Octave V 16 Single Ended, Owner'S Manual

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6. ADVANCED FUNCTIONS
6.3. Soft-Start
The V 16 Single Ended input- and output-tube-heaters as well as its high-voltage-rails are logic
controlled to ensure that the operation of the output tubes as well as input stage voltages are
constantly monitored and controlled by the
Power Management System to protect the vital internal
parts (tubes, rectifier, electrolytic caps, switches, etc.) against excessive turn-on current. This
increases the lifetime not only of the tubes, but also of the capacitors, while all other power related
components derive benefit through this system.
The Soft-Start is always activated within the first 60 seconds after the unit is switched on.
During this time you cannot listen to music, there will be no signal in the speaker- and
headphone-outputs.
6.4 Speaker Operation - BIAS Selector
The V 16 Single Ended is equipped with a BIAS selector. The BIAS selector allows to switch between
two BIAS settings. BIAS means the idle current of the output tubes. The value of the idle current is
directly related to the loudspeaker impedance. The lower the impedance the higher should be the
idle current for best performance
Changing the idle current is a practicable way to match the output Class-A-stage to the load
impedance perfectly. An additional positive aspect is to avoid unnecessary high current and heat
because of an idle current that would be too high in respect to the load resistance.
The values you can select with the BIAS selector – High and Low – correspond with the speaker
impedance 4 and 8 ohms.
Most of the high efficiency speakers have an impedance of 6 ohms
or higher, therefore you should select BIAS Low as the standard setting . In case of bi-amping,
with the V 16 Single Ended connected to the middle- and high-frequency-speakers of the bi-amped
speakers, you should also set the BIAS to Low.
For all speaker applications you should set the Output selector to OUT High.
6.5 Headphone Operation - OUT Selector
In case of headphone operation, the BIAS High is not meaningful due to the high impedance of
headphones in general. Therefore the BIAS is internally programmed in headphone setting to a value
that ensures the best results with headphones. The BIAS selector is therefore not active in this mode.
The idle current is reduced because of the low output power and is optimized for headphones with
an impedance down to 10 ohms and higher.
The most headphones have an efficiency that matches to the setting OUT High, but in some rare
cases headphones have a very high efficiency and an impedance lower than 25 ohms. In these
cases we recommend to change to the OUT Low position. The maximum output level is limited to 4
V in this position, preventing the user against excessive level and is protecting the headphone against
damage.
6.6 Ecomode
The Ecomode electronic in the V 16 Single Ended is a signal sensing electronic system that controls
the idle current of the power tubes. In case of no music playback longer than 2 minutes the Ecomode
drives the idle current down to 35 %. The unit is still working in this mode. If the playback starts again
the Ecomode is releasing the BIAS (idle current) to the adjusted value – High or Low – in the
loudspeaker mode. This process is not noticeable and needs only 10 seconds to restore the selected
BIAS level.
Thus power consumption during music pauses and the dissipation heat is reduced.