The P-Retro is a retrofit preamp that can be dropped into a Precision Bass with no need for internal routing or modification. Expect Fender to be taking note…


This simple but flexible active preamp has been designed to offer huge tonal variation to one of the most popular bass designs of all time, without the need to permanently modify the instrument itself. It connects using screw terminals, which means the wires don’t even need to be soldered on. Just remove the existing pots and jack socket, follow the instructions, and screw it in. The end result is an active EQ with a mid range boost, combined bass and treble boost, deep and bright functions, a high-quality relay for pure passive bypass, and Class-A FET input stage. The circuit all runs off an internal battery that’s charged using an included power supply/jack lead, with three different pin adapters for use in Europe and the US. You also have the option of installing an LED indicator for battery charge.


The first stacked control knob caters for volume and passive tone. Pulling up on this stack engages the active circuit, which adds 2.5 dB with a flat frequency response. The active stack consists of a boost control with a centre detent. Moving this control clockwise provides mid boost of up to 15 dB. Moving the control anticlockwise boosts the treble and bass, with the outer control setting the frequency bands. The pull switch on the active stack provides deep boost which can be preset internally to one of four frequencies (40, 60, 80 or 100 Hz). With this arrangement you can boost the bass and treble and then rotate the frequency to find exactly what works for you, and then turn down the tone control to get rid of the excess treble. Best of all, if you want the original sound of your P-Bass, you’ve still got it.

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Audio examples by Andrew McKinney.

“These recordings were made with a 1983 JV Squier 62 Reissue Precision Bass that has a Lindy Fralin pickup fitted and approx 1 year old Labella flatwound strings. I plugged straight into my Tascam US122 and recorded in Logic. There is nothing added to the sound (EQ, Compression etc.) The only thing I did was normalise each track to try and keep the volume as consistent as possible. They have also been converted to m4a files, so don’t take the sound as a completely true representation. It should help to give you a rough idea though!”

With the P-Retro installed and in passive mode with the tone up full

Active mode with bass and treble boosted slightly

Active mode with bass and treble boost, deep boost and tone backed off completely