Hartke 3500A Bass Guitar Amplifier HeadThe Hartke 3500A delivers a winning combination of tone and power that has made it the choice of professional bass players and our best selling bass head.
The 3500A features Hartke’s classic dual preamp design, dual EQs, and a ballsy 350-watt RMS power section (@4 ohms/mono) - this is the centerpiece of the Hartke Professional bass amp lineup.
Front panel controls feature both active and passive quarter-inch inputs, independent tube and solid state preamps each with volume controls for mixing the warm tone of the tube preamp with the clear piano-like tone of the solid state preamp, a super smooth compressor with a clip light and a Threshold control, 10-band graphic EQ with lighted sliders, bass and treble contour controls, and Master Volume control. The rear panel provides a studio-quality XLR balanced direct out (with ground lift and pre/post EQ switch), and an effects loop with Blend control.
Hardly changed in 10 years, the 3500A was given a new look with a new face plate and a vintage-style wooden cabinet.
Hartke 3500A Features
- Power to spare The 3500A delivers 350 watts to a 4 ohm speaker or 240 watts to a 8 ohm speaker.
- Hartke's unique Transient Attack circuitry ensures that every nuance of your bass performance is reproduced faithfully.
- Two Pre-Amp input knobs, allowing custom blending of tube and solid state sounds.
- Ten bands of high-quality graphic equalization, allowing you to create a broad range of tonal colors for your bass instrument. A dedicated in/out button allows you to preset an equalization curve.
- Two fully adjustable contour knobs (high pass and low pass), which provide further control over shaping your bass sound.
- A built-in compressor which not only adds real punch to your bass sound, but also allows you to smooth out volume differences between notes.
- Two independent inputs that accommodate both passive and active bass guitars.
- Protection relay circuitry that protects connected speakers from dangerous overloading and also prevents thumps when powering on or off.
- Effect loop send and return jacks that allow you to connect to professional outboard effects processors.
- An effect Balance knob which enables you to adjust the relative amount of Send (dry) versus Return (wet) effect signal being routed to the speaker outputs.
- Electronically balanced direct output that provides a means of routing signal to professional mixing consoles in both live performance and recording environments. A ground lift switch helps prevent hum or buzz from entering the signal, and a pre/post switch allows the direct signal to be derived either before or after the amp EQ section.
- LEDs that show you the settings of the graphic equalizer in low-light environments as well as a two-color LED that continuously shows the status of the compression circuitry in response to your playing.
- Rugged construction makes the Model 3500A eminently road-worthy.
Designed with more control in mind
The Hartke 3500A Bass Amplifier gives you enormous control over shaping the sound of your bass, using a process called equalization. To understand how this works, it’s important to know that every naturally occurring sound consists of a broad range of pitches, or frequencies, combined together in a unique way. This blend is what gives every sound its distinctive tonal color. EQ controls allow you to alter a sound by boosting or attenuating specific frequency areas—they operate much like the bass and treble controls on your hi-fi amp, but with much greater precision. The Model 3500A provides you with two different means for equalizing your bass sound:
- Low Pass and High Pass Contour controls provide 18 dB of cut or boost in two broad frequency bands.
- A Graphic Equalizer provides 15 dB of cut or boost in ten narrow frequency bands.
Normally, you will adjust the two Contour controls before fine-tuning your EQ with the Graphic Equalizer. The Low Pass Contour control affects a broad band of frequencies with 100 Hz as the center point; similarly, the High Pass Contour control affects a broad band of frequencies with 10 kHz as the center point. When either is in its center detented position (“0”), it is having no effect. When it is moved right of center, the particular frequency area is being boosted; when it is moved left of center, the frequency area is being cut (attenuated). Because there is very little bass guitar energy at 10 kHz, the High Pass Contour control should be thought of as your overall noise control - turning it down (to the left of the “0” position) will help to eradicate hiss and buzz while having very little effect on the bass guitar signal. Similarly, the Low Pass Contour control, when set left of 0, can be used to eliminate rumble and woofiness.
The ten-band graphic equalizer provides ten sliders, each corresponding to a single narrow frequency band (at 30 Hz, 64 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz, 5 kHz, and 8 kHz). This allows you to “draw” the desired tonal response of your system. When a slider is in its center detented position (“0”), it is having no effect. When it is moved above center (towards “+15”), the particular frequency area is being boosted; when it is moved below center (towards “-15”), the frequency area is being attenuated. Hartke carefully selected these frequency areas because they have maximum impact on bass signals. For example, the lowest slider (30 Hz) affects the very lowest audible frequencies (in fact, most humans cannot hear below 20 Hz), while the highest four sliders (2, 3, 5, and 8 kHz) affects the twang of a bass string.