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

[tomchr]

My market analysis showed that the vast majority of prospective buyers do not expect an XLR output on an amp at this price point, so I chose not to include one. There also isn't enough room in the chassis for another connector and I'm tied to this chassis for cost reasons. Market wanted Neurochrome HP-1 performance at a lower price point, so that's what I'm aiming for. It looks like I'm beating the HP-1 on performance at about half the price. In return, I have to drop the XLR output. To me, that's a reasonable tradeoff.

The answer to your second question can be found in Post #284. Yes. The HPA-1 has XLR inputs.

Tom

 

[deafenears]

It looks like I'm beating the HP-1 on performance

Do you have measurements comparing both? I tried checking your neurochrome.com site but the HP-1 is no longer there.

 

[tomchr]

You can find the HP-1 measurements in the Support section of my website. Or view Amir's measurements in Post #1.

I don't have any HP-1s to measure at this point, so I can't compare A vs B directly.

Tom

 

[August]

It looks great, but it seems a bit difficult to buy in China. took me 45 days to buy atom

 

[JohnYang1997]

It looks great, but it seems a bit difficult to buy in China. took me 45 days to buy atom

The new fiio k5 pro looks pretty good.

 

[Veri]

The new fiio k5 pro looks pretty good.

0,004%THD right? Not exceptional. Also let's keep it OT

 

[JohnYang1997]

0,004%THD right? Not exceptional. Also let's keep it OT

I saw 0.002%. The thing is the jrc volume control should be the limiting factor, using digital volume control should give performance gain. But at it's best it's just pretty good not amazing.

 

[tomchr]

It looks great, but it seems a bit difficult to buy in China.

I offer shipping by DHL if you want it fast. They deliver most places in the world within a few days. Faster if you're in a major metropolitan area.

Tom

 

[elnan14]

It looks great, but it seems a bit difficult to buy in China. took me 45 days to buy atom

Now you can understand the feeling of buying from Aliexpress from an American country (yes, people from the U.S., America is a continent, not a single country )

 

[Hemi-Demon]

My market analysis showed that the vast majority of prospective buyers do not expect an XLR output on an amp at this price point, so I chose not to include one. There also isn't enough room in the chassis for another connector and I'm tied to this chassis for cost reasons. Market wanted Neurochrome HP-1 performance at a lower price point, so that's what I'm aiming for. It looks like I'm beating the HP-1 on performance at about half the price. In return, I have to drop the XLR output. To me, that's a reasonable tradeoff.

The answer to your second question can be found in Post #284. Yes. The HPA-1 has XLR inputs.

Tom

Appreciate the explanation

 

[August]

I offer shipping by DHL if you want it fast. They deliver most places in the world within a few days. Faster if you're in a major metropolitan area.

Tom

One or two weeks is the transit time, and there is also an uncertain customs release time. Thank you for your reply

 

[JohnYang1997]

One or two weeks is the transit time, and there is also an uncertain customs release time. Thank you for your reply

I reckon dhl can do 3 day, if you pay the premium.

 

[tomchr]

One or two weeks is the transit time, and there is also an uncertain customs release time. Thank you for your reply

Yeah... To "far away" destinations, DHL generally takes about a week. Customs clearance usually happens while the package is in the air, but occasionally a package does get pulled for inspection, which can take a bit.

If you want faster customs processing, go with FedEx. You pay twice as much as with DHL, but they handle their own customs clearance and factor the processing time into their shipping times. At least they do here in Calgary. The FedEx place is by the airport and the planes literally taxi to the back of the FedEx building. Stuff is dropped off and processed right there. Trucks go out from the opposite side of the building (the side that faces the street, not the runway ). I get stuff from Mouser all the time shipped by FedEx. If I order by 5pm, I'll have the box of parts the next morning by 10.30/11am ... shipped from Texas.

I reckon dhl can do 3 day, if you pay the premium.

I offer DHL Worldwide Express, which comes in 2-3 "flavours" depending on whether you want the package by 9AM, 12 noon, or before the end of the day. I believe the official quote is that it's a 1-4 day service. If you're in a densely populated area, close to a major airport, the delivery time is closer to one day. For those who are in sparsely populated areas, delivery is closer to 3-4 days. Probably longer if you're on the opposite side of the planet from Canada.

Tom

 

[maxxevv]

You definitely don't want to use FedEx for sending stuff into China. They have got some trouble with the chinese government over the HuaWei case.

 

[tomchr]

Oh joy...

 

[Azeia]

It looks like I'm beating the HP-1 on performance at about half the price.

What gain level were those tests at? I ask because I notice you said 250mW at 300 Ohms, whereas the HP-1 was able to do around 395mW as I recall from Amir's measurements. I'm mainly curious whether the HPA-1 also beats the HP-1 in terms of clean power output at highest gain setting.

 

[JohnYang1997]

What gain level were those tests at? I ask because I notice you said 250mW at 300 Ohms, whereas the HP-1 was able to do around 395mW as I recall from Amir's measurements. I'm mainly curious whether the HPA-1 also beats the HP-1 in terms of clean power output at highest gain setting.

>300mw probably. Not going to be more than HP-1, I assume.

 

[tomchr]

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

 

[tomchr]

>300mw probably. Not going to be more than HP-1, I assume.

That's a valid assumption. To get more power than the HP-1 will require a discrete output stage. Or $200 worth of LME49600s in a bridge/parallel (non-starter).

At the $549 (intro); $699 final price point I'm targeting for the HPA-1, I think you get a lot of value where it matters (low distortion, low IMD, low noise, balanced and unbalanced input, integrated power supply, solid engineering, etc.)

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... 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.

Tom

 

[JohnYang1997]

For he6
The current output requirement is about 570mA for 120dB, not far off. But it needs 32Vrms voltage swing so......
But from a different point of view, since current is ample, there shouldn't be suffer from distortion when cranked to max. No one needs 120dB anyway.
And 105dB only requires 571mW. So for actual usage with ample dynamic. It is more than enough.