Hartke HA2500

The Hartke HA2500 is an amplifier that is ideal for performances at small or medium-sized events or, of course, for playing in the rehearsal room. It delivers up to 250 W into a 4 ohm load, and can produce up to 180 W into 8 ohms. It is designed so that you will find two preamps in front of the transistor end, one pure transistor and one with circuitry that simulates the sound of tube amplifiers.

In terms of construction, the HA is designed very clearly and simply. On the front panel, on the far left, there are two inputs, one for active, the other for passive instruments. Behind them are two potentiometers that affect the gain for preamp A and preamp B. A is a preamp with tube sound emulation, B is a classic transistor preamp. These controls are followed by the built-in compressor potentiometer, where you can change the compression level or turn it off completely.

The rest of the controls, except of course the Master Volume on the far right, are for adjusting tone parameters. Here you'll find a 10-band graphic equaliser, with which you can vary the volume by +/- 15 dB at frequencies of 30, 64, 125, 250, 500, 1000, 2000, 3000, 5000 and 8000 Hz. Together with the Contour High-Pass and Contour Low-Pass, whose controls are right next to the equalizer, you can adjust the sound to your exact liking. Just to add, these filters allow you to boost or attenuate by 18 dB for bands below 100 Hz and above 10,000 Hz, and the graphic EQ can be switched out of the signal path.

The rear panel is designed in a similarly spare manner, with only the effects loop input and output and, of course, two outputs for connecting to speakers. The load of the connected speakers must be at least 4 ohms.

The Hartke HA2500 is an instrument where the "simplicity is power" approach is clearly a success. On the one hand, it is a simple instrument, but it contains all the necessary features a bassist might need.