Midrange Increasingly Harsh

Thanks for the info.  I get the harshness with CDs as well as records.  I've changed around the speaker output taps and no change.

I apologize if I offended anyone with my modest problems.  I settled on the Audiogon forum since it looked like it had the most knowledgeable and experienced members around.  If it is strictly for much higher-end participants than myself, please let me know and I will move off.    

Thanks for all of the information, as well as confirmation that I'm in the right place.  I got this tube set from Upscale Audio, so I'll check with them regarding tube behavior.  Room acoustics is an interesting idea, but I've been here for four years and this is a recent phenomenon.  I plan on replacing speakers next year, and would like to get a new amp as well, but my CD player is at the end of its life and needs to get replaced first.  I'll report back when any repairs or replacements are performed. 

I listen at lunch and again in the evening with my adult beverage.  I have post-concussion phonophobia, which I suspected at first.  But my wife also noticed it so I can rule that out.  I don't have any sources for spare gear around here to swap in and out.  What I may try is plugging the CD player into other output taps from the amp, and fooling around with some different cables.  By my estimate I have over 5000 hours on these tubes, so they need to get replaced in any event.  I don't recall the brand but the were made in England and sounded wonderful for a long time.  Hopefully Upscale has my purchase history if I can't run down the receipt.

I did some side-by-side testing yesterday and discovered that there is no difference between the left and right speaker.  I swapped cables and no change.  But when I changed from the eight ohm to four ohm output, the harshness decreased somewhat.  My bride couldn't tell the difference.  I got in touch with Upscale Audio and ordered a set of Tung-Sol EL34B power tubes.  We'll see how that goes then get some new 12AX7 and 12AU7 tubes.

I replaced the Mullard  EL-34 tubes with Tung-Sol EL-34B tubes and after some run-in time I replay the Hildegard Von Bingren CD which started this.  The sound is much improved and not nearly as harsh.  The higher register soars rather than screeches.  I don't have back-up 12AX7 or 12AU7 tubes so need to get a set of them as well.  I'll roll them in to see how things change.