Cab inputs - mono, stereo and mic eliminators?

Discussion in 'Amps and Cabs' started by Jxff, Feb 13, 2015.

  1. Jxff

    Jxff Member

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    Hi all, I recently purchased a Randall RH100 head and started looking at cabs for it. I found a near new Randall RS412XL with V30's for under $300. My question is how would one use the stereo inputs? The RH100 has a 4 ohm output (rated at 120 watts) and a 8 ohm output (rated at 100 watts). The cab jack plate has a 4 ohm mono, a 16 ohm mono or 2 x 8 ohm stereo. I understand how the mono inputs work, but would I run both outputs from the head into the stereo 8 ohm inputs? Also, has anyone ever used "mic eliminators"?

    [​IMG]

    btw-I had to crack up, I have lurked on TGP since '08 and now I have had two posts in two weeks.

    Thanks! Jxff
     
  2. bigtone23

    bigtone23 Member

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    For foolproof, proper matching and maximum power--use a single speaker cable into the 4 ohm mono input on the cab. You can use the 16 ohm mono input jack for a little less power output and probably a slight change in feel and tone.

    The Stereo 8ohm inputs can be used, too. Since the head has 2 parallel-wired output jacks--just run two speaker cables out of the amp and into the cab's stereo 8 ohm l/r jacks. This is electronically the same as running the single cable into the 4 ohm mono input as the head is seeing a 2x8ohm parallel load--which equates to 4 ohms. The only difference is that you are using twice the cable to send the signal-which is more copper to carry the signal. Does it make a difference? Subtly at best-it just costs twice as much to connect the head as you are using twice as many cables. This extra cabling is not a big deal with a 100w solid state guitar amp.

    JUST BE REALLY CAREFUL NOT TO HAVE BOTH CABLES PLUGGED IN AND SWITCH THE CAB TO MONO WHILE THE AMP IS ON!! That can have a disastrous effect on the head from the speaker line shorting out due to the parallel (4ohm jack) and series/parallel (16ohm jack) wiring inside the cab.

    Give the mic eliminators a try and see if you like the sound of them. They are often quite handy and keep the amount of live mics minimized on stage.
     
    Last edited: Feb 13, 2015
  3. Jxff

    Jxff Member

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    I just don't understand the use of "stereo". It seems to me that it is sending the same signal twice to two pairs of 2 x 12's. Is that correct?
     
    Last edited: Feb 13, 2015
  4. tucsonsound

    tucsonsound Member

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    I have a Randall 4x12 with the same input plate.

    Your head is mono, so you can leave the cab switched to mono and drive the 4 ohm mono jack on the left.

    Stereo is for use with a stereo rack amp.

    The mic eliminator works surprisingly well. It makes a nice second feed for recording or hassle free main feed live.
     
  5. Ilduce

    Ilduce And now for something completely different! Supporting Member

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    The stereo also works good if you're running a stereo rig with two amps and recording it to two separate tracks using separate mikes. It may not sound great live because of the close proximity of the speakers, but when you play it back it'll sound massive!

    PS I can't say how the mike eliminator sounds on your 4x12, but on my Egnater Armageddon 4x12 it sounds awesome.
     
  6. bigtone23

    bigtone23 Member

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    Yes. Connecting to the Stereo jacks is just adding a cable to do the same job as running 4 ohms mono.
     
  7. Jxff

    Jxff Member

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    Thanks for the replies. I get it now:)
     

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