Which to buy · Every setting
Fellow Opus vs Niche Duo
Conical against flat — the Opus's scale curves where the other runs straight. The Opus is numbered 1–11; the Duo is numbered 0–50.
Which to buy
Choose the
Opus if you…
- want 40 mm conical burrs, which Fellow rates from espresso to cold brew
- want fixed steps you can return to exactly — 41 on the dial, plus a micro-adjust ring
- want a timed auto-stop at 30, 60, 90 or 120 seconds
Choose the
Duo if you…
- want separate 83 mm flat burr sets for espresso and for filter
- want stepless adjustment that Niche says needs no re-zeroing when you swap burrs
- single-dose — the hopper takes 60–70 g
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Fellow now sells the Opus 2 in place of the original; the settings on this page are for the original.
Sources: Fellow — Opus (archived) · Fellow — Opus gear guide · Niche — Duo user manual · Niche — Duo
| Opus | Duo | |
|---|---|---|
| Brand | Fellow | Niche |
| Scale | Numbered dial | Numbered dial |
| Dial range | 1 – 11 | 0 – 50 |
| Burrs | Conical | Flat |
| Espresso → filter | 5.7 numbers | 39.4 numbers |
| Filter → coarse | 3.9 numbers | 10.4 numbers |
The same number means different things
Both grinders use a numbered dial, which makes it tempting to copy a number straight across. Setting 6 sits at grind index 34.2 on the Opus but 5.8 on the Duo — far enough apart to change the cup.
Converting a setting
If a recipe quotes a setting for one of these grinders, read across for the equivalent on the other. Rows are spaced evenly by grind size, not by dial number — on a conical burr those are not the same thing.
| Opus | Duo |
|---|---|
| 1.2 | 0.2 |
| 2 | 16.7 |
| 3.2 | 24.9 |
| 5.3 | 33.1 |
| 7.1 | 40 |
| 8 | 42.2 |
| 8.2 | 44.3 |
| 8.3 | 46.4 |
| 9.1 | 47.8 |
| 9.3 | 48.5 |
| 10.2 | 49.3 |
| 11 | 50 |
| Duo | Opus |
|---|---|
| 0.2 | 1.2 |
| 8.5 | 1.2 |
| 16.7 | 2 |
| 24.9 | 3.2 |
| 33.1 | 5.3 |
| 40 | 7.1 |
| 42.2 | 8 |
| 44.3 | 8.2 |
| 46.4 | 8.3 |
| 47.8 | 9.1 |
| 48.5 | 9.3 |
| 49.3 | 10.2 |
| 50 | 11 |
Side by side, by brew method
Where each grinder lands for the same brew, worked out from its own dial curve.
| Method | Opus | Duo |
|---|---|---|
| Espresso | 1.2 | 5.2 |
| Moka pot | 1.3 | 15.1 |
| AeroPress (short steep) | 3.2 | 24.9 |
| Pour over — V60 / cone | 6.3 | 37.6 |
| Siphon | 7.2 | 40.1 |
| Pour over — flat bottom | 7.3 | 40.9 |
| Steep and release — Clever / Switch | 8 | 41.7 |
| Drip / batch brew | 8 | 42.2 |
| Cupping | 8 | 42.7 |
| Chemex | 8.2 | 44.2 |
| French press | 9 | 47.5 |
| Cold brew | 10 | 48.9 |
The shape of each dial
Where the connectors bunch, that grinder’s dial is compressed and single steps count for more. Comparing the two shapes tells you which gives finer control, and where.
Fellow Opus
Niche Duo
Dialing in the Opus
Marketed as all-purpose, and it genuinely does cover more range than the Ode, but the espresso end is workable rather than good — expect to chase it. Where it earns its place is the coarse end: cold brew and French press come out notably even. If you bought the Opus mainly for espresso, dial it as a brew grinder first and judge it there.
Dialing in the Duo
The Duo extends the Niche single-dose concept to cover both espresso and brew properly, rather than stretching one dial across both. Like the Zero it is stepless, so treat the numbers below as targets to land near rather than detents.