Basslines STC-2C-BO Blackouts Tone Circuit with Concentric Bass and Treble Knobs

I added this to a fresh install on a bass with passive pickups. The circuit provides much more tonal customization options and will definitely provide an overall change in tone. A few caveats however:1. The wiring on the board can be rather delicate. The wires are very thin and there is not much physical support for them where they attach to the small circuit board so be aware that the solder joints are not impervious to damage as you install.2. Ground circuit on mine had to be altered a bit. I had to add a ground wire to the ground loop on my bass to get rid of a hum/hiss combo coming from it. What I did was simply probe around with one end of a bare ground loop wire until I found the missing piece in the ground circuit which was on the case of the potentiometers that make up the tone circuit. Two seconds later after some soldering, the additional piece of the ground loop quieted things down to a great degree.3. The more treble you add, the more likely you are get to some hiss or noise. This is just a facet of active electronics and while some do things to get rid of this or greatly mitigate it, the circuit with this product is very solid and rather quiet.Overall, I would highly recommend this product for anyone looking to add some more tonal possibilities to an old(er) bass guitar. Very good product and would definitely purchase again.

Installed in a Warwick Rockbass because it wouldn't fit in my Epiphone TBird (the chip was a little too tall). I had to make the hole a bit bigger for the threaded portion but it works well and I would recommend it before jumping head first into more expensive pre-amps.

The only downside of this preamp is that there is no other knob option, like silver or gold plate, but that's easy peasy to fix.I run Fender Custom Shop '60s noisless pickups in my Jazz bass and they sound great, but have a really low output. This was the perfect addition. Now I can dial in all that great tone, give a bit of a boost here and there for picky venues that have bad bass response.I keep my treble switch in the "vintage" position because I do a lot of classic rock and groove kind of music. But if I'm called on to do some Suh-Lap!! or some metal where the punch is needed, man, just hit that little toggle switch and watch your bass become a freaking treble jackhammer!!10/10 recommend for any style of bassist.

The bass n treble controls are PERFECT ... but I also needed a solid boost from my fairly weak pickup, and this really does not provide any overall boost in level ... just boost/cut of highs and lows.

I have these in another bass, and they made a huge tonal difference, opening up a world of availability on my jazz bass. Bridge pickup need a bit of bass boost? It's there. Solo neck pickup, but you want want some more treble up top to accentuate the single-coil sound? Bam. Perfect!Inexpensive, and a great upgrade to your bass' voice. In all fairness, the one I received from this order was returned as it was non-operational. I opted for a refund as (if memory serves), they were out of stock. I still plan on buying another one and upgrading that same bass.

This preamp is awesome

Installed to replace the factory tone control in a Squier VM Bass VI. I replaced the instrument's stock 1Meg volume pot with a CTS 500K audio taper and have great results with it feeding the Duncan circuit. I primarily use this circuit at the center detent/flat setting where it seems to be pretty transparent relative to the original passive configuration. Setting the switch to the lower treble frequency (3.1K) rolls off very similar to the stock tone control (1Meg/.047uF). The bass control when fully counter clockwise also is very similar to the sound of the strangle circuit engaged-so close that I will be using the strangle switch for series/parallel pickup selection. This can be hissy when boosting the treble, but I don't do that as the bass is bright enough. The bass knob boosted adds a fatness the Bass VI cannot do when stock and that really expands the tonal options of this instrument.I really like this circuit, it's well built, sounds good and not very expensive. Just make sure you have a control cavity that is 1" wide and a touch more than 1" deep to accommodate the circuit.