One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | evenly matched | Effectively the same output - 100W against 90W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Room size | depends | We rate Cambridge EXA100 the better fit for a large room and a very large room, and JBL SA550 C for a small 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 increases strongly (155W and 150W). |
| Noise floor | B | JBL SA550 C is the quieter design on paper - 106dB against 91dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Cambridge EXA100 handles DSD. |
| Streaming | evenly matched | Only Cambridge EXA100 has Roon. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | A | Cambridge EXA100 takes more analogue sources - 5 against 3. |
| Phono stage | depends | JBL SA550 C has a built-in phono stage (MM) and Cambridge EXA100 does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Use with a TV | depends | Only Cambridge EXA100 has HDMI eARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | A | Only Cambridge EXA100 offers a subwoofer output - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | Cambridge EXA100 is Class A/B and JBL SA550 C is Class G. Class A/B runs warm and is the long-established mainstream choice; Class G/H switches its supply rails to cut the heat a Class A/B design wastes. Modern examples of both measure well - judge by the rest of the page. |
| Price | B | JBL SA550 C costs less - $1,999 against $2,199 at list. |
A Cambridge EXA100 B JBL SA550 C
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?
The usual trade-off: Cambridge EXA100 measures better, JBL SA550 C costs about 9% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If you play records, JBL SA550 C saves you buying a phono stage; if you do not, ignore that row entirely. If this sits under a television, Cambridge EXA100 is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.