> Perhaps the band noise is more obvious in the K3 because the low frequency > audio is restricted causing the noise to be distributed over a more narrow > range. This lack of bass tends to induce for ear fatigue. > Steve Ellington
I agree with Steve on this one. Once more low-end was rolled into my audio hardware changes, I noticed a significant reduction in my own listener fatigue. Others have noted the K3's audio frequency response variance across different headphone models, most notably the Heil product. The K3's headphone circuit uses 10 uF of series capacitance from the headphone amp to each of the headphone coils. For the moment, assume that your headphones are 32-ohms (ref 100Hz). What is the best possible low-end response from the K3? The answer is 500 Hz @ -3dB. That part of the circuit needs some help. With a headphone Z even lower toward 8-ohms, the attenuation of bass response is worse. Now upgrade the series caps to 330 uF and re-run the calculation. With 32-ohm phones (ref 100 Hz), the frequency response improves to 15 Hz. Now that's t real Hi-Fi on par with what Icom delivers and the difference is immediately noticeable to anyone -- not just the folks with "golden ears." Finally, compare the result of the modified K3 with the Icom '7700 or '7800. Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
