LL1527, LL1527A, LL1528, LL1530, LL1538, LL1540, LL1545E, LL1570, LL1571, LL1578, LL1579, LL1581, LL1670, LL1935, LL1951, LL1952, LL4611.

LL1544A, LL1545A, LL1550

Can select 6 Gain factors.
Additional, external Switch Board can be ordered, to change between two gain factors.

LL1674, LL1676, LL1922, LL1930, LL5402
LL1588, LL1592, LL1684, LL1690, LL1948

Can select 2 Gain factors.
Additional, external Switch Board can be ordered, to change between the gain factors.

LL1527, LL1527-XL, LL1570, LL1570-XL, LL1540, LL1545, LL1578, LL581-XL.

Add XLR input to standard RCA amplifier

LL1531, LL1532, LL1591.

Select 2 Gain factors, by means of solder jumpers, at back side of the board.

Breaks the ground loop, with XLR or RCA inputs.