Pass Labs HPA-1 Headphone Amp Review

[Tom C]

The DC Hi-Fi Group had a special virtual meeting with Nelson Pass yesterday.

One of the best comments from Nelson was "It's entertainment, not Dialysis"

Lots of good discussion about the art and science of designing audio from a true legend of the industry.

Well, it’s not dialysis, but it’s priced like dialysis

 

[danielsmi]

On the Pass Labs website it says that the HPA-1's power supply comes with a "faraday shield" but I didn't see a faraday cage in the internal pic amirm posted. Is the black cover on the toroid the faraday shield?

Headphone Amp Archives - Pass Labs

Headphone Amp

www.passlabs.com

 

[Extreme_Boky]

I do not see anything inside that amp that could be called a faraday shield. I see a fully enclosed aluminium box and a toroid transformer that, by close inspection, may have internal shielding sheets (but no ground-connected drain leads coming from that transformer). I might be missing something there that is not obvious to the naked eye...???

 

[WayneC]

I do not see anything inside that amp that could be called a faraday shield. I see a fully enclosed aluminium box and a toroid transformer that, by close inspection, may have internal shielding sheets (but no ground-connected drain leads coming from that transformer). I might be missing something there that is not obvious to the naked eye...???

The transformer has a mu metal shield and an electrostatic shield with a ground wire on the connecto.

 

[Extreme_Boky]

Thanks Wayne.

 

[GXAlan]

Sony TA-ZH1ES: A DAC/Headphone Amp with a Sonic Signature?

Sony TA-ZH1ES: A DAC/Headphone Amp with a Sonic Signature? Stop. やめる. Halt. Arrêt. You probably shouldn’t read the rest of this post, it's triggering. There's a lot of speculation even though there are a good amount of measurements too. If you're looking for a transparent DAC/headphone...

www.audiosciencereview.com

Posted a zero negative feedback headphone amp from Sony. Super high distortion like this Pass Labs but ultra clean power supply in comparison.

 

[dtaylo1066]

Second and third harmonics for Pass lovers, so I get that maybe, but power supply noise and other issues inexcusable.

 

[milosz]

The amp is spec'd at 1 volt. Measuring it at 2 volts is in keeping with measurements of other headphone amps, but expecting it to meet the published specs at 2 volts is somewhat of an unreasonable expectation.

Have any blind listening tests been done to see if anyone can actually hear a difference between this amp and say a Benchmark or TOTL Topping headphone amp? Audio equipment is made for listening - beyond a certain point measurements are meaningless. I'd like to know if there is any audible difference between a 101 dB SINAD and an 83 dB SINAD in actual listening practice.

At any rate, this amp is overpriced. It's likely handmade, more or less, in the USA by people paid at a local wage scale, and in small numbers - so I can understand that it is going to cost more than an amp made mostly by machines in Asia and with just a little poorly-paid human labor; still the cost is unreasonable. Perhaps the value of a product like this is it shows there really isn't a demonstrable correlation between price and performance in audio gear.

It's also interesting to point out that Schiit products are assembled entirely in the USA and they have much lower prices and better performance. I'm not sure I could hear the difference in performance, but I can afford to BUY a Schiit amp-