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XM6 & XM5 Output Buffer Options

Your XM6/XM5 has four DIP sockets:
  • Two of these sockets are for left-channel/right-channel amplifier chips;
  • The other two sockets are for left-channel/right-channel output buffer chips.
Amplifier Chips: The base XM6 and XM5 are equipped with two Burr-Brown single-channel OPA134 amplifier chips. These chips are well-respected, ultra-low-distortion (.00008%), low-noise, high-performance audio amplifier chips.

The AD8397 DoubleCat chip has both amplification and buffering built-in. See below.

If you are an advanced user, and wish to experiment, there are many other amplifier chips which you can use, as long as they match the semi-standard single-amp pinout of the OPA134. You can also use chips in a surface-mount SOIC package, by using the WhiteCat SOIC-to-DIP adapter.

Buffer Chips: You have several options for output buffering:
  • Texas Instruments' BUF634 High-current output buffers
  • AD8397 amplifier/buffer, plus copper busbars
  • No buffering. In this case, use the copper busbars as shown.

Texas Instruments BUF634 high-current output buffers installed.

AD8397 and busbars installed (AD8397 is a dual-channel chip with integrated 300mA very strong buffering).

Copper busbars installed.

How do I choose? All options have their advantages and drawbacks. All options provide excellent sound. The best battery life and lowest cost is from the OPA134's with busbars. The AD8397 has very high current output, but with the two-channel chip you don't have a monoblock configuration. The BUF634's also have very high current output, and mantain the monoblock config. Remember, you can always upgrade later.

Your User's Manual has full instructions on changing/installing buffers.

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