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THE PREAMP – full tube / high voltage bass and guitar preamp


A small classic tube preamp based on a very famous bass preamp (preamp that was inspired by the Fender Dual Showman), with some added features:

– separate gain and volume controls will enable you to enter in the overdrive domain, so you can keep a decent output volume and get that pumped tone.
– high-voltage FET buffer (optional)

The preamp uses an internal SMPS module for the High-Voltage and will need a 12V DC @ 1A wall-wart (provided with the preamp).

The version of the current preamp wi MK1-V2 and comes with the following updated features:

– Input pad (-6db)
– Deep switch
– Bright switch
– High-cut switch
– Output pad 1:10 attenuation

Please note that the color for the new versions is red.

Due to high volume of orders delivery time is between 14 to 20 working days from the order date. Thank you for your understanding.


Available on backorder

SKU: CLN-PRE-12AX7 Category:

5 reviews for THE PREAMP – full tube / high voltage bass and guitar preamp

  1. Mark Avnet

    Mark Avnet
    Really, really great! I ordered a prebuilt box, which was sent out instantly; took a bit of time to get to the US, but arrived well packed and intact. And it sounds amazing. Clean, quiet, tubey – the tone stack is definitely the F2B stack, and the interplay between the gain and volume knobs brings something missing from the Alembic original – easy overdrive that still keeps that warm sound. Between this and a small class D power amp, other than speakers my entire rig fits into my bass gig bag. I’m very happy with this preamp!

  2. Jonathan Chen

    Jonathan Chen
    Dexter built a F2B Preamp “in a box” form me. It has worked amazingly well. For live gigs, I use an original vintage Alembic F2B preamp to get that clean Peter Hook sound for my bass. Now with Dexter’s F2B Preamp stomp box, I am able to create the same sound without having to lug around my rack case. The sound is just as amazing as the original Alembic. Quality of construction is excellent. Highly recommend Dexter. In fact, I’ve asked Dexter to start another project for me — a preamp circuit board for the Yamaha BB1200S bass guitar.

  3. Felix Hubert

    Felix Hubert
    I have one of these and i am really in love!
    I play a Markbass LM3 as a portable amp solution, which is quite okay, but nothing special. The Preamp gives my basstone an intimate note and exactly these overtone frequencies i need to cut trough the mix without getting annoying.
    I do not use the Preamp with a hard scoop, like Fender Tone Stack suggested (like it would be when all knobs are at 12am), i turn the mid knob to the right and the bass and the treble to the left, exactly like on the photo. So i get a wonderful rich tone which is still a killer slap sound, but also a warm blues or fingerfunk sound.
    As a result of these possibilities of sound without calibrating my amp while the gig (the sound comes now only from my fingers), i am less nervous or stressed and focused more to the music!

    The master knob is an absolute necessary feature, the preamp has so much volume at the output. What i really mean is, there is absolutely no problem driving any poweramp.

    Thank you so much Gabriel, for your friendly support but also for your more then fair price. I would always buy it again

  4. Lopez

    My preamp is violent!
    My signal chain is as follows -> Warwick Thumb> Compressor> Dexter> SansampRBI (with BBE-Maximizer in the 50:50 EffectLoop) With the Compressor I turn down the Signal a little bit, then I crank up the Gain from the Dexter-Preamp til the Sound is rich an huge.
    With the Sansamp incl. the Maximizer I creat an very agressive metallic Sound in the High Mids. The Blend in the Sansamp is at about 40% (Main Sound from Dexter) The Dexter-Preamp Setting: Bass/Mids/Treble 40/80/30 Gain: 60 Vol:around 10-20%
    With this I have an huge/fat Sound with an very agressive Top-End.
    I also played the Preamp alone with an very old Single-Coil passive Bass and an Dean Freetless.
    I think the Preamp is very versatile. Super rich Clean-Sound for every Style of Music.
    You can also drive the Tube in a light Overdrive which I like very much.

  5. Harald

    Good Morning,
    It seems, it depends on style and impedance of the build in or stand alone Preamp what would be used in the Signal chain.
    I did also a test using my Mesa Bass Di Preamp. Results were always very good!
    Big difference with on/off bright switch. With bright switch ON, DeX Preamp is working like an enhancer on both settings.
    The preamp is useable everywhere. It could also be integrated in send/Return path of all amps, e.g. to enhance the signal.
    I use DeX unit straigt in SWR power amp and all sound shaping is done by passive tone stack or the active EQ from the instruments.
    DeX’s unit is used to produce sweet mids and add/reduced Bass Levels.
    Did a test with my 77 Ray. Stunnig sound! Using low gain level, bright cap “off”, Mid & Bass pots you can create total sweet pumping sounds.
    Treble boost can be adjusted from activ EQ of the bass.

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