Nobsound&Acirc; 6J1 HiFi stereo tube Pre-AMP Valve Power Audio Preamplifier with Power Adapter for CD/MP3 player, Model: GFB604, Electronics & Accessories Store Mini size:L108*W75*H50(mm), It's a very cool preamp and with warm sound output perfact for listen person singing this is normal preamp only.you can not direct connect it to your speaker or headphone.need connect Volume knob with volume and Turn ON/OFF function Best for your desktop headphone amplifier or home power amplifier, make the sound more warm. (This