No single best amplifier here. What decides it is what you have to drive, what you need to plug in, and how much of the system you want in one box.
| Area | Better | Why |
|---|
| Power | A | Rega Elex-R has more power - 72W against 45W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Rega Elex-R the better fit for a mid-size room, a large room and a very large room, and Marantz PM6007 for desk or near-field listening and a small room. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | B | Marantz PM6007 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | evenly matched | The same number of line-level inputs (4). |
| Room to grow | evenly matched | The same expansion options on both. |
| Shelf space | depends | Rega Elex-R takes up about 22% less shelf area (1376cm² against 1764cm²), and it is 79mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Marantz PM6007 costs less - $899 against $1,395 at list. |
A Rega Elex-R B Marantz PM6007
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Rega Elex-R has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 45 watts is already more than most people ever use, and the extra 27 watts would be headroom you pay for and never hear - we rate Rega Elex-R poorly for near-field use for exactly that reason. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Rega Elex-R becomes the more rational buy.
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.