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

Umm. I think it is normal, cause the ampeg guy told you that its normal...you should get a good power conditioner or something.

 

It's normal. That's why you use them in big places...

 

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:
POWER REQUIREMENTS 120VAC, 60Hz, 400VA
100/115VAC 50/60Hz, 400VA
230VAC, 50/60Hz, 400VA

 

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.

 

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.

 

No problems with mine.

 

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?

 

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.

 

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.

 

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?"...

 

Exactly what I was thinking. Sounds like a recipe for a let-down if this is really the case.

 

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 out...it 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.]

 

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.

 

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.

 

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.

 

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.

 

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.

 

+ 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...... (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.