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

tomchr

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Yeah... There's a reason I have the APx525 and not the 555. I simply could not justify the cost of the 555. As it was, I lost quite a bit of sleep when I dropped a 5-figure check on the 525. The performance of the AP gear is out of this world too, though. And unlike just about any other piece of engineering software I've come across, the APx software is a true joy to use.

Tom
 

JohnYang1997

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What about full frequency thd and thd+n for 1mw 10mw 100mw power into 32ohm?
In real world we hardly use more than 10mw so high frequency distortion and noise are sort of more important.(as 1khz high impedance load usually shows the best figure.)
 

tomchr

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I can't speak for the THX 789, but the HP-1 will show only noise at 1 mW, 10 mW, and likely 100 mW as well. Thus, the THD+N vs frequency measurement will show the +N and not the THD. You'd need to look at the harmonic spectrum, assuming the analyzer has enough dynamic range to resolve the harmonics.

Tom
 
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Tom,
Any chance you would submit one of your Modulus models for testing? I only kits kits of these for sale, but have not looked on Massdrop.
The specs and graphs you show are in the same range as the numbers seen for the Benchmark and Hypex models. SOTA.
I could almost use the HP-1 to drive my speakers. The low level linearity is most important to me. Usually I see testing of amplifiers close to clipping. I am more interested in testing way below one watt output.
 

amirm

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tomchr

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My products aren't on Massdrop, so no wonder you couldn't find them there. :) Are you looking for a fully assembled amp? If yes, I suggest looking out for the review of the Modulus-286 Kit that is currently underway by DHL to Amir. He has my permission to sell the amp after he's done testing it.

My long-term plan is to offer fully built amps. I can certainly start assembling Modulus-286 Kits - at least until supplies run out as the Kit will be a limited edition with only 28 made. Once Amir's measurements become available, those interested in an assembled amp can contact me privately with their offers.

Tom
 
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I've been eyeing the Modulus-686, and wondering if it'd be possible to maintain fidelity, but parallel more than 6 LM3886's for even more power. I like to run multiple 12"-18" midbass woofers. The 300+ uber-clean watts of the 686 is enough, though. I can make it work.

I like that Neurochrome will offer more completed amps, but I hope DIY modulus boards are still around when I'm ready.

I'd probably need something like the UcD2K for the subbass woofers I guess.
 

tomchr

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I've been eyeing the Modulus-686, and wondering if it'd be possible to maintain fidelity, but parallel more than 6 LM3886's for even more power. I like to run multiple 12"-18" midbass woofers. The 300+ uber-clean watts of the 686 is enough, though. I can make it work.
The Modulus-686 delivers 360 W into 4 Ω at < 0.1% THD+N. If you widen that to the 1% or 10% THD+N used by other manufacturers, you're over 400 W. In that end of the plot, the data points are tens of watt apart (even at 90 points for the complete plot), so selecting the next data point to the right on the curve will make a dramatic difference in the output power spec. I feel comfortable quoting 360 W, though. I like to be able to sleep at night... :)

You wouldn't get much from using eight LM3886es rather than six. The six LM3886es operate well within their max output current spec.

I like that Neurochrome will offer more completed amps, but I hope DIY modulus boards are still around when I'm ready.
I'll keep offering the DIY and OEM options as long as it makes sense to do so. Basically: Keep buying them! :)

It'll take time to ramp up on the commercial offerings, so I expect the DIY stuff to be around for years to come. That said, I'll push on Neurochrome 100% once I graduate with my psych degree in April.

Tom
 

amirm

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It'll take time to ramp up on the commercial offerings, so I expect the DIY stuff to be around for years to come. That said, I'll push on Neurochrome 100% once I graduate with my psych degree in April.
Is that degree to deal with crazy audiophiles??? :D
 

Sylafari

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Hopefully in the future you will have that speaker amplifier kit you are selling in a fully assembled version with a case like the one you use on the Neurochrome HP1 (the speaker amplifier kit case just looks too bare boned :D, doesn't even have the logo on it :eek:).
 

JohnYang1997

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I can't speak for the THX 789, but the HP-1 will show only noise at 1 mW, 10 mW, and likely 100 mW as well. Thus, the THD+N vs frequency measurement will show the +N and not the THD. You'd need to look at the harmonic spectrum, assuming the analyzer has enough dynamic range to resolve the harmonics.

Tom
Sorry i didn't check the forum til now. What about 1khz 5khz 10khz distortion spectrum at 1mw 10mw into low impedance load like 16 ohm 32 ohm? Not asking 8 ohm since it's still headphone amp. Looking forward to it. Because when i do my measurements it's hard for me to get low high frequency distortion at low impedance load out of lme49600. Thanks.
 

tomchr

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As I mentioned in the bit you quoted, at 1 mW, 10 mW, and likely 100 mW as well, you will see the +N part of the THD+N - not the THD part. At 100 mW, 10 kHz, you'd probably see a harmonic starting to develop at the edge of the noise floor. Whether that's of practical relevance is another thing. After all, the harmonics of 10 kHz are all beyond the range of human hearing (assuming you're older than seven years old anyway :)).

I'm working on a Distortion Microscope that'll allow me to boost the dynamic range of my APx525 by about 40 dB. Gimme a month or two then I'll have actual numbers for you. Right now I'm limited by the -112 dB THD+N of the signal source in the AP.

Tom
 

tomchr

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HP-1 is on sale at $999 for the fully assembled version while supplies last. I have five of them in graphite grey sitting on the shelf with another five boards ready for mounting in chassis. I will honour the sale pricing until I'm out of assembled boards.

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

Tom
 

W2S

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Would love to buy one of your Amps in Red fully assembled as just to busy for DIY method

But hate having to deal with Tax & Custom any Plans to have a UK or European distributor

@Keith Purité Audio

Maybe we have our own ASRDrop

o_O
 

tomchr

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You'll probably have to deal with taxes and customs either way. It's just a matter of whether they'll be rolled into the price or charged at the time of delivery. The customs fees should be manageable as Canada has a trade agreement with the various EU countries. The sales tax is the same as you pay for any other product you buy.

Would you like to become a distributor? ;)

Tom
 
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