Analog or Digital Audio - Which should we choose?

Ever since I got access to a 1939 Hammarlund Super-PRO (SP-210 LX) receiver when I was 13,
I always loved bigger radios and add-on units w/all kinds of knobs to twiddle.  A few years back
I jumped at the chance to buy one of N6VR's filter-laden FT-1000mp's.  He was retiring the Yaesu radios from SO2-R operation and switching to a pair of (much smaller) Elecraft K3's.  Ergonomically,
I way-prefer the FT-1000mp over the K3.  I really appreciate the BiG main tuning knob w/shuttle jog.  Having access to dual-receive in the FT-1000mp makes knob-twiddling infinitely more fun.

In addition to a series of reasonably sharp I-F filters, the Main RX sports a reasonably effective
e-DSP facility.  Even tho the e-DSP is not I-F based (like its successor - the FT-1000mp MK-V),
minus agc-pumping, the 1000mp's eDSP allows shaping the audio in a number of different ways
to peak the audio passband in such a way that muddied-signals often "PoP" a few db ABOVE the
ramble-mud; and, of course the auto-notch facility is, shall we say, "top notch".

While I LoVe the FT-1000mp design overall, what is often overlooked is the fact that the e-DSP
facility works ONLY with the Main-RX (VFO-A).  The Sub-RX is in reality, relatively wide-open. 
Prior to bringing the MP into my WQ6X operation, the JPS NIR-12 DSP and the MFJ-752c analog filters had been shelved in the storeroom.

During the 5-contest weekend in May 2017 (where I took 3rd place for 7QP QSO party and 1st-place for the INQP GiG), amongst other experiments, I devised a cabling-trick allowing the NIR-12 and 752c to be cascaded in the Sub-RX audio line.  Right after that weekend 2 BLOGs were posted describing what was done and how it turned out.  [CLICK HERE] to read that picture-laden description.

In time for 2017's Cw All Asia contest, I brought a languishing Autek Research QF-1A off the dusty storeroom shelf, inserting it in the laptop audio line for running NX6T remotely.  After I got the right-feel for the different filter configurations and settings w/the QF-1A, I was amazed at the peaking effects of the Peak & High-Pass filter settings of that vintage analog filter.  [CLICK HERE] to read about that.

Because the All Asia GiG was a Cw contest, I got a "quick-learn" about all the things 25+ year-old analog technology can still bring us, in an overly-DSP'd society.  As you can see, the QF-1A is equipped with Low-pass/High-pass filters, a pair of audio-notch controls and most important, an
audio peak filter (APF) that is as good as the inboard APF controls that came with the high-end transceivers released during the time-period the QF-1A was on the market.

The Autek filter design is of course an audio emulation of the classic I-F based Q-Multiplier circuitry; without the caveat of having to TAP the I-F signal line.  Except during moments of extreme agc-keying (when a strong station is near the RX passband) the Autek QF-1A is as good as ANY Q-Multiplier.
Because the audio passband is processing is analog, the operator can "fine tune" the passband shape characteristics more precisely than most DSP methods allow us to do.

A filter you may not be aware of is the WW-II Navy "BEAM" filter (or FL-8), initially intended for on board aircraft receivers.  Think of the "RANGE" switch position as a CW filter and the "PHONE" position as a medium-skirted SSB filter.  As I recall, the "BOTH" position effectively bypasses the filter.

Technically, there is enough room
inside the box to mount a small IC-based filter/amplifier.  I have seen a modified Beam filter with one of headphone jacks removed and replaced with a filter adjustment pot.


A major advantage of external filters is their plug-in and play operation; no circuit modifications
to the receiving equipment are necessary.  The major disadvantage is that most external filters are usually relatively worthless in the presence of adjacent signals down-pumping the receiver's AGC.  Nevertheless, while most analog audio-processing is vintage "old school", your ears don't
care about that.

Altho Digital Signal Processing is for the most part here to stay, you pay a premium price to purchase a DSP-laden radio.  In most cases, external analog and digital external filters do a near-equivalent filtering job, and quite frequently for well under $100.  Another advantage of external filters is that
with an audio cable switch box, they can be used with a multitude of transceiver and receiver units.

What approach do YOU take?

ANALOG?  DSP?  BOTH?  OR?.....