It is not ideal to plug headphones into the "to amp" output but it will work and nothing bad will happen. Many preamps are available with dedicated headphone outputs along with an appropriate volume control.
To test the output of an acoustic guitar preamp you may use output tubes to test. This will test the preamp voltage.
There could be several reasons why your acoustic guitar preamp is not working, such as a dead battery, loose connections, or a faulty preamp unit.
A guitar preamp is basically a guitar amplifier, but without the power amplifier section that drives the speaker. A typical guitar amplifier consists of two components: the preamp and the power amp. The preamp is responsible for generating most of the characteristics of the guitar tone. The power amp receives the output signal from the preamp, then raises it's level enough to drive a speaker so the guitar becomes audible. Physically, a guitar preamp can be an independent rack-mountable unit, a digital device (such as a Line6 POD), a floor pedal, or even circuitry inside the guitar itself.
I would not advise this, because of the difference of impedence.
To hook up a bass preamp to your bass guitar amp, first connect the output of your bass guitar to the input of the preamp using a standard instrument cable. Then, take another cable and connect the output of the preamp to the input of your bass amp. Make sure to set the gain and EQ settings on the preamp to your preference before powering on your amp. Finally, adjust the amp’s volume and tone settings to blend well with the preamp output.
A guitar preamp helps in amplifying the original sound produced from a guitar. One should look for sound quality, output voltage, as well as input sensitivity. All these can affect how the sound will be amplified.
A preamp A preamp.
The Fishman guitar preamp enhances the sound of acoustic guitars by providing features like tone shaping controls, feedback suppression, and onboard tuners. Its benefits include improved sound quality, easier live performances, and the ability to customize your guitar's tone.
An amp head is a component of a guitar amplifier that contains the power and preamp sections. It is used to amplify the signal from an electric guitar or other musical instrument before sending it to the speaker cabinet for sound output.
Using a Fishman preamp with an acoustic guitar can enhance the sound quality by providing better control over the tone and volume. It can also help reduce feedback and make it easier to connect to amplifiers or sound systems for performances.
sonicore is a coaxial undersaddle pick up sistem from Fishman trademark, Classic 4 is the related on board pre-amp system. It was a useful on board preamp system used by Fender and other guitar brands.
If you plug your headphones directly into your guitar you won't hear anything unless your headphone have some kind of amplifier built into them. You need to plug your guitar into something like a multi effects pedal or an amplifier that has an out put you can plug your headphones into