This reminds me somethnig. The audio in my K3 sounded much better with noise-canceling phones than with regular headphones. The first one had high amplification and probably high impedance. So the problem may be due to inadequate AF amplifier in K3.
I the AF mod helping much? Ignacy As I recall some of the "sharpness" in the audio can be attributed to the impedance of the headphones used. Low impedance transducers (particularly 8 and 16 Ohms) require the headset amplifier to run harder which brings up not only the broadband noise but results in higher levels of distortion. Use of high sensitivity, high impedance transducers with AF Gain = L should result in considerably lower levels of high frequency noise. 73, ... Joe, W4TV > -----Original Message----- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm > Sent: Sunday, April 05, 2009 7:29 PM > To: ev...@pa2kw.com > Cc: Elecraft@mailman.qth.net > Subject: Re: [Elecraft] K3 audio > > > Evert. > > I have no intention to dispute your observations. It is just > that mine > are different. You are justified in being persistent to find out if > there is a problem with some K3s or if it is a localized problem, or > exactly what, but as far as I can tell, it is not apparent on my K3. > > In my observations, I have concluded that the AGC has a lot > to do with > how the K3 sounds. > I particularly liked the way the K2 AGC response sounded, so > I have used > Jack Smith's charts at > http://www.cliftonlaboratories.com/elecraft_k3_agc_and_s-meter.htm to > modify my AGC parameters to have a response more like the K2 (strong > signals sound stronger, weaker signals weaker). Those > settings made a > great difference to me, and made the audio much smoother. > > Secondly, the AGC improvements with MCU 3.03 (and higher) made an > additional difference. > > Is it possible that the AGC settings make a difference in the > perception > of "hissing audio" that we have been discussing? I don't know the > answer, but provide it as "food for thought". > > 73, > Don W3FPR > > > Evert Bakker (PA2KW) wrote: > > Hi Don, > > > > It is definitely not band-noise what I'm talking about. > > You need a decent signal level (audio strength) to hear it. For me, > > I'm quite sure it has to do with the digitalization. That > sound is far > > from natural and is ADDITIONAL to the normal audio signal. That > > addition sounds sharp, metallic, like these "extreme low > cost" jingle > > bell" sounds in all kind of gifts (sorry for the comparison between > > these two). But it is "next" to the normal signal and many > db's down. > > That's why I called it the silver line around the cloud in the > > beginning. The normal signal sounds OK, not as > "comfortable" like my > > TR7 audio but very good for normal use as we do (at least > for me). I > > just would like to get rid of this higher freq component > which doesn't > > like to be influenced by whatever control except the power > and volume > > button :-) . > > > > I've got 2 K3's and they both give me the same result. > > I played with all kind of controls (RX-EQ, AGC-SLP/THR, > AGC-S/F, AGC > > ON/OFF) and there is no difference whatsoever! > > > > I apologize for being persistent in this. > > > > > > 73's, Evert PA2KW > > > > > > > ______________________________________________________________ > 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 -- View this message in context: http://n2.nabble.com/K3-audio-tp2590280p2593625.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
