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Last week I had played the first time with a PA. My acoustic guitar Epiphone ej160e using mini acoustic humbucker sounds more like a clean electric guitar, not like an acoustic.

But why? Can someone can give me a hint which setup I should use ( additional Pickup, footswitch...)?

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    Please add some info about the type of pickup the guitar has, the complete signal chain, etc.. – leftaroundabout Aug 23 '17 at 21:03
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So this guitar is quite a unique model, the John Lennon signature. Its pickup is not an acoustic-guitar pickup at all but, well, basically a standard high-impedance humbucker in small format.

It's no big surprise then that it sounds more like an electric guitar: such a pickup, together with the cable capacitance, forms a 2nd order lowpass filter, and that gives the characteristic electric-guitar sound. (Why did you buy such a guitar if you don't want its characteristic sound??)

To get a more acoustic sound, the best option is of course to use a microphone. Unfortunately that brings lots of problems in a live setting. Magnetic pickups actually remain the best in terms of feedback robustness etc.. They can also give a decent acoustic sound, but it's crucial that you avoid the resonant lowpass-filter effect. Properly designed modern acoustic PUs achieve this through a low-impedance spec, i.e. the coil uses thicker wire with fewer windings, which leads too a much smaller inductance. Unfortunately it also makes the signal voltage much weaker, but that can actually be compensated easily with a preamp.

If you want to keep the PU as it is in the guitar, there's another parameter you can change to keep the filter in check: you can lower the capacitance. It's mostly the cable that's responsible for this, so you want a decoupling circuit right after the pickup. This can be a very simple buffer:

Simple impedance decoupling circuit (created with CircuitLab)

After that, the frequency response should be much clearer.

Of course make sure you don't use an electric-guitar amp but an acoustic amp or go straight into the PA via a DI, best an acoustic-optimised one like a Radial Tonebone or LRBaggs ParaDI. But with the active circuit in your guitar, a cheap passive DI like the Palmer PAN01 should also be fine.

  • Wow, thank you for your very technical and detailed reply. I'm impressed! But back to your answer. That mean I have to solder the circuite based on your draft. Plug my guitar to the filter, the output to the acoustic-optimiser, those output to the passiv DI box and this output into the PA. You mark the Output in your draft, means that, ouput --> + and ground keeps ground at the conection wire. Is this correct? – michael-mammut Aug 26 '17 at 15:23
  • Yes, ground needs to be connected to everything that's currently ground. — I didn't include the volume / tone pots in the circuit; I suppose you want to use these too. You can re-wire the tone pot to a simple 1st order lowpass, and put the volume pot after it. Also keep the usual stuff in mind: a ≈10μF electrolytic capacitor parallel with the battery for smoothing, some way of disconnecting the battery (best with a stereo jack, so disconnecting the cable automatically disconnects the battery), and some protective resistor before the output. – leftaroundabout Aug 26 '17 at 15:37
  • Well, so much great information. It's great! Does you have a book recommendation about this topic. It is easier to me to read a circuite than a technical explaination. But I try to see what your meaning :) – michael-mammut Aug 26 '17 at 15:48
  • amazon.de/Elektrogitarren-Technik-Sound-Helmuth-Lemme/dp/…. (He actually has basically the same circuit on page 203.) – leftaroundabout Aug 26 '17 at 15:57
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The amplified sound comes from the humbucker pickup positioned between the sound hole and the end of the fretboard. Your guitar has steel strings and the pickup behaves exactly the same as the pickup in a solid-body guitar - which explains why the amplified sound is that of a solid body electric.

To get the acoustic sound you'll need to experiment with an acoustic microphone pointing at the sound hole on your guitar.

  • Thank you for your repyl, some people means, that there will be some problems with feedback, but I also strongly belive that this should be a good technique. Some means also to put a aditional piezo Pickup. So you have experiance about it? – michael-mammut Aug 24 '17 at 19:14
  • Frequently a pickup like a piezo will be used along with a microphone so the two signals can be filtered and mixed together for the "best of both worlds" - the electric pickup reproduces clean attacks and the microphone captures the characteristic resonant sound of an acoustic guitar. – Darren Ringer Sep 7 '17 at 20:32
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If you have plugged straight into the PA and not via a DI box that could account for your different sound. A cheap passive DI (and an XLR-XLR cable) is a good thing to carry around with your guitar gear.

  • The output from the pickup on your electric acoustic guitar is not optimised for the inputs on a PA. The DI unit matches up the impedances. en.wikipedia.org/wiki/DI_unit . just buy the cheapest passive DI unit you can find. They don't need batteries or power, but you will need an XLR (microphone) lead to connect to the PA input as well as a guitar lead to connect your guitar to the DI. – Areel Xocha Aug 25 '17 at 10:19
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I have never found a true accousic sound with humbuckets. Single coil pickups like fender is the only way I have gottin a true accousic sound

  • No magnetic pickups give a true acoustic sound. A microphone is really your only option. A piezoelectric pickup is closest if you must use a pickup. – Doktor Mayhem Aug 27 '17 at 16:47

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