The A-100 family of organs (A101, A102, A103, etc.) came in three different versions as follows:
1. AO-28 preamp + AO-35 reverb (5Y3,12AX7 (2) 6BQ5/EL84 (2) or 5 tubes in the reverb +AO-39 power amp.
2. AO-28 preamp + AO-44 reverb (6CA4/EZ81 91) + 6GW8 (2) or 3 tubes in reverb + AO-44 power amp.
The easiest way to determine which model you have is to look at the smaller chassis with tubes and count the number of tubes to determine whether it is a AO-35 or AO-44. Then choose the correct set.
(2) 6BQ5/ EL84
(1) 12AX7/ ECC83
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