#1
Ok I have a Ampeg SVT450H 450W Classic Series Head. I have been playing it regularly for about 6 months. The other night after a gig a bass player from another band asked if he could use my amp, I said shure. Well at the bar he comes up to me and says your amp does not work. Well after trouble shooting (speaker/insturment cables,bases, cabs, everything but the amp) I found out it is my effects loop causing the problem. The amp works fine minus some slight buzzing when I have my pedals (boss tuner and overdrive) plugged into the effects loop, but does not work (no sound) when somthing is not plugged in to the effects loop.

I am going into the studio this weekend, and do not plug in my pedals in the effects loop so will my sound be effected when I plug into the Pre/post EQ XLR line out (will the sound register)? Also what do you think can be causing this problem with the effects loop? Help, I need this fixed, I have a 1 year warrenty but what will I use while it is getting repaired?
#2
I bet the son of a bitch broke it, and just told you it didn't work
#3
I dont think so, besides I never, ever play this amp without my effects pluged in to the effects loop, the last time was at the studio 15-20 days ago, and 1 time 2 months before that during practice. will it still work in the sudio? HELP!!!
#4
I'm not really an expert on Ampeg, but you could contact Ampeg about the problem or take it to a shop and ask if they could fix it.
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#7
Quote by eaton1012
Don't let others use your gear.



+1

Youre fully within your rights to say "nah sorry mate", it's their fault for not having their amp and stuff.

Only time i've leant my amp out was to a rather hot girl bassist

If your amp doesnt work when theres nothing in the effects loop i think its because it thinks there is something in there!

Get a patch cable and put it in the FX loops (from the return to send) and it might work.

Gear:
Fender Standard Jazz Bass
Artec Matrix Pedal Tuner
BBE Optostomp
Boss GEB 7
EHX NYC Big Muff
Ashdown MAG C410T-300
Torque T100BX
GAS-ing for:
Boss SYB5
Behringer Intelligate IG9
#8
undead,

Is there something that could have been shoved into it? It almost sounds like the amp THINKS something is plugged into the loop but there isn't. Typically the effects loop is in direct line with the signal path through the amp. When you insert pedals into the jask, you break the path but now the signal goes through the pedals and back to the amp. Some amps do it differently. But if it is what I described, the jasck itself might have a problem which is keeping the path open.
#9
Its me again, a year later, and a bump becuase I still have the same problem.

"Ok I have a Ampeg SVT450H 450W Classic Series Head. I have been playing it regularly for about 6 months. The other night after a gig a bass player from another band asked if he could use my amp, I said shure. Well at the bar he comes up to me and says your amp does not work. Well after trouble shooting (speaker/insturment cables,bases, cabs, everything but the amp) I found out it is my effects loop causing the problem. The amp works fine when I have my pedals (boss tuner and overdrive) plugged into the effects loop or a patch cable, but does not work ( has little to no sound) when somthing is not plugged in to the effects loop..."


Ok this was my situation 12 months ago. I am in Korea now for one year and have not touched my amp since then, its in storage (crying...) but I still have the same problem. I have been doing some research and found out that most likely somthing is wrong with the effects loop send/return signal chain. My buddy (who is master guitar tech.) thinks that the only problem is a loose connection and can be fixed easily by soldering it, by looking at the wiring diagram. But he is not shure due to me not having my amp with me. How much would this cost,time? Any other suggestions or help? Thanks in advanced guys.

p.s. here is the online manual and diagram

http://www.ampeg.com/pdf/SVT450H.pdf
#10
Quote by Jonnomainman
+1

Youre fully within your rights to say "nah sorry mate", it's their fault for not having their amp and stuff.

Only time i've leant my amp out was to a rather hot girl bassist

If your amp doesnt work when theres nothing in the effects loop i think its because it thinks there is something in there!

Get a patch cable and put it in the FX loops (from the return to send) and it might work.

I totally agree with the scratch their back, they'll scratch yours idea.
if you know the person well, why not? I sometimes volunteer my gear to really great friends.

sounds like the dry wire (I would guess that would be it's name) is out, I would get it fixed, but a quality cable from your effects out to in, straight, should fix the problem (temporarily).
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HUMANITY WHATS WRONG WITH YOU.


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#11
undead,
humanity has a good idea. and it will also help troubleshoot the problem. If it works, then it pretty much confirms what I am going to tell you in the next paragraph.

the guitar tech might be right, but keep in mind that the drawing is only a bare bones drawing of what's actually in there. My thoughts are in the same ballpark as his, but I don't feel as strongly as he does about soldering. It almost sounds like the signal chain gets shorted to ground when you disconnect the effects. That would explain why the amp doesn't work but does when you plug in the loop. That makes me suspect that one (or rarely both) of the connectors may be bad. The connectors aren't cheap, but I would be surprised if it costs more than $15 for the connector. Depends on what the repair guy uses. The biggest cost will be his time. Don't know what the labor rates are where you live. If I were working on it I would probably charge $50 for labor plus the cost of the part. Depending on the design of the amp, it should only take about an hour to change it. Having said that, I've worked on some amps where it took all day to get them apart. That's where the repair guy starts to lose money. Good luck...