Primare I35 vs Primare I25 Detailed Comparison

Primare I35 vs Primare I25

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Primare I35

Integrated Amplifier | 150 watts RMS into 8-ohms

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Primare I25

Integrated Amplifier | 100 watts RMS into 8-ohms

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Primare I35

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Primare I25

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Primare I35

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Primare I25

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Primare I35 vs Primare I25 Integrated Amplifier Comparison

In this review, we will be comparing I35 and I25, two Integrated Amplifiers by Primare. Let's have a brief look at the main features of Primare I35 and Primare I25 first before getting into our more detailed comparison.

Key Specs	Primare I35	Primare I25
Brand	Primare Sweden · founded 1986	Primare Sweden · founded 1986
Power	150 watts x 2 channels into 8 ohms and 300 watts x 2 channels into 4 ohms	100 watts x 2 channels into 8 ohms and 200 watts x 2 channels into 4 ohms
Amplifier class	Class D	Class D
Built-in DAC	No	No
Phono input	No	No
Headphone output	No	No
Bluetooth	No	No
Weight	11.00kg / 24.2lbs	11.00kg / 24.2lbs
Dimensions (H x W x D)	4-1/4" x 17" x 17-15/16" 108.0mm x 432.0mm x 456.0mm	4-1/4" x 17" x 17-15/16" 108.0mm x 432.0mm x 456.0mm

What size room are the Primare I35 and Primare I25 Amplifiers good for?

The size of the room in which you are planning to use these amplifiers is an important decision factor. Here we have compared their suitability to various sizes of environments considering their max power parameters:

Listening Environment	Primare I35	Primare I25
Near-field	Are you nuts?	Poor
Small Room	Bad	Poor
Mid-size Room	Poor	Good
Large Room	Good	Good
Very Large Room	Good	Average

I35 and I25 are members of Primare's I series of speakers. Below you can find the loudspeakers from this series.

Primare I Series History

Model	Watts RMS (8-ohms)	Minimum Impedance	Built-in DAC
Primare I15	60 watts	-ohms	No
Primare I25	100 watts	-ohms	No
Primare I35 Prisma	150 watts	-ohms	Yes
Primare I15 Prisma	60 watts	4-ohms	Yes
Primare I25 Prisma	100 watts	-ohms	Yes
Primare I35	150 watts	-ohms	No
Primare I15 MM	60 watts	-ohms	No

The rest of this page covers where each one wins, how they compare in size, their inputs and outputs, the full specifications and a verdict.

Reasons to choose Primare I35 over Primare I25

Watts into 8-ohms	150 watts vs 100 watts	Delivers higher power into 8-ohms speakers
Watts into 4-ohms	300 watts vs 200 watts	Delivers higher power into 4-ohms speakers
Total Harmonic Distortion (THD)	0.01% vs 0.05%	Less Harmonic Distortion

Reasons to choose Primare I25 over Primare I35

MSRP Price(*)	3,295USD vs 4,595USD	costs less (*prices may change depending on the seller, location and time)

Size, drawn to scale

Both amplifiers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.

One scale for both, aligned at the back panels the way they would sit against a wall, so the deeper one visibly stands further out.

Near-identical footprints.

Inputs and Outputs

The input and output selections that are offered is an important factor when comparing two amplifiers. Here you can find how the I/O selections of the Primare I35 and Primare I25 differs from each other.

Primare I35 Inputs

Total Number of Analog Inputs: 5
XLR Input Port

Primare I25 Inputs

Total Number of Analog Inputs: 5

Primare I35 Back View (Click the image for the larger version)

Outputs

Stereo RCA (2) Preamp Outputs

Outputs

Stereo RCA Preamp Outputs

Balanced connections

Primare I35 has balanced XLR connections and Primare I25 does not. A balanced cable carries the signal twice, on two conductors of opposite polarity. Interference picked up along the way lands on both equally and cancels when the two are recombined at the far end, so the longer the cable run and the noisier the surroundings, the more it is worth. Whether it also yields more power depends on how the amplifier is built inside - some are balanced end to end, others convert to single-ended internally and deliver the same either way.

Primare I25 Back View (Click the image for the larger version)

What's in the Box of Primare I35?

Here are the items that are included inside the box of I35:

Integrated amplifier
6-feet AC power cord
Remote control (C25)
2 AAA batteries
Two 59-inch Mono-minijack cables
AC polarity pen
Thank You Letter
Safety And Warning Notification

What's in the Box of Primare I25?

Here are the items that come with the I25:

Integrated amplifier
6-feet AC power cord
Remote control (C25)
2 AAA batteries
Two 59-inch Mono-minijack cables
AC polarity pen
Thank You Letter
Safety And Warning Notification

Primare I35 vs Primare I25 full specifications

Every spec we hold for both, side by side

Specification	Primare I35	Primare I25
Overview
Brand	Primare	Primare
Type	Integrated Amplifier	Integrated Amplifier
Channels	2	2
Amplifier class	Class D	Class D
Output devices	Solid State	Solid State
Released	2018	2019
List price	$4,595	$3,295
Series	I	I
Power and performance
Power into 8 ohms	150 W RMS	100 W RMS
Power into 4 ohms	300 W RMS	200 W RMS
Power, as rated	150 watts x 2 channels into 8 ohms and 300 watts x 2 channels into 4 ohms	100 watts x 2 channels into 8 ohms and 200 watts x 2 channels into 4 ohms
Signal-to-noise ratio	100 dB	100 dB
THD	0.01%	0.05%
Frequency bandwidth	20 Hz-20 kHz	20 Hz-20 kHz
Digital and DAC
Built-in DAC	No	No
Network and streaming
Bluetooth	No	No
AirPlay 2	No	No
Chromecast	No	No
Roon	No	No
BluOS	No	No
HEOS	No	No
DTS Play-Fi	No	No
Inputs
Analogue inputs	5	5
XLR inputs	Yes	–
Phono input	No	No
Optical digital	No	No
Coaxial digital	No	No
USB input	No	–
Outputs
Preamp outputs	Stereo RCA (2)	Stereo RCA
Pre-out / main-in loop	No	No
Headphone output	No	No
Features and control
CD player	No	No
Handheld remote	Yes	Yes
Remote model	C25	C25
Auto power	Yes	Yes
RS232 port	Yes	Yes
Physical
Dimensions (H x W x D)	108.0mm x 432.0mm x 456.0mm	108.0mm x 432.0mm x 456.0mm
Dimensions, inches	4-1/4inch x 17inch x 17-15/16inch	4-1/4inch x 17inch x 17-15/16inch
Weight	11.00 kg (24.20 lbs)	11.00 kg (24.20 lbs)
Finishes	Black,Titanium	Black,Titanium
Removable power cord	IEC 3-prong	IEC 3-prong
Parts warranty	3 Years	3 Years
Labour warranty	3 Years	3 Years

A dash means the manufacturer does not publish that figure, or it does not apply. 43 specifications compared.

Verdict

Siblings in Primare's I range, so they share a design and a house sound. It comes down to power, features and price.

Area	Better	Why
Power	A	Primare I35 has more power - 150W against 100W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks.
Room size	depends	We rate Primare I35 the better fit for a very large room, and Primare I25 for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want.
Grip on hard loads	evenly matched	Both behave much the same into 4 ohms - output nearly doubles (300W and 200W).
Noise floor	evenly matched	Much the same signal-to-noise ratio (100dB vs 100dB).
Analogue inputs	evenly matched	The same number of line-level inputs (5).
Room to grow	evenly matched	The same expansion options on both.
Price	B	Primare I25 costs less - $3,295 against $4,595 at list.

A Primare I35 B Primare I25
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.

Which should you choose?

Primare I35 is ahead, but on only 1 of the measured areas, and it costs about 39% more. That is a lot of money for a narrow margin - Primare I25 is the sensible buy unless a specific feature above decides it for you. Think about the whole system: the roughly $1,300 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.

What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.