Current Drive Amplifier (Transconductance)
The speaker's voice coil requires current (not voltage) to provide motive force. The speaker cone displacement is proportional to the current in the voice coil rather than the voltage across the speaker terminals. The current is the primary mover of the voice coil. An amplifier that directly supplies current rather than voltage control has several advantages.
Current drive eliminates several speaker distortion mechanisms inherent with voltage control and speaker non-linearities. Speaker measurements have shown as much as 10dB reduction in distortion above 3KHz, mostly in odd-ordered harmonics. The DML panel speaker was measured comparing the Current Drive amplifier with a high-end Hypex Ncore Class-D amplifier.
Technical Specifications
The speaker's voice coil requires current (not voltage) to provide motive force. The speaker cone displacement is proportional to the current in the voice coil rather than the voltage across the speaker terminals. The current is the primary mover of the voice coil. An amplifier that directly supplies current rather than voltage control has several advantages.
Current drive eliminates several speaker distortion mechanisms inherent with voltage control and speaker non-linearities. Speaker measurements have shown as much as 10dB reduction in distortion above 3KHz, mostly in odd-ordered harmonics. The DML panel speaker was measured comparing the Current Drive amplifier with a high-end Hypex Ncore Class-D amplifier.
Technical Specifications
- Two channels, 25 watts/channel into 8 ohms
- Class A operation and no global feedback
- 24VDC 120 watt external switch mode power supply
- THD @ 1kHz:
@ 25 W: 0.05%
@ 1 W: 0.045%
SNR @ 25 W (up to 20 kHz, unweighted): 90-91 dB