Intended for electric bass, the HD150 from Hartke is a combo amplifier capable of delivering 150W RMS. Its 1x15" cabinet houses a 15" HyDrive paper and aluminum cone driver and a 1" tweeter to boot. After connecting your instrument to its 1/4" jack, you can manipulate the signal with bass, midrange, and treble controls, as well as a 7-band graphic EQ which lets you dive deeper into specific frequencies. 
 
The amplifier gives you 1/4" I/Os for looping outboard gear into your signal, as well as a headphone output, the use of which mutes the amplifier, and thus, enables you to practice silently through headphones. A 1/8" line-level input allows you to plug in CD players, MP3 players, or any compatible playback device, giving you the opportunity to practice along with a background track of your choice. An XLR DI output will let you route signal to mixers, interfaces, or PAs. Side handles allow you to grip the amplifier for transport, and on-board casters make wheeling the combo around relatively easy to do. This amplifier is suitable for use in rehearsal spaces, practice sessions, and small venues. 
 
The Features
- 1/4" input accommodates a broad range of input levels: use your HD150 with passive or active circuitry bass guitars
- Seven-band graphic equalizer plus bass, mid, and treble controls
- Dedicated 1/8" auxiliary input allows you to hook up a stereo line-level device such as a portable CD or MP3 player for practicing to a playback jack
- 1/4" effects loop to connect to outboard effects processors
- Balanced direct output for routing signal to mixing consoles, interfaces, and PAs
- 1/4" headphone output automatically disconnects the speaker output allowing use as a high-quality practice amplifier
- Built-in limiter protects the speaker and amplifier from overload
- Rugged construction
- Side carry handles and four rolling casters