The chances that there is something wrong with the ZH-270 is extremely low to nil, chances that there might be a problem with a tube is somewhat higher.
I recommend that you leave the ZH-270 on for the next week or so and play as much music as possible through it, it will break-in more.
The tonality of a ZH-270 is as neutral as it gets, any and everything you do will make a difference in what you hear, unshielded cable, metal shelves, stacking, will all hamper/change performance, this is not a short coming of this amp, it's ultimate performance without coloration.
However, ultimate performance without coloration might not be for everyone, wait a week or so, then contact me and let me know where it's at.
Changing tubes is for taste, not to bring up the performance, not everyone is ready nor do they want an amp that reveals everything, there must over 60 ZH-270 owners, all extremely happy, so much so that used ZH-270's have one of the highest resale values in audio, that is if you can find one.
The tube changes can be suited for your taste, while keeping the attributes of the speed and clarity that Berning has designed into these amps, it's not a performance upgrade but a taste that you might be more use to, I hope this explains it better.
Allan
I recommend that you leave the ZH-270 on for the next week or so and play as much music as possible through it, it will break-in more.
The tonality of a ZH-270 is as neutral as it gets, any and everything you do will make a difference in what you hear, unshielded cable, metal shelves, stacking, will all hamper/change performance, this is not a short coming of this amp, it's ultimate performance without coloration.
However, ultimate performance without coloration might not be for everyone, wait a week or so, then contact me and let me know where it's at.
Changing tubes is for taste, not to bring up the performance, not everyone is ready nor do they want an amp that reveals everything, there must over 60 ZH-270 owners, all extremely happy, so much so that used ZH-270's have one of the highest resale values in audio, that is if you can find one.
The tube changes can be suited for your taste, while keeping the attributes of the speed and clarity that Berning has designed into these amps, it's not a performance upgrade but a taste that you might be more use to, I hope this explains it better.
Allan