K2572
8
USAGE
10 connections are provided on the PCB to connect the circuit
with signal inputs, grounds and power supply. These
connections are identical to those of the RIAA K2573; you can
connect them by the numbers.
1. ground
2. out left
3.
ground
4.
in left
5. ground (power supply)
6.
plus (power supply)
7.
in right
8.
ground
9.
out right
10. ground
The ground connections near the IN and OUT connections are
used to connect the stranded wires (-) of the connecting leads.
The output amplitude of the right and the left channel are totally
independently controlled by RV1 for the right channel and RV2
for the left channel.
As current consumption is very low, voltage can be taken from
any stable power supply of between 10VDC and 30VDC. Lower
the gain from 100 to 10 if the input signal is higher than 50mV;
this is done by replacing R5 and R6 with 100k
Ω
resistors.
REMARKS
An unstable power supply will give noise and hum. The leads to
and from the PCB must be as short as possible and use only
screened wires
Never place the preamp in the vicinity of transformers or mains
power lines
