K3 Assembly Rev D, and Rev C, DSP Board Information
All K3DSPUPGD boards, and all currently shipping K3s with new DSPs, use Assembly Revision D DSP boards. This is the latest DSP board assembly level. (For the K3DSPUPGD, the Rev D board is just DSP assembly Rev C with the LPF filter (rolls off audio above 4 kHz) added.) We were able to get the LPF boards in in time to do this and have added them to the upgrade at no additional cost.
We started shipping DSP Assembly Rev D DSPs on new K3s about November 4th, 2009. That corresponds to K3-F Serial number 3626 and later. the Rev D point for Kit K3 serial numbers will be about +/- 10 of 3626. Any K3 DSP board Rev D or later will have the extended low end audio response enhancement on RX and TX and the LPF audio roll off above 4 kHz.
(We started shipping DSP Assembly Rev C DSPs approximately May 1st, 2009. Any K3 DSP board Rev C or later will have the extended low end audio response enhancement on RX and TX. This corresponds approximately to K3 serial number 3018, plus or minus 10 to 20.)
Since assembled -Fs and kit K3s flow through different manufacturing paths, there is a slight variance in s/n for the phase-in.
If in doubt, check the DSP board Rev as noted above. A picture of the Rev label location :
The 'D', or later, revision letter at the bottom of the label is what is important.
Note that some of the upgrade Rev D DSPs may have their assembly revision level marked by hand, and its possible a few not have been marked with new Rev D, but if the LPF piggyback board is added on those DSP boards, or if they have the Rev D assembly marking, they are Rev D.
New K3s are shipping with a new Rev D assembly level DSP board that does not need the small piggyback LPF board.
Also, do not confuse the Rev D assembly level with the PCB fabrication
revision level that is etched into the PCB artwork. K3DSPUPGD boards can be Rev
D assembly level boards but have either Rev B or C etched in the copper artwork.
Rev D at the assembly level means they have had their parts changed to match
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