Dobro / Resonator tuner – Open D (DADF#AD)
D-A-D-F#-A-D · Open
Press “Start tuner” – the browser will ask for microphone access. Sound is analysed on this device and never uploaded.
This free online tuner listens through your microphone and shows how close each string of your Dobro / Resonator is to Open D (DADF#AD) tuning (D-A-D-F#-A-D). Play a string, watch the needle, and turn the peg until the meter glows green. If you prefer tuning by ear, tap any string card to hear its reference tone.
About Open D (DADF#AD) tuning
Compared with Open G (GBDGBD), Open D (DADF#AD) moves 4 strings. Every change is downward, the largest by 5 semitones, so the instrument sits at lower tension than in Open G (GBDGBD).2 strings stay exactly where they were.
| String | Open G (GBDGBD) | Open D (DADF#AD) | Change |
|---|---|---|---|
| 1 | G2 | D2 | down 5 semitones |
| 2 | B2 | A2 | down 2 semitones |
| 4 | G3 | F#3 | down 1 semitone |
| 5 | B3 | A3 | down 2 semitones |
Played open, the strings sound D-A-D-F#-A-D – from D2 at the bottom to D4 at the top, a span of 2 octaves. Step by step across the neck the intervals are a fifth, a fourth, a major third, a minor third, a fourth, and that is what decides how chord shapes fall under the hand.
Strummed open, with nothing fretted, the strings spell D. That is what makes a tuning like this useful for slide playing and drones – a full chord is one straight barre away at any fret. See D shapes in this tuning →
Open D on a resonator gives the same lap-style logic as Open G in a different key, with the root doubled top and bottom. Blues and Hawaiian players tend to prefer it; bluegrass stays with G.
The choice between the two is mostly about where the melody sits and which bar positions you want the tune to fall into.
This is a long drop: 5 semitones below Open G (GBDGBD). Standard gauges will flap at this pitch. A heavy set, and often a longer scale, is what makes the tuning playable rather than merely possible.
History
Where the Open D (DADF#AD) tuning comes from
Open D (DADF#AD) is the older resonator tuning, shared with the blues and Hawaiian slide players of the 1920s and 30s – the era when the resonator guitar itself was invented. Blues players using round-neck resonators still prefer it, and it remains popular for slower, more bluesy styles.
Other Dobro / Resonator tunings
Chords for this tuning
How do I tune my Dobro / Resonator to Open D (DADF#AD)?
Allow microphone access, pluck a string, and the tuner will detect it automatically. The needle shows whether the string is flat or sharp – adjust until the reading is within ±5 cents (D-A-D-F#-A-D).
Which notes are used in Open D (DADF#AD) tuning?
Open D (DADF#AD) tuning for Dobro / Resonator uses the notes D-A-D-F#-A-D, listed from the lowest string to the highest.
Can I tune without a microphone?
Yes. Every string card plays a reference tone – tap it and match your string to the sound by ear.