Anyone using Airtight ATM 211 to recommend?

[mtemur]

Dear @BP4007 @Dante Choi @bonzo75 and @ogschile I hope you are biasing your amplifier every time you change 211 tubes cause output tubes need proper biasing. especially when you are tube rolling.
Additionally every tube (even the used old stock ones) requires at least 20 hours of burn in after a long unused period. I believe IOT accurately evaluate an output tube's sound, biasing and burn in period should not be skipped.

I hope your prior comments about sonic differences of various 211 tubes are based on regarding these considerations.

 

[BP4007]

Yes, I always bias my amps. It is quite easy on the ATM 211. I generally consider proper burn in time for 211 tubes at about 100 hrs.

 

[cuntigh]

Tube amps need to be biased regularly, not only when you change the tubes. Auto biased tube amps are ideal for that matter. With Air Tight it is very easy to do. If you biase high or low you can modulate the sound quality. With ATM3 and ATM1S we are several users who found the sound better when power tubes are biased lower than recommended by the manufacturer.

 

[mtemur]

Tube amps need to be biased regularly, not only when you change the tubes.

thank you, output tubes also need to be biased when the line voltage changes. biasing in general is very important and needs to be done regularly as you mentioned but my prior comment based on tube rolling.

 

[new2Krell]

Tube amps need to be biased regularly, not only when you change the tubes. Auto biased tube amps are ideal for that matter. With Air Tight it is very easy to do. If you biase high or low you can modulate the sound quality. With ATM3 and ATM1S we are several users who found the sound better when power tubes are biased lower than recommended by the manufacturer.

I guess it all depends on where the manufacturer specified the bias level. I don't know anything about ATMs.
I have EL34's in my amps, the "usable" range is 50 - 70%. The manufacturer specifies 26-29 ma (52 - 58%), already at the lower end of the range. I have just settled on a bias level of 53% for my recently installed tubes. I find I get the best sound from my amps when biased "cool".

 

[Dante Choi]

Finally sold my ATM-211, have changed by Audio Note UK Ongaku Shinguru. If some one love 211, please consider ANUK…

I love Amperex 211D, but not possible to use with my Ongaku’ auto bias. I’m using with original WE-242C, incredible sound.