NuForce HAP-100 High Performance Preamp and Headphone Amplifier (Black)


Modern Modder Man of Manitoba
HTML... uphill, both ways!
Pros: excellent preamp, extremely low amp noise floor, plays very well with high impedance headphones, excellent digital attenuator
Cons: limited current capacity in the amp


Headphoneus Supremus
Pros: Excellent Synergy with HD800 headphones, remains versatile with other headphones that demand more power and current output, digital volume pot
Cons: With very sensitive headphones the noise level can intrude during quiet parts AFTER the volume knob goes above 75-80 out of 99 max, slight mid fwd
See the following link for my DAC-100 impressions in the DAC-100 announcement thread from Sept 2012: - update - summary post with everything previously posted in it - added LCD-2 rev2 - clarifications - clarifications - can also cont reading all of DAC-100 thread for a few tidbits here and there
See the following link for my DAC-100 Impressions in the HD800 thread (for good synergy):
I started with the DAC-100 last July and had posted impressions in the Nuforce announcement thread, where I posted very similar things to the review that Project86 posted recently.  The DAC-100 is a near perfect match for the HD800, driving them better than my DACmini or maxed Woo WA6.  I typically don't enjoy the DACmini nearly as much with HD800, and the tubes I have to put in the WA6 for the HD800 don't work as well when using any other headphones.
Still, the Nuforce DAC-100 drives the LCD-2 and HE-500 about as well as the WA6, but neither amp is as punchy as the DACmini with those phones.  The Nuforce DAC section seems to be on par with that of the DACmini and Stello DA100 Signature in overall performance, but not as smooth as the Stello.  Like the DACmini, the DAC-100 is more detailed than the Stello or more revealing, but the Stello is more forgiving of poor source material.  The Stello USB input is also not nearly as good as the Nuforce or DACmini USB input.
The DAC-100 is good enough that I'm using it as my primary source in the bedroom rig, and feeding the RCA output into my HAP-100 (with the HAP-100 RCA out feeding the DACmini, and then feeding the DACmini output into the WA6).  But, I haven't turned on the WA6 or EF5 amps in weeks.  I mostly use the DAC-100 for source and directly driving HD800, or the DAC-100 for source plus the HAP-100 or DACmini driving the LCD-2 and HE-500 or IEM.
I also found that the DAC-100 high noise floor could be an issue with very sensitive low impedance phones like V-MODA M-100 and D7000.  As for the level of engagement of the midrange, it's not bad at all in the DAC-100 but the Nuforce HAP-100 amp paired with this DAC does have a more involving midrange, along with lower noise floor and a bit more power.  With the HAP-100 added I don't really need the DACmini or WA6, but I do still use them for IEM; and I sometimes enjoy the slightly more engaging mids of the DACmini or WA6 at times.
As a DAC/amp combo I prefer the DAC-100 to my old Apogee Mini-DAC which had a slightly aggressive sounding flat soundstage headphone amp, but an excellent DAC.  I found even a $180 Travagans Red amp to be an upgrade over the Apogee headphone amp, which still worked well enough with high end Grados and HD600. I'd still prefer to use an external amp with the DAC-100, but with HD800 that isn't necessary and with many other popular orthodyamics the external amp is still optional.  The only thing that is an absolute NO with DAC-100 are all my IEM (hiss), and HE-6 (power).
[size=10.5pt]Nuforce HAP-100:[/size]


[size=10pt]I'm feeding the DAC-100 into the HAP-100, but looping out into the DACmini (and looping out of the DACmini into my WA6 or SR-71b amp for IEM).  Crazy, but it's a good way to quickly compare the output from each of these amps with one source.  I'm using ALO SXC interconnect cables or similar quality for my connections, and a Nuforce brand USB cable.  My transports were a retina Macbook Pro via USB, a Nuforce iDo with iPod Nano via coax, using lossless music in 16/44.1 and 24/96, and a Nuforce CDP-8 CD Player with Coax and RCA outputs.[/size]


[size=10pt]HAP-100 FEATURES - $595 MSRP:[/size]

[size=10pt]§  [/size][size=8.5pt]A preamplifier stage providing 5dB of gain with zero negative feedback for fatigue-free listening[/size]
[size=10pt]§  [/size][size=8.5pt]A single-ended Class A headphone amplifier stage (a design topology long held by audiophiles to be the last word in headphone reproduction)[/size]
[size=10pt]§  [/size][size=8.5pt]Top-grade relays for input selection[/size]
[size=10pt]§  [/size][size=8.5pt]A linear power supply employing a toroidal transformer, large capacitor reserves and high-speed regulation for fast, clean power to all circuits[/size]
[size=10pt]§  [/size][size=8.5pt]A signal-to-noise ratio in excess of 100dB[/size]
[size=10pt]§  [/size][size=8.5pt]THD+N = 0.002%, assuring the ultimate in accurate reproduction[/size]
[size=10pt]§  [/size][size=8.5pt]Four low-noise, stereo RCA inputs[/size]
[size=10pt]§  [/size][size=8.5pt]One RCA stereo output offering a full 7.8Vrms to effortlessly drive any amplifier. This output can be turned off (by pressing On and then Input buttons on the remote control) while the 6.3mm headphone output remains enabled.[/size]
[size=10pt]§  [/size][size=8.5pt]A front-panel 6.3mm jack for large, over-ear headphones[/size]
[size=10pt]§  [/size][size=8.5pt]A stylish three-digit display (setting 1 for input selection / settings 2 and 3 for output levels from 00-99)[/size]
[size=10pt]§  [/size][size=8.5pt]A full-featured remote control[/size]

[size=10pt]The DAC-100 and HAP-100 have a nice symmetry when stacked together - both have the volume knob on the right of the front panel, a 1/4" headphone jack on the left, and in the center of the front panel they have indicators for which input is selected.  They differ in how the inputs are selected - the input of the DAC-100 is selected by pressing a different button on the front for each input (USB, coax x 2, optical), while quickly pressing in the volume knob on the HAP-100 will cycle through one of the four analog inputs with each press.  A press-hold-release on the HAP-100 volume knob will put it into standby mode after you release the volume knob.  However, a quick press-release on the volume knob on the DAC-100 will put it in standby mode.  The HAP-100 also has a digital display for the volume level 0 - 99.  [/size]


[size=10pt]Both the DAC-100 and HAP-100 use a standard IEC cable for power, with an internal power supply and a power-on switch next to the IEC input on the back.  They both have an RCA output, in which the output level is controlled by the digital volume pot.  Both units have a slight wobble to the volume knob when intentionally wiggled, a normal consequence of using a digital rotary encoder.  Otherwise they feel solidly built.  They also both run a bit warm, due to the class-A biased circuitry inside.  The rubber feet are short, but tall enough to allow air to circulate between the units when stacked.[/size]
[size=10pt]After a few hundred hours of burn-in I was more confident in where the HAP-100 has some small differences in it's capabilities and strengths over the DAC-100's headphone amp. [/size][size=x-small] I found three most noticeable differences in sound vs the DAC-100 that stand out for me - namely more power, more detail, and less [/size]noise.  Those don't really change the timbre and tone much between devices, but a fourth area may be in the sense of a slightly more forward midrange that can affect synergy a little vs the DAC-100.


[size=10pt]First off[/size][size=10pt] - as discussed before on the forums I find that the HAP-100 has a bit more power and impact than the DAC-100 with the LCD-2 rev2 or other low impedance headphones, although the DAC-100 is pretty good with the Rev2 as well.  My LCD-2 rev2 pair better with both Nuforce amps than my previous LCD-2 rev1, and I don't find the Rev2 to be as underpowered with the DAC-100 as the Rev1 were (or HE-500).  I am so glad that I upgraded the LCD-2 to the more recent model, which pairs well with more amps.  With double the voltage swing of the DAC-100, the HAP-100 can better drive less efficient headphones too.[/size]


[size=10pt]But with my sensitive 300 ohm HD800 the extra power really doesn't make a big difference, and then the two amps sound more alike than different.  However, with the LCD-2 rev 2 or HE-500 headphones the HAP-100 has a bigger advantage.  For most listening, I'd be fine with just the DAC-100 to drive my HD800 and LCD-2 rev2 if I couldn't add an external amp.  For HE-500 and for IEM I'd be looking for an external amp, and the HAP-100 is a good contender.[/size]


[size=10pt]If not maxing out the volume on the DAC-100 when it's being used as a source-only for the HAP-100, with any given volume level out of the DAC-100 headphone jack the HAP-100 volume must be set to 88-90 on the display in order to match the volume of the DAC-100's headphone jack.  At 88-90 out of 99 max I can swap the headphones between the DAC-100 and HAP-100 and have the volume matched.  This still leaves room for the HAP-100 to be turned up to 99 and reach much louder volumes than the DAC-100 can achieve.[/size]
[size=x-small]While the DAC-100 output and power[/size][size=small] levels s[/size][size=x-small]eem to be on par with my maxed Woo WA6 (less than half a watt), that's only just enough to get decent performance from an LCD-2 or HE-500, [/size]although [size=x-small]being more than enough power for more efficient phones like Grado HF-2, HD800, D7000 or V-moda M-100.  But the HAP-100 power level seems to come closer to the DACmini's 1.5 watt output, and you can't max it out with most phones.  It's at least 2-3x more powerful than the DAC-100.[/size]


[size=10pt]Secondly[/size][size=10pt] - while using the DAC-100 as the source for everything I found the HAP-100 headphone output has a little bit more detail and depth than DAC-100 headphone amp in terms of hearing further into the music, so that the sound was also slightly more transparent and more open using the HAP-100.  Initially, before burn-in the HAP-100 sounded a bit more forward in the midrange and in it's overall presentation.  Over time the aggressive nature of the HAP-100 mellowed, and it was only slightly more forward than DAC-100.  Music reproduction seems just a little more effortless with the HAP-100 now.  While the DAC-100's built-in amp has a similar level of detail, I still think the HAP-100 takes things just a little further, and with a better signal to noise ratio with low impedance headphones to boot.  This is a big part of what allows me to hear deeper into the music.[/size]
[size=10pt]With the LCD-2 rev2 or HE-500 I think the midrange is still a little more forward with HAP-100 than DAC-100, but with HD800 the mids are more similar than different despite an audible improvement in midrange presence.  This is good news, since the HAP-100 retains the great synergy with HD800 that the DAC-100 has.[/size]


[size=10pt]Which brings me to my last finding[/size][size=10pt] - the HAP-100 has a blacker background than DAC-100.  When used with very sensitive low-impedance IEMs or headphones, there is a much lower background noise level than with the DAC-100.  With my JH Audio custom in ear monitors (or very sensitive low-impedance headphones) I don't hear any appreciable hiss from the HAP-100 until the volume control gets close to or above 75 out of 99 (music paused, using DAC-100 as source), and even then it's only with very sensitive IEM or very low impedance full size phones near the top of the volume control.[/size]


[size=10pt]That means that with actual music playing at those high volume settings it would become quite loud and uncomfortable with my IEM before hiss was ever an issue.  So basically, with normal listening levels in very dynamic musical performances, a person will not have any noise intruding into the music between songs or during quiet passages.  As the volume rises above 75/99 towards the max volume of 99/99, the HAP-100's background noise goes up but it's never higher than that of the DAC-100's headphone amp with it's volume all the way down.  [/size]


[size=10pt]In contrast, the DAC-100's audible background noise level with IEM is audible at zero volume but does NOT increase with the volume knob being taken from zero to max (while the music is paused).  This is what makes the HAP-100 a much better choice with IEM and sensitive headphones.  So, in this DAC/AMP combination I found that it's best to set the source to max output and then control the listening volume with the HAP-100 (mostly when using it with very sensitive low impedance IEM or headphones), so most listening is done with the volume below 80/99.[/size]


[size=10pt]SUMMARY[/size][size=10pt] - what I love about this DAC/AMP combo is that it gives me 4 digital inputs and 4 analog inputs between the two units, and they can drive a wide variety of headphones and IEM between the two amp sections.  The only feature I'm missing from the DAC is a balanced XLR output to feed my balanced electrostatic headphone amp, so I sometimes use a single ended HEV70 amp in the bedroom rig with loop out to another amp.  So far I still believe that both Nuforce headphone amp sections are best with HD800, and I can't think of another headphone amp near this price range that can match the HAP-100 for listening with the HD800.  [/size][size=10pt]Sure, you can get a cheaper budget amp that is pleasant to use with HD800, like the EF2A, but it can't match the detail, depth, transparency, and refinement of the HAP-100.  [/size]
[size=10pt]Upgrading that EF2A to a more expensive EF5 amp is actually less enjoyable with HD800, as would be a $1200 maxed Woo WA6 with the wrong tubes (my warmer WA6 tubes also compress the soundstage).  [/size][size=10pt]The $800 DACmini is not bad with HD800, but over long listening sessions the sound can start to become a little fatiguing.  From memory I would say the similarly priced Grahm Slee Solo II (summer 2009) was still slightly below the DACmini with HD800.  The HD800 are just that demanding for synergy, and a Locus-Design or Black Dragon headphone cable only helps a little (source and amp more important).  [/size]
[size=10pt]So while DAC-100 was better with HD800 than LCD-2 or HE-500, in contrast I thought the DACmini was better with my LCD-2 rev1 or HE-500 than the HD800.  But adding [/size][size=10pt]the HAP-100 into the mix seems to bridge that HD800/orthodynamic gap, especially since I just got the LCD-2 Rev2 which seem to be more balanced sounding and easier to drive.  I'd say that the HAP-100 offers me an amp that's good with HD800 and power hungry orthodynamics alike (also it still leads with HD800).  [/size][size=x-small]With my very sensitive Westone ES5, JH Audio 16Pro custom IEM, V-MODA M-100, and Sony MDR-V6 I think that the HAP-100 and DACmini perform on a similar level, as both of these amps have a headphone output that's a bit quieter with sensitive headphones than the DAC-100.  The main difference is that the HAP-100 is slightly more refined and slightly less forward sounding with these phones than the DACmini, while still being slightly more forward than the DAC-100 which was a little more laid back [/size]sounding (maybe too laid back for LCD-2 rev1)[size=x-small].[/size]


[size=10pt]It's pretty clear that the DAC-100 is still a good bang for the buck for the HD800 owner, who could use it as their sole piece of gear with the addition of a digital transport (CD, computer, digital dock).  But [/size]for those who already have a good DAC or have several analog sources, [size=10pt]the HAP-100 is a better way to get that same HD800 synergy in a decent mid-price amp, while also working better with more sensitive or more difficult to drive headphones and IEM.  [/size]


[size=10pt]The HAP-100 sounds pretty neutral and colorations are kept to a minimum, although I sometimes find myself wishing for just a little more warmth and euphonic tube-like sound, but I'd say the same thing about my DACmini at times.  When that happens I find myself reaching for my Nuforce CDP-8[/size] CD player [size=10pt]and feeding the analog outputs directly into the HAP-100.  I suspect that using my Stello DA100 Signature DAC or HiFiMan HM-801 would have a similar effect in adjusting the tone, but I prefer the CDP-8 for it's greater depth, detail, and transparency.  The CDP-8 is a great match with the HAP-100 if one listens to $10 Amazon Prime CDs as much as I still do, and I rate the musicality and quality of sound as top notch. [/size]
[size=10pt]In general, the HAP-100 is a very nice and affordable solid state "jack of all trades" headphone amp, which serves as an upgrade to the amp built into the matching DAC-100, but also pairs very well with other sources with RCA outputs.  The fact that it can compete so well with my $1000+ maxed Woo WA6 or $800 DACmini is icing on the cake.  It doesn't remove my need for my HiFiMan EF6 and Eddie Current ZDT amps in my big basement rig, but it does make it much easier for me to enjoy my music upstairs more often, especially with my HD800 at 1/4 - 1/2 the cost of my better amps. [/size]