Rupert Neve RNHP vs SMSL SH-X

Short answer

More power: the SMSL SH-X, with 5.50 W into 32 Ω; the Rupert Neve RNHP has 262 mW. The SMSL SH-X drives 1 headphone to 100 dB that the Rupert Neve RNHP cannot (Symphonium Titan).
Hiss with sensitive IEMs: cannot be compared — the maker of the SMSL SH-X publishes no noise figure.
Price: the same, $699.

Both are desktop amplifiers, both at $699.

The SMSL SH-X reaches 100 dB on 567 of the 567 models here, the Rupert Neve RNHP on 566.

Side by side

Every published figure, next to each other

Specification	Rupert Neve RNHP	SMSL SH-X
Power into 32Ω	262 mW	5.5 W
Power into 150Ω	175 mW	1.2 W
Power into 300Ω	88 mW	600 mW
Power into 600Ω	44 mW	300 mW
Output impedance	0.08 Ω	<0.1 Ω
Output noise	8.03 µV	not published
Price	$699	$699
Headphones it reaches 100 dB on out of 567	566	567

Not published means the maker leaves it out, so that axis cannot be compared.

How solid these numbers are

Where each power figure comes from

Load	Rupert Neve RNHP	SMSL SH-X
32 Ω	Derived	Published
150 Ω	Published	Derived
300 Ω	Derived	Published
600 Ω	Derived	Published

Both makers publish a power rating. Rupert Neve RNHP publishes at 150 Ω; SMSL SH-X at 32 Ω, at 300 Ω and at 600 Ω. The other rows are worked out from those.

So the two columns are not equally firm row by row: at 150 Ω only the Rupert Neve RNHP figure is the maker’s own and at 32 Ω, at 300 Ω and at 600 Ω only the SMSL SH-X figure is the maker’s own. On those rows the derived number is the one to doubt first.

What the labels mean.

What separates them

The headphones that tell them apart

1 headphone reaches 100 dB on the SMSL SH-X but not on the Rupert Neve RNHP — Symphonium Titan.

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

On real headphones

Headroom and hiss on 8 models, both sources

Headroom is at a 100 dB SPL peak.

The widest gap on the list is the Campfire Audio Andromeda 2020: SMSL SH-X has +32 dB of headroom there against +15 dB. 17 dB is about 50 times the power, which matters for peaks rather than for how loud the music sits.

The hiss columns are empty for SMSL SH-X because that maker publishes no output noise figure.

Headphone	Impedance	Needs	Rupert Neve RNHP headroom	SMSL SH-X headroom	Rupert Neve RNHP hiss	SMSL SH-X hiss
Shure SE846	9 Ω	0.04 mW	+35 dB	+52 dB	33 dB	not published
Campfire Audio Andromeda 2020	9 Ω	4.0 mW	+15 dB	+32 dB	13 dB	not published
Audeze LCD-2 Classic	70 Ω	0.79 mW	+25 dB	+35 dB	11 dB	not published
Beyerdynamic DT 1990 Pro (250Ω)	250 Ω	0.63 mW	+22 dB	+31 dB	6 dB	not published
HiFiMAN HE400se	25 Ω	7.9 mW	+15 dB	+30 dB	5 dB	not published
Audio-Technica ATH-R70X	470 Ω	1.6 mW	+15 dB	+24 dB	-1 dB	not published
Sennheiser HD 600	300 Ω	6.6 mW	+11 dB	+20 dB	-5 dB	not published
HiFiMAN Susvara	60 Ω	50 mW	+7 dB	+18 dB	-7 dB	not published

What the price difference buys

The gap in dollars, against the gap in numbers

These two cost the same, $699, so price settles nothing. Out of the 567 models here, the SMSL SH-X drives one model to 100 dB — and on the other side there is no such advantage at all.

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

Each in full: Rupert Neve RNHP and SMSL SH-X.