Conference napalm::guitar

    I played with Taco for that gig, and he told me about the note he had
    put in that conf. To be more precise, the sound is more a "Frrrrrr"
    than a "Frfrfrf", even if the frequence is low. If that can help
    anybody, I don't think that this "Frrrrr" really alters the sound
    which is still a (nice?) cleany warmy sound (used during the 60's) that
    Taco likes so much. No, this "Frrrrr" is more added to the "normal"
    sound.
    
    Hope this helps,
    
    Patrick.

    The symptom you describe is not normal, and certainly not a
    characteristic of Celestion drivers.  Are you sure the sound
    is coming from the speakers?  The reason I ask is that I also 
    experienced a noise problem with a 2x12 celestion loaded cab
    which turned out to be vibration of the cab itself. Is your
    cab open or closed back?  Open back cabs allow the cone to
    travel a greater distance which can translate into vibration
    problems.  With my cab (a Fender open back) I actually had to
    seal some of the screwed-on panels with a gasket material to
    prevent the vibration.
    
    As far as other hi-power speaker options, EV and JBL are generally
    regarded as the highest quality. Keep in mind that a speaker which
    can handle mega-wattage will have a clinically-precise sound, and
    will not normally add it's own 'distortion' to the sound. I mention
    this because the warm 60's sound was produced with lower-wattage
    speakers which colored the sound significantly.  Celestions are
    a good compromise between the two extremes.
    
    Steve

    re: .2
    
    Good point Steve.  I had a vibration on my KH that was driving me nuts.  
    I tried a lot of stuff including sealing the speaker panel, adding foam
    rubber to the inner walls/floor, and mounting the chassis on fiber
    washers.  After all that, it turned out to be a transformer that was 
    loosely secured to the chassis.  I tighened the screws and all is all.
    I left the mods 'cause I like 'em.  I also secured the front panel with
    six screws/finishing washers to beef up the stock 4 it comes with. 
    It's bullet proof now.
    
    -pat

    I use an open back but I'm a 100% sure the sound comes from the
    speakers. I think that I need to let a specialist listen to it,
    because as reply .1 from my good friend and bass-player in our band
    says, there is no powerloss, no difference in sound, just that strange
    frrrrrrr as he discribes it (i still think it's a frfrfrfr). I have
    to add that it's not really loud which means if your just listening
    to the amp at high volume I think a non specialist wouldn't even
    notice, but it's still perceptable enough to ennoy me and I'm sure
    as you mentionned that it's not normal.
    
    Taco

    Another thing that could be happening is tube microphonics. If your
    amp sets on top of your cab, at higher volumes the cab can vibrate
    the amp chassis.  If there is movement inside the the tubes themselves,
    it will affect the signal being amplified.  It's a good policy to
    place a cusion between amp and cabs.
    
    re: pat, with your KH combo, vibration is not surprising - that's
    what happens with an amp capable of putting out that much bass and
    midrange.  BTW-haven't seen you in the KH note for awhile. Did you
    ever get the reverb fixed??
    
    Steve

    I also think you've got tube microphonics, or some type of tube
    noise.  My old Fender would produce that tone, actually more of
    a gzzzsh, but like frfrfr or frrrr, that was a real bother to me.
    Replacing the tubes helped, since I let them age significantly,
    but of course you have a new amp.  I could get the amp to create
    the sound by itself by lightly lowering it onto the floor - shut
    of the reverb first - enough to lightly jar the tube and create
    the gzzzsh sound.  This type of simple test, done carefully,
    may lead you to simply put a piece of foam or carpet under the
    head instead of incurring a bill from an electronics specialist.
    Good luck.

    
    	My Marshall had similar problems....the cause was a HT bias
    resistor going soft in the preamp stage.  I'd get it to a repairshop
    for an overhaul.
    
    Cheers
    		Pete. 

    I've had a similar problem where the coils in the speakers were
    partially frozen.  You could tell by pressing gently on the speaker
    cone.  If there is any feeling of scraping as the cone moves, it's bad
    and needs to be rebuilt.
    
    I also had a kind of similar problem with my Hiwatt when a preamp tube
    was failing.  Probably the microphonic problem described earlier.
    
    Can you duplicate the problem with the amp away from the speaker?  If
    it's easy to reproduce, you might be able to talk your local music
    store or a friend into letting you play the amp through a different
    cabinet to see if it's the amp or the cab.
    
    Good luck, I really hate equipment problems!
    
    Greg

    Thanks a lot for all the input, I tried to reproduce the problem
    yesterday in my appartement (poor neigboors) and it didn't occur
    immediatly just like if either the amp or the speakers needed to
    warm up but after a while it was there (the neighboors too BTW).
    I checked the speaker coil problem mentioned in .8 but no scraping
    appeared. So I would indeed say It looks more like being tube
    microphonics problem but the strange thing is that the amp is and
    was on the gig far away from the cab and even better, my brother
    who played a transistor amp using exactly the same (second) cab
    during that gig had exactly the same problem but his amp was to
    powerfull 200W rms. This would be a point in favor of a speaker
    problem again. Anyway I'll try to get it fixed and I'll let you
    know the result. It might take a little while though.
    Taco

    Are you SURE the problem is in your amp/speaker?  Could it be a problem
    with your instrument, patch cords, or effects?  Just grasping for
    other possibilities....
    
    
    Steve

Hi,

Remember the frfrfrf problems with my Amp/Speaker ? I talked to a Hifi 
specialist who told me that it can impossible be a speaker problem if the over-
all sound is still as loud and with the same quality and if there is no scraping
So I ran through the doc supplied with my CARVIN amp where I found a little
test to check whether the Tubes are okay. They say to perform the following :

     1) Switch the amp and than the standby on
     2) Turn all volumes as well as the reverb down to 0.
     3) Unplug all instruments but keep the speakers plugged in
     4) Unplug the footswitch (for channel selection, reverb, effect-loop)
     5) Select the lead channel
     6) Turn the lead drive, bass, mid, treble, presence up to their maximum 10
     7) If there are any push bright etc. switches adding some db's switch them
        on
     8) Then slowly increase the master volume until you get feedbeck or ringing

Note at what master volume setting the feedback starts. The CARVIN doc says that
if you get feedback before 5 (half way of the master volume), there is a tube
problem, and they even say with which of the 3 preamp tubes. And indeed I get
feedback with a master volume at 3 already. And if I look at the tube they
describe that may have a problem, it doesn't seem to glow or have the same 
aspect as the 2 others when working.

I haven't changed the tubes yet but I will soon and I'll let you know the result

Taco

    Interesting.  Could definately be it, but how would that explain the
    problem your brother had with the cabinet using a different amp?
    
    I'm impressed that the Carvin documentation has such complete
    troubleshooting information!
    
    Greg

    Indeed that's the only little thing that bothers me. Thinking back
    I have to admit that I heared the problem on my brothers amp on
    stage the day of the gig, so maybe I still had some frfrfrf in my
    ears from listening to my amp but I'll check it out this weekend.
    BTW how much do GROOVE 12ax7's (or something like that) cost in
    the US I'll be over next week so if they're really much cheaper
    I 'll buy them over there.
    Talking about CARVIN amps, I can only recommend them it's my first
    all tube guitar amp after owning a roland cube 60, a peavey heritage
    130 a dean markley rm-80-dr and i'm really happy with it. Superb
    and very loud clean channel, fantastic overdriven sounds on the
    lead channel, a lot of different possibilities but the thing that
    amazed me the most was it's very low call it hum or background noise
    even at loud volumes. Okay I haven't tried a Boogie yet but I'm
    sure I'll never trade my carvin for a marshall. 
    If people are interested in more info on the carvin amps (especially
    the X-100B) just let me know and I'll give you all the info you
    need.
    
    Taco

    I might add that while I've never tried a Carvin I was real impressed
    with the salesman I spoke with on the phone one day.  I got a catalog
    after two days, with a personal note attached...  I was interested
    in their PA speaker cabs. 
    
    Anyway, they had some sharp looking guitars in there, and they had
    a 400watt hybrid (tube/solid state) guitar head in there too...
    Wow.  400watts ??  Yowza !  I get shivers and chicken skin just
    thinkin' about it.
    
    BTW - I spent $5.50ea (x5 !) for my GT 12ax7's for my Marshall.  Power
    tubes cost you though...  I think a duet (matched) GT 6550's are
    about $75 and a duet of EL34's are about $65.  This is strictly
    from memory, so take it with a grain of salt.
    
    jc 
      

    re .13
    
    I have the baby brother of your amp-the X-60B. I've been 
    gigging with it and like it alot. The distortion channel
    is great. Nice reverb, too. The footswitch has a *long*
    cord (what a nice suprise). No complaints. Oh yeah, it
    has active tone controls, so if you ever try one out, 
    tweak the tone controls. It takes a little while to get
    the right sound.
    
    The only problem I've had is with the speaker. It has an
    EV 12L (300 watts) which had a defective coil. I had to
    get it reconed at New England Speaker.
    
    -Tom

    re: 12AX7 tubes
    
    I haven't priced Groove Tubes, but Mesa sells these for $8 each.  I
    thought that GT was usually a little more.
    
    re: Carvin amps
    
    I played with a fellow noters X-60 awhile back and was quite impressed. 
    It's a very flexable amp and it sounded great!
        
    Greg