Is there an appetite for non-discrete solid state DIY headphone amps anymore?
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iamwhoiam

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More of an discussion piece, but just wanted to generate some thoughts. Sorry for the long post. As a precursor, my affinity between subjective and objective analysis lies very much in the middle. I had a decade long break from DIY audio (Warren Young and Ti Kan's designs were fresh off the block back then) but I think I have now caught up back to speed. Henceforth, this post.

With the development over the past decade of better solid state ICs, there has been an overall drive towards objectively brilliant commercial amps, resulting in JDS (Atom, Element), Topping (A90, now single-ended L30), and THX AAA-based amps dominating large sectors of the market. The ASR.com or "Audio Precision" effect.

Looking at these design topologies, they all use implementations of ultra low-noise opamps (NJM2068 in Atom, OPA1612 in A90) combined with ultra-high feedback loops / nested topologies and buffers (LME49600 in JDS amps, TPA6120A2 "Nested Feedback Composite Amplifier" quad-channel in Topping's A90).

Correct me if I'm wrong but ever since the Objective 2, there does not appear to be many that have made a significant impact in SS-IC amps in the DIY arena. I'm aware of The Wire but haven't seen much more progress for a while. There is also a PCB layout from Pavouk of LME49720 gain + LME49600 DC servo, based on TI's own evaluation board schematic, but again this hasn't really taken off in DIY circles. A rough and readily conjured chinese PCB implementation of this is available for £3 at your favourite auction site. I haven't found any complete non-modular designs which surpass Objective 2's objective qualities.

Then there is Tom's incredible Neurochrome HP-2. However, this is closed source with no schematic available. This is no criticism though, as the design is absolutely first class, with obvious and understandably huge amounts of effort being put in. However, I would classify this more as a commercial implementation.

I'm curious then, why more ultra-low noise solid state IC-based high-feedback designs haven't been pursued any further in open source discussion? Perhaps we've reached a nadir of DIY performance? ASR would disagree, but striving for inaudible gains might not be in the DIY ethos? Perhaps it's a limitation of measurement, given that commercial amps are approaching the noise limits of $25k testing equipment? Are commercial implementations simply too good in value versus performance that it hasn't been worth it? Perhaps DIY audiophiles prefer deliberate sound signature modification through discrete designs? Maybe, I am simply looking in the wrong place and need enlightening?

I really don't know the answers. What are other people's thoughts? Clearly there have been some great discrete DIY amplifiers recently and elsewhere, but what is happening to IC-based development?
 
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tranhieu

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As much as people raved about the Objective 2, I found it the most boring headphone amp I've ever built. It just lacked authority and control. Good for a starter project to have fun, but I won't bother considering it as something serious.
 
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gimmeheadroom

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I haven't built anything in decades but at heart I prefer tubes or discrete devices. It's just easier for people to whip together something based on chips and the meme factor is out of contro, just look at the success of el-cheapo THX amps. There's no glory in that, though.
 
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individual6891

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Given the lack of posts, I suspect not
 
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