Scratchy, tiny sounding receive on SSB

For the lack of better words, that's what my Washington and 142gtl sound like. Both radios have been recapped and aligned. They perform very well and have great sensitivity. However, the receive has a very high treble with signals sounding a bit crackly, especially on the stronger signals. Even a decent external speaker doesn't help a whole lot.
So what can this be? The I.F., band pass, crystal filter? Or is it just the nature of the beast? I
Thanks!