Headphone Amps comparison test

Cavalli Audio Liquid Spark, JDS Labs Objective 2 and Schiit Magni 3+ Headphone Amplifiers

[JDS Labs Objective 2 Headphone Amp]
[Italian version here]

Product: Liquid Spark
Manufacturer: Cavalli Audio/Monoprice
Price: $109.99
Product: Objective 2
Manufacturer: JDS Labs
Price: $99
Product: Magni 3+
Manufacturer: Schiit Audio
Price: $99
Reviewer: Bevan Court - TNT USA
Reviewed: November, 2021

As part of a greater focus on headphones and headphone amplifiers here at TNT Audio, I thought that I would explore some entry level headphone amplifiers to lay down a basis, or starting point.

But, first, why the increased focus? TNT-Audio has championed two things. Firstly, value in quality hifi components and secondly, the importance of stereo over multi-channel and compromised mass market products.

Over the last decade or so, there has been a movement toward headphones for high quality stereo sound reproduction. The industry stalwarts, Sennhesier, Grado, Beyerdynamic, AKG and others upped their game with some great headphones. But new companies, such as Meze Audio, HifiMan, Dan Clark Audio, Focal, Audeze, Campfire and a host of others have taken up the challenge. The options as you look around sites such as headphones.com and Head-fi.org are staggering.

Open back, closed back, dynamic driver, planar magnetic, ribbon drivers, high impedance, low impedance in-ear monitors (IEM), headphones with bluetooth and those with active noise cancellation. There are even planar magnetic IEMs. Admittedly, they look a little weird, but who knows, they may sound amazing.

And while Apple plotted to kill the headphone jack on the phone and try and spoil the party, companies such as Audioquest, Topping, Burson, Cavalli Audio, FiiO, iFi, Chord and Schiit have started a trend of using dedicated amplifiers and DAC's for those headphones. No longer do you just make do with the compromise of the phone output, or an afterthought output on your main amplifier or CD player. You can now get a dedicated amplifier, sometimes including a DAC, that can actually drive high impedance planar magnetic headphones, or have a quiet enough noise floor to drive highly sensitive IEM's.

The Contenders

This test was conceived as a test of designs from three of the bigger personalities in headphone amplifier design and their offerings at around $100.

You might have missed our previous comparison test: Bravo V3 vs Bravo Ocean vs Trends PA-10.1D.

[Schiit Audio Magni 3+]

First up is Jason Stoddard of Schiit Audio. Outspoken, slightly abrasive, but in some ways brutally honest about both his own products and the industry as a whole. Schiit is doing something that is quite remarkable, trying to set a benchmark for value, whilst still competitively manufacturing most of the product in the USA using innovative industrial engineering.

Jason Stoddard sits firmly in the middle ground between subjective and objective amplifier design. He designs with measurements, but confirms with listening.

I am reviewing Schiit's Magni 3+ here, a fully discrete amp that retails for just $100.

The second designer is Dr. Alex Cavalli. Formerly of Cavalli Audio, he partially retired a few years ago to focus on his family. However, he has partnered with both Drop and Monoprice to bring some of his designs to the market at a cost effective price. We will be looking at the entry level Monolith by Monoprice Liquid Spark that he designed. A bit of a mouthful of a name, but it retails for $109.99 in the US. Again, this is an all discrete design, but manufactured in China.

[Cavalli Audio Liquid Spark]

The final designer is an enigma. The engineer, personality and blogger who went by the moniker NwAvGuy is no longer active on any forums under that name, but for a long time, was very active. He measured and reviewed many designs and made a name for himself, even going toe to toe with both Schiit and NuForce when he felt that they had made design mistakes.

Interestingly Stoddard posts a fascinating section in his blog where he freely admits that maybe he made some mistakes and could have handled the situation differently. It also resulted in a change of design on the first generation Asgard amplifier. Schiit Goes Evil?

Here is an interesting thing, in the furor of the controversies with both Schiit and probably more so with NuForce, NwAvGuy simply disappeared. He vanished from the forums and was never heard from again. His site nwavguy.blogspot.com is still maintained, however, it has no recent posts. Conspiracy theories abound about what happened.

Before he disappeared, NwAvGuy released two designs, the ODAC and the O2 headphone amplifier. However, these were open source designs with a full BOM for DIY hobbyists. However, in time, various companies like JDS Labs, Grace and Drop all offered versions of these. I am reviewing a JDS Lab O2 headphone amp here, although they no longer offer it in its original form. Drop and Grace have options that are based on the original design and JDS Labs have updated designs. All of these are in the $99-$149 price range.

The name gives this away, the Objective 2 headphone amplifier is made to measure really well, and to NwAvGuy, everything was about the measurements. If it measures well, then it must sound good. Objective design is the only way he knew how to do it. This design does use opamps, so isn't discrete, but it does interestingly use two 9V batteries in the case, allowing for it to be used as a rechargeable, portable amplifier.


So, how do these budget headphone amps compare?

For this test, I am using my new Hifiman HE400i planar magnetic headphones and a Schiit Modius DAC. The HE400i are an open back design and give a nice sense of space and wider soundstage that I didn't get with other closed back options. For each track, I have presented my listening notes in the same order.

All of the amps have a high and low gain option and for this test, the high gain was enabled on all.

Monolith by Monoprice Liquid Spark puts out 1.3W into 32 Ohms.
Schiit Magni 3+ puts out 2.4W into 32 Ohms.
JDS Lab O2 puts out 613mW into 33 Ohms.

First up, was Nirvana's “Come As You Are” from their “Unplugged” album.

Liquid Spark - Bass guitar is thick and menacing, still stunning in the mids and treble. Magni 3+ - Feel a greater tension in Cobain's vocals, the raw emotion comes through O2 - Comes second to the Magni on vocals, good strong bass.

Next up was “Willow” from the album “evermore” by Taylor Swift. Her collaboration with Aaron Dessner has taken her artistry and performance to another level.

Liquid Spark - Clean, detailed, with good bass definition.
Magni 3+ - Cleaner, more detailed, vocals and instrument separation is better. I found the bass to be thinner than on the JDS and the Liquid Spark, but the overall balance is really good with these headphones.
O2 - I felt that the bass was maybe a little bloated, otherwise, great.

None of the amps seem to be altering the soundstage, just the timbre of the music.

“Desert High” from the album “Hardware” by Billy Gibbons. Released only weeks before the sad death of Dusty Hill, his bandmate in ZZ Top, this album is a lot of fun. Maybe the best stuff he has recorded in a decade.

Liquid Spark - Good atmosphere and detail.
Magni 3+ - Again, it is the tension in the vocals that just edges it above the Liquid Spark. The combination of the Magni and the HE400i just digs deeper into the darkness.
O2 - Guitar is fabulous on this track, but lacks the vocal tension of Magni 3+

“Skeletons” from the album “Human” by - Harvey Summers, feat Laura Cole. There is so much going on here, this track is great to identify instrument separation.

Liquid Spark - Slightly more bass heavy. The bass guitar is just amazing. Not quite as well separated as Magni 3.
Magni 3+ - Percussion is great, it is detailed, with good separation and the banjo really stands out.
O2- Good rhythm, with great pace, rhythm and timing. Makes you shake your head. Trumpet is fabulous.


There is so very little between the amps. Of the three amps, I found myself reaching for the Magni 3+ most often. It has good tone, detail and bass and has lots of power available, considerably more than the other amps.

With brighter headphones and maybe a brighter DAC, maybe the Liquid Spark would be a better match. But you are talking about tiny differences. The extra power that the Magni 3+ has on tap will potentially give you more options with higher impedance headphones.

The JDS O2 perhaps shows its age and lack of power in comparison to the other three amps. The Hifiman HE400i does require a little more power than my Meze Audio 99 Classics to drive. The JDS works really well with the Classic 99s, which I felt needed the clean, crisp edge to add to their already warm, full sound.

But, of the three amps, which would I choose? In truth, this is a tough choice. I have actually decided to keep them all. The Magni 3+ possibly is the better all rounder of the three, capable of driving different headphones, of handling different music and just digging into the emotion of the vocal performances. The Liquid Spark, in terms of value, is an incredibly close second.

But, really, you cannot go wrong spending this sort of money with the value on offer. These amps will drive most headphones, even if the O2 did struggle with matching the dynamics of the other two amps.

I feel that the best way to describe it is its a question of different flavours. Imagine a fine Scotch, Bourbon and Rye. All great whisk(e)y, but if you have all three available, you won't always reach for the same one. However, you would also be completely happy if you had just the one to choose from.

Each one will potentially mix better with different headphones depending on impedance and sonic profile. In truth, it may come down to the equipment you pair it with - headphone amps and DACs are often found stacked together, so maybe find the best stack that suits you and your favourite headphones.

DISCLAIMER. TNT-Audio is a 100% independent magazine that neither accepts advertising from companies nor requires readers to register or pay for subscriptions. After publication of reviews, the authors do not retain samples other than on long-term loan for further evaluation or comparison with later-received gear. Hence, all contents are written free of any “editorial” or “advertising” influence, and all reviews in this publication, positive or negative, reflect the independent opinions of their respective authors. TNT-Audio will publish all manufacturer responses, subject to the reviewer's right to reply in turn.

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