Well, they forgot to connect the feedback loop…It doesn't perform like it.
Last edited:
Well, they forgot to connect the feedback loop…It doesn't perform like it.
Its power consumption doesn't change depending on the volume level or how much bass there is, even with the inefficient DCA Stealth. That's class A like behavior as far as I understand it.It doesn't perform like it.
Stereophile measured this and both objectively and subjectively evaluated it as excellent:
Pass Labs HPA-1 headphone amplifier Measurements
Sidebar 3: Measurements I measured the Pass Labs HPA-1's electrical performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I performed a full set of measurements from both the HPA-1's preamplifier and headphone outputs. The graphs all refer to the headphone...www.stereophile.com
Thoughts Amir? @amirm
I'm very interested in what you think of the stereophile evaluation.
I'd like to hear @amirm 's perspective. It's interesting to me how JA can twist the measurements to make it appear to have "superb measured performance that reflects equally superb audio engineering."
When it is incorporated into an RME ADI 2 DAC. But that is a cheating answer.Can someone answer the question when would spending over $1000.00 for a headphone amp be a good idea ? I’m seriously asking.
It is hard to analyze some of his measurements as they lack clear parameters. Take THD+N vs frequency:Stereophile measured this and both objectively and subjectively evaluated it as excellent:
Pass Labs HPA-1 headphone amplifier Measurements
Sidebar 3: Measurements I measured the Pass Labs HPA-1's electrical performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I performed a full set of measurements from both the HPA-1's preamplifier and headphone outputs. The graphs all refer to the headphone...www.stereophile.com
Thoughts Amir? @amirm
I'm very interested in what you think of the stereophile evaluation.
A shame as I did not see any hostility there. Folks were just talking back and forth. Answering some of their questions, I am driving the amp harder than the 2 volt dashboard. That 1 khz tone also the best case distortion rating for the amp, not the worst which occurs in higher frequencies. And distortion in high frequencies is precisely jumped out at me. Folks said I "hate" pass labs. I am without emotion as I go into every review. I can't afford to act differently as measurements must back what I claim. I am not like a subjectivist reviewer who can say anything and you have no way of disproving it. An amp that runs out of power is going to sound poor into a power hungry headphone. There is no two-ways about it unless you listen at very low levels which I noted.Idiots from diyaudio.com locked the thread.
If you don’t do a listening test:As to the review not being "scientific," it is not supposed to be. I am doing a review which includes subjective remarks about the look and feel of the unit in addition to fidelity.
If you do a listening test:But did you listen to it?
You can never win…But that’s not science!
Oh yes. They say for example that benchmark HPA4 cannot drive susvara but pass hpa1 is very good option.....inb4 somebody claims this amp made their hifiman HE6 or sennheiser hd800 sound glorious
Wrong guerilla bossman.The reviews read like this, "it is a Pass Labs so of course it sounds great." What amazing brand he has built. Power of gorilla marketing in forums....
Switching to high impedance Sennheiser HD-650, to my surprise, made it worse. Yes, there was enough volume now but distortion would set in early and keep getting worse. At max volume, the sound was miserable
I listen to range of volumes from below to above the measurement in the dashboard.@amirm , is my assumption correct that for the listening test you were using higher levels than for the measurements?
I listen to range of volumes from below to above the measurement in the dashboard.
Stereophile measured this and both objectively and subjectively evaluated it as excellent:
Pass Labs HPA-1 headphone amplifier Measurements
Sidebar 3: Measurements I measured the Pass Labs HPA-1's electrical performance with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I performed a full set of measurements from both the HPA-1's preamplifier and headphone outputs. The graphs all refer to the headphone...www.stereophile.com
Thoughts Amir? @amirm
I'm very interested in what you think of the stereophile evaluation.