Build your own preamp

[Michiel Wildenberg]

Hi All,

Long time since i've posted on the forum but I have a small dilemma with plans for a new acoustic guitar. I want to build an acoustic guitar with preamp knobs on the top of the guitar, like on an electric guitar. So say 4 knobs (volume, bass, midd and treble), the battery holder will be situated somewhere in the guitarsides. Did any of you ever build your own onboard preamp? is it an easy thing to do? Are there suitable systems already on the market?

Cheers,
Michiel

[Peter Wilcox]

Michiel, there are lots of suitable preamps already on the market, but those that I'm familiar with are mounted in the side of the guitar and have slider controls, rather than hookups that go to rotational pots mounted on top. I have put several of these in my builds, very cheap ones ($10 - $15), and they seem to do a reasonable job. There are certainly more expensive ones on the market. There are even some with both piezo and microphone pickups such as this, which I will be putting in my next one: https://www.amazon.com/dp/B01N77TIYZ/re ... B07HHTNR4L

If you want to build your own, check this thread, especially the last post of a schematic for an op amp circuit. https://www.mimf.com//phpbb/viewtopic.php?f=10&t=5849

[Mark Wybierala]

I built a number of preamps but was never happy with the result. A commercial preamp that I did like was the Artec CLE. I don't know if they still make it or who might be a distributor.

[David King]

I'm pretty sure that the EMG saddles are compatible with their eq systems designed for bass guitar and those use regular minipots you could mount through the top. The low frequency control is probably shelving at a lower frequency than you would want but the treble control shelving frequency can be shifted between 3.5k and 8k and they make a semi-parametric mid control that might be pretty handy on an acoustic. Any system with slider pots could have the pots replaced with same value minipots.

[Brian Evans]

The thing about an acoustic guitar pre-amp, presumably for a peizo pickup, is the modern, good sounding ones are quite sophisticated in their processing of the signal. It's not just a gain amplifier, they process the signal to change the frequency response to make the pickup sound like an actual guitar, just as David King points out. You could buy a kit, but you're probably not going to design a digital eq system, and program it on your own.

[Mark Wybierala]

Unfortunately, I gotta agree with Brian. Newer (in the last 15 years) good quality preamps seem to do a lot more than simply amplify the signal. Kinda like they promote the acoustic flavor via lots of stuff beyond my level of understanding. The $20 premaps on ebay work okay if they're replacing the same generation of preamp but you get what you pay for. I've called Fishman and asked if they can provide a modular internal preamp that the builder can fit as desired and they do not have anything. The older preamps don't sound bad but rather the latest ones can sound so much better. I suppose its a matter of demand. I once started to take apart a manufactured preamp and extend the pots so I could mount them individually but I got distracted... I'm sure it can be done.