Conference hips::uk_audioo

    
    On the question of amp tweeking, people I know have taken to wrapping
    the transformer in the amp in tin foil. A friend has offered me
    this service for free, should I take him up on it?
    

    re .0....
    
    Chances are that the wire itself is adequate. It's more likely that
    switching for multiple speaker pairs, and the routing of the speaker
    return (negative) via the same pcb track where the preamp gets its
    ground is compromising the sound - not to mention those nasty spring
    clip speaker connectors fitted to some amps. I bypassed this on
    an old Technics SUV-5 a few years ago, and fitted some good 4mm
    binding posts; the improvement was out of all proportion to the
    cost/effort involved. ideally both speaker returns should go direct
    to the mains transformer secondary centre-tap, provided the power
    supply uses this type of transformer, of course - if it doesn't,
    go direct to the power supply return; this isolates the heavy speaker
    return current from the relatively high resistance pcb ground track,
    thus giving the preamp a more stable reference ground. Bypass speaker
    switching by wiring both speaker `lives' direct to the switch input
    - even better, direct to the pcb if you can. Changing the wiring
    topology is more important than the type of wire itself; Monster
    cable's probably too thick for this, try QED 79 strand - even a
    smaller guage will do since lengths are short, but try to select
    wire that uses good quality copper. Personally I avoid solid core
    like the plague, but there are others who like its sound; if you
    like the sound of your Monster cable then stay with stranded.
    
    re .1...
    
    What an extraordinary thing to do, probably highly unsafe apart
    from anything else. If an amp hums enough to make you think this
    is required, it's probably broken.
    
    Dave
    

    RE .1
    
     Apparently, my friends all swear by the tin foil treatment, saying
    that the extra screening that results does make a difference, but
    care must be taken. I know of someone with a dead audiolab 8000
    because they punctured the plastic around the transformer, letting
    the current reach the tin foil, which just happened to be touching
    the casing ofthe amp. 240v ac current through EVERY component is
    the result, but he was unlucky.
    
    I just wondered wether anyone else used this method of improving
    an amp. Obviously this tweek only really applies to integrated amps,
    where the power supply thingy is so close to the pre amp bits. 
    
    juju
    xxxx
    
    It is just lucky that the amp earthed before sending out to the
    unlucky owners Sondek ect.
    
    

    Re: .2
    
    The AR amp has only one speaker pair output and has 4mm sockets only
    on the output.
    
    
    Stephen.
    
    PS. I'm leaving DEC today to finish my studies at Poly. I'll pass over
    the role of IT audiophile to Juju. Maybe I'll be back next year, bye
    all!

    Over a year sibnce the last note in this subject...
    
    
    �
     PS. I'm leaving DEC today to finish my studies at Poly. I'll pass over
    the role of IT audiophile to Juju. Maybe I'll be back next year, bye
    all! �
    
    Actually, Juju the placement student is leaving too...... after a happy
    year at DEC.  I now go back to sunny Hull, and, if on one trip to
    Scarbrough beach, I should see a poor K9 less, run down Field Service
    engineer Muttering about the cost of a Linngo board, I shall say hello.
    
    
    
    Good luck everyone. 
    

    Juju
    xxxx
    
    
    Ps Dave, (Mr Sallitt) should you be in Hull ever, Do drop into 83 Perth
    St, Hull, (Nr Chanterlands Ave)....
    
    

    I'm back from poly now Juju, thanks for keeping up the student
    perspective on audio.
    
    Stephen.