spa1

The spa1 is the LINNENBERG interpretation of a true high end headphones amplifier.

As all our other products it follows a purist approach to accomplish the highest sound quality. The symmetric amplifying stage operates without feedback, enabling a relaxed, open and detailed acoustic image. Listening to music with headphones can be a real pleasure, but mediocre amplifiers often lead to ear fatigue. The close proximity of the transducer to the ear demands very high quality audio components such as the spa1.

Swiss made ELMA rotary switches are used for volume and gain control. These gold plated contacts guaranty perfect channel and phase balance for years. A special feature is the sliding high pass filter tracking with the selected gain. For the -5dB gain setting you will see a frequency response starting right from 0Hz (DC) while at +20dB the low frequencies are limited to 7Hz removing highly amplified subsonics from the valuable headphones.


	Balanced circuit design ; balanced sound !

Features:

Suitable for all headphones with impedances ranging from 32 … 600 Ohms. The lowest permissible load impedance limit is 8 Ohm; here the spa1 delivers 4W of peak power.

Interchangeable output connector for use with standard 6.3mm jacks. This option is compatible for headphones with single sided cable outlets, where rewiring often is impossible. No symmetric drive possible in this configuration.

Precision volume control with stepped attenuators consisting of ELMA switches and 0.1% resistors for perfect channel and phase balance.

To accommodate with the wide range of load impedances and thus with the wide range of sensitivities a second ELMA switch is build in to control the over all gain of the circuit. Gain select ranges from -5dB, 0dB, +5dB … +20dB.

Zero feedback, discrete voltage amplifier; same topology as in udc1 and cdp3E.

A very high speed linearization loop operating locally around the current buffers enhances the driveability and lowers the output impedance.

High current, high voltage output stage in H-bridge configuration made up of four 1A buffers easily driving the headphones transducers with an output impedance of less then 1 Ohm.

Ultra high bandwidth (up to 1MHz -3dB) enabling a linear frequency and phase response.

Built-in linear regulated 15VA power supply with far better ripple and noise performance than your usual switching-mode cheap wall wart PSU.

Specifications:
Frequency response	5Hz - 1MHz -3dB (gain dependent)
Distortion and noise	<0.01% 10Hz - 20kHz (load dependent)
Channel balance	0.5dB
Gain	-5dB ... +20dB
Output power	3.5W continuous, 32 Ohm, both channels driven
Output level	14V rms max. balanced
Output impedance	1Ohm balanced
Mains voltage	115V, 230V factory set
Dimensions (H x W x D)	55 x 165 x 224 mm