lundgaard.amps - technical stuff.

Power amplifier classes:

Class A/B amplifiers sound great, but need cooling, and are heavy. Class D amplifiers provide supreme sound quality, small weight and size, run cool and use very little energy. lundgaard.amps use class D modules supplied by IcePower. These modules represent the most sophisticated amplifier technology available. They comply to all international standards, regarding safety, radiation and environment.

Lundgaard.amps offers 3 different power levels: For bass and other power demanding instruments like a jazz guitar, choose the 550 or minimum 300 watt version. For PA and instruments in the higher frequency regions, choose 300 or 220 watt versions. For international touring, without any voltage switching problem, choose the 300 watt version.

Preamplifier topology:

Preamplifiers can be made in many different ways. Tubes are popular among guitar players, giving audio qualities that relate very well to the electric guitar. But they have problems, like stability and heat issues.

lundgaard.amps use the best audio opamps available. Burr Brown opamps provide the warm clean sound musicians like, and they are extremely stable under all conditions.

Microphone input:

A high quality transformer is the first stage in the microphone pre -amplifier. It gives a warm, natural amplification of the microphone signal. This device is combined with a Burr Brown audio - op amp, and together they produce a sound quality comparable to high end studio gear.

Phantom power can be fed to the XLR/Jack compo socket in order to power condenser microphones.

Equalizer section:

The equalizer section is based on the Baxandall topology invented in the fifties. This circuit cuts and boosts the frequency areas in a very natural way.

lundgaard.amps chose a 4 band equalizer, since it gives a lot of possibilities, without the complications of the parametric equalizer. A low cut filter is also provided to give even more tonal flexibility.

Phase switch:

Instruments like the double bass, are sensitive to your playing position related to the loudspeaker. Its a matter of wavelengths and perhaps you will be located in a spot that results in sound problems. Often the reversal of signal polarity or phase will solve the problem.

lundgaard.amps provide a phase switch on both channels. This is a great tool for making your double bass sound tight, and for removing feedback. Any acoustic instrument benefit from this feature.

Effects unit:

The 24 Bit effects unit provides 16 different reverbs, delays and modulated effects. The sound quality is very good thanks to the high bit rate and the specialized circuit. The chosen effect can be mixed between channel A and B. On the single channel version it can be mixed with an outboard effect. A footswitch socket lets you activate or deactivate the effect. Footswitch cable must always be screened.

Line drivers:

A good line driver is a must in a serious instrument amplifier. You need it on stage and in the studio. Often there is a need to get separate signals from every channel.

lundgaard.amps feature separate balanced linedrivers sending direct from channel A and B plus a balanced linedriver sending the mixed signal with effects. Mixed linedriver features ground lift switch.

Voltage switch:

The touring musician need the amplifier to work on all voltages.

lundgaard.amps  provide a voltage switch with 115/230 positions. However the amplifiers will work between 85 and 250 volt AC. The 300 watt version switches automatically between 115/230 volts.

Important: The voltage switch must be set in the correct position, or the amplifier can be destroyed, and the warranty will be void!!


The unbalanced lineout also acts as a headphone output where the gain control determines the volume. The output is unaffected by the master volume control. Turn down the master control for silent listening.

Effects send return:

All lundgaard.amps provide an effects send & return that allows outboard effects to be attached.


A tuning device can be attached to the effect send socket.

Mute and channel mute:

The channel mute enables switching between instruments. In the middle position both channels are active. The mute switch cuts everything coming out of the amplifier except the signals from the direct line drivers and the signal from the send socket.

Aux input:

Input for any external signal, like a mixer, MP3 player or a keyboard. The level is only affected by the master control.

Speaker sockets:

The loudspeaker connection is established via the Neutrik combo speakon socket. It allows both jack and speakon plugs to be used.

Important: Never connect a total speaker impedance below 4 ohms, and never short circuit the terminals to ground!!!


The speaker cabinets are made from lightweight plywood. The color can be dyed to many different finishes, but will normally be like ebony with a silky surface. The boxes are assembled with dowels, and 140 dowels are used in the biggest cabinet. The parts are glued and pressed together with a 2 ton pressure force, and the result is a very strong, light and beautiful cabinet.


The loudspeakers are supplied by Italian SICA. SICA are specialists in neodymium drivers. Using neodymium magnets, heat resistant voice coils and super strong cones results in 250/500 watt loudspeakers weighing under 2 kilos.


Output: choise between 220, 300 or 550 watts RMS in 4 Ohms.

Input impedance:

Instrument, 3,3 Mohms.

Microphone, 200 ohms.

Dimensions and weight:

Heads: W/H/D: 28x7x20 cms. 1,8 kilos.

Double Combos: W/H/D: 32x30x25 / 32x37x25 cms 7,5 8,5 kilos.       Compact Combos: W/H/D: 32x27x25/32x35x25 cm's 6,1 - 8,1 kilos.