[Arny Krueger]

wrote in message

On Dec 5, 2:22 pm, Chris Morriss
wrote:
In message
,
writes

Hello all,
First, I like my 901s regardless so no flaming please.
I need help with this condition:
I have two sets of 901's. One pair of series IV and
one pair of series VI, both with the matching Bose EQ.

My problem is that some CD,s and even some passages on
soother CD's cause distortion when using the EQ. This
can be at any volume level. I have only had this
problem with recent CDs. (Diana Krall, Chris Botti) All
my older CD's and the radio plays fine and loud. I
have tried different recievers, CD decks and even
replaced all the caps in one of the EQs. Anyone else
having issues or know where I can find a service manual
for these EQ's?
Really appreciate the help

Perhaps the high output signal is overloading the input
on the equaliser. Can you make up a simple 6dB pad (a
couple of 10k resistors in an 'L' network for each
channel)? This may drop the signal enough. What is the
input spec for the equaliser? Modern highly-compressed
CDs may be putting out 2V rms or so and that may be the
problem. --
Chris Morriss

Thanks for the help folks. Yes the problem seems to be
on both channels and I have tryed it on two different
systems. I was thinking to try attenuation as well. I
have tried different CD players and even drove the eq's
input off of a portable cd deck headphone jack with
varied volume output and could detect the distortion at
very low levels.

Distortion at low levels could be due to corroded contacts.

Does the RMS voltage value remain
constant on a headphone channel?

No. The sound level in your earphones changes, right?

I don't know the input spec on the bose Eq but would
apprecieate it anyone has that information or a link to a
service manual.

It is probable that your equipment isn't meeting spec. IOW, it has failed to
operate properly.

I can't belive that I am the only person haveing these
issues or that I have aquired two systems with the same
problem.

Both samples could be failing the same if it is due to something like
electrolytic caps failing, or problems with a common power supply...



A call to Bose says they will check out the EQ for 60
dollars.

Typical.

I assume new systems they are selling have
upgraded EQs. What are they doing or changing?


The eqs are designed to match the speakers, and newer models of the speakers
no doubt need different eq. There will also be some changes due parts from
the old eqs no longer being available.