Paul I can see how this mod would improve headphone audio but what about low frequency audio for the speaker(s)? Steve Ellington n...@carolina.rr.com ----- Original Message ----- From: "Paul Christensen" <w...@arrl.net> To: <elecraft@mailman.qth.net> Sent: Monday, April 06, 2009 6:54 AM Subject: Re: [Elecraft] My K3's hissy and noisy audio
>> 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 ______________________________________________________________ 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
