Guys ... you're overworking this issue.
Acrylic or aluminum or no cover at all .... it's all BS. I've listened to my Ref 150 SE and Ref 5 SE with and without aluminum covers. Couldn't hear a difference. The real problem is audiophile-nervosa.
I have metal covers and am happy as a clam. Oh ... and here's some audiophile heresy. I don't screw down the cover on my amp. Why??? So I can check tube bias more conveniently. OMG ... think of the microphonics.
And ... IMHO, based on pics, I think the acrylic cover looks chinsey (sp).
Acrylic or aluminum or no cover at all .... it's all BS. I've listened to my Ref 150 SE and Ref 5 SE with and without aluminum covers. Couldn't hear a difference. The real problem is audiophile-nervosa.
I have metal covers and am happy as a clam. Oh ... and here's some audiophile heresy. I don't screw down the cover on my amp. Why??? So I can check tube bias more conveniently. OMG ... think of the microphonics.
And ... IMHO, based on pics, I think the acrylic cover looks chinsey (sp).