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Acoustic Image Clarus Tips???

Discussion in 'Amps and Cabs [BG]' started by jokerjkny, May 31, 2003.

  1. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    Hey all,

    still in the honeymoon stage with my Clarus, but was wondering if there are any tips, y'all would like to share with your dealings with it.

    i've been using the Low Z input like the manual says, and fiddling with the EQ, but how should i handle the power amp?

    like my Stewart and Peavey, should i keep the Master ALL the way up, and control the volume with the input level? the effects loop is Parallel, right? so should i keep that ALL the way up for the most sound from my tube DI?

    any other tips or tricks you have with the Clarus?

    and one little niggle i was hoping you guys could clear up for me:

    after a while, i start to hear a very high pitched whine coming from the speakers. it doesnt really get in the way of the tone, but if i dont play and stand next to it, i can hear it a bit audibly. its kinda annoying in a dog whistle kinda way. its happened with my Epifani setup, and a PA speaker i had lying around. i also tried swapping cables, and it's still there, tho the cable that comes with the Clarus is very clear!

    should i have it looked at, or is this something y'all sorta deal with?
  2. With my Clarus, I tend to use the master to control volume and put the Input Volume control at 12 o'clock at all times.

    The FX loop is parallel. The first-generation ones (like mine) don't have a blend knob. Presumably, you should keep yours all the way up, yeah; otherwise, you might run into phasing problems.

    AI must have significantly revised the Clarus from the one sitting 5 feet from me right now.
  3. Phil Smith

    Phil Smith Mr Sumisu 2 U

    May 30, 2000
    Peoples Republic of Brooklyn
    Creator of: iGigBook for Android/iOS
    Peter here's the new layout:


    They added an Effects Loop Level, Switchable Notch/High Pass filter, Ground Lift Switch and a Fuse.
  4. Reefer

    Reefer Guest

    Mar 9, 2003
    I had a whining noise coming from my 300ia, so I got rid of it cause I didn't trust the amp. I found running the pre at about 3o'clock and adjusting master worked for me.
  5. I've never had any problems with mine. Sucker goes loud, too, when I hook it to a pair of GS112s.
  6. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    so, did you get a new one? or was this your temporary fix? how new was yours, and how recent was this? maybe i got one from the "bad" batch?

    btw, if i run the master too high i get relatively more hiss/noise, unlike bumping of the input level which stays nice and quiet.
  7. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Ive read from a few sources (for other amps admitedly) that to get the best signal to noise ratio you should boost the input level as high as possible without getting any clipping from your playing style, and then adjust the master volume from there.

    I doubt its any different for this amp.

  8. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY

    Mine makes a weird subliminal "howling" noise, sort of like there's an almost imperceptible sandstorm going on inside the power section. My take on it is that I'm hearing some "digital switching" going on. When the power is clean, it's not an issue once I start playing. When the power is dirty, the Clarus makes some really frightening static kind of sounds when first turned on, then settles down and behaves as normal.

    I hardly use mine now that I have the iamp800, but when it was my regular rig, I'd keep the preamp at high noon and adjust the master to taste.
  9. bollefen


    Mar 13, 2003
    hi joker,

    the clarus utilizes a uhf switching power supply, don't recall the operating class but a switching supply and the epi's are somwhat hungry, perhaps you're pushing the amp and the whine is the speakers somehow picking up the switching or pehaps the power supply is running at the rails or poorly filtered letting the switching whine into the amp stages.

    while this is not really supposd to happen, i've had this experience in other situations using switching power supplies where a large surge is required (as in a bass amp)i sloved the problem by adding capacitance to the power supply.

    i looked at the clarus and ultimately decided against it for that particular reason, felt the amp needed more storage capacitance. this increases weight and size of the amp negating its design criteria.

    just a thought, ymmv you're in the city, see if they have another amp where you got it and see if it does the same thing. if not there is a bad filter or other prob with the amp.

    as the amp is so highly regarded is suspect the amp.



    and yes i think the acme would have been great with my mesa, but the aggie does swell. we'll have to meet sometime, i'm in and out of the city regularly. :)
  10. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    thx for the replies all!

    just this morning at my usual church gig in midtown, the Clarus performed without the annoying whine. it was there, but disappeared after two songs! strange.

    but i'm gonna see if i can hunt one down, and see if the problem persists in others, or if its just mine.

    thx again guys!


    its all good. i was still able to sell the Acme regardless, but thx for the interest. glad the GS112 is working out for you!
  11. Suburban


    Jan 15, 2001
    lower mid Sweden
    Not being an electrician of any sort, I toss in a few cents:

    It seems to me that switching amps are sensitive to resonance with the source, i.e. the wall socket current.
    So if the source is "clean" the problem would be less, but if there are surges or other variations, there would be reactions form the amp.
    Also, it may be sensitive to phase. Which could be reduced very simply: by pulling the plug in the wall, turning it 180 deg, and putting it back again! This latter kind of disturbance can also occur in tube or non-D solid state amps.
  12. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL

    sounds like voodoo to me, bro. but, still very cool! can you explain how this works in theory?!
  13. Suburban


    Jan 15, 2001
    lower mid Sweden
    Nope, I'm no electrician, remember!:rolleyes:

    But you know, there are two leads to the wall socket, phase and zero. Zero acts like ground in a DC circuit - almost. Phase is the directing lead, which provides the sinus current.
    Some electronics are sensitive to which way this phase comes in. Why? Beats me, big time:confused: :bawl: Perhaps some speaker guru can tell, speakers are very sensitive to polarity of an alternating signal.
    And, as with speakers, these sensitive little electronic gadgets will be very pleased, if you just turn the plug, and let the phase in the right way:meh: :bassist:

    (No further questions, please! )
  14. Alas, simply turning the plug doesn't work in the US.