[Elecraft] K3 weak rx audio when AFX is NOT active?

[Sam Morgan]

Problem solved!

it seems a brand new 4' long 3.5 male to 3.5 male cable was the culprit, 
when I removed it from the mix, the problem went away. Some how Murphy 
managed to mess with the cable, and my feeble mind. It went from out of 
the box working one day, to weird failures the next day, all in only 8 
hours, sigh.

With the recent 'I blew up my audio chip' thread fresh in my mind, 
paranoia took over, and I feared the worse, due to the loud pop I hear 
when I turn on/off the new amplified M-Audio AV40 speakers, so figured I 
had killed something.

It's still very weird that it would change/fail only with the AFX on/off 
setting?

I will be purchasing/installing the K3AUDPROTMDKT in the near future!

http://www.elecraft.com/order_form_parts.htm#K3%20Parts

<quote>
Even though the K3’s audio output I.C. has internal protection, a small 
number have failed under extreme conditions such as a dead short across 
the speaker output. This modification adds a 1-ohm resistance to each 
speaker output that tests show prevents failure even under these 
conditions. Some soldering of leaded parts is required to make this 
modification.

Included with all new K3s shipped after mid May 2013.
</quote>

$9.95 seems like a very cheap price to pay for the piece of mind that a 
bit more insurance against a potential Audio IC failure. My K3 is of 
2009 vintage, so it doesn't have it installed as of yet.

-- 
GB & 73
K5OAI
Sam Morgan

On 7/17/2014 1:49 PM, Don Wilhelm wrote:
> Sam,
>
> Try re-positioning your speakers a bit.  I suspect what you may be
> hearing is acoustical cancellation of the output from the speakers. You
> may not hear that the same in the headphones.
>
> 73,
> Don W3FPR

> On 7/17/2014 2:16 PM, Sam Morgan wrote:
>> I just added a different set of stereo amplified speakers to my K3 #4123.
>>
>> Yesterday all was ok, if I switched from AFX active to OFF,
>> my volume levels remained the same, just the sound changed.
>>
>> Today I was listening with the AFX BIN active (my normal setting)
>> and then I switched the AFX OFF, and my volume level dropped way down.
>>
>> If I listen through my headphones, the volume level stays the same.
>>
>> Have I killed my audio out?
>>
>> Why would volume still be ok on both speakers and headphones when the
>> AFX is active if it the dreaded 'killed my speaker amp IC chip' problem?