[Elecraft] Low headphone audio level

[Jim Brown]

On Sun, 27 Jun 2010 12:52:47 -0400, Steve Ellington wrote:

>The K3's audio is just fine and there's plenty of it.

I agree. There are at least seven problems. First, Elecraft has a 
design philosophy of minimizing current drain so that a rig works well 
from batteries. That is a good thing, but it places limits on how loud 
the audio outputs can get. Second, hams, and those who design ham 
products, generally don't understand the concept of impedance, nor do 
they understand audio. Third, hams as a general population are a bunch 
of old farts (like me), and we have hearing loss for a variety of 
reasons. As an audio professional, I must be aware of that. I had my 
hearing tested several years ago, and I had at least 15dB of loss then. 
Fourth, some hams seem to confuse their ham rig with their high 
futility sound system. Fifth, hams seem to confuse the setting of the 
front panel controls with how much audio the rig can put out. Sixth, 
there are several places within both the K2 and the K3 where audio 
gains can be adjusted for various conditions like filtering and 
bandwidth. Seventh, because the K3 has much less IMD than other rigs, 
it is much quieter under crowded band conditions than other rigs, so it 
gives the illusion of not being loud. 

Even with my hearing loss, I've never felt that ANY ham rig I owned was 
weak on RX audio, and the Elecraft radios I've owned (K2, K3) are no 
exception. They are quite sufficient for communications purposes for 
anyone without serious hearing loss (that is, enough to need a hearing 
aid). My K2s and K3s happily drive Sony MDR7506s, the Yamaha CM500, 
Etymotic Research ER4s, Shure in-ear headphones whose model numbers 
I've lost, and a variety of miscellaneous elcheapo headphones I've got 
laying around. Now, a stock K2 IS weak on TX audio, and there are 
several well documented mods to improve that considerably. 

As to those gain adjustments -- there are the RXEQ settings that Fred 
mentioned, and there is gain adjustment to compensate for the loss in 
each of the roofing filters. One must be careful with pushing either of 
these too far -- depending on the internal design of the K3 RX audio 
path, that could result in clipping within the signal chain. My guess 
is that you could safely add a total of 10dB if you wanted. If I were 
Elecraft, and if I hadn't already done so, I would be looking at RX 
audio gains and trying to figure out if there might be another 6-10 dB 
available. That won't increase the maximum audio level without 
clipping, but it will mean that you won't have to turn the front panel 
gain up so high, and I suspect that dumb reason (which doesn't matter) 
is who most folks are complaining. :)  

73, Jim Brown K9YC