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Conference hips::uk_audioo

Title:You get surface noise in real life too
Notice:Let's be conformist
Moderator:GOVT02::BARKER
Created:Thu Jul 28 1988
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:550
Total number of notes:3847

464.0. "MF A100 upgrade consideration" by HGODC1::NICHOLASHO (Nicholas Ho, Digital Consulting Hong Kong) Fri Jan 07 1994 03:46

        Hi,
        
        I own a Musical Fidelity A100 Class A integrated amp rated at
        50W. It drives a pair of small speakers (JM Lab Profil 3, French
        Speaker). The sound is sweet and smooth. It gives me a lot of
        pleasant time.  The only weakness of it is the lack of power and
        bass. I am considering an upgrade of the amp.
               
        Has anybody used the new Mcintosh 7100 power amp? The size and
        price of it is very attractive to me. It's slim and price of it
        in Hong Kong is about US$1300. However, the pre-amp from Mcintosh
        is very expensive. I can't afford any of them.   
                          
        Is there any recommendation of what pre-amp should be chosen to
        match the 7100? My budget is around US$1000. Will it sound better
        than my current MF (sweet, smooth)?          
                          
        Besides of the Mcintosh solution, any other suggestion for the MF
        upgrade are welcomed.                                  
                                                               
                                                               
                          
        Thanks and Regards
        Nick              
                                           
        P.S. There is no power switch in the Mcintosh 7100. That means I
        have to power it on all the time. I can't find this feature in
        other higher Mcintosh model (7150, 7200 etc). Is it a new design?
        What's the benefit of it?          
                                           
        This note is posted in both VAXWRK::AUDIO and SAC::UK_AUDIO notes
        conferences.                       
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464.1It may not be your ampBAHTAT::SALLITTDave @LZO 845-2374Fri Jan 07 1994 09:5832
    Nicholas,
    
    I know nothing about the McIntosh hardware you list, but perhaps the
    clue to lack of bass and volume lies with your "pair of small
    speakers". Small speakers rarely give a lot of bass, and are often less
    sensitive than larger models. Doubling output power to a 100W amp will
    only give you 1.414 times the sound pressure for a given volume
    setting, and that is only if you can be sure that you will get twice
    the signal into the speakers that would get with a 50W amp. Chances are
    it won't be much different; if the music signal doesn't use the full
    dynamic range of the power stage you won't hear any difference at all.
    
    Upgrading to more sensitive speakers will give more sound for a given
    volume setting. Speakers with 88dB sound pressure level at 1 metre for
    1 watt input will sound twice as loud as a pair rated at 85dB sensitivity
    and may not necessarily be bigger than the ones you have now.
    
    Provided your source (CD or whatever) is capable of delivering
    reasonable bass, upgrading to larger speakers should give more bass as
    well as being more sensitive.
    
    Always listen before you buy, preferably at a dealer that will let you
    take in your own system and let you hear where the real differences are
    as you substitute first the amp, then the speakers. I don't know how
    easy that will be in Hong Kong, but if you can do it I guarantee you
    will hear what I mean.
    
    Have fun, anyway.
    
    Dave
    
    Dave
464.2Just might be the ampWOTVAX::MEAKINSClive Meakins @OLOMon Jan 10 1994 13:2311
    How old is your A100?  It's a bit remote, but it's just possible the
    performance of your amp has very gradually gone off.  I'd expect the
    A100 to be very slightly soft in the bass, but not unduly so.  Like
    Dave I expect your speakers to be the culprits. (Don't worry Rob, my A1
    looked fine!)
    
    The reason I mention the slight possibility of the amplifier being to blame
    is that I once looked inside an A100.  Even though it has cooloing fans, 
    the commponents, especially the electrolytic capacitors looked cooked. 
    If they are damaged due to heat, then anything could have happed to the
    sound, lack of bass being quite probable.
464.3CHEFS::TAFF::WobRobert Screene, UK Finance EUCTue Jan 11 1994 12:3511
Hi Clive.

The A1 Seems to be providing sterling service.  It does get the odd squirt 
of contact cleaner into the source selecting switch.  I wish I could get at 
the volume pot in the middle but can't get the cover off easily.  Just the 
odd crackle if the volume is moved.

Is the A100 simply an A1 with bigger output stages hence twice the power?

Rob.

464.4WOTVAX::PC0905::MEAKINSClive Meakins @OLOTue Jan 11 1994 13:1519
>The A1 Seems to be providing sterling service.  It does get the odd squirt 
>of contact cleaner into the source selecting switch.  I wish I could get at 
>the volume pot in the middle but can't get the cover off easily.  Just the 
>odd crackle if the volume is moved.

A few months before you took the A1 over it was given a new source selector 
switch by MF.  I also fitted a new volume control, I guess the heat is just a 
little hostile, it uses a 100K ALPs pot.  The top comes off easily, just undo 
the allen bolts on the heatsinks, these screw into the central inverted U shaped 
heatsink.  When I re-fitted the heatsinks I found the A1 felt warmer.  I made 
sure the heatsinks were screwed down very tight and used quite a lot of heat 
transfer compound.  It seems I achieved a better thermal contact than MF did 
when the A1 was manufactured.  The outside may have been hotter, the inside 
should be cooler.

>Is the A100 simply an A1 with bigger output stages hence twice the power?

All I know is that it is designed around the same principles and they do sound 
very similar.  An A100 just having bigger balls than the A1.