The Sony S100CD is a premium 'portable' CD player + DAB/FM radio for the European market, giving good sound quality from DAB radio and CD
The model number and specification for this radio made me wonder if it could be the European equivalent to the US 'XDR' models which use DSP for amazing weak-signal FM performance, especially the rejection of adjacent-channel interference. The two types, XDR-F1HD & XDR-S3HD have been widely acclaimed by long-distance reception enthusiasts. Unfortunately, the S100CD is not such a receiver
In its present implementation, the XDR-S100CD reception quality on FM is quite unacceptable except for the strongest signals, as it suffers from constant crackling and 'chuffing' from internal noise sources. A power-cable cluster runs adjacent to the lead between the telescopic aerial and the receiver module, injecting internally-generated noise into the receiver. This is doubly disappointing since the FM section has the same powerful noise-reduction algorithms as the XDR-F1HD & XDR-S3HD
Listen to some audio clips, below
The S100CD does appear to use DSP for all FM & DAB selectivity and demodulation, but with a much more 'domestic' performance than the earlier US models. The manufacturer has not fitted an external antenna connection, so the telescopic aerial is used at all times. There is no sign of the hardware bandpass IF filtering one would expect, and probably because of this and a simpler front-end section, spurious responses were found all over Band II when an external antenna was connected to the RF input connector on the receiver board.
The selectivity is better than normally found on domestic receivers, and is comparable to the performance of a radio with three 150kHz ceramic filters, such as the Roberts R938. However, strong signals appear up to 300kHz off-channel.
It has 50kHz tuning steps and can be tuned by the rotary encoder or the up/down buttons, but there is a 'tuning mute' which prevents quick tuning for weak signals
Battery drain is too high for true portable use, being 420mA minimum on DAB, 540mA on FM(!) and typically 560mA for CD
The receiver module is the Venice 4 FS2024 DAB/FM-RDS digital radio module from Frontier Silicon
and the RF front-end device is the Frontier Silicon "Chorus 1 FS1010 Advanced Programmable Multimedia Processor IC" (marked A815XAH)
The DAB radio does all that you would expect, with good audio quality, and the display menu includes received signal level. It has a 'rewind' facility which is very simple to use, storing at least 25 minutes of programme, depending on the broadcast bitrate.
Overall the S100CD is a well-made product giving good sound quality from DAB radio, CD or external input. The menu includes proper tone controls
AUDIO CLIPS
Clip 1 Quiet music & spoken word, first from DAB, then a weak-ish FM signal, and finally from a strong FM signal. With strong FM signals, the noise is insignificant except for the most demanding programme material, and the XDR-S100CD stereo noise-reduction processing gives better overall quality than a conventional FM receiver
Clip 2 The same FM programme material as Clip 1 but on a conventional FM/DAB portable radio. Note that there is none of the crackling interference, but the stereo (pink) noise level is quite conspicuous
Clip 3 Another example of speech plus music, on FM (strong signal), first from the XDR-S100CD then from the other portable radio
Clip 4 A longer example of the XDR-S100CD FM interference
POSTSCRIPT - DEMISE of my S100CD
My S100CD has, after 2 years of service, declined progressively. to the point where it is effectively unusable. First, the DAB receiver sensitivity declined rapidly, until after a few days even the strongest local multiplex could only be received upstairs on the 2nd floor of a commercial building, with the telescopic antenna fully extended. DAB has now failed completely. FM reception remained possible, but the S100CD software became unable to control the switching between CD and FM Radio, often until power has been removed for at least several minutes. Sometimes a CD may appear to play normally, but makes no sound. FM Radio may sometimes show "TUNING" for an indefinite period, again with no output, and sometimes all control may freeze
J.Hardstone Oct.2009 revised Aug.2015
