Schiit Midgard vs Schiit Vali 2+

Short answer

More power: the Schiit Midgard, with 4.80 W into 32 Ω; the Schiit Vali 2+ has 1.50 W. Both drive 567 of the 567 non-electrostatic headphones here to 100 dB, so on that test the difference changes nothing.
Hiss with sensitive IEMs: no headphone here hisses audibly on one and not on the other.
Output impedance: 72 headphones are left alone by the Schiit Midgard under the one-eighth rule but coloured by the Schiit Vali 2+ (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 69 more).
Price: the Schiit Midgard costs $70 more; what that buys on these numbers is set out further down, under What the price difference buys.

Both are desktop amplifiers, $219 against $149.

On raw power they are level: each reaches 100 dB on 567 of the 567 non-electrostatic models here.

Specification	Schiit Midgard	Schiit Vali 2+
Power into 32Ω	4.8 W	1.5 W
Power into 150Ω	1.2 W	496 mW
Power into 300Ω	750 mW	400 mW
Power into 600Ω	375 mW	200 mW
Output impedance	0.1 Ω	1.8 Ω
Output noise	1.59 µV	25 µV unverified
Price	$219	$149
Headphones it reaches 100 dB on out of 567	567	567

Specification

Schiit Midgard

Schiit Vali 2+

Power into 32Ω

4.8 W

1.5 W

Power into 150Ω

1.2 W

496 mW

Power into 300Ω

750 mW

400 mW

Power into 600Ω

375 mW

200 mW

Output impedance

0.1 Ω

1.8 Ω

Output noise

1.59 µV

25 µV unverified

Price

$219

$149

Headphones it reaches 100 dB on
out of 567

567

The 4.4 mm or XLR socket, rated on its own

Balanced	Schiit Midgard	Schiit Vali 2+
Socket	XLR4	no separate rating
Power into 32Ω	4.8 W	—
Power into 300Ω	750 mW	—
Output impedance	2 Ω	—
Output noise	not published	—
Headphones it reaches 100 dB on out of 567	567	—

Only the Schiit Midgard has a separate balanced rating from its maker; through it, it reaches 100 dB on 567 of the 567 models here. The Schiit Vali 2+ may still have a balanced socket — its spec sheet simply gives no figure for one, so there is nothing to put beside it.

Where each power figure comes from

Load	Schiit Midgard	Schiit Vali 2+
32 Ω	Published	Published
150 Ω	Derived	Derived
300 Ω	Published	Published
600 Ω	Published	Published

Both makers publish a power rating. Schiit Midgard publishes at 32 Ω, at 300 Ω and at 600 Ω; Schiit Vali 2+ at 32 Ω, at 300 Ω and at 600 Ω. The other rows are worked out from those.

The two publish at the same loads, which is the one case where the rows of this table can be read straight across.

What the labels mean.

The headphones that tell them apart

On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.

72 headphones are left alone by the Schiit Midgard under the one-eighth rule but coloured by the Schiit Vali 2+ (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 69 more).

567 of the 567 models here reach 100 dB on both.

Headroom and hiss on 8 models, both sources

Headroom is at a 100 dB SPL peak.

The widest gap on the list is the Shure SE846: Schiit Midgard has +49 dB of headroom there against +40 dB. 9 dB is about 7.3 times the power, which matters for peaks rather than for how loud the music sits.

The hiss columns are empty for Schiit Vali 2+ because that maker publishes no output noise figure.

Headphone	Impedance	Needs	Schiit Midgard headroom	Schiit Vali 2+ headroom	Schiit Midgard hiss	Schiit Vali 2+ hiss
Shure SE846	9 Ω	0.04 mW	+49 dB	+40 dB damping	18 dB	not published
Campfire Audio Andromeda 2020	9 Ω	4.0 mW	+29 dB	+20 dB damping	-2 dB	not published
Audeze LCD-2 Classic	70 Ω	0.79 mW	+35 dB	+30 dB	-3 dB	not published
Beyerdynamic DT 1990 Pro (250Ω)	250 Ω	0.63 mW	+31 dB	+28 dB	-8 dB	not published
HiFiMAN HE400se	25 Ω	7.9 mW	+28 dB	+22 dB	-9 dB	not published
Audio-Technica ATH-R70X	470 Ω	1.6 mW	+25 dB	+22 dB	-15 dB	not published
Sennheiser HD 600	300 Ω	6.6 mW	+21 dB	+18 dB	-19 dB	not published
HiFiMAN Susvara	60 Ω	50 mW	+17 dB	+12 dB	-21 dB	not published

The gap in dollars, against the gap in numbers

The Schiit Midgard costs $70 more than the Schiit Vali 2+. Out of the 567 models here, that difference buys 72 more models left alone under the one-eighth rule.

Nothing runs the other way: there is no axis here on which the cheaper of the two does better.

Only published figures count here; blank axes are counted separately.