Honey I ACG-ed The Ibanez

[cytania]

The Subject: Ibanez SRX400

The Mod: ACG EQ02 preamp 3K/S

The Problem: Nice bass, lightweight contoured body, slim neck that's just the getting worn in but nasal, false, snidey tone. Ibanez use 'phat eq' a single tone knob lo-mids boost. Adds big balls but now I've gotten used to playing bass it seems artificial with a shimmery/shuddering quality, particularly when compression is used.

Price £180 (but hey you could pay that for a pedal that just makes things worse).

Tools Required: allen key, spanner, philips screwdriver, watchmaker's screwdriver, bib wire stripper and cutter, successive drill bits to 8mm, wet/dry paper, dowel.

Installation: the Ibanez SRX400 has a precision style big scratchplate. Before I even ordered the preamp I checked underneath and mercifully found a big cavity. ACG send a battery clip and jack but since the Ibanez already has a battery compartment and a decent jack I didn't use these. Next I cut out the removed the vol and phat-eq carefully clipping the wires close-in and stripping 3-4mm of wire. Then it's poke them in the hole and screw down. Takes a steady hand. The tone stack pots connect with ribbon cables that terminate in prongs. Again care is needed to gently insert these into the connector without bending a prong.

Once wired up I checked all was working without the scratchplate. Make sure the volume is up. All very good. I used pritt sticky pads to secure the board to the bottom cavity back. The board is coated with a thick insulative layer. Several stuck together hold it firm, but I'm working with gravity placing it where it would come to rest anyway.

The next stage was to add a hole to the scratchplate. I specificly went for the 3 knob version as I could see the passive tone knob would be a squeeze. As it was Ibanez left quite a space between their two controls so I drilled a third hole halfway between the originals. Start with small drill bits and work up. Larger drill bits may leave a slightly ragged hole so wet/dry paper on a 6-7mm should be used to finish. The filter stack knobs are slightly larger than 8mm whereas the volume pot fit straight in. So I gently whittled the holes fractionally larger with wet/dry paper constantly checking with the pot thread. At last they both fit through.

At this point look to see if the ribbon threads are naturally folding into the cavity. Try not the fold or crease them too much. Flex them to where they should go around the other components and wires. Start securing them to the scratchplate with nut and washers. Tighten and again check they are folding away neatly. Check no wires are caught as you finalise the scratchplate. The knobs fasten to the stack shaft with an allen key. Here the trick is to work the shaft anti clockwise and then fix the knob where you'd expect it to be, then work it clockwise and see if everything makes sense visually.

Result: a purer more open sound. Haven't yet really mastered the two filter stacks but I'm thinking of the lower knob as a sweeping spotlight across the strings and the top knob as an enlivener. You can produce some silly settings that are flat, muddy or piercingly bright but I quickly found a magic combination that made this bass more alive than it's every been before. It's like the strings have more bounce and life. A pleasure to play.

Snags: Beware a picture in the instructions of the single pickup versions that is different from what you will receive. A quick email from Alan put me right. The current preamp is one board for all configurations with differing connectors

There is a slight noise when I touch the knobs, suspect I need to improve grounding but it's no biggie.

[GreeneKing]

Welcome to the ACG pre club.

I've a thread somewhere 'wot I wrote' to try to help folk get their head around the filters.

Ere' it is:

[url="http://basschat.co.uk/index.php?showtopic=41878&hl=acg"]http://basschat.co.uk/index.php?showtopic=41878&hl=acg[/url]

I'd love to have the ability to produce a graphic website that showed how these work with an interactive frequency spectrum and sonic output controlled by virtual knobs.