[Elecraft] Question about K2 pre-amp

[Todd Gahagan]

Just finished all the mods to bring K2 #726 up to B version status.  I had a
little trouble with a solder bridge on the SSB board but once that was taken
care of things seem to be back to normal.  I also did the AF "scratchy pot"
mod and it took care of the majority of the scratch.  Two diodes were
installed to comply with the latest mod for strong signal problems.  One
thing I do notice is that to get sufficient audio I seem to need to run the
pre-amp on all bands. It makes a dramatic difference and I can run the audio
at about 9:00 with the pre-amp compared to 12:00-2:00 without it.  I checked
receiver sensitivity (thanks to N7GS) and we found it to be well within
specifications.  Also, filter alignment via Spectrogram looks to be very
good (Thanks much to Tom Hammond for his clear instructions).  The filter
flattening mod worked very well.  Has anyone else run into this need to run
the pre-amp, even on 40 and 80 Meters?  I did not need to do this prior to
the mods.
 Thanks,  Todd WA7U