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I tried to recorde myself with my new guitar through the internal passive pickup, and got some serious noise issues. First, when I am recording plainly, the signal is very silent, and when I am applying Effects/Compressor in Audacity to make it louder it becomes very noisy.

I tried an identical setup with my bass guitar, and with it the noise was much lower, so it must be an issue with the guitar.

What can I do to lower the noise? Are there some special thinks to pay attention to when using an passive pickup?

The guitar is an Journey OF660 with an "Proprietary under-bridge transducer pickup system", I am hoping the guitar is not broken as it would be very involved to claim warranty as I ordered it overseas. And according to some youtube videos (like this and some other reviews) the pickup system in general should work fine.

I append a picture of the preamp I am using, with the settings:

enter image description here

  • Is there a battery and volume controls built into the guitar or are you using an external preamp? If the answer to both of those questions is "no" then that's probably the cause. BTW that picture is not what I would normally call a preamp, it's an audio interface with a high impedance 1/4" input but often those inputs are not very good at what they are supposedly good at. Undersaddle piezo pickups generally need dedicated preamps. – Todd Wilcox May 6 '17 at 21:21
  • Okay, thought this interface would be enough, for my mic it works wells. No my guitar has not any batterie or volume controls, just something to plug the cable in. – StefanH May 6 '17 at 21:28
  • Quality of the piëzo aside: I hope you only use it as a supplementary means for recording the guitar, and the mic input is occupied by a decent condenser mic that's the main channel for the guitar? For even the best piëzo recording won't sound as good one with a properly mic'd guitar (provided the room acoustics permit it). – leftaroundabout May 6 '17 at 22:13
  • Seems odd in the picture: Phantom power probably shouldn't be on for most transducer pickups. Is there a reason for that? Also, try setting the mic/line : guitar switch to mic/line. It's a slightly different signal strength, and sometimes that works better on acoustic pickups. P.S. You can get great sound with an under saddle/piezo pickup; don't believe the hype. I know professionals who use them to record. Practicing is more important. – dogoncouch May 7 '17 at 4:09
  • @dogoncouch: Yes, as I was also recording with my mic which is connected through XLR, and it needed Phantom power. According to the manual "[...] 48V phantom power supplied to the MIC IN jacks [...]", so the LINE IN should not receive any power, but suprisingly if I switch off the phantom power the noise lever for the pickup indeed reduces, strange or??? – StefanH May 7 '17 at 23:10
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Nice guitar! I looked up the specs on the manufacturer's website and they suggest it is in fact a "passive" under saddle pickup which means the pickup does not have "active electronics" or a built in pre-amp and therefore would not require a battery. I don't believe the problem is in your guitar.

The undersaddle pickup in your guitar is most likely a piezo pickup which would be a high impedance pickup which basically means the signal will have a high resistance and need an extra boost in the chain to get enough volume. Without a pre-amp the amplifier or mixer must supply this extra boost or compensate for the higher impedance in the circuitry.

The Tascam interface you pictured does have an input switchable to "guitar" - which is short for - high impedance input from a source such as an electric guitar or bass with passive magnetic pickups or an acoustic guitar with a passive pickup as yours seems to have. This is accomplished on your interface with a switch that can switch the right input from "mic/line" to "guitar".

Theoretically an interface or mixer with a "guitar" level input or "Hi-Z" input should allow you to input the signal from your passive pickup with good results. Checking some on-line reviews of the Tascam you are using suggests that other users have experienced noise and electrical interference issues with that interface similar to what you have described. So the issue may be in the Tascam itself.

The better results you have with your bass might reflect the difference between the way the signal is processed and output from a passive magnetic pickup (typical on most electric guitars and electric bass guitars) which is quite different than from a passive Piezo pickup which your acoustic guitar likely has.

Your guitar connected to the right mixer and amplification system (PA or acoustic amp) may not require a standalone Piezo Pre-amp. But you may benefit tremendously in most applications (particularly recording) by using what is known as a DI Box (which is abbreviation for Direct Injection or Direct Input) also referred to as simply a "Direct Box". I recommend that you try one that is made specifically for acoustic guitars.

Besides acting as a pre-amp for your passive pickup - The most important thing a Direct Box will do is convert the unbalanced signal (subject to the noise you are experiencing) to a balanced signal that will cancel out or otherwise eliminate much of the electronic noise in the signal chain. The output from the DI Box will plug into a balanced XLR input on your interface.

Since your guitar has a passive pickup you will most likely want to use an active Direct Box made specifically for acoustic guitars. See picture below of one example. An active DI (a/k/a Direct Box) will act as a pre-amp for your passive pickup as well as balance the signal from the guitar pickup so that noise is eliminated. Most will also give you other controls such as volume and EQ.

A pre-amp alone would boost the input signal and give you more volume, but would not solve the noise issues resulting from the unbalanced signal (and might even amplify them). What you need is an active direct box which will act as a pre-amp but will also create a balanced signal between pickup and recording interface so that the noise should be abated dramatically if not eliminated altogether.

enter image description here

Pictured above is the LR Baggs Para Acoustic DI Also check out the LR Baggs Venue

The Radial PZ DI box pictured below is advertised as being optimized for piezo input.

enter image description here

Another acoustic DI with good reviews is the Fishman Aura Spectrum DI.

Good luck with your music and enjoy that fine guitar!

  • Good, practical answer. The Para-Acoustic DI is definitely a great tool for getting acoustic instruments live to the PA; it has long been my preamp of choice. But José David is quite right that it's a bit ridiculous to spend hundreds of $$ on piëzo preamps, since all that would be needed to drive any old low-Z mic input (with 48V phantom) is a single, good-quality jFET transistor. I wish all the PU manufacturers built one (for, like, 3€) into their products. Unfortunately, these brands all make their own seperate preamps, which are probably just too good a source of revenue. – leftaroundabout May 7 '17 at 10:55
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I don't know this instrument, but a passive transducer "suitable for any PA system" is hard to believe. An under the sadle pickup is most likely a piezo pickup (unless there's some technology inovation I'm not aware of, but the manufacturer web site does not mention any). If it is a piezo pickup it requires a very high impedance preamp input, not normally found in most "normal" equipments (mixers, etc.) Without a very high impedance input results can vary a lot, depending on circumstances and requirements , from passable to very bad. A loss of low frequencies (thanks @leftaroundabout for correcting my mistake) will almost for sure happen. Noise is also very likely, as you will need to put your preamp gain very high to have a minimum of signal level, and that will bring up the noise level of most preamps (but the very high-end ones). Distortion by the preamp may also occur.

A good branded piezo preamp is (for some reason I fail to understand) quite expensive (100 to 200 euros), but that would be the recommended solution if you can afford it.

As a cheaper alternative you can buy a Chinese piezo kit for guitars for less then 20€ and canibalize the preamp. It's not pretty and the sound quality will not be that good, anyway, but it will put the signal at an appropriate level and will help match the input impedance of the preamp in the mixer, allowing it to work to its best.

Edit: You'll need to adapt the input jack, but other than that it should work seamlessly. You can leave the preamp lying on the floor beside you or use putty to attach it to the back, or wrap the cable around the guitar strap, or some other solution that suits you as best as possible. As I said, not pretty, but should work.

  • Thanks for the good answer, could you also please suggest some good branded piezo preamps? I guess you do not mean something like this: amazon.com/Pickup-Pre-Amp-Acoustic-Guitars-EQ-7545R/dp/… I do not plan to cut something out of my guitar to install such a thing.... – StefanH May 6 '17 at 21:08
  • Spot on. However: plugging a piëzo into a preamp with insufficiently high impedance actually leads to a loss of low frequencies, not high frequencies (because the piëzo has a capacitive impedance, not an inductive one like magnetic pickups). – leftaroundabout May 6 '17 at 21:59
  • Also: the US144mkii guitar input has an impedance of 1 MΩ. That's not a lot for a piëzo preamp, but it should be enough for acceptable result with a properly-working piëzo PU. – leftaroundabout May 6 '17 at 22:07
  • @leftaroundabout you're right of course, thanks for the correction. – José David May 6 '17 at 22:23
  • @leftaroundabout As stated in the answer I just posted, it is possible the Tascam Interface used is not optimized for piezo so much as it is for a magnetic pickup. – Rockin Cowboy May 6 '17 at 23:07

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