These caps - near Front Panel Phone Out. C9=C13=100uF 10V Also add 1uF: "+" to pin 10 U2; "-" to ground. Picture here: C9 and C13: http://forum.cqham.ru/download.php?id=43285 (big photo) new 1uF cap: http://forum.cqham.ru/download.php?id=43286 (big photo)
Yes, IF buffer amplifier also have to be modified. Using only electrolytic caps C84 and C92 not is enough, they must be bypass by ceramic caps. Photo: http://forum.cqham.ru/download.php?id=43287 (big photo) All these modifications are not simply. I think the best way to settlements of the problems call to Elecraft Tech. Support and Repairs. 73! Alex UR5LAM Brett Howard: > Where are these caps? I see them on page 28 of 52 on the schematics but > where do they physically live in the unit. I assume they are on the main > DSP board. Also as far as the "grounded 1uF cap" are you talking about the > lil decoupling nugget they had sitting there? Guess it couldn't hurt... > > Your pictures say after AF and IF amplifier modifications. What IF mods did > you make? > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Alexander Ponomarenko > Sent: Tuesday, June 23, 2009 12:16 AM > To: [email protected] > Subject: Re: [Elecraft] K3 headphones > > I has tried replacing the 10uF caps with 100uF in AF-amp, also in > data-sheet for LM4811MM we see grounded pin 10 have to add for 1uF cap. > The result is excellent with my ProSet. > Sound clean and deep. Signals became more raised, proturberant, appeared > "body of the sound", clearly differ the most small details in signals. > Such sensation, that earlier the signals got through blanket, > but now here is they, straight before my eyes, and they proturberant and > volumetric. > As my ears as SpectroLab also "sees the difference". You can see my > plots "before" and "after" same mods. > > before mods: http://forum.cqham.ru/download.php?id=43281 > after mods: http://forum.cqham.ru/download.php?id=43282 > > before s9 level: http://forum.cqham.ru/download.php?id=43279 > after s9 level: http://forum.cqham.ru/download.php?id=43280 > > 73! Alex UR5LAM > > Joe Subich, W4TV: >>> K9AC has recommended replacing the 10 uF caps >>> with 220 uF caps which would reduce the corner frequency >>> for low impedance headsets to about 50 Hz but since my >>> primary headset is the Proset I have not tried it as yet. >>> >>> 73, >>> >>> ... Joe, W4TV >>> > > ______________________________________________________________ > 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
