[Martin]

Hi all
 You know the nice woooosh sound your speakers make when
you power down your Aksa's? Mine have taken on a nasil tone and
are not in sync...first one channel shuts down, then the other.
 Unbalanced bias?
 Thanks
Martin

[PSP]

Hi Martin,
Mine have always shut down out of synch, maybe a second apart.

Nasal tone, I don't have that.  Do you get "nasality" (cool term, yes?) from both channels or only one?  If both channels, I'd suspect the power supply, but I don't know enough to suggest anything specific.

good luck,
Peter

[Martin]

Sounds right Peter
 I probably wood hav usd "nasality" if we had spel cheker heer
Maybe I'm hearing more thru my nose than ears.
 I do notice that most lead vocals tend to be a little left of center.
However my left speaker is kind of boxed in a corner, which may account for a stronger prescence. Our house was built in 1917...before TeeVee...and my setup options are very limited...large windows...large doorways...little wallspace.
 
Thanks
Martin (USA)

[AKSA]

Hi Martin,

There are only two significant issues with your amp operation;  output offset voltage with respect to ground, and bias.

Output offset from each channel should be within 30mV, plus or minus, in normal operation with a speaker connected.  Output stage bias should be 50-55mV, preferably 55mV, across the output device emitters of pairs of devices (that is, the inner devices for a 100W amp, and the outer devices of same;  for the 55W there are only two devices anyway).

Nasally noises at power down are a byproduct of the discharging boostrap connection and the slow turn off of the voltage amplifier.  Samples do vary a little in their time constants.  If music is passing through the amp as you turn it off, it will sound nasally, but this is quite normal.

Don't be concerned!  We humans might be bilaterally symmetrical, but usually one arm is slightly longer than another.....  amps are the same!  

Cheers,

Hugh

[DSK]

Don't be concerned! We humans might be bilaterally symmetrical, but usually one arm is slightly longer than another..... amps are the same!  ...

...and our feet are usually slightly different in length ...I can only put one foot in my mouth