Differential Output Stage

It’s one thing to build and amplifier, it’s another to build a pre-amplifier. I selected a CS4398 [PDF] as DAC; this chip has a differential output for both channels, an I2S input and up to 120dB dynamic range.

What’s nice is that Cirrus Logic made a very well designed evaluation board for this chip, the CS4398. I’ve used the XLR output as a starting point for my own output stage.

The DAC will run at 96kHz with an oversample of 512x. The master clock is just over 49MHz (49.1520MHz). The input (I2S) will be feed from either a DSP or my “Core Module”; I have not yet tested if the ColdFire v2 @ 66MHz will be able to keep up with video & audio. As for the PCB, all the components will be surface mount to minimize space and keep the trace length to a minimum.

Differentail Output Stage

JLH Amp PCB

Well I just finished my PCB layout for one of my class A power amplifier;
PCB for my JLH Amp

I will now attack the blanced input stage. I was thinking about a simple op-amp with a buffer right before the “input”.