Buckle up. Gonna rattle this off from the top of my head.So what’s the deal with all the SVT variants? I assume the classic standard all tube one retroactively became number 1, but then there 7 other ones.
Some are huge, some aren’t, some are hybrids, some are huge and others not so much, I think one is a newer class D one, etc.
Which are the good ones and why?
SVT: The OG, all tube. 300 W. Started in 1969, I believe. A few variations over the years, depending on who owned Ampeg at the time. Generally, they all sound similar/good, but heavy AF. I don’t know much about the minor variations with the reissues and such (SVT-AV, SVT-VR, etc).
SVT II (non-pro): Basically the same as the SVT, but in a 4U rackmount case. Made in USA. I own a very early one from 1989 (number 12 in the run, I believe).
SVT-IIP: 1U rackmount preamp. Same circuit as the SVT/SVT-II/SVT-III (non-pro). 3 preamp tubes. Costs as much, if not more, than an SVT-III, and you don’t get the output stage. It’s small and light though. I’ve owned a couple over the years. Tim Commerford from RATM lowballed me on the first one I repaired.
SVT-II Pro: All tube, different preamp section from the non-pro version. Adds a Master Volume. Later ones are named “SVT-2 Pro.” Some were built in USA, some in China or Vietnam, I think.
SVP Pro: 1U preamp, but with the “pro” circuit from the SVT-2 Pro. 5 preamp tubes.
SVT-CL: Essentially the same as the SVT-2 Pro, but in a traditional non-rackmount case.
SVT-III (non-pro): Same preamp section as OG SVT, but with solid-state BJT output stage. 300 - 350 W. 2U rack case. I’ve been looking for a reasonably priced (i.e. broken) one of these for a while.
SVT-III Pro: Similar preamp to the SVT-II Pro, 450 W MOSFET output stage. Later ones are named “SVT-3 Pro.” Some were built in USA, some in China or Vietnam, I think.
SVT-IV Pro: They didn’t make a non-pro version of this, as far as I can tell. 3U rack. 3 tubes in the preamp. 1200 W solid-state MOSFET output section. They sound good, but they suck to work on and are somewhat unreliable due to their complexity and I refuse to work on them anymore. Again, later versions are named “SVT-4 Pro.” Some USA, some overseas builds.
SVT-5 Pro: 3U rack. All solid-state, 2-channel preamp, some sort of octave-down effect built in. ~1000 W MOSFET output. I’ve never seen one in person. Some USA, some overseas builds.
SVT-6 Pro: 6 preamp tubes, 1100 W MOSFET output stage. 2U rack case. Haven’t worked on one of these before, I think they’re somewhat rare.
SVT-7 Pro: Lightweight 2U rack, switching power supply and 1000 W Class-D output. Single 12AX7 tube in the preamp for tube “color.” Notorious for blowing up power boards. Have repaired a few, wouldn’t buy one to use regularly.
SVT-8 Pro: Tube/SS hybrid preamp, 1300 W MOSFET output. Can drive 2 ohm loads at 2500 W. Very rare, didn’t make many, never seen one in person. Supposedly unreliable. Almost bought a broken one last year, but somebody snagged it before I could check out. Some USA made, some overseas.
There’s some other preamps I don’t really know about. SVP-BSP (Billy Sheehan preamp), SVP-CL, among them.
There’s also some special edition “skunkworks” SVT-HDs that were built later from a stash of original parts when Ampeg changed hands in the late 80s. They’re rare, and have a special plaque on them. Limited run of 500.
Basically, anything below “4/IV” are the good ones. The others are either overkill (power-wise), too complicated, or too unreliable to mess with. The SVT-III (non-pro) is the sweet spot in terms of tone vs. size/weight.