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Quick Overview

The J-RETRO 01 is designed to fit directly into standard "Jazz" style basses without modification, including a PP3 battery, in most cases. Its high quality circuit uses three stacked knobs and includes an active blend circuit plus a 3 band equaliser with bass, variable frequency mid, treble and bright function.

Installation & Operation

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J-RETRO Top View

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The J-RETRO 01 is designed to fit directly into standard "Jazz" style basses without modification, including a PP3 battery, in most cases. Its high quality circuit uses three stacked knobs and includes an active blend circuit plus a 3 band equaliser with bass, variable frequency mid, treble and bright function.

A very gentle built in contour gives immediate colour without detracting from the basic sound of any bass.

The active blend circuit prevents the loss associated with many passive basses where, when both pickups are up full, the signal from one pickup feeds into the other and vice versa.

However, a switch is included to allow a passive equal mix of both pickups. A second switch - basic "get-you-out-of-trouble" passive mode is included in case the battery dies in crucial circumstances, and this mode allows some useful settings too.



HARDWARE OPTIONS: Chrome, Black or Gold. (Can be mixed by special request)



There are two versions of the J-Retro, the original with a slight low and high end pre-shaper boost built in. And by consistent requests, a flat response unit, where when the controls are set in their most neutral setting, there will be no coloration, or difference in response, when switching between active and passive. The standard pre-shape unit gives a slight lift and fatness with a slightly brighter top end, whereas the flat response type retains the original sound, except that the pickups are buffered by the preamplifier of course.

Some players go for more of a bridge pickup mid rangy sound, so the flat response is a better starting point. Otherwise, they have to dial out the pre-shape to some extent. Some prefer a fatter fuller sound in which case the pre-shape gives a head start. The pre-shape isn’t exactly dramatic in any case, with just a few dBs gentle boost at the low and high end. So you can get either style of sound from both but depends where you want to start from. They are just slightly different starting points.

J-Retro 01 YouTube Demo


John gives a complete walkthrough on how to install a J-Style preamp.


What they say!

*  I know you took a little shine to my Squier Vintage Modifed Jazz 5 string when I popped down for you to install the JE Preamp so I thought I’d send you a pic if he finished article. Including a Peter Allen pro set up the whole thing cost me around £900 and I don’t think the fender custom shop could better it whatever I spent there - my dream bass. The bass + J Retro + Seymour Duncan pickups Plus high mass bridge (black). Martin - UK

*  I was so pleased with the new preamp (Marcus Retro). Thanks a lot. Hauke - Switzerland

*  I wanted to take a brief moment to thank you for creating a high quality product that delivers what it promises. I recently upgraded my Fender American Jazz V with some Nordstrand pickups and one of your J-Retro preamps. I am absolutely blown away at how good it sounds with only very minimal settings. The sweepable mids are absolutely amazing. The pickups sound great passive if I choose to use my external preamp, but honestly there is no need. I have everything on my board shut off other than the compressor and the tone is just wonderful. The only change I’d make is a three way toggle for active/neck/bridge pickups. Fantastic stuff!! Thanks! Chad - USA

*  I just want to say a big thank you. I haven't done or left a feedback in a while but I felt I'd oblige to. My Jazz bass has never sounded so good or better, It's a 10yr old American Standard Jazz bass, the bass itself opened up really well and resonates deeply through my body, every single notes just ring. I never thought how much improvement your preamp would add, I just can't believe the possibilities now. Every detail, parts on the pre amp speaks quality. Not only the sounds are amazing, they're all practical in a sense, they're all usable, particularly in Live settings. (My Fellow Bass Players) just wondered around me after the GiG last night and the sound man was very excited and asked me to use the bass in a recording setting. Once again, I cannot thank you enough. Jay - USA

*  I used my old Tokai Jazz bass now fitted with your active electronics for the first time in anger yesterday. Very pleased with the results. It’s like having a new bass, with lots and lots of new sounds in it. Most impressed. FYI the unit didn’t exactly fit first time. I had to sharpen up a chisel and cut a little wood away from the bottom edge of the cavity to allow room for the two toggle switches. Even then I could only get two of the plate mounting holes to line up with the original screw holes, but the original plate was much the same so I guess Tokai are to blame for that. I’m well chuffed now. Brian - UK

*  It arrived about 12 and I installed it after lunch. Thanks for such prompt service. Your retro pre-amp gives an amazing range of tones for me to play with, like having a totally different bass, but still a Jazz.  Can't wait to see how it sounds in the band mix in a couple of days. All the best!  Tony - UK

*  I’ve purchased one of your J-Retro 01 preamps for my fretless ’98 Mexi Jazz, and installed with no problems.  I’m using Lindy Fralin split-coil pickups, with a 5% overwound bridge pickup. Oh my…I think this just became my favorite bass! Those Fralin pickups have all sorts of growly tones buried in there, and the preamp brings them out VERY nicely.  Scott

*  I got my bass back today from Feline Guitars, with the new Pre-amp fitted. What can I say? I love it and It's made an amazing difference to the sound. Many thanks for a great piece of kit!!  Regards Roy - UK

*  Hello John, The J-Retro already arrived today and I just popped it in my bass within a few minutes. It sounds great. At first I thought it was putting its own very big EQ curve on the sound when set to neutral but then I figured out the notch on the bass knob is meaningless because its boost only, which is perfect. A little bass boost is all I want most of the time. The black knobs look perfect. Thank you John.  Paul - Canada

*  The J-Retro transformed my Geddy Lee Jazz and the pickups were well balanced. They really are great preamps. My home made bass which uses a status graphite jazz neck, seymour duncan p/j and a badass bridge is absolutely perfect and your circuit / bass beats the pants off a few high level instruments I've had! Thanks very much. Vin - UK

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