The Positive Grid Spark 40 offers rich sound quality and a variety of features. Defective Input Jack Even when connecting a guitar directly to the amp, only a hissing noise is produced. There are no problems with other amps. Also, external audio via Bluetooth works fine. 【High-Quality Sound】 The Positive Grid Spark 40 is a high-quality amplifier perfect for guitar playing. It is equipped with a wealth of controls to achieve a variety of tones. 【Multi-functional Connectivity】 It has input jacks, output jacks, and a headphone jack, allowing connection to various devices. Convenient for practice and recording. Also, it can be used as a regular speaker via Bluetooth. - Brand: Positive Grid - Model Name: Spark 40 - Function: Guitar Amplifier - Accessories: Power cable Please understand that this is a used item before purchasing.