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

tomchr

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Hmmm.... Let's see if we can get that set up. Would you toss me an email? Take my username here and add @neurochrome.com

Tom
 

tomchr

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I'll be discontinuing the HP-1 and it's currently on clearance sale. It uses too many good parts, hence is way too expensive to produce. If you want an extraordinary headphone amp, now's your chance.

I have one (1) blue HP-1 sitting in Los Angeles. It was demoed at CANJAM in NYC in February. It will ship via USPS Priority Mail from LA. Since it's a demo, I've shaved a few bucks off the price: $949 (down from $1250).

I currently have one (1) graphite grey HP-1 in stock and four more arriving within 1-2 weeks. $999 (down from $1250).

You can find them here: https://www.neurochrome.com/product/hp-1-ultra-high-end-headphone-amp-2/

My website keeps track of the inventory, so what you see there is what's currently available. I'll take backorders on the graphite grey HP-1 until four have sold. Then the HP-1 will be allowed to retire.

Thanks,

Tom
 
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I'll be discontinuing the HP-1 and it's currently on clearance sale. It uses too many good parts, hence is way too expensive to produce. If you want an extraordinary headphone amp, now's your chance.

I have one (1) blue HP-1 sitting in Los Angeles. It was demoed at CANJAM in NYC in February. It will ship via USPS Priority Mail from LA. Since it's a demo, I've shaved a few bucks off the price: $949 (down from $1250).

I currently have one (1) graphite grey HP-1 in stock and four more arriving within 1-2 weeks. $999 (down from $1250).

You can find them here: https://www.neurochrome.com/product/hp-1-ultra-high-end-headphone-amp-2/

My website keeps track of the inventory, so what you see there is what's currently available. I'll take backorders on the graphite grey HP-1 until four have sold. Then the HP-1 will be allowed to retire.

Thanks,

Tom
Are you planning on creating something cheaper?
 

tomchr

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Nothing I do is cheap... :)

The HP-1 is a stellar performer, but at the current manufacturing cost, it needs to sell for around $2500-3000. That's unrealistic for a couple of reasons, some of which have been discussed here. Also, many perceive DIY as cheap, and it's delusional to charge $3k for something that you advertise as a DIY project for a lot less.

Any reincarnation of the HP-1 will need to have a lower production cost. This may reduce performance slightly, but I'm obviously planning to keep the performance as-is or improve on it if possible. Any reincarnation of the HP-1 is guaranteed to have a higher price tag than the current HP-1.

I am toying with the idea of a lower cost "starter amp". It would be nice if I could hit a $500 price point, but doing so even at QTY 100 is tough. It is also guaranteed to be lower spec'ed than the HP-1, especially on output power.

I do not have any designs ready at this time. I'm working to wrap up my psychology degree. I'll be done with my degree requirements in April, but there might be a few loose ends (publications) to tie up. Then I'll take a break for a few weeks before focusing full time on audio. I should be hitting full stride over the summer.

So there you have it. Life in the business. :)

Tom
 

JohnYang1997

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Nothing I do is cheap... :)

The HP-1 is a stellar performer, but at the current manufacturing cost, it needs to sell for around $2500-3000. That's unrealistic for a couple of reasons, some of which have been discussed here. Also, many perceive DIY as cheap, and it's delusional to charge $3k for something that you advertise as a DIY project for a lot less.

Any reincarnation of the HP-1 will need to have a lower production cost. This may reduce performance slightly, but I'm obviously planning to keep the performance as-is or improve on it if possible. Any reincarnation of the HP-1 is guaranteed to have a higher price tag than the current HP-1.

I am toying with the idea of a lower cost "starter amp". It would be nice if I could hit a $500 price point, but doing so even at QTY 100 is tough. It is also guaranteed to be lower spec'ed than the HP-1, especially on output power.

I do not have any designs ready at this time. I'm working to wrap up my psychology degree. Then I'll take a break for a few weeks before focusing full time on audio.

So there you have it. Life in the business. :)

Tom
Come on. Just make a opa2156 + tpa6120 composite amplifier, easily beat down atom and sell it at twice of the price.
 

tomchr

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The Atom sells for $99. Twice that would be $199. That leaves less than $40 for components, chassis, etc. at common on-line retail margins. Of course you'll want brushed aluminum and a volume knob that's large and "feels right", right?

The TPA6120 data sheet does not have enough information to actually design with the IC. No AVOL curve, for example. That's unusually retarded. I could request one through TI's E2E channel, though. Or buy one and measure it. Thanks for mentioning it. It looks like a quite nice amp, but a little error correction could really make it shine.

Tom
 

JohnYang1997

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The Atom sells for $99. Twice that would be $199. That leaves less than $40 for components, chassis, etc. at common on-line retail margins. Of course you'll want brushed aluminum and a volume knob that's large and "feels right", right?

The TPA6120 data sheet does not have enough information to actually design with the IC. No AVOL curve, for example. That's unusually retarded. I could request one through TI's E2E channel, though. Or buy one and measure it. Thanks for mentioning it. It looks like a quite nice amp, but a little error correction could really make it shine.

Tom
Main issue is the stability/output resistor. Solution is to just wrap the 2156 around the tpa6120 and the resistor then it'll be stable and low output impedance. Ths6012 is essentially what tpa6120 is grab simulation model and datasheet through that. Also take a look at ada4870. It shall perform as well.
 

tomchr

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ADA4870. Nice chip. $15 at QTY 100. That leaves about $25 for everything else, including the power supply and chassis. :)

I think you might have missed my point about retail margins.

Tom
 

tomchr

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The TPA6120 has higher output current too, which is nice. I'll keep thinking about it. I think a selling price of $199 is completely out of reach, though. Also, if it performs well, it should cost more than that. I have no plans for joining the race to the bottom and compete on price.

Tom
 
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My website keeps track of the inventory, so what you see there is what's currently available. I'll take backorders on the graphite grey HP-1 until four have sold. Then the HP-1 will be allowed to retire.
Do you happen to have it in black?
 

Shadrach

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I would buy this as a build it yourself project.
I have nothing but admiration for tomchr whose threads on other forums I've read.
If I had read this review and the various threads associated with it's build before I had ordered the jds atom this would probably have been my preference. As it is, I shall probably look into re casing the atom once it's arrived.
It's a bit expensive but it's not a mass production item so this is to be expected.
I'm looking at the other products and I'm getting that soldering iron twitch.
There are always things that could have been done 'better' with such products but 'better' costs money and often has nothing to do with the performance.
@tomchr if you do build a lower priced headphone amp please have it reviewed here.
 

tomchr

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I just ordered unpopulated board from your website. I was wondering if there is detailed guide for assembly?
There is. I just packed up your order and it'll be underway today. You should now see an email titled "Please download your design documentation". That'll have a download link to the documentation.

There are a few parts out of stock currently with Mouser. If you have trouble finding substitutes, just toss me an email and I'll help you out finding substitutes. There are substitutes available for everything (as far as I know), so you can get going as soon as your board arrives.

Do you happen to have it in black?
I can special order a black chassis. It's $299... My vendor charges $280+shipping for QTY = 1 orders, so I'm selling it at cost to help people out.

There are always things that could have been done 'better' with such products but 'better' costs money and often has nothing to do with the performance.
You are absolutely right. The things I need to improve on the HP-1 (volume knob size, volume knob feel, aesthetics of the chassis, tweaks to make it easier to assemble in production, production cost) have nothing to do with the technical performance of the amp. Rather, they have everything to do with consumer psychology and the experience of using the product. Better and more luxurious experience -> higher price.

Then you add the DIY vs retail conundrum. This is why I with Neurochrome will focus on delivering amplifier modules for the DIY and OEM market going forward. Any retail products I offer will be offered either as a separate product line under Neurochrome or as a separate brand. These retail products will not be available in DIY form and will offer better performance than my DIY products. But they will also be in pretty and expensive boxes. :)

@tomchr if you do build a lower priced headphone amp please have it reviewed here.
I hope Amir will be willing to review any of my products, regardless of price. :) If he is, I'll be happy to ship my stuff to him. You can also see the measurements on my website. I use an APx525.

Tom
 

tomchr

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I would appreciate it if you'd toss me an email with customer support requests. Just take my user name here and add @neurochrome.com

Tom
 

WLX

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Tom, I just ordered an HP-1 from your website.

I plan on using this headphone amp to drive my Avantgarde Duo horn speakers ( rated at 107db/w, 16ohm ). The amp should be able to deliver 2.4w power to the speaker load and give me around 111db.

Do you think this is a reasonable thing to try?
 

tomchr

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Yep. You should get around 110-111 dB from each speaker, so 113-116 dB in the room depending on the correlation between signals. That's almost loud enough to instantly cause permanent hearing damage. :)

With that kind of sensitivity, you'll really enjoy the low gain and low noise floor of the HP-1.

Tom
 

chriskilbourn

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