• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Benchmark HPA4 based on THX AAA Amplifier

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,198
Likes
16,981
Location
Riverview FL
The sound levels with the DAC direct config seem more like an On/Off switch after a certain point --- with just an increase of one additional detent

Ok. My DAC2 has no detents with which to compare.

I think in my case the purchase of the HPA4 is still well justified

I won't argue, as you've done the experiment with a critical eye, and come to the same conclusion.

---

The only other thought I have is to be sure the attenuation jumpers are set correctly for the XLR outs...

Page 29 - https://cdn.shopify.com/s/files/1/0321/7609/files/DAC3_DX_Manual_1.0.pdf?1825706725623701216

upload_2018-4-30_21-38-58.png
 

WondrousHippo

Active Member
Forum Donor
Joined
Mar 22, 2018
Messages
168
Likes
113
I think the date for the monoprice version has pushed out. No?

View attachment 12433

I thought it was supposed to ship in June originally.

Worth noting that the release date has slipped a whole bunch of times. Design changed to add the line output too.

I am curious if that's going to be any good. Wish it had balanced line outputs, if only so I could use it with my LSR305s.
 

WondrousHippo

Active Member
Forum Donor
Joined
Mar 22, 2018
Messages
168
Likes
113
I thought LSR-305 has input selectivity switch so you can drive it unbalanced. No?

Yeah, it does, and it's not a problem, but hey...it's the one piece of equipment I have that has XLR inputs. I'd love to actually use them someday!
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,368
Likes
234,384
Location
Seattle Area
Yeah, it does, and it's not a problem, but hey...it's the one piece of equipment I have that has XLR inputs. I'd love to actually use them someday!
:)
 

etc6849

Active Member
Joined
Apr 28, 2018
Messages
132
Likes
241
Location
Columbia, SC
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.
 

RedCometZero

Member
Joined
Apr 13, 2018
Messages
64
Likes
82
Interesting, that'll make it the first THX AAA product to be released. The others I believe aren't coming until October.
 

watchnerd

Grand Contributor
Joined
Dec 8, 2016
Messages
12,449
Likes
10,408
Location
Seattle Area, USA
Yeah, it does, and it's not a problem, but hey...it's the one piece of equipment I have that has XLR inputs. I'd love to actually use them someday!

I've had two sets of all XLR systems, my Wyred4Sound mPre & 2 x mAMPs, which were great budget ICEpower amps, and my Schiit Freya, which self destructed its XLR input when I tried to use it in passive mode one time.

Sadly, the best, legitimate use case I would want right now is to go direct via XLR from my turntable into my Devialet Expert, but it only has RCA inputs.... :(
 

etc6849

Active Member
Joined
Apr 28, 2018
Messages
132
Likes
241
Location
Columbia, SC
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.

IMG_20180717_183302.jpg

IMG_20180717_143815_1.jpg

IMG_20180718_190004.jpg
 

etc6849

Active Member
Joined
Apr 28, 2018
Messages
132
Likes
241
Location
Columbia, SC
You're welcome. You should send me your APx555 so I can measure it :D ;) Too bad I don't live closer to you.

Thanks for the review and nice pictures. Seems very promising.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,368
Likes
234,384
Location
Seattle Area
I will pay for shipping it back if you pay to send it to me. I use post office fixed price boxes where weight doesn't matter. If it fits in those boxes, it is pretty cheap to ship things back and forth.
 

etc6849

Active Member
Joined
Apr 28, 2018
Messages
132
Likes
241
Location
Columbia, SC

Sal1950

Grand Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
14,068
Likes
16,598
Location
Central Fl
Good to see the cheaper price on "B" version for people who don't need headphone output. $500 is good bit of discount there.
Also smart marketing.
Now if you want Benchmarks SOTA DAC and a HP/Line controller you need to get both.
Yes, they still have the original DAC3 but it can't sound as good as the dedicated separates. :)
 

Grave

Senior Member
Joined
Jun 30, 2018
Messages
382
Likes
204
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.
 

etc6849

Active Member
Joined
Apr 28, 2018
Messages
132
Likes
241
Location
Columbia, SC
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?
 
Top Bottom