> It would be really neat if somehow Elecraft could product audiophile audio > in the K3...
The K3 audio chipsets already offer quasi audiophile-grade performance for a single-supply rail device. Taking the performance to the next level almost certainly requires the use of a bi-polar +/- 15 VDC supply to take advantage of really low noise op-amps (or discrete transistors), the ability to use DC servo control, and the use of a high-current temperature-compensated, complimentary-symmetry transistor pair at the output. The result? Super fast slew rates, ultra low noise & distortion, total elimination of audio coupling caps, and low damping factor -- all the elements needed for a true audiophile-grade amplifier. In the alternative, one could simply purchase an audiophile-grade integrated amp and tap the audio at the DAC. In the past, I've done this with '70s vintage Marantz and McIntosh equipment and attained excellent results. Regarding the low-pass filter solution: I would want to critically listen to any active filter before permanently embedding it into a transceiver. With yet another active stage of audio in the path, one problem may be cured while another is introduced -- like phase distortion at the knee of a sharp active filter. Based on Jack Smith's data, I would be more inclined to try a simple 6dB/octave passive circuit, using one R and one C. At 12 kHz, the reduction in grunge would be between 8-10 dB and that may be just enough for other factors to mask the effect of the 12 kHz artifacts. Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
