Charles & Sandra Cohen
There is a previously-reported problem with IC-7000 SSB transmit audio:
. . It's really bad with narrow TX bandwidths!
I've experimented with our club IC-7000, and I think the problem happens when the TX "high freq limit" is set lower than 3000 Hz.
Since the problem showed up when you changed the TX bandwidth (strictly handled by logic inside the IF DSP, not inside the head), I doubt that it was caused by your repair.
Try it out on some HF band, with a "known-good" receiver. As I remember it, you can narrow the TX passband from the _low-frequency_ side (that is, eliminate low-frequency speech components). But if you narrow it from the _high-frequency_side, audio quality really degrades.
The "stock" filter setting for "narrow TX bandwidth" both raises the low-frequency limit, and reduces the high-frequency limit -- not a good choice.
. Charles / VA7CPC