@Kannan thanks for sharing your honest observations.
My experience has been quite nice.
The first step for me was to double the IC from source to buffer. I used two different pairs of unbalanced cables, both of which I like a lot. RCA splitters used was very cheap, chrome-plated ones costing Rs 10 per piece. I felt a hardness in the sound but despite that the highs became much sweeter than before. The sound stage also expanded a bit. There was more bass weight. I blamed the lack of refinement on the new splitters but felt there was clearly potential in this mad scheme. I actually had to turn up volume by 2 notches. In hindsight, I realised that this was counter intuitive.
Step 2: added second speaker cables. I don't recall the exact details but I recall that the volume still needed to be 2 notches up and in general it sounded better than doubling only source to preamp/buffer. This bore out the assertion in the originally linked article that the effect is cumulative.
The next day I bought better RCA splitters and replaced the earlier ones, and the sound became instantly more refined. The hardness was completely gone and in its place was much better sounding music. However, the volume still needed to be 2 notches up to have the same subjective SPL that I was used to before introducing double ICs.
This was when I got convinced that I must fill in the gap between buffer and power amp too to complete the chain. That Hari doubled his preamp to power amp link gave me lots of encouragement. On doubling this link the first thing I did was to decrease the volume by 3 notches from the original (no doubling anywhere) state. What I heard was:
a/ improved midrange - it sounded almost like hearing a “tubey” (in a nice way) SET tube amp. Voices stood out like I've never heard before. The closest I had heard in my setup was when I briefly had a Line Magnetic DAC at home. This DAC produced dense and highlighted mids and was likeable in many ways but the mid-range was spotlighted at the cost of higher frequency details; bass was poorly defined too. I never warmed up to that sound though I appreciated it for certain types of music. What I'm hearing now in the mids is less denser, yet sufficiently spotlighted to accentuate voices and mid-centric instruments. The quantity was just right for my taste. I know that it's not neutral in its frequency response but that didn't deter me because I've never aimed for ruler-flat amplitude response in my room.
b/ however the bass weight was clearly more than my liking. This was cured by disconnecting the super tweeters from speakers. Weird, but it's worked that way.
c/ highs: lesser than before but surprisingly it still sounds better than before and I'm actually hearing more details despite the high frequency roll off and the volume knob being 3 notches down.
More subjectively, this is the most musical I've heard my setup. The proof is in the number of hours I'm spending in listening to music without getting bored. The bass weight is now more than what I had before and this allows me to enjoy acoustic bass much better than before (small speakers - so it inherently suffers from limited bass extension). It feels like I'm listening to bigger speakers. The texture of bass is also better defined than before. Overall, I'm hearing more details at much lower volume. This reminds me of a Quad ESL I hadb heard a few years ago at a friend's place at very low volume without missing any details. For me, this ability had long been one of the hallmarks of a very good speaker. Besides the Quad, I've heard this type of sound in only one other setup (a really high end setup). Of course I'm not saying that my speakers now rival those speakers I mentioned. Just suggesting that it has gained some of that property I so admired.
After I doubled the IC from from CD player (actually an old bluray player) I observed the same improvements observed in the previous source, namely, improvements in midrange density and weight, bass weight and texture, and the slight roll off in the highs. So I am guessing that the effect can be replicated in other setups too.
The last refinements I had done was to bundle the same ICs in the same link. I didn't bother to revert to mixed ICs as it is a tedious job so I'm not 100% sure if using the same ICs bring further refinement. But even when mixing different ICs they sounded pretty damned good to my ears (and I must say, in my setup, since I haven't tried this anywhere else).
I'm certainly not reverting to single IC.
