For sale used Tesla EZL444 line amp module from early 1970-s big Tesla studio mixing console. Discrete design, input and output are transformer balanced. Can be used as mic pre. Modules are tested and they work - sold as is . I will add a suitable connector with the module for diy racking.
Pin a4 : input +
Pin b4 : input -
Pin ab3 : input ground
pin a6 and b6 : should be linked
pin a9 : output +
pin b9 : output -
pin b2 : -24v dc supply
pin b1 : +24v dc supply (ground)
pin a1: chassis ground
( TIP : gain control range increase mod - Remove R14 and use 10k pot instead of the trimmer R15 )