The Cambridge Audio 650BD is a universal Blu-ray player
that is affordable, and has excellent build and finish for the price.A recent What Hi-Fi review gave it a 5 Star
rating, commenting; that it did not have quite the best Blu-ray picture for the
price, and it did not badly compromise CD playback.
We agree that the players all round performance is good,
choosing to show a spread of strengths for picture and sound, but is not a
class act in any particular area.
Inside the 650BD the players resembles more than just a
smack of the Oppo BDP-80, a £350 zone free player which sits at the bottom of
Oppo’s Blu-ray player line-up. Such is the resemblance that the 650BD circuits
appear an OEM version of the Oppo BDP-80. This observation is not a criticism,
in fact considering the improved build and finish of the Cambridge Audio player
it becomes an even bigger steal for the price!
Our thinking is that anybody looking to buy the 650BD
will be doing so for CD /SACD music as well as movies, after all it is a
‘universal player’. So considering the players performance is that if it nearly
as good as the best of the crop £400 Blu-ray players, and could use a healthy
boost in its stereo CD playing abilities, then we would can achieve this with a
couple of hundred pounds (pounds sterling) of upgrade modifications.
This is exactly what our 650BD upgrades achieve, far
better sound from CD, SACD & DVD-A, and improved Blu-ray picture. General
purpose parts are upgraded in the Switch Mode power supply, ultra-low ESR, low
impedance capacitors are installed as well as Ultra-fast recover diodes. The
power supply upgrades lower the noise of the supply so that all video and audio
circuits benefit from a cleaner power. Moving to the audio board we replace the
7805 voltage regulator which powers the DAC chips with a “Super-regulator”.
This discrete regulator has excellent PSRR, the regulators ability to reject
noise at its input. This combined with an ultra-low noise output ensures a
noise free supply to the DAC chips. The general purpose regulator bypass
capacitors are replaced the excellent Rubycon ZA capacitors, the ZA is a very
fast capacitors, with extremely low ESR and for specific circuit applications
are the best sounding electrolytics available. The 650BD’s analogue stage is
based around the NE5532 op-amp, now decades old, it is far from being retired
and still finds its way into audio products. We replace the NE5532’s with the
LME49720 (LM4562), this op-amp is clearly superior to the 5532’s in terms of
detail, imaging, sound-staging, rhythm and texture. Following the op-amps
circuit, the audio output is capacitor coupled using an electrolytic (one per
channel) with a polystyrene bypass to improve high frequencies. The electrolytic is a poor quality type for
signal coupling, and being directly in the signal path it degrades the sound.
We replace the electrolytic’s with Silmic II (RFS), the premium grade audio
grade capacitors from Elna. This results in a cleaner, more open and detailed
sound, with improved tonal qualities.
Cambridge
Audio 650BD Level-1 Upgrade
■ Upgraded electrolytic capacitors for bulk decoupling of SMPS.
■ Upgraded electrolytic capacitors for decoupling regulated & unregulated
DC lines.
■ 4x Ultra-fast recover diodes for SMPS.
■ 6x Rubycon ZA regulation bypass capacitors for 7.1 channel audio board.
■ 1x Super-regulator for 2-channel DAC Supply
■ 1x LME49720 op-amps for 2-channel audio output.
■ 2x Elna Silmic II (RFS) output signal coupling capacitors (2-channel).
Cambridge
Audio 650BD Level-2 Upgrade
■ Upgraded electrolytic capacitors for bulk decoupling of SMPS.
■ Upgraded electrolytic capacitors for decoupling regulated & unregulated
DC lines.
■ 4x Ultra-fast recover diodes for SMPS.
■ 6x Rubycon ZA regulation bypass capacitors for 7.1 channel audio board.
■ 1x Super-regulator for 2-channel DAC Supply
■ 4x LME49720 op-amps for 7.1 channel audio output.
■ 2x Elna Silmic II (RFS) output signal coupling capacitors (2-channel).
