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Unfair Competition: Orchard Audio Bosc Monoblocks vs. Pass Labs XA30.8

After hearing a friend's Orchard Audio Starkrimson Integrated Amplifier in my system (https://systems.audiogon.com/systems/9074) a few weeks ago (it sounded pretty good!), I arranged to audition a pair of used Bosc $1500 monoblocks (now called Starkrimson) for close listening.  Was curious to see just how well this "distortion-free" class D amp (https://www.audiosciencereview.com/forum/index.php?attachments/orchard-audio-bosc-pdf.47492/) could replicate my beloved Pass labs class A beast costing >$6000 new.  Close listening was done after several days of casual listening/break-in.

Bosc - The Good:
- Wide and tall soundstage
- Convincing central image
- Extremely quiet -- less baseline hiss than the Pass
- Fast transients
- Excellent instrument decay/echo
- Obviously more energy and space efficient

Bosc - The Not as Good
- Lacked soundstage depth/separation
- Less vibrant and engaging, lacking difficult-to-articulate "magic" of the Pass
- Inconsistent bass performance, some tracks sounded firmer and tighter, others weaker than the Pass
- "Flat sounding" with less fleshed-out midrange

After having the Bosc in my system for a few days and listening to nothing but that with a variety of music, I would have been very happy to keep it for the long-term.  It was only after A/B with my Pass that I realized what I was missing.  

Not a fair comparison dollar-wise, but I was, perhaps naively, prepared to be convinced the Bosc could go head to head.  A nice reminder of what I enjoy about the Pass in my system, though.  How to measure these qualities, though?
redwoodaudio
charles1dad's avatar
charles1dad
10,250 posts
 
I agree with @mikem. Given the stated listening impressions I’d find the Pass amplifier to be clearly superior (Based on what I consider to be more important/meaningful criteria). More "vibrant and engaging", less "flat" with a more "fleshed out midrange". This to me means a higher and deeper level of musical -emotional involvement and more as one (Pulled into) with the performance.

The Pass is connecting you more to the music and thus increasing listening enjoyment and pleasure. The "magic" referred to by the OP.  This would be an easy choice for me based on the above described amplifiers direct comparison.
Charles
b_limo's avatar
b_limo
2,274 posts
 
Yes, hard to quantify or describe the magic but once you have it don’t change a thing you can’t undo.


redwoodaudio OP
413 posts
 
Oh, I'm not changing out the pass amp for the Orchard. It's interesting to me how much of what the amp is doing (or not doing) has nothing to do with standard measures. 
charles1dad's avatar
charles1dad
10,250 posts
 
Redwoodaudio,
But that’s been the case forever in regard to audio. Measurements have a place and provide some pertinent data but are poor predictors of sound quality. As was confirmed with your listening experience , you actually have to hear an audio product.
Charles
redwoodaudio OP
413 posts
 
I wonder if even Nelson Pass understands exactly how his amp works its magic... Certain harmonics prevailing over others? A specific type of transistor? 
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