← 65edo 66edo 67edo →
Prime factorization 2 × 3 × 11
Step size 18.1818 ¢ 
Fifth 39\66 (709.091 ¢) (→ 13\22)
Semitones (A1:m2) 9:3 (163.6 ¢ : 54.55 ¢)
Dual sharp fifth 39\66 (709.091 ¢) (→ 13\22)
Dual flat fifth 38\66 (690.909 ¢) (→ 19\33)
Dual major 2nd 11\66 (200 ¢) (→ 1\6)
Consistency limit 3
Distinct consistency limit 3

Template:EDO intro

Theory

Approximation of odd harmonics in 66edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) +7.14 -4.50 -5.19 -3.91 -5.86 -4.16 +2.64 +4.14 -6.60 +1.95 +8.09
Relative (%) +39.2 -24.7 -28.5 -21.5 -32.2 -22.9 +14.5 +22.7 -36.3 +10.7 +44.5
Steps
(reduced)
105
(39)
153
(21)
185
(53)
209
(11)
228
(30)
244
(46)
258
(60)
270
(6)
280
(16)
290
(26)
299
(35)

The patent val is contorted in the 5-limit, tempering out the same commas 250/243, 2048/2025 and 3125/3072 as 22edo. In the 7-limit it tempers out 686/675 and 1029/1024, in the 11-limit 55/54, 100/99 and 121/120, in the 13-limit 91/90, 169/168, 196/195 and in the 17-limit 136/135 and 256/255. It provides the optimal patent val for 11- and 13-limit ammonite temperament.

The 66b val tempers out 16875/16384 in the 5-limit, 126/125, 1728/1715 and 2401/2400 in the 7-limit, 99/98 and 385/384 in the 11-limit, and 105/104, 144/143 and 847/845 in the 13-limit.

109 steps of 66edo is extremely close to Pi with only +0.023 cents of error.