[Elecraft] [K3] Audio circuit distortion

[Doug Person]

I once wired a guy's $20K audio system with RG8.  He claimed it made all 
the difference.  He also claimed that vinyl was vastly superior to 
CD's.  I told him he had a wonderful imagination.  The very best and 
cleanest vinyl with a radial tracking arm turntable and a top of the 
line cartridge could just barely make a 40db s/n.  Digital audio can do 
100db anytime.  Many years of selling audio gear taught me about the 
psychology of hearing.  It takes an experienced ear to appreciate a 
truly flat response. Most people prefer a very unbalanced equalization.  
I got lots of chuckles switching between a $300 system and a $3000 
system and having most people prefer the cheap setup.

Having designed loud speakers professionally (of which 1,000s were 
sold), I am equipped with very refined and experienced hearing. Unless 
you were listening to FM broadcast, how could you possibly appreciate a 
.3% THD?  I always assumed anything less than 1% was more than adequate 
for our kind of communications.  If we get down to this level of 
performance, we'll need to work on the 50% or so of stations that only 
concern themselves with output power - not audio quality.  There is a 
lot of dreadfully distorted signals on 20 meter SSB.  Nothing beats 
working a station that is s9+20 and barely understandable because he has 
compression and mic gain pushed up so he sees 1500 watts on his output 
meter all the time.

So, IMHO, the K3 has absolutely splendid audio when I have a chance to 
work another station whose audio is actually adjusted correctly.  It 
amazes me that most rigs today have a monitor function.  Must be the 
most unused feature of all time.

73, Doug -- K0DXV

On 7/23/2013 2:52 PM, Wes (N7WS) wrote:
> Are you one of those guys who can hear the difference in speaker wire?
>
> I had a guy working for me who was a musician and audiophile who 
> claimed he could tell the difference.  I referred him to Bob Pease.
>
>
> On 7/23/2013 1:22 PM, Wayne Burdick wrote:
>>   Don Putnick <don.na6z at earthlink.net> wrote:
>>
>>> I watched the presentation again. Yes, Rob said the K3 was fixed in 
>>> 2008. He also said the fix wasn't as good as he'd like. It didn't 
>>> compete with the <0.3% distortion of the Icom 756 Pro III. So if you 
>>> look at the distortion products at 44:20, would the average amateur 
>>> (like me) be able to hear that?
>> Short answer: No.
>>
>> I have excellent hearing (I'm an acoustic guitarist and pianist in my 
>> "spare time"), and after we made all the updates to the K3, I burned 
>> quite a bit of lab time trying to hear what Rob was talking about.  I 
>> tried *really* hard, as did my staff. We couldn't hear it. Rob is 
>> superhuman :)
>>
>> True, it would be possible to reclaim a bit of extra AF headroom by 
>> using an AF amp that's heavily biased (class A). But 99% of operators 
>> would not benefit, the radio would draw an extra 200-300 mA with no 
>> signal in receive mode, and the chip(s) would need fairly extensive 
>> heat sinking. Doesn't seem like a good tradeoff.
>>
>> (Disclaimer: I'm biased towards energy efficiency and portability.)
>>
>> Wayne
>> N6KR
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>