Well, I've now had substantial time to compare the ES1sl and the RX-F10...my findings:
RX-F10 - Absolutely the better choice for 6 channel needs, for lower impedence loads (it drives my Maggie MMG's quite admirably for $249.00), ergonomics are better (LED off setting is very slick particularly), DSP setting s are kinda' neat, and slightly better (subjective) looks.
ES1sl - For 2 channel audio on 6-8 ohm speakers, it sounds better. This much I'm sure - yet I don't know why. It had 'tingly' and very translucent midrange and more delicate and open treble response.
At no time since the very beginning did I get those delightful chills that I got when I played the ES1sl on my Vandy 1c's. Playing the same tracks on the Vandy with both receivers (Eva Cassidy's 'Songbird' on heavy rotation here) and I kept coming back to the same conclusion. Both are 'tweeked' and set up in exactly the same manner...fed by a BPT-2, on LAT International 'pud' feet, all connections (inside and out where I could) treated with Mapleshade silver bearing grease. The ES1sl is the better sounding unit to these ears.
Comparisons of both with the Maggies are not possible...the ES1sl cannot drive 4 ohm loads adequately and will thermally shut down at moderate/high volumes.
I sold my ES1sl so direct comparison now is not possible, but I know what I know.
In fact, right now, I am getting more enjoyment from the little Sonic Impact and a 7aH sealed lead acid battery than the RX-F10. Perhaps it's yet another case of audio nervosa at play, or 'familiarity breeding discontent', but I'm pretty sure in my convictions on this one.
The RX-F10 is terrific if only because it drives 4 ohm loads for $249(!!!), but outside of that rather extreme case, the ES1sl was better.
Interestingly, I wired in a 10 guage LAT International silverfuse power cord the other day into the F10...I noticed no perceptable change in the sound. The LAT is one of my favorite inexpensive tweeks (about $125), it has never previously failed to better an IEC equipped unit before (this is the first time I hard wired it in).
However..... this is the first time I changed out a power cord, and compared vs. 18ga throw-away cord, while running it thru the BPT-2. Seems the BPT-2 removes much of the electrical and aerial garbage that the LAT (or perhaps any well shielded power cord) helped with previously.
It's all about trade-offs and I am a bit happier with the F10 driving the Maggies than the ES1sl driving the Vandy's. But, if you have a easier driving load than the Maggies, the Es1sl may be a better (and cheaper) choice.
Additionally, the Sonic Impact produces a stupid amunt of great music for $55.00 (with SLA battery), as well, with 87db+ speakers in small rooms. Simpler really is better (one input, 2 channels, 6 watts, and a volume control)and there ain't much better than pure and adequate DC current. I am getting over 60 hours of play time at moderate volumes on one charge!
I can see somehow that Vinnie's ClariT in my future...dratz!
