On 14 Jul 2004 03:49:36 -0700, (Ben Coffman)
wrote:

My early, plastic-cased, Cyrus 2 amp has developed a DC offset in one
speaker. It's about 1.5v.

The Cyrus 2 design does not appear to include output capacitors, so
somewhat ruling that out.

Has anyone else experienced this fault? Does anyone have any thoughts
as to where I should start to look?

Many thanks.


hi Ben,
sounds like you have a leaky transistor or capacitor, can be a little
difficult to locate due to the amp being dc coupled, another
possibility is a noisey preset pot there may be 2 in each channel , 1
for I.Q adj and 1 for DC offset adj, cant remember on this model.
does the faulty channel actualy work? i would not reccommend that you
use speakers to test this however, just in case it blows them. i use
an old speaker in series with a 0.5A fuse for testing. if the faulty
channel 'works' with no audable distortion suspect leaky comps as
above, if the sound is distorted then it is more than likely a
compleatly failed transistor/capacitor.
to find the failed part the only way is to remove them from the
circuit board one bye one and test them, (putting the good devices
back as you go) starting with the output devicies
regards
bob