A few users are surprised with large gain increases when they install the 610 into their audio chain. Here’s why.

The 610 uses a balanced, bridging input. It does not present a 600-ohm load to the output of the device which drives the 610’s input. In other words, your console output is not loaded by 600 ohms when the 610 is in the circuit and operating.

When the 610 is in the bypass mode, a relay connects the output connectors to the input connectors. This is a “hardwire” bypass, a copper path between input and output. This means that when the 610 is in the bypass mode, the console output sees the load of the input circuit of the device connected to the 610’s output connectors. Your console output connects directly to the input of your audio processor anytime that the 610 is not in delay.

If the audio processor input presents a 600-ohm load to the console output, the 610 will remove the load to the console output when it goes on-line. Because the console output is no longer connected to a 600-ohm load, its output signal may rise as much as 6 dB, depending upon the output circuitry.

This level increase will pass through the 610. The input of the audio processor will receive a signal which is 7 dB hotter than when the 610 is in the bypass mode. This is because of the 6 dB gain change caused by removal of the 600-ohm load, plus a 1 dB gain increase inside the 610. We use a heavy duty output driver in the 610. It is able to supply the same output level to either a bridging input (high impedance) or a 600-ohm load. The 610’s output does not drop when it is loaded with 600 ohms. The output drivers of some equipment are not this robust.