The J Retro Bass Preamp is a beast. One of the first preamps to be created specifically for Jazz Basses®, it’s high functionality and tone is loved by many.
From players with $3000+ custom J basses, to others that have found excellent-playing sub-$500 basses - this preamp has taken a lot of basses to a higher level. A bassist that was in the house band of a very well known late night variety show confided to us that one of his main basses was a Fender® Squire® outfitted with a set of Bartolini Jazz Bass Pickups and a J Retro.
Some unique features make the this preamp stand apart: Solder-less pickup connections, variable mid frequency selection, and easy installation.
Jazz cavity plate, jack, switches, as well as knobs are included with this pre-wired and read-to-install preamp.
In most cases, the required 9 Volt battery will fit under the control plate.
There is a built in “color’ to the tone of the J Retro. Most players here it as immediately adding a little thickness and oomph. Not too drastic, your bass still has ‘its’ tone, but a bit thicker.
NOTE : John East J Retro & J Retro Deluxe preamps use an active blend. In passive mode, the blend pot does not function. Therefore, a player can use the pickup switch to alternate between both pickups on or the bridge pickup on only. For most players, the passive mode is a ‘get out of trouble’ mode for situations such as live gigging where a battery failure occurs. If you are looking for full blend capability in passive mode, we recommend the 2 band John East J Tone preamp.
VOLUME & BLEND (Knob stack nearest the neck pickup)
VOLUME
The Volume is controlled by the top knob of the stacked knob set.
A low impedance signal is served to your amp by initiating the active signal post volume control.
BLEND & PICKUPS SWITCH
Blend balance is controlled via the bottom knob of the stack.
Move the knob counter clockwise for the bridge pickup, and clockwise for the neck pickup. The blend control has a center detente for a balance signal of both pickups.
Using very high quality potentiometers, the blend control is well graduated.
BASS & TREBLE (The middle knob stack)
TREBLE (+12dB @ 3 kHz, -12dB @ 1kHz)
Treble boost and cut is managed from top knob of the knob set. When cut, the treble controls lower frequency for rolled off, deep tone effect.
BRIGHT (+8dB @ 7kHz)
Get bright tone by pulling up on the Treble knob
BASS (+15dB @ 50Hz)
The Bass potentiometer (bottom knob) is a boost only control. As the boost is added, the frequency band gets lower and lower. To give a reference point, the bass control also has a center detente.
MID LEVEL & FREQUENCY (The knob stack nearest the jack)
BOOST/CUT (+/- 12dB)
The Mid Boost and Cut are controlled by the upper knob. Flat mid frequency is set at the center detente
FREQUENCY (150Hz - 3kHz)
A wide range of frequencies are at hand with the variable control. This is the bottom knob of the stacked set.
ACTIVE PASSIVE SWITCH
The active/passive switch is found near the jack. Push the switch toward the knobs for passive mode, and toward the jack for active mode.
POWER
When a jack is plugged into the bass, the active circuit is engaged. Be sure to remove your instrument cable to not draw power from the bass when not in use.