Ampeg SVT pro 3

[jford]

I was playing my bass a few nights ago and all was well and all of a sudden, I accidently pressed one of the gain brigth button and I got a real loud noise. Now, I get no gain from the head. I don't even get any sound from my speakers. I have a Genz Benz 410 and one 15 inch Ashdown. I have no spare head to test my speakers to determine if they are blown or if the problem is with the ampeg head. Any help would be appreciated before I am off to repair shop. Thanks

[Jazz P Bass]

SVT 3

Do you have any spare 12AX7 tubes.
You may have popped V2 or V3.

[guitician]

Could it have been that MUTE switch? It doesn't seem that a bright switch would have that effect on an amp.

[jford]

I checked the mute button but still no sound. I also checked my BASS into another amp and I am not getting any sound after changing the battery. Whatever happened, now my BASS is not working either.

[jford]

No i dont have any tubes but I will try to purchase some. Can you purchase these tubes at any electronics store? Thanks

[Jazz P Bass]

Hot input

Something took out the active bass circuit.
Before doing anything else, can you hook up a DVM to the input jack.
Insert a known good instrument cable into the input jack.
Measure across the tip & the ring of the cable.
Set the DVM on Vdc, then Vac.
Tells us what you read. DC & AC.
There may be nothing there at all.
The voltage path may have been V1a Plate to Grid, internal tube short.
In that case you may have had 150 Vdc, through a 68K resistor, to your bass input.

[jford]

Thanks Jazz P but what is a DVM? Is that a switch or cable? I guess I am not much of an electronics person but I am beginning to learn. Google, here I come. Thanks..
Is that a 5 or 6 string Bass in your profile. I like the color.

[Jazz P Bass]

DVM

Digital Volt Meter.
Does not have to be digital.
Just a term that is used.

That is a pearl white 1987 Fender jazz p bass special. 4 string.
At least until the bar smoke changed the color.
Love it.

[jford]

Okay. I will go purchase one and let you know my findings. Hopefully, I can get this rig together b/c i am missing it right now.

Do you prefer the 4 string over the 5 string?

[Jazz P Bass]

Bass strings

I prefer 4 strings.
I run a lower gauge on the E string just to get rid of boom.
Some of the clubs we play are small.
I would imagine being able to drop down to the 5th string would come in handy, I just do not feel like buying another bass.

[Steve Conner]

Did you check the amp with another bass or signal source? Maybe the amp is fine, and only your bass is broken.

Better use a passive one in case the amp somehow turned into an active bass killer I've never heard of that happen until JPB suggested it.

Also try different cables.

5 strings are unnatural

[Jazz P Bass]

Bass

Preferably a Nonactive one.

[jford]

Thanks Steve for your input. Yes, I have tried another Bass and still no sound from the amp as well as the speaker.

I take it you are a 4 string player as well. I too love the 4 strings but also like the 5 strings.

Jimmy

[jford]

I love the 4 strings especially since I am getting back into playing more b/c I am more accurate with the 4 string. I mostly play the 5 string Bass trying to get a feel for it and I was coming along very well until now. Now, I ahve nothing to play with and I am bored. Can't wait to get this amp working.

Jimmy

[ThermionicScott]

That's interesting. It may be a good idea to install an input cap on the amp if you're using an active bass (or if you have scratchy pots on your instrument. )

- Scott