Installed a manual APE CCT 2 years ago.

I've had a strange " buzz" while in gear throughout the RPM band 3-5k+. Some shops just sit there and rev it and say it sounds " normal" without riding it. Usually does it underload and in gear.

It has gotten persistently louder over time. I've tried redoing all my adjustments to basically a fresh install with almost zero pressure on the CCT then turning it a quarter turn and reving listening for any chain slap, then locking the nut down. These adjustments had very little effect on the noise. The engine rev's strong in my opinion. Ironically about 90% of the noise disappears when I clutch in. Someone suggested a noisy " clutch basket" or the springs.

I replaced my entire clutch basket assembly, all the disks and guides/bearings. I even had a chance to inspect the lower timing chain guide, everything looks great. I haven't seen the the guide that pushes down on the chain ( will need to remove the valve cover). Any advice?