Audiophile Journeys with a PC

Decisions, Decisions

Okay, let's apply room correction based upon the measurements taken earlier. I use a slight slope with 5dB of gain towards sub bass. I did try a flat line approach but found that the bass becomes too thin with the filter applied. Reading over the Audiolense guide, I noticed that there is a suggestion to slope things downward somewhat from low frequency to high frequency and I've found this to be my preference.

Let's have a quick look at the estimated room response for both DACs before we continue further. Unfortunately, Audiolense does not provide an option to record a frequency sweep after the correction has been applied. We've contacted Juice Hi-Fi about this and they've told us they're looking at providing this option in a future update. They did tell us that the estimated result is remarkably accurate based upon tests they've conducted themselves. If such an update is made available, we'll be sure to use the feature to present data in the future if the need arises.

Doede DAC

Opus

There is an unfortunate side effect at this point once the correction is applied to the TDA1543 DAC. The 20dB or so of attenuation applied by the filter means I have to turn the volume control to near maximum to get anywhere near the test volume I was using prior to applying the filters. A 6dB gain switch on the TVC does give me headroom of a couple of clicks, but it's far from optimal. To use this DAC with DRC, you'll either need to stack a number of TDA1543s in parallel or use some kind of gain stage on its output. Still, there's just about enough volume on tap for me to get an idea of its sonic signature in comparison to the earlier sound and in comparison to the WM8741.

With DRC engaged, instruments become far easier to pick out and subtle details are more noticeable at the listening position. The best word to describe the effects of DRC is balance. The other shocker is that the basic nature of both DACs remains the same. The TDA1543 midrange gains more edge definition especially on vocals (not that it needed them). The Opus soundstage gains pinpoint precision with lots of air. Complex passages of music are rendered without any perceivable congestion on both DACs.