Zesto Audio EROS 500 Select
2022
14 |
P a g e
About the Bias Select Switch
The Bias Select switch changes the power of the amplifier.
The bias switch settings are clearly labeled for the specific output tubes and are
not
interchangeable.
Left Position:
Rated at 150 Watts is the maximum output for a KT88 and KT120.
Caution! Any other position will exceed its maximum power rating and will damage the
tube known as “Red Plating” and possibly damage the amplifier.
Center Position:
Rated at 200 Watts is an optional power rating for KT150 & KT170.
Right Position:
Rated at 250 Watts is the maximum power rating for KT150 & KT170.
Only the KT150 and 12AU7/ECC82 supplied by Zesto Audio are covered under the
manufacturer’s warranty. 90 days on the KT150s and 6 months on the 12AU7s. All
other tubes are purchased separately and are the responsibility of the owner.
How to use the Bias Select switch
This switch gives you the option to customize your system.
Each setting not only changes the power but also changes the sound.
This feature is designed to be easy to use. You can change the bias on the “FLY” while
the unit is on, so you can hear the difference.
It will take a few minutes for the tubes to react, to either heat up or cool down to hear
the difference.
Tip!
KT150 and KT170 can be changed to all 3 positions, however you can damage a KT88
and KT120 in a few seconds if you overload them on the wrong bias setting.
You may find a more musical option for your system then the maximum power setting
and may prefer the sound on a lower bias setting.
KT150’s set in the right bias position at maximum power, will be a livelier and more
powerful presentation.
KT150s in the center bias position will tend to have a more open sound, which maybe
more suited to your system and musical preferences. We like it in the center position.
