Cables - Amp to Cab???

Discussion in 'Cabinets & Speakers' started by Jenovaslegacy, Dec 10, 2009.

  1. Jenovaslegacy

    Jenovaslegacy New Member

    Joined:
    Sep 30, 2009
    Messages:
    106
    Likes Received:
    0
    Location:
    Midlands, UK
    Okay,

    Heres a basic question for you. Eve since I started playing I have used a standard instrument cable (basiclaly the same I use to connect guitar to pedal, pedal to amp etc) to connect my head to my cab. I am since informed that these cables, while being similar in construction, are not the same and there are specific cables for connect amp and cab. This I am told can affect performance of the entire rig.

    Is this right? What should I be looking for?
     
  2. slowhand

    slowhand New Member

    Joined:
    Dec 9, 2009
    Messages:
    177
    Likes Received:
    0
    Location:
    NY
    correct. Use speaker cable from amp to cabinet, use instrument cables for instruments. I'm no tecky, but instrument cables have braided wire around the outside of a single shielded wire, speaker cables have two shielded wires and no braided wire & are typically heavier guage. Instrument cable will usually be 16 guage wire and I've used speaker wire at 12 guage.

    The opposite way around (using a speaker cable as a guitar cable) will work, will not risk anything, but it will be an unshielded cable and you will get a lot more noise.

    Those with more technical detail can correct me if I'm wrong.

    Peace.
     
  3. 5er driver

    5er driver New Member

    Joined:
    Dec 22, 2007
    Messages:
    447
    Likes Received:
    24
    Location:
    St. Augustine, FL
    An amp can fry an instrument cable between the amp & cab like a fusable link.......and that's bad news for an amp.
     
  4. Adwex

    Adwex New Member

    Joined:
    Sep 12, 2006
    Messages:
    9,024
    Likes Received:
    4,080
    Location:
    I'm not sure.
    Just to clear up a slight misconception...You are correct that a guitar cable and a speaker cable are not the same, but this is because they are NOT similar in construction.

    A guitar/instrument cable consists of a small, light gauge wire surrounded by a braided steel shield. These cables are designed to carry a low current, low voltage signal, like that from a guitar. The shield prevents outside interferance from causing noise on the low level guitar signal.

    A speaker cable consists of two identical, heavier guage wires to carry the higher voltage, and (more importantly) higher current signal coming from the amplifier going to the speakers. Since this speaker level signal is higher, it is not vulnerable to outside interferance, so no shield is needed. But, the higher current signal needs a heavier guage wire to travel through, other wise the wire could overheat and fail.
     
  5. Jenovaslegacy

    Jenovaslegacy New Member

    Joined:
    Sep 30, 2009
    Messages:
    106
    Likes Received:
    0
    Location:
    Midlands, UK
    Okay, thanks guys. I keep feeling like such a spaz askign the questions I do, but then what is the point of this forum if not to share the expertise of you altogether more well travelled chaps with people relatively wet behhind the ears such as myself.

    So while I'm at it:

    Would have having used a pretty cheap and nasty instrument cable for a considerable amount of time between amp and cab caused the feedback problems I have been discussing on the 'Nuclear Feedback/Squealing' thread in Workbench? It should be noted that the amp is being serviced by Marshall currently and they say its tip top, so thankfully none of the potential damage mentioend above thankfully. But could this have been the problem?
     
  6. MartyStrat54

    MartyStrat54 Well-Known Member

    Joined:
    Feb 21, 2009
    Messages:
    25,999
    Likes Received:
    9,455
    Location:
    Licksville
    Well when you get the amp back from Marshall, please do not use a guitar cord again between the amp and cab. I think it's safe to say we've learned our lesson there.

    Also, I don't know if Marshall leaves the tubes in the amp when they ship, or if they take them out and pack them separately. Regardless, make sure all of your tubes are seated in properly before turning your amp on. Watch the tubes for at least five minutes to make sure they are stable.
     
  7. Wilder Amplification

    Wilder Amplification New Member

    Joined:
    Oct 12, 2009
    Messages:
    6,163
    Likes Received:
    700
    Location:
    Fresno, CA
    I remember a Crate Blue Voodoo amp I fixed for a kid a few years ago. Opened it up...all four cathode fuses were blown, plus a couple of screen resistors. Replaced the valves/rebiased. Played on it for a couple of hours and no issues.

    So I called to let him know it was done but told him I'd like for him to bring his cab and speaker cable so that I could take a look at the setup and make sure it's right and make sure it was not something wrong with the cab/cable that could've fried those valves like that. So he comes by to pick up the amp and brings the cab with him. I asked "Where's your speaker cable?" He pulls out one of those paper thin 6" patch cords that you use between your pedals!

    So I explained to him that he needed to get SPEAKER cable specifically, and took the ends apart on an instrument cable and a speaker cable to show him the difference between the two so that he knew that there was in fact a HUGE difference. Never heard from him again...I assume he followed my advice and his amp lived.
     
  8. MartyStrat54

    MartyStrat54 Well-Known Member

    Joined:
    Feb 21, 2009
    Messages:
    25,999
    Likes Received:
    9,455
    Location:
    Licksville
    Another one of those stories where you could just go on and on. You know Jon? You're right. Tube amps are a lot of work. It's like being at the helm of a spaceship. "Captain, there's a problem with the amp to cab cable." "She's too light...she's going to blow!"

    There's been people who have admitted doing this and like you said in a different thread, it may be they just did it and didn't care, or they were unaware of what they were doing. Some people have posted that I know for a fact were running guitar cords, but they never admitted it. I'm surprised there isn't more damage done like what you described. I mean you got hair thin wire handling all of that power. The electrons are probably stacked on top of one another trying to get into the flow.

    Oh well. I hope this thread saved a few more amps.
     
  9. 5er driver

    5er driver New Member

    Joined:
    Dec 22, 2007
    Messages:
    447
    Likes Received:
    24
    Location:
    St. Augustine, FL
    That's called saturation, that's where the distortion comes from! :io:
     
  10. buzzerjim

    buzzerjim New Member

    Joined:
    Nov 11, 2009
    Messages:
    8
    Likes Received:
    0
    Location:
    Edinburgh, Scotland
    Heres another daft question.....I realise its is something to be avoided,but exactly what damage will you do to your amp if you forget to connect the cab to the amp o/p.
     
  11. Wilder Amplification

    Wilder Amplification New Member

    Joined:
    Oct 12, 2009
    Messages:
    6,163
    Likes Received:
    700
    Location:
    Fresno, CA
    You can blow the output transformer doing that.
     

Share This Page