MODEL - ZEN TORII MK V - OWNER’S MANUAL DATE 11/2021
cause a rectifier tube to arc internally and thus blow the fuse. If this happens the rectifier
tube may still work or may not.
INSTALLING TUBES
Using the diagram above you should be able to install the tubes in their correct locations.
Remember the left side is a mirror image of the right side. On the smaller tubes it is wise to
visually inspect the pins to be sure they are not bent. Inserting tubes with bent pins can
damage your amplifier.
TUBE SUBSTITUTIONS
The 5U4 rectifiers can be replaced with 5AR4. 5U4 and 5AR4 typically give the best
performance.
The Voltage regulation tubes OA3 are used to feed the input stage of the amplifier,
and can not be changed except to another brand without changing the sound of the
amp.
The input tube (6N1P-EV) can be substituted with a 6N5P (Russian Tube) if a better
focused sound is desired with a touch less gain. Also you may use 6922, 7DJ8.
Since there are two of these 9 pin tubes on each channel, you should understand
that the rear one is almost always best served by the high current 6N1P-EV and the
front tube is the one that can be changed for different voicings.
OUTPUT TUBES
The Torii MK IV is by default shipped with EL34 output tubes. It can however use
the following alternates: KT66, 6550, KT88, 6L6, 5881, 7027, KT77.
MATCHING
It is important to run a matched PAIR of output tubes in each side of the TORII MK
5. If each pair of output tubes do not draw the same amount of current that
channel will develop hum. You can check to see if your tubes match at any time
once they are warm by simply using the meter.
Manufactured by High Fidelity Engineering Co.
