all due respect, I don't know where you are coming from here.

    We aren't perfect, and I'll tell it like it is when we aren't, but I am having trouble figuring out this one.

    I did pass it along to the Product Manager and some other folks in QC, just in case.