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Review and Measurements of Neurochrome HP-1 High-Performance Amp

wadec22

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If performance = power, then yes. The HP-1 will outperform the HPA-1.

HPA-1 has lower distortion (at least at normal-to-high listening levels where I'm currently able to measure) and lower IMD. So if performance = low distortion, the HPA-1 performs better than the HP-1.

The HPA-1 also has lower output impedance that the HP-1, so if performance = output impedance, the HPA-1 wins.

I can't give you something for nothing. There is no free lunch. To reach the price point I target for the HPA-1, something had to give. I traded output power and 4-pin output in exchange for a lower price. I was able to improve other parameters, including those mentioned above. To me, those tradeoffs were well worth it. You're free to disagree.

Tom

How do you see it faring in the 50mv SNR? Right there with RME, JDS & THX? With so many headphones getting lower impedance to work with phones and portable sources - this is one of my most coveted measurements. In fact, if I was to hope for anything different with my JDS and your amp would be the inclusion of 1/8" jack for IEMs too. Adapters are a pia.
 

JohnYang1997

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How do you see it faring in the 50mv SNR? Right there with RME, JDS & THX? With so many headphones getting lower impedance to work with phones and portable sources - this is one of my most coveted measurements. In fact, if I was to hope for anything different with my JDS and your amp would be the inclusion of 1/8" jack for IEMs too. Adapters are a pia.
Let me guess, better than atom, better than 888, on par with 789, worse than adi2dac(iem).
 

wadec22

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Let me guess, better than atom, better than 888, on par with 789, worse than adi2dac(iem).
Pretty sure current rankings go RME>JDS>789

so you think on par with JDS maybe? Can't be on par with 789 and better than JDS ;)
 

tomchr

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tomchr

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1/8" jack for IEMs too. Adapters are a pia.
I'll keep that in mind. I can't squeeze another connector into the HPA-1. I'm out of room!

Tom
 

Azeia

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The 250 mW (300 Ω), 1 W (20 Ω, 32 Ω) of the HPA-1 is enough to destroy most headphones. Is that really not enough power? Sure, if you run a pair of HifiMan HE-6 and want 120 dB SPL, you won't get enough power from the HPA-1. But then, you won't get enough power to do that from most other headphone amps either...
I was mostly asking because in the HP-1 review, Amir had this to say about it's massive power output:
As always, I started my listening tests with my Sennheiser HD-650. Ah, you have not heard clean bass until you power this headphone with this class of amplification. It is authoritative and at high volumes, it has no trouble making your ear lobes resonate with the music! :eek: Here I started with medium gain but then switched to high-gain for inconvenience for my "audiophile" recordings that have lower levels.
I don't know enough about this stuff to know if 250mW will provide the same effect that Amir was talking about, but yeah.
If that's your idea of a good time, you may just have to wait until I design that discrete output stage, wrap a fancy box around it, and charge $2-3k. :)
Will Neurochrome ever have any other DIY headphone amps in future or is it just going to be speaker amps and so on for the most part?
 

tomchr

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I was mostly asking because in the HP-1 review, Amir had this to say about it's massive power output:
Fair enough. I will also admit that I was so excited by the low THD and my ability to finally measure something (even though I may post even better measurements later) that I forgot about the lower power output of the HPA-1. In 99.9% of practical cases, the lower power output is inconsequential.

I don't know enough about this stuff to know if 250mW will provide the same effect that Amir was talking about, but yeah.
250 mW is less than the 400 mW I got from the HP-1. Not much less, though. 2 dB less to be exact. Audibly lower, but only barely.

Will Neurochrome ever have any other DIY headphone amps in future or is it just going to be speaker amps and so on for the most part?
I just wrote about that in my latest newsletter (which you can sign up for here: www.neurochrome.com/newsletter). I'm toying with the idea of a DIY headphone amp. It'll be lower spec than the HPA-1 and it will *NOT* be available as an assembled product. I don't want to compete with myself.

Tom
 

tomchr

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I'm getting better at this product photography thing. :)

Observant readers will note the audiophile compatible Torx-Plus screws. Cryogenically treated, of course (i.e. I threw them in the freezer overnight :)).

Tom
 

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elira

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I'm getting better at this product photography thing. :)

Observant readers will note the audiophile compatible Torx-Plus screws. Cryogenically treated, of course (i.e. I threw them in the freezer overnight :)).

Tom
What is the expected lifespan of those switching power supplies?
 

tomchr

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MTBF is specified to be 1210000 hours (a bit over 138 years). Do you think that's enough? :)

Tom
 

tomchr

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As soon as I have one to send, yes. I'll wait until I have the first production batch, though. What you've seen so far has been prototypes that I've hand-soldered. The machine assembled boards tend to perform better, both in terms of consistency and in terms of absolute performance. The downside of this is that we'll likely have to wait until Christmas to get Amir's results...

Tom
 

escalibur

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I'm getting better at this product photography thing. :)

Observant readers will note the audiophile compatible Torx-Plus screws. Cryogenically treated, of course (i.e. I threw them in the freezer overnight :)).

Tom
How about silver version too?:)
 

tomchr

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At this price point I can't justify the extra expenses and inventory involved with maintaining two colour options. Sorry.

Tom
 

tomchr

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My site is up and open for pre-orders: www.tomchr.com I suppose I should edit my signature line at some point... :)

Tom
 

tomchr

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Great indeed!
All the best for the most wonderful starting of your business!
Thank you!

Looks nicer without the top! How about one with clear top?
Heh... A few years back, I presented the HP-1 sandwiched between two sheets of plexiglass. Quite a few who saw it wanted it in that "chassis". The metal chassis arrived one day late - the day after the HeadFi meet. Grr....

Tom
 
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