Problems with my Berning ZH270

George. We need to know HOW bright it is. You must be comparing with something else (your previous amp, perhaps?). In my experience, ZH270 has much better and controlled bass than many other tube amps. In fact, I deferred sub-woofer purchase for a year. Your expression sounds like the "brightness" you suffer is not something cable swap or tube rolling can resolve. Did you buy it new? I suggest you check the ZH270 whether it is in perfect condition. Maybe you want to talk to David, who is known to be very sensitive and keen resolving these issues from his amps. Or, maybe it is just not your cup of tea.

Hello gain, George.
Well, glad you got ZH from Allan because I had heard that outdated worn down ZH270s are floating in the used market.
I never mean to imply that the stock unit is inferior in any way, but cryoed output tubes will give you one notch up. ERS kit, in my case, would give another TWO notches up. And, yes, good feet (Stillpoints, specifically) would give further notch. Since I don't have your speaker and source, I don't have any more meaningful suggestion except for adding subwoofer. Hope you will find ZH an exceptional piece of equipment. Welcome to the club.