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Looking for advice on an SVT
- Thread starter moff40
- Start date
I don't know how familiar you are with taking these things apart, but some models are real pigs to work on, especially the ones that have the SLM designs that have the EQ up top, the preamp board on the bottom, and the two stacked PCBs in the power section. Because of the high voltages that are involved the units are designed not to be able to power up when they are disassembled. They'll only work when they're fully reassembled, isolating the high voltage parts in a fully assembled chassis and rendering them "user safe."
These models are difficult to bench test. When fully assembled you only have access to the bottom of the PCBs, and there aren't any labelled test points on the bottom of the PCBs. You have to disassemble the entire amp to get to the top sides of the PCBs where the test points are, and once you've found them you can't test the amp in action because it's been disassembled! These amps really should have test points labelled on the bottom of the boards, but they don't. Working on them is sort of a Catch-22 situation.
To work on these amps you have to disassemble them, test passive parts on an unpowered amp, replace parts, & fully reassemble them to test amp in action. If you find that something else needs to be changed then you get to repeat the whole process over again: disassemble, change parts, re-assemble & test. You have to do this every time that you find a new passive part that needs to be checked. So you're given a choice of replacing a lot of parts while you have the amp apart the first time, and paying for parts, or not replacing parts all at once and paying for labor to do several rounds of assembly/disassembly. That means that parts and/or labor costs can be high.
The older Magnavox type amps involve less disassembly and re-assembly, because they don't have so many different PCBs all jammed into a tight space. You can even test & service many of the circuits without fully disassembling the amp.
The time and effort that it takes to service these things is why an SVT that is not in working condition is only worth $200.
These models are difficult to bench test. When fully assembled you only have access to the bottom of the PCBs, and there aren't any labelled test points on the bottom of the PCBs. You have to disassemble the entire amp to get to the top sides of the PCBs where the test points are, and once you've found them you can't test the amp in action because it's been disassembled! These amps really should have test points labelled on the bottom of the boards, but they don't. Working on them is sort of a Catch-22 situation.
To work on these amps you have to disassemble them, test passive parts on an unpowered amp, replace parts, & fully reassemble them to test amp in action. If you find that something else needs to be changed then you get to repeat the whole process over again: disassemble, change parts, re-assemble & test. You have to do this every time that you find a new passive part that needs to be checked. So you're given a choice of replacing a lot of parts while you have the amp apart the first time, and paying for parts, or not replacing parts all at once and paying for labor to do several rounds of assembly/disassembly. That means that parts and/or labor costs can be high.
The older Magnavox type amps involve less disassembly and re-assembly, because they don't have so many different PCBs all jammed into a tight space. You can even test & service many of the circuits without fully disassembling the amp.
The time and effort that it takes to service these things is why an SVT that is not in working condition is only worth $200.
Thanks everybody for your input. I've got my feelers out now...
I've had SVTs (and V4Bs and B15s) in the past (from the early '80s to the late '80s, when I moved to Trace-Elliott) but they were older Magnavox-era units that were built before three-prong AC plugs were made mandatory. I've also been given SVT-CLs and VRs as backline, so I'm not unfamiliar with the sound, I was just unsure about which series, if any, to avoid owning.
The reason I was asking is that in the late '80s and early '90s, I recalled hearing a number of criticisms of "newer" (at that time) SVTs. Maybe it was just the "they don't make 'em like they used to" crowd blabbing.
If you guys are saying that most of the SVT Classic/CL/AV/VRs out there are generally decent (allowing for the odd dog or one that needs some work), I'm good with that.
I've had SVTs (and V4Bs and B15s) in the past (from the early '80s to the late '80s, when I moved to Trace-Elliott) but they were older Magnavox-era units that were built before three-prong AC plugs were made mandatory. I've also been given SVT-CLs and VRs as backline, so I'm not unfamiliar with the sound, I was just unsure about which series, if any, to avoid owning.
The reason I was asking is that in the late '80s and early '90s, I recalled hearing a number of criticisms of "newer" (at that time) SVTs. Maybe it was just the "they don't make 'em like they used to" crowd blabbing.
If you guys are saying that most of the SVT Classic/CL/AV/VRs out there are generally decent (allowing for the odd dog or one that needs some work), I'm good with that.
Well, I bit the bullet and bought a new-in-box CL (Korean manufactured). It was probably a bit impatient on my part, but I'm the guy who, when I want something, I want it "now". The place where I bought it had two CLs in stock - I didn't have to drive all over the place or special order, and it has warranty that I wouldn't have had with a used unit.
I originally wanted a VR because it would be (I thought) close to the old ones I had, but after some thought, I decided people here were right: I only ever used channel 1 on my old ones, so the CL having a master volume is a plus. At any rate, I can't complain at all about the sound; it sounds like every other SVT I've played.
The downside is that now I just have to find (or make) a silver grill to match my AV cab...
I originally wanted a VR because it would be (I thought) close to the old ones I had, but after some thought, I decided people here were right: I only ever used channel 1 on my old ones, so the CL having a master volume is a plus. At any rate, I can't complain at all about the sound; it sounds like every other SVT I've played.
The downside is that now I just have to find (or make) a silver grill to match my AV cab...
Ampeg is supposed to be coming out with replacement grills so you can match cabs to heads. Don't know when, but they said they were coming a couple months ago. In the meantime, www.fliptops.net can make you one if you'd rather not DIY.
BTW, master volume to full, use gain to control volume, and I seriously doubt you could tell the difference between it and a VR. Not that I don't love the VR as well, but the CL is still a great head.
BTW, master volume to full, use gain to control volume, and I seriously doubt you could tell the difference between it and a VR. Not that I don't love the VR as well, but the CL is still a great head.
You should be happy, and you should have no remorse at all about buying a new amp. There's NOTHING wrong with buying a new amp and getting a warranty. your time is valuable. by buying a new amp you've got what you needed without spending a lot of time on the hunt for used gear. Who knows how long it would have taken to hunt down a good bargain on a used amp? Sometimes buying new makes sense. It sounds like that worked for you. Good deal.
Congrats on the new amp!
