[Elecraft] [K3] Shorting K3 PHONE jack outputs (WAS OT: Stereo to mono adapters)

[Paul Christensen]

Jim (K9YC) is right.  When looking at the K3 schematic, realize that the 
headphone amp's 8-ohm build-out resistors are not on the same schematic page 
as the headphone amp.  At least it wasn't the last time I looked.

Paul, W9AC

----- Original Message ----- 
From: "James Sarte (K2QI)" <k2qi.nyc at gmail.com>
To: <jim at audiosystemsgroup.com>
Cc: <elecraft at mailman.qth.net>
Sent: Friday, December 03, 2010 6:08 PM
Subject: Re: [Elecraft] [K3] Shorting K3 PHONE jack outputs (WAS OT: Stereo 
to mono adapters)


I will have a look a the schematics tonight after dinner; just find it
a bit hard to believe that I'd get conflicting information direct from
Aptos.

Tnx,
James K2QI

On Fri, Dec 3, 2010 at 5:57 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
>
> The manual is correct -- the HEADPHONE output is isolated with
> resistors. The SPEAKER output is NOT, and putting a two-circuit plug
> (mono plug) into it can cause the output chip to fail destructively.
>
> Again, the SCHEMATICS are on line. Study them. We're hams. We passed
> exams showing that we know this stuff.
>
> 73, Jim K9YC