I think you're on the right track...tube(s) or cap(s). If tube swapping doesn't fix it, best to take it into the shop.
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Ampeg SVT-II appreciation thread
- Thread starter i_got_a_mohawk
- Start date
Send/return jacks.
Plug a cable from send to return.
Plug a cable from send to return.
This.
The weirdest, inconsistent problems seem to be a result of old and dirty send/return jacks on the back.
I didn't try this yet but I did plug in return from another preamp which worked so at least power section is fine. You're saying the send jack itself could be causing all this?
Can someone explain to me preamp tube positions from this picture? I'm guessing v1 is the bottom left one.
Recently acquired a SVT-300 to accompany my 2 pro. UPS made sure to bend the rack ears for me. 
Took a soft cloth and some channel locks to repair. So far its been awesome.
Took a soft cloth and some channel locks to repair. So far its been awesome.
Its the return jack that typically causes the problem, they have a shunt that can become dirty/tarnished over time. That shunt in the return jack is what makes the connection between your amps preamp section & poweramp section, when your not patching any outboard effects into the send/receive jacks.
When you simply plug a guitar cord in-between the send & return jacks; this cord ends up serving the same function as that shunt normally would. My SVT-II developed this problem, I just left a short (angled guitar pedal) cord plugged in between the send & return jacks for serveral years.
Its easy, give it a try. If this instantly corrects your problem, just explain the situation to your amp tech the next time he services your amp. Then he'll either clean or replace your return jack.
Hi.I've mentioned my setup previously(svt 2 np,svr 215 cab) and now im looking at expanding with a second cabinet.The svr 215 is 2x15 isobaric(opposite) firing and rated 4 ohms.Im looking at stacking a second cab on top (with svt 2 in the middle inside the svr built in 4 rack space.I would appreciate any inputs on what cabinet configuration (ampeg) might go best on top of the svr.(2x10,2x12,4x10,1x15..etc)..Price is not a factor..i play mostly classic rock,blues,jazz,funk & punk.My main axe is a Hamer Cruise bass(4 string) with a 2Tech bridge with semour 1/4 pounder j pickups.Any input appreciated.
Whatever you do, I'd be sure it's a 4-ohm cabinet and that you switch the output on the amp to 2-ohm.
That being said, I could see maybe a 410HLF. That would be one MASSIVE rig... on many fronts.
Perfect timing... my 2 pro seemed to develop this same issue, a drop in volume during practice/ show and then back to normal along with audio distortion as you described. Need to bring it to a tech just haven’t had time. The drop in volume also seemed to affect the DI signal as our sound guy noticed the difference as well.
Whatever you do make sure the floor it sits upon is sturdy as F. You could easily create a 300lb rig.
99% of the time v1 is closest to the input socket. So, yes bottom left.I didn't try this yet but I did plug in return from another preamp which worked so at least power section is fine. You're saying the send jack itself could be causing all this?
Can someone explain to me preamp tube positions from this picture? I'm guessing v1 is the bottom left one.
Question:
So mine starts making a crazy spaceship sound (like oscillation) every once in a while. If I switch the standby and back to run, it sounds normal again.
Is this the effects-loop jack issue? A cold solder joint somewhere in the amp?
I wouldn’t think it’s a tube issue, given that the standby-to-run switch makes it go away. I don’t think that would somehow make a failing tube happy again.
Thanks!
Sean
So mine starts making a crazy spaceship sound (like oscillation) every once in a while. If I switch the standby and back to run, it sounds normal again.
Is this the effects-loop jack issue? A cold solder joint somewhere in the amp?
I wouldn’t think it’s a tube issue, given that the standby-to-run switch makes it go away. I don’t think that would somehow make a failing tube happy again.
Thanks!
Sean
I’ve plugged a patch cable in the FX loop and played through the amp a few times and the issue hasn’t shown up. Hoping that’s it, but I dunno yet.
Amp sounds so good though.
just curious... is the cabinet vented at all on the side where the amp vents are? Any extra fans or anything like that?
Sounds like the jack send and return jack shunts need cleaning. Scrubbing with deoxit should take care of it.
That’s typically a tube related issue, the tube or the socket contact. A jack problem is more consistent, not something that fades in and out.
