Ferrum OOR / HYPSOS Headamp Review: Girl You Know It's True

This is an honest review* of the Ferrum ORR headamp and HYPNOS power supply. Due to the very recent release of a number of headamps which have really pushed what solid-state headamps can do (tube expressiveness), the Ferrum OOR is going to have some stiff competition. I'm going to be direct and succinct without much extraneous bullshit and technobabble (some it probably wrong or misleading) that other Internet reviewers spew.

The HYPSOS is a power supply does guud things. I have not heard the OOR without it and I won't because I don't have the time. Ferrum Audio should just sell both together instead of offer an "optional" power supply that makes the base headamp guuder. For Jeebs sake, f'ing sell the best product that you can instead of something gimped that requires an extra attachment that makes it how it was supposed to be in the first place. If it sounds like this kind of audiophile bullshittery bugs the F outta me, it's because it does. (I mean GM doesn't sell a Vette with a V4 at $50k but ask an extra $30k for the V8.)



That being said, the Ferrum OOR does a lot of things right. The blackground, which I assume the HYPNOS has major role to play, is utterly refreshingly black. It's like being in the middle of a rural area without city lights staring up into the sky. The tonal balance is neutral. By neutral, I mean not lean, not bright, not warm. I mean neutral in the universe of headamps I have heard in the past fifteen years. The presentation is mature, refined, stately, liquid, effortless. The highs are smooth are silk, yet at the same time the OOR doesn't hide what's there. I like to use Alanis Unplugged for listening tests because there's a lot of sibilance in her voice on that CD. I fully expect the sibilance to be there, but I don't want it presented in a way that's unnatural or an assault to my ears. The OOR pulls it off well, if anything, maybe a bit on the mellower side, which is perfectly fine. The transient speed is moderately fast but with a twist. The terminal ends of transient attacks are not edgy, sharp, or hard. They are delicate. The OOR has no problem keeping fast planars fast (there is a reason why the LCD-R, a pseudo-ribbon, is in the photo above).

There are two amps that remind me of the OOR. The Monoprice Liquid Gold and Nitsch Sound Pietus Maximus. The OOR has this mature smooth delicate neutralish presentation that reminds me of the Pietus. And it's got this misty liquid midrange quality that reminds me of the Liquid Gold. I would be curious to send to off to people who run their planars with the Liquid Gold to get their take. No doubt the ergonomics and build quality of the OOR are x472 better than the Monoprice. From memory, the OOR has an extra level of refinement over the Liquid Gold.

I'll get to some impressions with a variety of headphones and comparisons with Pietus because they have so many similarities.

*</sarcasm off> I F'ing hate it when people say at the beginning of reviews that their reviews are honest. If they are honest, they don't need to say it. It's only when reviewers are compromised (pressure to produce positive reviews to keep the review gear coming in courtesy of manufacturers who want good press). At SBAF, we have to either buy or beg, chase after manufacturers to send stuff. Keep in mind that many manufacturers are scared to send stuff to us. A lot of this is because of Jude at Head-Fi who tells vendors I am unpredictable hot-head. Tl;DR: anytime you hear "honest", it's probably not.

 

First of all, let's get one thing out of the way. Dynamic headphones suck balls on this amp. Yeah, the Ferrum OOR with the HYPSOS sucks balls with traditional dynamics like the JAR600, Atrium, Grados (all headphones terminated in balanced). The Grados fare a little bit better because OOR takes the edge off a bit with its refined rendering. The biggest problem I am having is that the OOR just sounds insipid. I'd rather hear any of these dynamics from the cheapo Magni Unity. The iFi Diablo, a transportable, slaughters the OOR with it comes to traditional dynamics.

The soul that the Sennheisers are capable of with amps that can scale with them just isn't there from the OOR. The Atrium still slams, but that "hits like a freight train" quality has been restrained. Grados are now smooth, but their essence of crunch and raw liveliness has been neutered. Yeah, insipid. The only other amp that reminds of this insipidness is the Questyle CMA600 from back in the day. I'd rather take a Topping L50 over the OOR for dynamic headphones, and that says a lot.

I mean, the insipidness with dynamics is really really bad. This literally sounds as flat, no flatter, than one of my first nested opamp* designs (unity gain with gobs of negative feedback because of the massive open loop gain) that I implemented on a breadboard just after my second child was born. (I was poor back then fifteen years ago and couldn't afford Singlepower amps).



However, all is not lost...

*Now I'm curious about the topology. Oh Jeebs I hope this isn't one of those super massive open loop gain deals.

 

So here's the really weird thing: the OOR actually sounds really good with orthos, among which the LCD-R is one of them (let's face it, The LCD-R really isn't a ribbon, it's a pseudo planar that is really closer to an ortho). A true ribbon is basically a short circuit. 2-ohms (LCD-R) isn't the same as 0.2-ohms (RAAL). FWIW, the Ferrum did nothing for me with the RAAL CA-1a headphone through the TI-1b transformer box.

Now there are amps in existence which are just like this, they suck for dynamics, but turn out to be magical with orthos. The aforementioned Monoprice Liquid Gold is one of them. it's a mystery why this is, but it just is. Let's take the LCD-X or LCD-R which are very similar in presentation of tone and timbre.

In these cases, the OOR holds nothing back in bass slam or bass heft and sustain with Daft Punk's Something About Us and Bjork's Hollow (16-bit remix). In addition, both the LCD-X and LCD-R have a peak at 8kHz which can overemphasize sibilants. The OOR's refined render helps to take the edge off. I would also imagine incredible synergy with a variety of the higher-end HiFiMan's where I found the highs to be difficult.

After I get some measurements done (I get the feeling this is one of those high SINAD deals), this will be going on the loaner program. But not before I compare to the Pietus with some orthos and pseudo-ribbons. (I am hoping it holds up because I don't feel like burying this somewhere in Texas and making a treasure hunt for a hundred Head-Fiers)

I forgot to mention, I preferred using the Gungnir A2 DAC, easily my most energetic slightly upper-mid forward DAC to account for the OOR's mellowness.

To be continued tomorrow...

 

Pietus can have very slight tendency toward lean and upper mid forward. Gungnir A2 is a horrible match with it.

Gungnir A2 can work with the Mjolnir 3, but I ended up with Yggdrasil MILF for greater compatibility with widest selection of music and the occasional use of Grados.

While Mjolnir 3 is mellow and Pietus is refined and smooth, neither are insipid or flat & boring sounding. Both are very expressive with oodles of microdynamics and expansive sense of space.

Jot 2 works with Gungnir A2 because the Jot 2 is kind of 300B sounding.

 

In general yes looking at it simplistically.

What we are trying to do is plug in gaps. Fill in and shave off perceptual dips and bumps respectively. Calm or sharpen transients. Take the edge of highs or energize them. At times even play to existing strengths.

On occasion, there are combinations that just work that we wouldn’t think they would. Or combinations that don’t work when we think they would.

And then there are cases of making weaknesses less apparent or not applicable. For example, source of amplification with flat or closed-in headstage won't be noticed as much on orthos compared to HD800, most ZMFs, etc.

In this case of me pairing the ORR with the Gungnir A2, it's a matter of an energetic and aggressive DAC to feed the sleepy Ferrum. I happened to bet right in this case, but I don't always. I am also using Audezes for headphones, so take that into account too.

 

The Violetric G200 is just too murky while sounding insipid and not quite in the same class. I guess you can say that the G200 has got some character to its boringness. The Questyle is similar, has some warmth, but less murky.

The ORR commits fewer sins of commission. Come to think of it, it reminds me of a more refined Benchmark AHB2 or ultra refined THX789. More fluid, more delicate transient edges, capable of sounding full-bodied, but unfortunately flatter stage.

With respect to “wire with gain”, I don’t know what this is exactly and even if I did, it would be different for everybody.

Is the GSX2 wire with gain or wire with razorblades? Are the high “SINAD” Topping L50 or Schiit Heretic "wire with gain" or warmish amps that commit sins of omission. Or is the similarly high SINAD but leaner sounding THX789 "wire with gain"? Heck even the DSHA 3F, the one amp that I feel commits the fewest sins of commission and sins of omission on the whole, isn’t wire with gain as the transformers no doubt are chosen for their sound.

90% of the time I hear "wire with gain", it means razorblades or insipid. It's a marketing term used by manufacturers, maybe retailers, and most definitely fanbois of a certain piece of gear.

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Anyway, here is the scorecard of the cage fight between the Ferrum ORR/HYPNOS against the Nitsch Sound Pietus Maximus. Again, these amps are quite similar to each other. The length of the bars indicate the extent of the win.

 

Once we get out of no-mans land past $500-$2000, it's just embarrassing. Better to offer all inclusive package at $3k or whatever. The only exception would be if a single power supply could power two of their units at once, their DAC and amp.

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In a nutshell:

Neutral, mature, refined, liquid, smooth, controlled, mellow if not reticent. Pretty good with expensive orthos, all of which have some sort of treble f'kery, often the more expensive, the weirder the highs. (Audezes IMO have the least, but may be excessively laid-back for some people). Sucks balls, coming off as too insipid, with traditional dynamics from the likes of Sennheiser, Grado, ZMF, etc. The more cynical may ask: do two wrongs make a right? The experienced audiophile curator may reply: it's all about synergy.

 

Firing up the AP.

 

Getting a few things out of the way first before distortion surface. Going to be using balanced output and high-gain. 2Vrms with 20kHz bandwidth to get a sense of things, even though 2Vrms is too high. ASR uses 4Vrms for balanced output, which is utterly stupid because that is just gonna kill a lot of headphones and if not cause perma hearing damage after 5 seconds. Heck, 2V will do similar, just takes slightly longer than 4V. Load will be 29-ohms.




Out to 1MHz. Now this is kind of funky. A noise-shaped hybrid linear and switched power supply? Wild guess. Interesting though.

 

I can see this working out very well on the Susvara and HEK. The OOR has got the ease, doesn't hold back on transients, will grip that slightly bouncy bass, and definitely iron out that last bit of splashy steely highs.

The insipidness for traditional dynamics stands out for me because I'm more of a dynamics (and ribbon) guy. I'm used to that magic. The release of Pietus and Mjolnir 3 have been game changers with respect to "magic" for dynamics. I've been too lazy to fire up my expensive tube amps because of these two.

Yes, dynamics suck in many respects compared to orthos, but they are capable of their own magic. TBH, I'd rather listen to any of my dynamics even from Magni Unity or Piety over the OOR. I've never liked high open loop gain amps on dynamics. But I don't want to go there because it's gonna piss off a lot of people, so will just hide this statement in the middle of this thread. Besides no one will believe me (and I'm perfectly fine with that).

 

Slapping a few distortion surfaces for now since I don't want to keep you guys waiting. New Asian market opened up where I can get thinly sliced brisket and short-ribs. Gonna head out to Walmart and grab a George Foreman grill. We doing KBBQ on our new deck in the backyard. Will come back to fill in the test condition details and complete this thread this afternoon.

Ferrum OOR/HYPSOS

• HIGH-GAIN
• 29-ohm load
• Voltage on Hypsos set to 24V
• 90kHz bandwidth
• APx555 "cheat" HPSA mode on
• Volume knob of headphone amp was set for unity gain
• Input signal output set on the APx555
• APx555 "cheat" HPSA mode on

H2


H3


H4-20 (sum)


Commentary:

• Nothing out of the ordinary. Very low THD throughout.
• Slight rise in THD in the highs toward 20kHz for the second and third harmonics
• Second and third harmonics are close to each other
• The sum of fourth to the 20th harmonics have a bit of a bump in the upper mids
• Also, the sum of the fourth to the 20th harmonics at the output levels where headphones will typically be used are a bit high relative to the stellar H2 and H3. I do wonder if this is contributing to the relaxed or smoother sound of the Oor. Pure conjecture. Need more data.

Notes:
H2, H3, and H4+ above do not include the noise component
H2 and H3 tend to be dominant over the higher orders, additional graphs will be added if this is not the case
H2 and H3 do sound different from each other, as to how, that's another discussion
H4+, the higher order distortions can be considered to be "crap" factor
There is thought that higher order distortion may have an outsized negative affect on sound quality
THD+N does include the noise component as well as THD (sum of H2, H3, and H4 and above)
Distortion is signal that is not supposed to be there
These graphs tells us how loud the distortion is at that harmonic (freq) vs output level (dBu)
H2 or second order at 100Hz means there is stuff at 200Hz that is not supposed to be there
H3 or third order at 100Hz means there is stuff at 300Hz that is not supposed to be there
Distortion that lands in the ultrasonic region matters, if SOTA chip companies like TI care, then so should you
0dBu (0.775Vrms) output level on most headphones will cause hearing damage after a few minutes of exposure
0dBu output level may burn out the voice coil on sensitive headphones with extended use