The VT3-Twin-EQ-Bass-RM uses three 12AX7 (ECC83) valves to generate classic pure
valve tones. There are two separate selectable channels Red or Blue with separate
3 band active EQ on each. The VT3-Twin-EQ-Bass-RM is capable of producing a very
wide range of gains to suit all types of playing. It is intended to be used in front
of a valve amplifier, but will also work well with solid state amps or even recording
set ups acting as a valve pre-amp. The third valve is used in the valve driven FX
The VT3-Twin-EQ-Bass-RM is fitted with 2.1mm external PSU adaptor for use with a
12v @1200mA external supply. A suitable low noise power supply is included in the
The inner of the connector is the positive, there is reverse polarity protection
so no harm will be done if you get it wrong.
Blue channel – This channel is clean to crunch using both stages of the first valve.
The circuit is the same as our VT1-EQ-Bass-Drive. There common I/P pad control between
the Red and Blue channels as well as the main DI out and Headphones. The Blue channel
controls are I/P pad, Gain, Level, Treble, Middle, Bass pot plus a Bright and Boost
switch. When the Blue channel is selected via the Red or Blue foot switch or front
panel then the blue led will light.
Red channel - This channel is clean to overdrive using a shared first stage of one
valve and both stages of the second valve giving 3 valve stages in all. The Red channel
controls are I/P pad, Gain, Overdrive, Level, Treble, Middle, Bass pot plus a Bright,
Colour and Boost switches. When the Red channel is select via the Red or Blue foot
switch or front panel then the red led will light.
Red or Blue Level sets the output level of the effect to your amplifier, there is
a lot of gain generated by the valves and selectable op-amp generated boost and this
will overdrive the input of your guitar amplifier with ease.
Red or Blue Gain sets the level into the second stage of the valve on the selected
channel and hence the level of gain. Use your volume control on your guitar to control
the gain on the first stage of the valve, you will find that the VT3-Twin-EQ-Bass-RM
responses very well to this and you can control the break-up distortion like this.
Red Overdrive sets the level into the second stage of the valve on the Red channel
and hence the level of Overdrive on that channel.
Each channel has its own active 3-band EQ which cuts and boosts around 15dB in each
band, so the 12o’clock position is a flat response.
Each channel has its own Bright and Boost switches. Bright increases the treble response
and Boost switches in a clean Op-Amp boost to the signal.
The Red channel has a “colour” switch which adds negative feedback via two clipping
diodes. This produces fuzz type distortion, extra gain and compression. There is
a drop in output level so the boost or output level will need to be adjusted.
The I/P pad is useful when using high output or active pickups or when using the
effect in a line level loop. The I/P Pad control is common to both channels.
The XLR connectors on the back provide balanced DIs out for recording and low noise
feeds to the desk or amp. There is a 3 position ground switch with each DI out with
ground, float and ploat positions which are useful should a ground loop hum occur.
There is DI level pot for each DI out. There are separate DI’s for main out, red
and blue channels, there is also a separate ¼” jack line out for out of these outputs.
There is a tuner mute and tuner jack feature which is selected via the front panel
or the foot switch.
The valve driven FX loop has a wet/dry blend control plus send and return jacks on
the back panel.
The by-pass switch on the front panel and on the foot switch provides a by-pass of
the red and blue channels but the main DI and the headphones remain on. The by-pass
switch on the front panel must be in the off position if the foot switch is to be
The Headphone out socket is for quiet practice. There is Headphone level pot which
is common to both channels and it and the Headphone output act upon the selected
channel or by-passed signal. There is some background hiss on the headphone out socket
and hence it is not intended as a line out.
The stereo Line in socket routes the line in signal to the headphones so that you
can play along to CD’s, MP3’s, iPods, etc.
So, just plug your bass into the in jack on the back or the front your amplifier
into the main out jack and you are off and running!
The unit is covered for any parts and labour required to repair it should it go wrong
within 12mths of purchase. This does not cover misuse of the product but we will
be happy to repair this at cost as we will for any units which fail outside of the
12mths. The owner of a faulty unit will pay all the postage costs.