Conference napalm::guitar

    The Dunlap ROTOVIBE is supposed to be a reissue (sort of) of the
    original ROTOVIBE from the late 60's. The original is a two piece unit.
    One part is a speed control pedal which plugs into a tabletop box
    containing the actual electronics. The ROTOVIBE was one of the first
    phase shifters on the market. Hendix had a fondness for it.
    
    The original ROTOVIBE has the same controls as your reissue, though
    they are more ergonomically located. As an owner of the original, I can
    tell you that the effect doesn't bleed through with the effect
    bypassed.
    
    I haven't tried one of the new ones yet, though I've seen them in local
    shops for around $100 (originals go for $450 and up). Try another one and
    see if you get the same results.

    	Thanks for the advice but I ordered this thing in from out of town.
    I tried for months to find one around here but was unsuccessful. You
    are one LUCKY dude to be the owner of an original! Is that actaully a
    ROTOVIBE or a UNI-VIBE? The UNI-VIBE was originally built for a
    keyboard set up and I think the major difference between the two is
    that UNI works like a leslie, you can actually hear the simulator speed
    up when acivated rather than being all ready at selected speed when
    switched on. You would think jimmy dunlap would have thought of that!
    
    	Bye the way, if you can pick up A ROTOVIBE for "around $100", send
    me a dozen! I paid over $200 for mine.
    
    Kevin

    Yes, it's actually a UNI-VIBE. The speed is controlled by the pedal
    position; there's a microswitch in the pedal heel that bypasses the
    effect with slight backwards foot pressure from the slowest speed.
    Works for guitar, organ, Rhodes, or any electric instrument (there's an
    input level control). AKA Rotovibe.
    
    I won't discourage you by telling you that I've seen a Dunlop for $110
    locally (New Orleans). Next time I'm in a store that has one I'll try it 
    out and see if it bleeds through. 

    	
     	Sorry for being so nosey, but the ROTO advertises a built in
    chorus,(thats tha swish we were talking about with both our units) does
    the UNI also use a chorus for this effect, or something else. Can you
    shut that effect off or is it on constant?
     
    Kevin
    

    Chorus and Vibrato are closely related. The UNI's basic processing
    function is to generate vibrato. To obtain chorus, the UNI mixes the
    processed (vibrato'd) signal with the unprocessed signal. This results
    in a series of cancellation notches in the frequency spectrum of the
    combined signal which constantly move as the UNI sweeps the pitch of 
    the processed signal (speed dependent on pedal position).
    
    All the vibrato/chorus switch does is turn off/on the addition of
    unprocessed signal to the UNI's vibrato output. I suspect the Dunlop
    does exactly the same thing; in fact, all modern chorus units use a
    variation of this theme ( a long story for another note).
    
    The depth control sets the amount of pitch deviation (within design
    limits, maybe a quarter tone). This translates into chorus depth.
    
    Thus the UNI can produce chorus or vibrato, but not both at the same
    time. Either effect, of course, can be completely bypassed.
            

    	Thanks for the info. Now, if I could just ditch that "ghost" thats
    hiding in my 'VIBE'......
    
    	Kevin
    
    

   
    
    I finally tried a DUNLOP ROTOVIBE. I have two comments:
    
    1) The unit I tried had no effect bleed through when bypassed, so I
    suspect that yours has a defect.
    
    2) The DUNLOP version sounds much more like most other modern phase
    shifter than like the original, which has a "smokier, more liquid"
    sound. The original would produce strange effects with the depth knob
    advanced more than 3/4 way; the DUNLOP remained well behaved at all
    depth control settings.
    
    Not bad for what it is, but no match for the original. The standard
    mail order price seems to be about $140. 
                                            

    Another idea for those searching for that original Uni-Vibe sound, there's
    another re-issue out called the "Deja-Vibe".  It's made by a small company,
    out of NY I think; I can dig up details if anyone's interested.  At $595
    these aren't nearly as cheap as the Dunlops.  I've seen original Uni-Vibes
    being advertised lately for $1000.
    
    /roger_the_engineer

    
    After spending much time with my ROTO, I have decided...It's backwards!
    When iI step to turn it on, it is in 'full speed' mode. What i would 
    like, and think would be much more logical, would be to step into
    'slow' speed, then move the pedal to speed it up.(sounds like a speaker
    simulator eh?).
    Anyways, I figured that although I am no electrical guru,I could 
    switch the poles of the 'POT' the controls the speed, thus being 
    able to switch to 'slow' speed. Didn't work! To my suprise, Mr.DUNLAP
    used a Reostat instead....so much for the easy way out.
    The stat is simaler to the pot in a WAH in appearence, but is soldered
    into a pc board. 
    If any body has a suggestion on how I might complete my little Mod,
    in lay-mans terms, please feel free.
    
    Kevin