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Anyone on here good with the technical aspect of an amp?

Discussion in 'Amps and Cabs [BG]' started by bstew483, Mar 10, 2014.

  1. bstew483


    Jan 30, 2014
    Fort Collins
    To begin, I apoligize for my lack of fluency on the topic. I took my SVT-3 Pro to a friends house who has a moderate knowledge base on the electrical side of things so i am primarly going off my recolection of what he said.

    here is my setup:
    The SVT-3PRO
    I replaced all of the 12AX7s as soon as the first problem became apparent.
    a schecter custom 5-string diamond series with an active eq and EMG-HZs
    Boss TU-2
    Boss GEB-7
    Fulltone Fulldrive 2 MOSFET
    B115 acoustic cabinet

    About three weeks ago during my bands rehersal I noticed a huge difference in my tone, the only way I can think to describe it is "Farty" After spending time eliminating all of the variables I found that there was an issue with the GEB-7 and/or the Fulldrive 2 through the effects loop in the svt-3. After talking to my friend he told me that this is the case because both of these pedals are digital and are not ment to run in a parallel loop as presented with the effects loop. So after hearing this I ran all the pedals through the input jack in the front of the amp. When I did this the Fulldrive sounded exactly the same as it did when I put it through the efects loop and the GEB-7 seemed to only give the farty tone in the lower register of the B string. When I plug the bass directly into the amp there were no apparent problems.

    I am at my wits end with this stuff I am so frustrated with my newly purshased SVT-3. I have no idea were to go from here to fix the problem. ANY INFORMATION OR TIPS AT ALL would be dearly appretiated.

    I did my best to get all of the information up here that I thought to be relavant but I think it would be easier if someone would post their question.
  2. CL400Peavey

    CL400Peavey Supporting Member

    Nov 7, 2011
    Grand Rapids Michigan
    Have you tried the amp and cab with out the FX? Have you isolated what is causing the problem? Add one pedal in at a time till you figure out what is causing the problem. I would also try a different amp with the cab, and cab with your amp. I bet you a penny you may have blown the speaker.
  3. RickenBoogie


    Jul 22, 2007
    Dallas, TX
    Big +1 a single 15 isn't a lot to work with, and IS the limiting factor of your rig. Two of them would run much louder, without stressing the amp. Also, not all of the tubes in the amp should be 12AX7's. Make sure the driver tube is a 12AU7.
  4. Jim Carr

    Jim Carr Dr. Jim Gold Supporting Member

    Jan 21, 2006
    Denton, TX or Kailua, HI
    fEARful Kool-Aid dispensing liberal academic card-carrying union member Musicians Local 72-147
    Distortion effects can result in unanticipated damage to the speaker. The audible warning of the speaker distorting is obscured by the effects.

    As noted above, verify the speaker is unharmed.
  5. JohnMCA72


    Feb 4, 2009
    "Isolate" is good advice for any troubleshooting, not just this particular scenario. Strip your signal chain down to the least possible stuff involved. If the minimum setup still has the problem, try it with another speaker cabinet (or your speaker with a different head, if that's all you can get).
  6. father of fires

    father of fires Commercial User

    Nov 29, 2006
    Chief of Medicine at Damnation Audio
    The GEB7 is probably farting out because the low frequencies of your bass is too much for it to reproduce so it's clipping. If it's not clipping the pedal then you're putting too much bass into the amp and the amp is clipping. If the amp is not clipping then you are putting too much bass through the cab which will fart out in a heartbeat when too much low end is present.

    Oh...and those pedals are not digital. They are all analog. The reason you don't want to put them in the effects loop is because they are built to handle small signals from a bass. Not strong signals from the amps preamp.
  7. Cirk


    Jan 16, 2011
    Pittsburgh, PA
    One cheap and easy test....try putting a fresh battery in your bass. Worth a shot.