Owners Manual

4826 Sterling Drive, Boulder, CO 80301 Owner’s Reference

PH: 720.406.8946 support@psaudio.com www.psaudio.com 15-070-01-1

Rev A8

Owner’s Reference

Owner’s Reference BHK Signature Ampliﬁers

The BHK Signature ships with a hand matched pair of vacuum tubes pre-installed in the unit. There is

no need to install tubes, simply set the ampliﬁer up and you are ready to play it.

There are many who will wish to experiment with different tubes on the BHK input in a practice known

as tube rolling. The BHK will accept and work with most 6 or 7 series dual triode tubes. Different

tubes require different bias currents, but the BHK will automatically adjust the current to exactly what

is needed.

To replace tubes in the BHK, follow these steps:

• Turn off the main AC power either by unplugging the power cord from the AC source or turning off

the main power switch on the rear panel.

• Remove the rear tube cover by loosening the two screws and remove the tubes currently installed.

• Wait for LED to go out.

• Place the tubes in the sockets making certain the orientation of the pins is correct. There is an

obvious break in the circular array of pins that matches the socket they are going into. Refer to

the pictures below.

Tubes are shipped

already installed

Tube rolling

How to change

tubes

Remove the

tube cover

using Phillips

screwdriver