Push

Pin 2 = Hot (+)

Pin 1 = Screen

Pin 3 = Cold (-)

Fig 2.6.3: Pin arrangement for XLR inputs on the SPX20

For unbalanced operation join pins 1 and 3 and connect to Screen (signal ground) and use pin 2 as Hot (signal +).

Input 1 also has a pair of front panel inserts on TRS jacks which are wired as follows -

Sleeve	Ring	Tip
Screen	Cold (-)	Hot (+)

Fig 2.6.3: Pin arrangement TRS jack inserts on Input 1

For unbalanced operation join Ring and sleeve and connect to screen (signal ground) and use Tip as Hot (signal +).

Plugging a mono jack into these inserts effectively unbalances the connection.

Sleeve	Tip
Screen	Hot (+)

Fig 2.6.4: Mono jack pin arrangement

Tip Hot (signal +)

Sleeve Screen (signal ground)

Page 6