[Elecraft] K3 New DSP board installed

[Eric Tichansky]

The audio level differences remind me of a situation I had w/ a DSP 
board, but had nothing to do w/ the Rev D upgrade.

Your original DSP board may have been "defective".  I had to replace one 
of my K3's DSP board a while back as I was noticing a significant audio 
level difference between the two K3s, ie. AF gain, monitor level, 
et.al., always had to be much higher on the one vs. the other.  Swapping 
in a replacement DSP board resolved the issue and audio levels now match 
w/ similar settings.  While the audio levels were drastically different 
on the "defective" DSP board, it still worked in all respects and would 
otherwise have appeared to have been a 100% perfect board if there was 
no point of comparison.  The settings required to achieve similar audio 
drive on the removed DSP board were much higher, as you report on your 
original board, so I suspect your original had the same issue mine did, 
and was simply defective.

73
- no3m

>>
>> --- On Sat, 1/9/10, Steve Ellington <n4lq at carolina.rr.com> wrote:
>>
>> From: Steve Ellington <n4lq at carolina.rr.com>
>> Subject: [Elecraft] K3 New DSP board installed
>> To: Elecraft at mailman.qth.net
>> Date: Saturday, January 9, 2010, 9:41 AM
>>
>> The installation of the Rev D DSP board went smoothly. I updated the 
>> firmware and all is well.
>>
>> The first thing I noticed was how much louder the headphones (Bose 32 ohm) 
>> are. I use the FP jack. The difference is huge. Before the upgrade, I ran 
>> the CW sidetone at 38. Now it's at 14! I'm not sure about the speaker volume 
>> but I don't believe there was much if any change.
>>
>> I don't
>>  hear any change in the low frequency audio. It had already been 
>> improved earlier with one of the FW updates. Headphone impedance can affect 
>> this too.  Using MixW, I can see a well defined null in audio level below 50 
>> Hz.
>>
>> The 3rd harmonic is still present in the low level audio output. This has 
>> bugged me from day one on the K3. It's weak but visible on the waterfall. 
>> See the photo at
>> http://n4lq.webs.com/apps/photos/photo?photoid=65288758 Don't bother telling 
>> me it's my sound card or my level is too high. I've already been trough that 
>> routine.
>>
>> As for audio quality and listener fatigue, time will tell. This radio is 
>> such an improvement over my IC-7800 that anything I say is just nit picking.
>>
>> Was the upgrade worth the money? I guess it depends on how you feel about 
>> money and your K3.
>>
>>
>>