Benchmark LA4 vs Topping Pre90 - Listening impression

[SoulsHarbor]

Neither the Benchmark AHB2 nor the NAD C298 are "fully balanced."

Maybe there are semantics involved? Is there a difference between balanced and fully balanced? This from Paul Seydor’s review: “A few technical matters before I close. First, the amp has balanced inputs only, so you will need to use an adapter for a single-ended preamp. Benchmark also markets excellent balanced interconnects and recommends full balanced operation if possible (see sidebar and REG’s comments for more on this).

 

[Kal Rubinson]

"Fully balanced" (2 separate amplifiers for + and - branch) makes no sense. When talking about truly balanced, it means that the balanced output is floating.

Agreed but, as in other things audiophile-related, not everyone speaks clearly.

 

[mdunjic]

The two technologies were Topping's NFCA vs Benchmarks's typical THX AAA "patented feed-forward topology" stuff. I'm sure they might sound 99% similar, but maybe that 1% does not?

Oh for sure I don't expect the noise to be audible on any level for me. I expect the implementations to be coloring the sound (even if only microscopically). At first part of me suspected that the topping flavor of dacs and preamps kinda artificially sharpen the sound a little bit. I'm probably wrong so thats on me. Anyway, that's the type of coloration that I lookout for, and whether I want it in my system or not.

Since it’s not headphone amplifier, Benchmark LA4 doesn’t use THX-AAA technology … just saying … it is pure pre-amp … only Benchmark HPA4 uses THX-AAA for its headphone amp section … and Benchmark AHB2 uses THX-AAA as well … LA4 doesn’t

 

[Dougey_Jones]

Since it’s not headphone amplifier, Benchmark LA4 doesn’t use THX-AAA technology … just saying … it is pure pre-amp … only Benchmark HPA4 uses THX-AAA for its headphone amp section … and Benchmark AHB2 uses THX-AAA as well … LA4 doesn’t

I understood what he was saying about THX-AAA feed forward error correction. Benchmark is the only licensee for power amplifiers. THX licensed it widely for headphone amplifiers, but I'm only aware of one company licensed to make power amplifiers with their tech and it's Benchmark, unless that changed? It's widely speculated that the Shenzhen boys reverse engineered it for power amplifier use (I believe this as well).

I don't really have an opinion one way or the other regarding whether that's appropriate or not, I've read that feed forward topologies aren't new and have existed for decades, so maybe THX-AAA was just a good integrated example of how well it can be applied where nobody had paid attention previously.

 

[mdunjic]

I understood what he was saying about THX-AAA feed forward error correction. Benchmark is the only licensee for power amplifiers. THX licensed it widely for headphone amplifiers, but I'm only aware of one company licensed to make power amplifiers with their tech and it's Benchmark, unless that changed? It's widely speculated that the Shenzhen boys reverse engineered it for power amplifier use (I believe this as well).

I don't really have an opinion one way or the other regarding whether that's appropriate or not, I've read that feed forward topologies aren't new and have existed for decades, so maybe THX-AAA was just a good integrated example of how well it can be applied where nobody had paid attention previously.

The only two components that Benchmark has licensed for and using THX-AAA feed-forward error correction technology are
- HPA4 … headphone amp (this section uses thx-aaa) + pre-amp (that section is equivalent to what LA4 is and doesn’t use thx-aaa)
- AHB2 power amp

Benchmark LA4 is pure pre-amp and doesn’t use THX-AAA at all … and that’s what I was saying