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Benchmark HPA4 based on THX AAA Amplifier

Grave

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#81
My Sennheiser HD800 headphones have the most improvement compared to the headphone amp in the DAC3 DX. Very easy to hear more dynamic slam at high volumes. Before for some quiet tracks, one could turn the DAC3 all the way up when using the HD800's, not anymore! Low volumes definitely sound like they have more dynamics.

The Focal Utopia headphones are a little more sensitive, so the difference from the added headroom is not as great. The low level details are definitely easier to pick out, but this type of comparison is hard without knowing the voltage levels of the DAC3 and HPA4 and having them set the same.

Definitely there is no degradation with the HPA4 in between the DAC3 and AHB2 (and that's really saying something). I can turn the unit down to -89dB and still understand the spoken words if I put my ear into my horns. Too bad these speakers have passive crossovers in them unlike my other setup ;) But really, for having passive crossovers in the mix, the driver control is very very impressive and distortion is incredibly low. It definitely sounds like a much much more expensive setup (even though retail on the speakers and Benchmark gear is pushing $12k.

The volume control is very neat and works smoothly. The relays sound asolutely cool when you turning the volume up and down too. The unit is very nice. It's a pity I only plan to use one of the analog inputs (for the DAC3 DX input), but I am 100% digital.
This is obviously the placebo effect, and the cost is irrelevant since cheap DAC/amps have excellent performance.
 

sprellemannen

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#82
Mine is shipping Monday July 9th :) I'm really looking forward to using it; I've been waiting a while since I pre-ordered.

It could even ship this Friday per an email I got last week, but the website says available July 9th so it seems like a firm date.
Can you tell us about your experience with HPA4?
 
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#83
My post is on the previous page. A tad expensive, but at least it delivers in performance unlike so many units wrapped in snake oil that cost thousands more. It is definitely a quality built unit, and the noise floor is unheard of. No longer will my headphone amp be the limiting factor in my signal chain...

Hopefully Amir measures the HPA4 soon, but Benchmark has posted many AP measurements. The THD vs output power measurement Benchmark posted in the manual looks to beat the best headphone amp Amir has measured thus (Massdrop THX AAA 789) far by ~10dB!?! The lower distortion of the HPA4 even at higher output levels certainly isn't a bad thing, but up to your use case on if the cost difference is worth it. If you want the best, the HPA4 is it. I am anxiously awaiting Amir's thorough review when he receives one to test :D

Can you tell us about your experience with HPA4?
 

sprellemannen

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#84
Thanks for sharing your experience regarding your Benchmark gear, etc6849: Interesting to read!
Really looking forward for Amir's review! (If you were sending him your unit for review, then you deserve a great thumbs up for that!)
I guess it will be the benchmark (literally) in headphone-amplification.
Do you have some words regarding its line amplifier compared to DAC3's (or DAC2's, which to my knowledge is the same as DAC3's) line amplifier?
And it looks amazing too, with a dimension making it stackable with other Benchmark products as well.
It would have been great to listened to the HPA4.
Enjoy your amazing Benchmark units: I guess your systems sound amazing! (the headphone rig and the speaker systems)
 
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#85
@amirm
I can if he needs me to send an HPA4 still I can, but I think Benchmark is sending him one?

I mainly use the office setup for headphones, and actually have the speakers posted on craigslist right now. I know there are measurements in the HPA4 manual for line in to line out, and it is discussed here: https://benchmarkmedia.com/blogs/application_notes/benchmarks-256-step-relay-controlled-attenuator

If you were sending him your unit for review, then you deserve a great thumbs up for that!
 

amirm

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#87
@amirm
I can if he needs me to send an HPA4 still I can, but I think Benchmark is sending him one?
They made an offer a while back but I have not yet asked them to send one in. As noted though, testing an independent unit is always best, even though it will cost both of us a few dollars for shipping.
 
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#88
@etc6849 , with my focal headphones that are sensitive, like my elegia, I can hear the noise when I turn the amp to its absolute max. Is it the same with you?
 
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#90
@amirm
I'm not against it and completely trust you. However, it's the insurance on it that is expensive :( Just sold a lot on ebay, and I'd guess it'd be around $50 each way with insurance.

@ShiZo
Using my Focal Utopia's:
I hear a slight noise at +15dB (max), almost can't hear any hiss at +10dB, and can't hear anything at +7dB. This is with the DAC3 connected.

EDIT: however, you shouldn't have it anywhere near +15dB unless the source you are using doesn't have enough output...
 

sprellemannen

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#91
I hope Amir says yes to receive an HPA4 from Benchmark for review, it should not be necessary that etc6849 has expenses (say $100 = $50 x 2 + postage) for the review.
I am really looking forward for Amir's review of the HPA4, if it will happen and hope he measures both its pre-amplifier and its headphone amplifier.
It will definitively be among the most interesting reviews on this forum, since (in my opinion) HPA4 is one of the most interesting hi-fi products on the market, and I love Amir's reviews of gear (great writing skills etc.).
Unfortunately, no hi-fi shops in my home country has HPA4 in store (but I hope to get a listen on it on a vacation abroad some time this year, or that the shop selling Benchmark gear in the town where I live buys one unit for demonstration).
 
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#92
I don't doubt Amir will do a fantastic job and cover the return shipping. It's just shipping something that expensive worries me. It probably shouldn't though. I also don't blame him for doing cheaper amps first since that covers a bigger audience.
 
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#94
Has anyone heard or own the LA4? I have been thinking about getting one to put into my Benchmark system.
 
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