Uni-Pre 4 Knob
2 Pickup, 4-knob
- Volume/Blend Stack
- Treble/Bass Stack
- Midrange/Midrange Freq. Stack
- Passive Tone (Push/Pull for Active/Passive)
The Uni-Pre 4 Knob is a new generation bass preamp system from East UK.
It's a brand new design that sets new standards with unique features, designed to fit virtually any bass which has 3 knobs with rear cavity electronics.
It also requires a toggle for active/passive switching.
Its main components are a Volume/Blend module and EQ.
The Volume/Blend has totally independent dual active and passive signal paths, controlled simultaneously with a conventional knob set.
The EQ module allows internal voicing adjustment for the treble as well as the lower and upper bass frequencies.
This is in order to allow finely tuned focus on the most crucial bass spectrum.
Modular construction makes for easy installation, with simple plug connections between modules.
External wiring, such as pickups and power, are simply connected using screw terminals.
The potentiometers have 10.0mm threaded bushings designed for rear cavity mounting in the bass. Flat wire connections to the potentiometers and toggle switch allow for a flexible layout.
The preamp comes fully wired including battery clip and Switchcraft jack.
For ease of installation, pickups are connected via screw terminals.
A ground wire will need to be connected to grounding points such as the bridge and any internal shielding.
Out of the box, just connect the pickups using the screw terminals, snap in a battery, and you'll get sound.
John East Uni-Pre does it all!
By Curtis from on 1/24/2017
Sound guys don't complain (and thats rare), other band members compliment (rare too) and all goes well (which makes the listeners happy).
Kudos to John East for looking after the bottom end!
John East Uni-Pre : Homerun from across the pond!
By Alex Mouroulis from on 11/2/2016
Worth every penny!
By Keith F. Kelly from on 7/20/2016
By the mauler from on 2/9/2016
This unit sounds clean, quiet, and it's operation is very smooth. It gives the bass an exciting tone and sparkle without changing the overall tone and feel of the bass much.
The EQ is voiced where I like it. I love the bass control's restraint. It gets big big big, but doesn't overpower the other frequencies or the tone of the bass itself. The bright pull is voiced ideally for that top sizzle without having to crank up all the highs in order to get it. Very slick. The high is high, not high-mid, if you know what I mean. I like that.
I got the mid sweep, too, which is also very quiet, clean, and voiced for pretty much all of our needs. it can pump the low mids for a punchy motown groove or cut the high mids for a contemporary slap sound. Plus, at center, the mid control is neutral. The midsweep is worth getting, in my opinion. Most preamps offer a fixed or switchable mid frequency. This is design offers more flexibility.
A cool feature of this preamp is that you can use the trimpots to gain up or down each pickup individually. This allows you to make the bass hotter, but also to balance the output of each pickup. This is a great feature for my bass, which has mismatched pickup outputs. However, this feature is bypassed in passive mode, which is another reason I'll not use passive mode unless the battery dies.
I usually play passive, but this preamp doesn't really support passive mode. The passive mode works fine (even with no power, if your battery dies!) and sounds good/clean, etc. But the active/passive modes are very different in gain/volume. You can't go from passive to active on the bandstand without a major change in gain. Even with the trimpots at the lowest setting, the active mode is hotter than passive. I'll only use the passive mode when the battery dies.