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Pass Labs HPA-1 Headphone Amp Review

Rate this headphone amplifier:

  • 1. Poor (headless panther)

    Votes: 320 90.4%
  • 2. Not terrible (postman panther)

    Votes: 19 5.4%
  • 3. Fine (happy panther)

    Votes: 6 1.7%
  • 4. Great (golfing panther)

    Votes: 9 2.5%

  • Total voters
    354

Billy Budapest

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I thought I would post this to clarify things a bit. This was designed by Jam and not Nelson or myself. It also isn't the commercial version of the WHAMMY. Jam was given autonomy in the project since headphones were an interest of his. Our website and numerous reviews and interviews make pretty clear who designs what.

If you want something that measures below .0005% distortion and noise look at the BA20018 circuit I did. It is in the public domain and I think you can even get boards for it.
The Whammy is another dedicated headphone amp you can build. It is an op amp driving source followers and you can roll in your favorite one and set the bias how you like.
FYI I don't make a penny on these.

Given the measurements on the HPA1 and the loose connector I would like to see it at the factory. Call and ask for Kent and he can arrange to get it back.
Wayne, is this you?


Just confirming. Always good to see members of the industry here!
 

dustinyo

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Wow this is a shame, I don't own any of their products, but Pass Labs is a company I still root for to succeed. After seeing the internals and performance though, how in the world do they come up with the pricing that they do? There's no way this cost more than a few hundred dollars to manufacture.
 
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amirm

amirm

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they said they had rubber ones but changed them to felt because of the amp's weight and how it would leave marks or something. @amirm did you notice this?
I shipped the unit back to its owner already but pretty sure I remember it having rubber feet.
 

WayneC

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Wow this is a shame, I don't own any of their products, but Pass Labs is a company I still root for to succeed. After seeing the internals and performance though, how in the world do they come up with the pricing that they do? There's no way this cost more than a few hundred dollars to manufacture.
If a manufacture sells to dealers as we do the typical wholesale price is about half retail. One of the most expensive parts of the headphone amp is employee health insurance. Add in rent on a California building and paying a livable wage with a median home price of $800,000 and you can start to see where the money goes.
 

Loomynarty

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Is this the commercial available version of the WHAMMY diy headphone amp that Wayne designed ?
Definitely not. WHAMMY uses an op-amp input stage with MOSFET output stage not JFET input stage like the HPA-1. WHAMMY was also designed years later and from the measurements I've seen, measures much better.
 

KR500

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Definitely not. WHAMMY uses an op-amp input stage with MOSFET output stage not JFET input stage like the HPA-1. WHAMMY was also designed years later and from the measurements I've seen, measures much better.
Cool, that explains why it sounds fine as wine to me
 

HiFiBob

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I've read all the reviews of the HPA-1. They're all very positive, except Amir's. I've also listened to the HPA-1. It played loud without noticeable distortion. It was detailed but not really neutral, which makes sense given the design. It's a relaxing sound and gets a good groove on. That's just my subjective impression, don't freak out.

Reverse-engineered schematics for the HPA-1 are posted on diyaudio.com. I put the circuit in SPICE and it simulates almost exactly the same as the Stereophile curves. The HD650 is rated 100 dB/mW sensitivity. The HPA-1 shouldn't break a sweat driving these headphones to ear-splitting levels. I want to say, if Amir's listening test is valid, the review amp was probably damaged in shipping, beyond the loose control board connector. Or maybe it was just worn out from being left powered on continuously for years (bad idea).

I wish Amir had arranged to have the amp inspected at the factory before publishing such a scathing review.

Measured -83dB SINAD seems bad, but don't forget it's a log scale. THD of 0.007% is still very low, below the audible threshold, and it'll be lower at normal signal levels. There's no real need for amps with vanishingly low distortion. This is just a marketing gimmick, not an objective or "scientific" requirement.

I wouldn't buy this amplifier myself for a bunch of reasons. But I don't hate it for existing. I'm glad there are choices in the market. I appreciate that Nelson Pass employs American workers and provides them health insurance and benefits. You can build your own HPA-1 clone. Good luck making it the same quality for under a thousand dollars, and that doesn't account for the costs of labor, marketing, customer support, and keeping the factory lights on.

It legit makes me sad to see people hating on this amp, and I'm not even a Pass fanboi. I do get tired reading about cookie-cutter Chinese gear all the time. Pass Labs' design philosophy is different. It's a big world, full of injustice. There are plenty of more important things to lose sleep over. IMHO and YMMV.
 

Extreme_Boky

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You see, with all these $100 devices that measure phenomenally well, but sound like crap.... this site will slowly get to a point where.... there will be no point to measure anything anymore. Of course, there will be $50 devices in a year that will measure better than the current $100 device... but people will lose interest. What's the point? Who cares... at that price point the subjective vs objective would lose any meaning.

What will remain is going to be the question: despite the phenomenal measurements that Amir is showing here, why does this still sound like crap...
 

Alcophone

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I wish Amir had arranged to have the amp inspected at the factory before publishing such a scathing review.
That would have been up to the new owner, Amir had to wrap up the review because the owner at the time sold it to someone else who was waiting to receive it.
But yeah, if this unit makes its way to Pass Labs, I'd love to hear their findings.

This amp is really bad because whenever I foolishly decide to listen to a few songs before going to bed, I keep listening way longer than I should.
 

oleg87

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Measured -83dB SINAD seems bad, but don't forget it's a log scale
Worth pointing out that human perception of loudness is also logarithmic.

Agree that the vitriol against such amps is silly. This amp is not advertised as a measurement monster, and seems to more-or-less meet its limited provided specs, so any mismatch of expectations and the numbers coming out of an AP box is on the person spending four grand on such an amp.
 

Purité Audio

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You see, with all these $100 devices that measure phenomenally well, but sound like crap.... this site will slowly get to a point where.... there will be no point to measure anything anymore. Of course, there will be $50 devices in a year that will measure better than the current $100 device... but people will lose interest. What's the point? Who cares... at that price point the subjective vs objective would lose any meaning.

What will remain is going to be the question: despite the phenomenal measurements that Amir is showing here, why does this still sound like crap...
So reasonably priced fine measuring equipment sounds like crap does expensive fine measuring equipment also sound like crap?
Does crappy measuring expensive equipment ( see thread title) sound good?
What about crappy measuring inexpensive equipment?
Keith
 

Drakkar Noir

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As the owner of the amp being discussed here, I was really happy with the amp in general. As to the way Amir received it, my guess UPS will have to answer for this after the guys at Pass Labs take a look at it. Because of the review, by buyer backed out; so will either find a different buyer or simply keep it.

As I've stated before, my only gripes about the amp are the felt feet and possibly the headphone jack. In the sound department, measurements is not my top concern.
 

Hart

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So much of our hobby is a big name, hubris, and follows up by junk. PT Barnum business plan. They should be ashamed. I can't remember how many reviews I have read for Carver/Sunfire products that were absolutely glowing. They were ironically also big advertisers in said magazines. The amps test terribly, the current tube amps are abysmal. Etc.
 

fpitas

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You see, with all these $100 devices that measure phenomenally well, but sound like crap.... this site will slowly get to a point where.... there will be no point to measure anything anymore. Of course, there will be $50 devices in a year that will measure better than the current $100 device... but people will lose interest. What's the point? Who cares... at that price point the subjective vs objective would lose any meaning.

What will remain is going to be the question: despite the phenomenal measurements that Amir is showing here, why does this still sound like crap...
Wait...what? Forget the wink emoji?
 

Geert

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Amir received it, my guess UPS will have to answer for this after the guys at Pass Labs take a look at it.
You mean you're going to send it to Pass Labs for inspection?
 
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