Problems with my Berning ZH270

You might try some Marigo bands and dots on your speaker cones and basket arms, especially on the woofers and midrange drivers. If you have any windows apply the Marigo dot treatment to them as well, if you don't mind their visual effect.

I have a very bright listening room, and a very sensitive system, and the Marigo resonance control products have helped me in very significant ways. Not only will they tame problems areas, they will also improve performance of your whole system.

If you choose to try these, do the woofer bands and windows first.

I share Duke's hunch on the issue of tonal balance. It is amazing how improving the performance of one element in the spectrum will improve other areas passively.

84audio, are you Larry's former friend? Just curious.

George, my observations match those of Allan. If you follow his advice, and still have a problem with the high frequencies, I would again direct you to the Marigo dots, especially on windows.

You are in for a treat with Andy Bouwman's matched tubes. I recently put a pair of Andy's Sylvania 6SN7 tubes in the input section of my OTL amps and the high frequency performance was just outstanding. I have a complete set of Andy's Sylvania 6SN7's in my preamp and they were a great upgrade as well. His tubes are expensive, but well worth the cost IME.

If you end up trying the Marigo dots, I would enjoy hearing about your results. BTW, do you have windows in your listening room?