DHA Hand built guitar, bass and keyboard amplifiers
and effects from Devon in the UK
Dave Hall Amplifiers www.davehallamps.co.uk
The VT1-EQ-Bass-Drive from DHA is a hand built valve Overdrive effects pedal which
uses a 12AX7 (ECC83) pre-amp valve to provide true valve tone, the tone generated
has to be heard to be believed! The VT1-EQ-Bass-Drive is designed and voiced for
bass players looking for subtle clean to crunch valve tone for blues and rock. This
model in our VT1 range has a 3 band active EQ with mid range Q, Line in/out, headphone
amp plus an XLR balanced DI out.
A review in the UK BassPlayer Magazine described the VT1-EQ-Bass-Drive as follows...
"Plugged in this little beauty has a genuine ECC83 valve to warm up your tone and
this was immediately noticeable during our testing. Plugged into a passive Jazz Bass
the overall vibe was a soft warm blues tones and when cranked at the gain stage,
a rather splendid, gritty 60s classic rock grind. Essentially, when you access the
VT1-EQ-Bass-Drive, it's like plugging straight into a vintage valve head without
the weight and unreliability issues."
There is a "cool blue" back light which acts as a power on light and it is visible
via the valve vent holes. There is also a blue LED for effect on.
Overdrive is achieved by using both gain stages in the 12AX7EH valve/tube to generate
the classic valve pre-amp overdrive tone plus a clean op-amp boost is available for
extra output volume. It is great with modern solid state amps by adding valve warmth
and fantastic with valve amps by overdriving with a true valve signal path. The VT1-EQ-Bass-Drive
sounds great when plugged directly into a desk or a digital recording setup via the
low noise XLR balanced DI output.
The Gain and Level controls let you select that tone you been looking for! And don't
forget the volume and tone on your bass which will react well with the VT1-EQ-bass-Drive
just like a real valve amp/pre-amp. There is a true By-Pass Foot Switch which is
used to select the Overdrive and EQ part of the circuit but the DI, headphone and
line in/out remains on all the time. This means you can use the VT1-EQ-Bass-Drive
to DI your other effects or just the bass with or without adding the VT1's valve
The 3 band active EQ provides +/- 15dB of cut and boost in each range plus the mid
tone control has a Q control so you can adjust the sweet spot frequency.
There is a bright switch on this model which boosts the treble when selected without
losing the bottom end. There is an i/p pad control which is useful when using active
or high output pickups.
There is also a "Colour" switch which selects negative feedback to the circuit, this
means more gain and compression. At higher gain settings Colour can push the effect
into an almost fuzz tone.
The tone is pure valve/tube, fat and warm and completely different to silicon effects
pedals which tend to fizz and compress the signal. Unlike silicon pedals you can
use the volume control on your bass to control the amount of distortion you want,
just turn it up for the solo.
There is a selectable boost function. This adds additional clean output volume to
the valve signal using a low noise op-amp. This function is very useful when very
low levels of gain are required for clean but fat valve tones. The boost control
allows the user to set the boost level.
The output of the VT1-EQ-Bass-Drive is connected to a standard 1/4" jack for use
with an amp and an XLR balanced DI connector which is in parallel. This means both
outputs can be connected at the same time, so the 1/4" might go to the amp for the
stage back line and the DI to the PA or desk. The DI is also intended for studio
recording as the pedal is really a valve/tube pre-amp so will add warmth to any set
up. There is a DI ground lift switch which is useful if a ground loop hum occurs.
There is a headphone amp which will also drive two 8ohm speakers (left and right)
at around 1W each. There is a headphone out level and the connection is a 3.5mm stereo
The 3.5mm Stereo jack Line in allow you to play along via the headphones or line
out to MP3's, CD's, iPod, etc. great for practising to backing or just playing along
The VT1-EQ-Bass-Drive runs from a 9-12VDC 500mA (12VDC 1200mA recommended) supply
via a standard 2.1mm socket. A 12VDC @1200mA power supply is provided free if the
pedal is ordered from this web site.
The VT1-EQ-Bass-Drive is totally hand built using a quality PCB, even the box is
hand painted and marked. There is a one year return to manufacturer guarantee which
covers parts and labour in case of failure with each unit. There is also a user manual.