Balance in - balance out, balance out - single end out. Single end in - single end out, single end in - balance out. Use ecc82, ecc88 2 each, 6x4 1.
According to the feedback of the three years of experience adjustment debugging summary The circuit has been slightly modified, the original figure 100R to 20R,47k to 51k. 8 10uf output to 8.2uf