PBC-L475 Transformer Isolated Mono Sum Card

The PBC-L475 can be used in either Sum-to-Mono mode or Mono-to-Stereo Split  mode. The transformer provides isolation and balancing for audio level signals. The card is very simple to hook up and the frequency response is great – it’s almost a flat line from 30 Hz to over 20 kHz. The unbalanced audio can be connected with screw terminals or RCA plugs. It comes with a strip of foam tape for mounting.


Model #:

Frequency Response (Sum-to-Mono mode):
40 Hz to 20 kHz ±1 dB
25 Hz to 40 Hz ±2 dB

Frequency Response (Mono-to-Stereo Split mode):
30 Hz to 20 kHz ±1 dB
20 Hz to 30 Hz ±2 dB

Impedance (Both Modes):
Source: 200 Ohm
Load: 10K Ohm

Insertion Loss:
<1dB @ 1 KHz, 0.5dB typical both modes

Recommended Level:
-30 dBu to +4 dBu

Primary to secondary: 1500 VAC
Primary/Secondary to core: 500 VAC

2.1″ L x 0.8: W x 0.7″ H

Click here for wiring diagram

Click here for specification sheet

PBC-L475 Case

An optional grey plastic case is also available. It’s a nice way to mount the board. Delivery is two weeks. Shorter delivery is available for a small surcharge