“What an amazing gadget. works perfectly, like a guitar supercharger.”
Suitable for use with Ironstone or other pickup system, this guitar pre-amp / multi overdrive effects PCB is designed for on-board guitar installation. Powered by a standard PP3 9V battery (not supplied) giving between 1000-2000 hours of use, this easy to install pre-amp mounts through a 9mm (approx) diameter body or scratchplate hole.
Easy to install with just some basic soldering skill, these little wonders will protect and enhance your guitar’s tone no matter what pickups you use as well as giving you a range of distortion / drive tones at the turn of a knob. For example, on a Stratocaster style guitar, simply replace one of the tone pots with this rotary switch (using your existing knob) and reconfigure the remaining tone control as a ‘master’ tone – circuit diagram included with each item. The photos include a typical pre-amp installation for a Stratocaster style guitar, using different coloured wires to give an easy reference and with the unit in place of the Neck tone pot (the remaining tone pot is configured to control the Neck and Middle).
Each pre-amp unit is supplied with;
One multi-effects PCB and integrated rotary switch
Full installation diagrams for Stratocaster & LP style guitars and annotated photos
A battery connection clip and harness (Note; PP3 9 volt battery not supplied)
A switched Stereo jack socket to allow the unit to be powered only when a (normal) guitar jack / lead is inserted
All in simple, cost saving protective packaging..
Please note: The price above is the UK total price including standard Royal Mail postage. Non UK customers will be advised of an additional small postal charge during the checkout process.
Note; It is suggested when switching from passive to active modes (first to second switch position), to first turn down the guitar volume. This will eliminate any small switch over noise.
The following sound clips give a sense of the tonal changes stepping through the switch positions. The recordings were made via GarageBand on the ‘Clean Combo’ setting, with tone controls at Bright. No effects are used other than the pre-amp unit. The recording process naturally tends to equalise out some of the gain changes described on the settings above.
Each clip has 4 ‘quarters’ (of 12 bars), moving from Bridge to Middle to neck and back to Bridge Pickups.
And thanks to Robin Thompson for the following YouTube clip, stepping through the pre-amp settings against some well known guitar pieces.
Maybe you like the idea of active electronics in a Strat’ but don’t fancy the idea of burying a battery under the scratchplate?
Well check out this neat solution from Ironstone customer Gus Hunnybun. Using 2 springs for the trem., a PP3 battery fits perfectly in a normal Strat’ trem. cavity. A bit of velcro or double sided tape to hold it in place, and some foam for a tight fit under the back plate, this is easy battery change personified! It just needs the battery clip leads to be extended through the normal access hole, or a larger aperture cut as the photo. Worth investing in a robust pair of steel springs rather than the weaker alloy jobs that are often stock, to ensure the whole set-up process keeps integrity.
Using the Pre-Amp
No matter how great your pickups and guitar are, the effects of electrical loading due to the guitar cable, stomp boxes and amplifiers can be devastating on tone, particularly loss of treble ‘brightness’ (see the ironstone guide to Impedance Matching ). The most effective way of minimising these losses is to use a buffer guitar pre-amp at the point the signal leaves your guitar. Using surface mount technology, that is exactly what the Clean Boost setting is designed for. The difference the Clean Boost setting will make in preserving your guitar’s tone is enough to justify the cost of this device on its own! But there’s more! On top of the bypass and sparkling Clean Boost tones, you also have access to 3 increasing levels of drive / distortion. These range from ‘just breaking up’ blues (i.e single notes are relatively clean, chords and double stops just break) to a full bore Heavy Metal distortion setting with masses of bottom end grunt as well, by way of a solid 70’s classic rock distortion effect. And just like in a good multi-stage amplifier, your guitars volume control effectively becomes the ‘gain’ knob, allowing you even more control of when and how strongly the drive / distortion effects kick in. it really is like having a set of stomp boxes in your guitar!The units built in rotary switch gives 5 modes;
True-bypass; can be used even without a battery connected (or in case of a flat battery) to revert to the normal guitar tone
Clean Boost; A slight gain increase (equivalent to approx 1.5 digits on a Strat volume knob) giving crystal clear tones
Vintage ‘Blues’ style overdrive (equivalent to approx 2 digits on a Strat volume knob)
Classic Rock distortion
Heavy Metal distortion
While the gain steps between each setting are fixed, a small user adjustable pot on the device allows tailoring of the gain of position 2 (relative to the true bypass setting). This is initially factory set, allowing the unit to be used ‘out of the box’, but users can alter the position 2 Clean Boost to be at the same level as the bypass, or with a level of initial boost.
It is suggested when switching from passive to active modes (first to second switch position), to first turn down the guitar volume. This will eliminate any small switch over noise.