5348 Whitepaper

Radiance Pro 5348 Introduction January 24, 2021
The Radiance Pro 5348 uses the same software as the 4XXX models. So, video processing
operations are currently identical. What sets the Radiance Pro 5348 apart is the electrical
improvements in the design. While using the same HDMI chips, and FPGA, the use of linear
regulators for 28 critical power supplies, and the addition of an HDMI dejitter output
buffer, has dramatically reduced output jitter and noise. The use of Faraday cages for all
nine DC-to-DC switching-regulators dramatically reduces EMI.
As an example, the current 18 GHz Rev 1.4 output card in a 4446 has a HDMI data jitter of
about 80 pS (HDMI specification requires 102 pS or less for 18 GHz). In comparison the
measured HDMI output data jitter on the Radiance Pro 5348 is 45 pS, or just about half.
More importantly for audio, the HDMI output clock jitter has been measured at about 10
pS. This is a nearly ideal clock to send to the audio processor.
People have asked me if reduced jitter and electrical noise matters. Yes, it does. I have been
discussing HDMI jitter on the forums for many years. What I can say based on my A-to-B
testing is that, with the Lumagen Demo Theater’s Trinnov Altitude 16, the Radiance Pro
5348 does make a significant improvement for appropriate content (e.g. Greatest Showman
“Never Enough”). For the current 444X products I get calls on a fairly regular basis asking
“the Radiance Pro does not process audio. So how come audio sounds better when it is
running through the Radiance Pro?” The difference is lower jitter and reduced electrical
noise. The Radiance Pro 4XXX output jitter and electrical noise are already dramatically
better than other products we know about, but 5348 takes jitter and noise reduction to
what we consider is the ultimate audiophile level.
Some have said that a high-end audio processor’s dejitter circuit can handle higher jitter
levels. In my experience, audio processor dejitter circuits can improve the jitter as the
signal works toward the DAC’s, but there is a limit to the improvement. The advantage the
Radiance Pro has compared to traditional dejitter circuits is it completely regenerates the
HDMI audio output using a very low jitter crystal clock chip for the HDMI audio clock, and
then passes the HDMI signal through two stages of PLL dejitter circuits. Using linear power
supplies also helps keep the jitter low by isolating the noise from the digital circuits away
from the HDMI integrated circuits.
I am also being asked if the lower jitter of the 5348 will improve video. Since the 4XXX
series already has output jitter well below specification, the 5348 going from 80 pS down
to 45 pS for the data is not likely going to improve the Bit-Error-Rate (BER) on the HDMI
connection. The data reaching the projector/TV should be identical and so there should not
be any visible difference.
But, what about the reduced electrical noise on the Radiance Pro 5348 output? This gets
into the question of can electrical noise injected into a projector through the HDMI cable
affect the image’s background “analog” noise. For a digital display technology such as DLP,
the answer in my opinion is no. For a projector with an underlying analog display chip
technology (LCOS, DiLA) the answer is that there is a chance it might make a visible
improvement. Each system needs to be evaluated individually to determine if there is any
visible change. As with any image quality analysis, the final assessment must be done at