Check the listing for details. Positive Grid Spark Combo Amp. Condition: New. Listed at 322.80 USD. 40W Smart Amp with Tone Presets and Practice Features Positive Grid's Spark is a breakthrough new way to jam, track, practice, and learn songs. This powerful app-driven smart amp delivers a bedroom-filling 40 watts of 10,000+ classic BIAS amp/pedal/cab presets through its twin 4-inch ported hi-fi speakers, ready for direct injection into your DAW recording session or live PA via USB or 1/8-inch TRS headphone output. And impressive as that is, it's just scratching the surface of all that Spark can do for you. Voice control via the Spark App gives you Slash-worthy lead tones and solo-ready rock and blues backing tracks without lifting a finger. You can even feed Spark your own chord progressions and listen in amazement as a virtual session drummer and bassist accompany you in real time.