INTRODUCTION
Thanks for purchasing a Diamond Boost-EQ combination clean boost / parametric EQ.
The Boost-EQ combines a very transparent discrete clean boost circuit with a unique se-
lectable parametric EQ combination of a ‘tilt’ EQ and midrange boost/cut filter.
Remember to protect your hearing and wear appropriate hearing protection when play-
ing loud…
DESIGN BACKGROUND
The concept for the Boost-EQ be-
gan with a customer request for a
‘compressionless’ Diamond Com-
pressor - i.e. a clean boost circuit
coupled with the Compressor’s tilt
EQ. A custom pedal was built and
shipped that added a ‘pull’ function
on the Compressor’s COMP control
to remove the opto compression
element from the circuit, using the
Compressor’s remaining make-up
gain section as a boost circuit. This
was then followed by the tilt EQ as
usual in the Compressor chain. The
next step in the Boost-EQ evolution was the decision to take the J-Drive MK3 clean
boost circuit and couple that directly with the tilt EQ. This became the first officially an-
nounced Boost-EQ (it had a large paddle ‘EQ defeat’ switch where the middle knob usu-
ally goes) and was shown at summer NAMM 2007. The pedal worked really well, but it
was decided that a little something extra was needed, so an additional midrange boost/cut
filter was added to the EQ chain, centered at the fulcrum of the tilt EQ ‘seesaw’, to give a
very unique parametric filter combination. This became the official production Boost-EQ
design.
FEATURES
•discrete clean boost circuit with JFET input buffering and bipolar drive
•premium audio components, including 2% polypropylene capacitors, 1% metal film resistors,
Vishay transistors, and a Burr Brown OPA2134 opamp
•post-boost ‘tilt’ EQ provides a very musical tailoring of frequency response - seamlessly transi-
tion from a darker jazz voicing to a brighter jangle, with flat frequency response at the center
detent position.
•midrange boost/cut filter placed at the fulcrum of the tilt EQ for a unique parametric EQ re-
sponse
•EQ section can be removed from the signal path via toggle switch
•dual AC capacitive coupling paths for improved transient response
•true bypass signal path
Boost-EQ user manual v1.00
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