取り敢えず、エクセルで可変抵抗を動かした時の減衰量を計算してみました。
どうやら R1=1.2KΩ R2=3.3~4.7KΩ が良さそうです。
R1 | VR1 | R2 | VR1-R2 | R1 | 合成抵抗 | 減衰率 |
可変抵抗 | パラレル | 合成抵抗 | ||||
1,200 | 5,000 | ∞ | 5,000 | 1,200 | 1,005 | 80.6% |
1,200 | 4,000 | ∞ | 4,000 | 1,200 | 975 | 76.9% |
1,200 | 3,000 | ∞ | 3,000 | 1,200 | 933 | 71.4% |
1,200 | 2,000 | ∞ | 2,000 | 1,200 | 873 | 62.5% |
1,200 | 1,000 | ∞ | 1,000 | 1,200 | 776 | 45.5% |
1,200 | 0 | ∞ | 0 | 1,200 | 600 | 0.0% |
1,200 | 5,000 | 10,000 | 3,333 | 1,200 | 949 | 73.5% |
1,200 | 4,000 | 10,000 | 2,857 | 1,200 | 926 | 70.4% |
1,200 | 3,000 | 10,000 | 2,308 | 1,200 | 894 | 65.8% |
1,200 | 2,000 | 10,000 | 1,667 | 1,200 | 846 | 58.1% |
1,200 | 1,000 | 10,000 | 909 | 1,200 | 765 | 43.1% |
1,200 | 0 | 10,000 | 0 | 1,200 | 600 | 0.0% |
1,200 | 5,000 | 5,600 | 2,642 | 1,200 | 914 | 68.8% |
1,200 | 4,000 | 5,600 | 2,333 | 1,200 | 896 | 66.0% |
1,200 | 3,000 | 5,600 | 1,953 | 1,200 | 869 | 61.9% |
1,200 | 2,000 | 5,600 | 1,474 | 1,200 | 828 | 55.1% |
1,200 | 1,000 | 5,600 | 848 | 1,200 | 757 | 41.4% |
1,200 | 0 | 5,600 | 0 | 1,200 | 600 | 0.0% |
1,200 | 5,000 | 4,700 | 2,423 | 1,200 | 901 | 66.9% |
1,200 | 4,000 | 4,700 | 2,161 | 1,200 | 884 | 64.3% |
1,200 | 3,000 | 4,700 | 1,831 | 1,200 | 860 | 60.4% |
1,200 | 2,000 | 4,700 | 1,403 | 1,200 | 821 | 53.9% |
1,200 | 1,000 | 4,700 | 825 | 1,200 | 753 | 40.7% |
1,200 | 0 | 4,700 | 0 | 1,200 | 600 | 0.0% |
1,200 | 5,000 | 3,300 | 1,988 | 1,200 | 872 | 62.4% |
1,200 | 4,000 | 3,300 | 1,808 | 1,200 | 858 | 60.1% |
1,200 | 3,000 | 3,300 | 1,571 | 1,200 | 837 | 56.7% |
1,200 | 2,000 | 3,300 | 1,245 | 1,200 | 805 | 50.9% |
1,200 | 1,000 | 3,300 | 767 | 1,200 | 745 | 39.0% |
1,200 | 0 | 3,300 | 0 | 1,200 | 600 | 0.0% |