Vox Amplug3 US Silver martin standard Genuine solid German spruce is

Genuine solid German spruce is used for the top while the back

For good pitch and tone

so the SB-1 does not require batteries or external supply to make it work

Plugging into the Phones jack mutes the onboard speakers and Sub Out

High impedance

Vox Amplug3 US Silver martin standard Genuine solid German spruce isamPlug3, the latest generation of the worldwide best selling amPlug headphone amplifiers, is a seamless way for any guitarist to deliver serious sound to their headphones. Practice anywhere, at any time. amPlug3 is the third generation of the amPlug series of convenient plug and play headphone amplifiers for guitarists and bassists. With a wide range of amp flavors, each delivers iconic and instantly recognisable amplifier tones. amPlug3 provides