No problem...Just grossly out of specs. Whatever happens....happens 73 Steve N4LQ
On Mon, Dec 28, 2015 at 2:53 PM, W2RU - Bud Hippisley <w...@frontiernet.net> wrote: > What am I missing? > > I use 600-ohm stereo headphones plugged directly into the front panel jack > of my K3S. > > I run the Audio Gain control at 9 o’clock — roughly a 25% rotation toward > full volume. > > I have more than enough audio for my elderly ears, and when I pull the > headphone plug out of the jack, my speaker audio is at a comparable level. > > What is the non-problem with high-impedance phones that you guys are > trying to solve? > > Bud, W2RU > > > On Dec 28, 2015, at 1:59 09PM, Steve Ellington <steven...@gmail.com> > wrote: > > > > K3 uses the. > > > > LM4811 Headphone Amplifier > > > > Texas Instruments Specs for output Z > > > > RL = 16Ω 105 mW > > RL = 32Ω 70 mW > > > > At 60 ohms the output power drops to 20 mw. Per their graphs. > > > > 300 ohms is not even considered. > > > > Amplifier gain control is done digitally within the chip. With such a > high > > Z load, gain would likely need increasing. > > The results of doing so are unknown. Consider pop, click, white noise > etc. > > > > Also consider what happens when switching from headphones to speaker when > > the AF Gain control is turned up high. Blasting? > > > > I suggest sticking within the 16 to 32 ohm range. > > > > Steve N4LQ > > > > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
