Dear visitor,
the majority of our deliveries are made abroad. Orders are usually shipped the same day. With Corona, however, the times for shipping per country have increased considerably. Many customers view this with great impatience.

We have therefore decided to interrupt sales in December to wait until the situation has eased. Since paypal as payment processor does not want to be able to distinguish between different countries of the buyers, the sale has to pause for all countries - the buy buttons are deactivated.

We wish you a contemplative and healthy christmas time and hope to welcome you again as a customer in January 2021.

Active sub crossover class A

•  active lowpass subfilter
•  balanced mono output
•  decoupled channel summation
•  zero stereo impairment
•  Filter Class A with JFet cascade
•  separate signal (0) and shield mass (S)
•  Level and frequency via switches
•  zero potentiometer, hum, noise
•  sub driver: 100 x 58 mm, high 12 mm
•  sub driver

sub driver

Crossover with supply

•  sub driver - supply: 100 x 100 mm, high 40mm
•  sub driver - supply class A

sub driver

Crossover with supply and trafo

•  sub driver - supply - trafo: 100 x 175mm, high 40mm
•  sub driver - supply class A - trafo

supply pre amp

PCB without components

•  Board without components: 100 x 175 x 1,6 mm
•  Board, heat sink, circuit diagram

supply pre amp

The heat sink is included, all other components are freely available. The board is suitable for transformers of Talema type 70063K (25VA) or 70040K (10VA). Maximum flexibility is provided by separating the corresponding areas. With separation of the active crossover you get e.g. the High-End Class A power supply for preamplifiers.

Musical foundation

The sub driver generates the analog deep bass signal for the subsequent amplification from the stereo input. Correction and pre-filtering are done without gimmicks. The limit frequency, which is designed for a reasonable range, and the level for adaptation to the satellites are set. We do not use inequalities, scattering or inhibiting layers of coal from Pots.

sub driver

Two phase-shifted signals are available at the output. An existing stereo amplifier can be used symmetrically - each stereo channel receives one signal, the speaker is then connected to both "plus poles" L + R. Prerequisite: The stereo power amplifier has no capacitors in the signal at the output. Any mono amplifiers are operated at one of the two outputs if they do not have a balanced XLR input.

supply pre amp

The experimental setup shows the sub driver in a balanced arrangement with two SAC amplifiers. Since the transformer for the output stages (not in the picture) also supplies a reduced auxiliary voltage, the sub driver with Class A power supply was chosen here but without its own transformer. The class A voltages are looped to the side in the sub driver in order to be able to connect further pre-stage components.

SAC amplifiers for the drive of the satellites remove low-frequency loads by changing only one capacitor without additional active crossover.

SAC amplifier