> 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."
On the other hand, plug a Heil ProSet with its 200 Ohm elements into an unmodified K3 and the -3dB point is 80 Hz ... low enough for communications use without being overly sensitive to hum and other low frequency noise, Similarly, with 8 Ohm speakers, the -3 dB point is 40 Hz with the 470 uF coupling capacitors in the speaker amp. 73, ... Joe, W4TV > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Paul > Christensen > Sent: Monday, April 06, 2009 6:54 AM > To: [email protected] > 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
