Ampeg SVT VR Head requiring at least 115 volts from wall socket

Discussion in 'Amps and Cabs [BG]' started by djshawn47, Jun 24, 2008.

  1. Just recently got a made in Vietnam Ampeg SVT VR- for the record, the amp sounds and looks as good as any other VR Ive seen or played through. Nails "the tone" as it should.....


    The first time I plugged it in, I let it warm up for about 2 mins or so, flipped the "stand by" switch....and nothing....the light didnt turn from red to green, no volume....

    after about 5 mins it did kick over. So I tried another wall outlet and this time it never kicked off of standby....even after 10 mins...I could hear some volume want to come out of would come out very faint and then dissapear within 2 seconds.

    I could easily return it and wait a month until the shop gets another one in, but Im not that I called Ampeg/Loud and spoke to a pretty cool tech. he said:

    "These amps are extremely power hungry and require at least 115 volts out of the wall to kick off of standby. 110 volts wont do it."

    So I went and bought a voltage checker from Radio Shack and checked every socket in my apartment. Every socket that was under 114.5 would not kick the amp off of standby. Many of them were in the 112-113 ranges. Two were coming in at around 116v and those two would kick the amp off of standby after 2 mins of warming up.

    So...My question is....Is this normal? Has anyone else had this experience? Seems a bit inconvenient, espescially if youre at a gig and the outlets are less than 115. Should I return this head or is this truly the case with every VR out there?
  2. Umm. I think it is normal, cause the ampeg guy told you that its should get a good power conditioner or something.
  3. It's normal. That's why you use them in big places...
  4. Handyman


    Sep 4, 2007
    Austin, TX
    Either the support person is feeding you a line, or these amps have issues. This amp's owners manual shows that it is spec-ed to work down to 100V/50Hz:

    From the SVT-VR owner's manual:
    100/115VAC 50/60Hz, 400VA
    230VAC, 50/60Hz, 400VA
  5. It is possible that each of those three specs are for different taps on the transformer. I've heard of this problem before.

    A piece of professional grade equipment should be able to handle something like this without completely failing to work. Anything this fussy about it's wall voltage is nowhere near a robust enough design to be trustworthy in the real world.
  6. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Washington, Utah
    John K Custom Basses
    I have an SVT-VR and a very good variac. i'll try to find time to test mine tonight to see what the lowest AC voltage that will still allow it to come off of the standby mode. that should verify if the rep in customer support at ampeg was correct in his statement.
  7. peterbright


    Jan 23, 2007
    On The Bayou
    No problems with mine.
  8. I have a Vietnam model that does EXACTLY what you described! The first time I ever tried to play it was in my practice shed and it would do the 2 secs of sound then fade away thing like you were describing. However, at my apartment, it works perfectly in EVERY socket. So.. I've considered a furman voltage regulator. This would correct my problem, wouldn't it?
  9. v-12


    Mar 3, 2005
    FL Panhandle
    i don't own a vr, but i would NEVER own a piece of gear, especially a head, that was that picky about voltage. if you are gigging it, you'll never know for sure what venues are going to make your amp power up. a voltage regulator would probably work, but they are pretty expensive.....i would return it and hope the next one works better.
  10. bobyoung53

    bobyoung53 Supporting Member

    That's ridiculous, return it as soon as possible and get a 70's SVT the only real SVT made, whoever you spoke with is giving you a line of BS or else these heads really suck. Line voltage varies all over the US although it is usually over 120 VAC, but still if that is true that is the most ridiculous design I've ever heard of. Get a 70's head, sounds better and will last much longer and no BS like this, both of mine are over thirty years old ands work like clocks. Neither have been retubed for at least five years. I check the bias once in a while that's all. Anyone that spends 2000.00 for these when you can get the real thing for 1000.00-1500.00 needs a reality check. I've brought mine up on variacs and they will work at 100 VAC. Incidentally real SVT's have manual standby switches like all other tube amps ever made.
    iceboxbass likes this.
  11. Yes, because there are 70's ampeg SVTs everywhere... Sure.......... Get real please. We already have our amps, is it a lot of problem to ask for advice without getting a "your amp is crap, you need the real deal?"...
  12. BassyBill

    BassyBill Still here Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    Exactly what I was thinking. Sounds like a recipe for a let-down if this is really the case.
    iceboxbass likes this.
  13. Jazzman


    Nov 26, 2002
    Raleigh, NC
    I have an SVT-CL (made in USA) that has worked down to 92VAC. I got to a gig and plugged in my power conditioner and it showed 92VAC - I was amazed when it clicked out of standby and made noise. When it dropped below 90VAC, (when the guitars started), it cut didn't go into standby, it simply stopped working then came back on when they stopped. Of course, 90VAC is a lot less than 115VAC. ;)

    [On a side note, my backup head, a GK 1001RB-II, worked all night long below 90VAC without a hitch.]
  14. I've got an SVT-CL too (USA made) and I've never had any problems with voltage, but I've never checked what levels I was getting either as a result.
  15. bobyoung53

    bobyoung53 Supporting Member

    That's right they are everywhere, which begs the question, why buy a new one when the real ones sound better, last longer and are cheaper and simpler. The reason they are the real deal is because an American SVT has not been made since 1979, and the last Japanese SVT was made in 1984, everything since has been SVT-XX. those are not SVT's, they are variations of. Even the Skunkworks head of which I owned one, was an SVT-HD and the real ones also blew them away. St Louis Music never made a real SVT. There was only one SVT made sorry to say and they haven't been made for a long time. Do you realize how many times you will play in a club with a close to overloaded circuit in which you'll be lucky if the line voltage is 110v? Or how about on the back of a trailer bed with one or two extension cords, how low do you think the voltage will go there? If that design is really the way you say it is it is really a bad design. A manual standby switch is the only way to go, it is only there to warm up the filaments before the high voltage comes on which prolongs the life of the power tubes.
    iceboxbass likes this.
  16. Handyman


    Sep 4, 2007
    Austin, TX
    Yes, I considered that they use a different transformer for the 100V Japanese version, but assumed Ampeg wouldn't be so sleazy as to ship a design so marginal that it won't even properly power up at 110V. Of course, is appears that Loud's tech support is telling people that it won't function at that voltage, which is quite disturbing.
  17. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Washington, Utah
    John K Custom Basses
    oops. i forgot that i left my VR at my drummer's house (70 miles away) since our next gig (this saturday) is down the street from him so i won't be able to verify the low voltage problem until this sunday.
  18. John K- That would be great if you could test yours against different voltages to see if there is some consistency to this.

    A voltage regulator would work (and is probably a worthy investment), but it sucks to have to shell out another $500-$600 to have the comfort of knowing your amp will always work regardless of location.

    I love the amp. It sounds and looks great (that's why I havent returned it), I just want to verify that Im being given accurate info and I dont have a faulty amp.
  19. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Washington, Utah
    John K Custom Basses
    yeah. i wish i would've brought it home from practice. if i did i would be testing it right now. mine has never had a problem coming off of standby yet.
  20. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    + 100

    The Loud person who said it's normal doesn't know.

    The SVT actually WILL work that low..... EVEN the VR ought to. In fact, old SVTs used not to have a 100V tap...... but worked OK (a bit reduced in power) at 100V.

    As far as I can see, it is the silly automatic time delay deal that is causing the trouble. I'll have to give George M (the VR guy) trouble about it!.

    Looking at the schematic, I think the relay circuit is simply set at the wrong voltage.. so that some marginal parts need too much mains volts to close it. If Loud wants to pay for consulting, I can oblige...... :D (The last two remaining SLME people with Loud are still here in the 'Lou, and Ray is the QC liason.............)

    Anyway, a person who got really tired of that might find a way to wire around the "super safe" delay relay, and avoid the issue. I think it would then work just as low in mains volts as any other SVT.

    Of course, the chinese transformers might be part of the issue, if they do not faithfully reproduce the original. I can't tell about that.
    spatters and P A U L like this.