- Written by John E. Johnson, Jr.
- Published on 20 July 2009
Most CD players these days are built for consumers who don't want to spend a lot of money, so the chassis is thin. In fact, you can usually lift them with one hand.
Not so with the SA-7S1, unless you are an Olympic weight lifter. This thing is almost 50 pounds. It's chassis is copper plated and all six walls are thick, along with a heavy front panel. The unit is absolutely gorgeous, as you can see if you click on the photo at the beginning of this review. In fact, it is so pretty, I have taken the liberty of practicing my PhotoShop skills with the photos that Marantz supplied for the review, and will present a few of the abstract results here and there.
I suspect that the toroidal power transformer is a big part of the weight, because the output did not change very much when I tortured it with dual 600 ohm loads.
The player uses dual NPC SM5866AS DACs. Remember that SACD, aka DSD (Direct Stream Digital), is presented one bit at a time instead of a group of 16 bits or 24 bits as is the case with PCM (Pulse Code Modulation - CD, DVD-A, and music on Blu-ray discs). Another term associated with DSD is Delta-Sigma, which is the type of modulation.
But we really don't need to concern ourselves with the way the bits are presented. It is the total amount of bits that is important. So, for example, CD is 16 bit, 44.1 kHz sampling, which is 705,600 bits of data per channel, per second. For 24 bit, 96 kHz audio (DVD-A), there are 2,304,000 bits per channel, per second, and for 24/192, it is 4,068,000 bits. And that is for just the one channel. If you are talking about some of the newly released 24/192 5.1 Blu-ray music discs, 23,040,000 bits per second are zooming through the players DAC(s). That 23 million figure is about what a Blu-ray movie has, which includes the image as well as the sound, so the image has to share the bit rate with the surround sound audio, and you won't be getting it at 24/192. More like 20 to 24 bit, at 48 kHz.
For SACD, the bit rate is 2,822,400 bps (bits per second) for each channel, which is very near what it is for 24/96 PCM.
But there is much more to the story than just the fact that the bit rate for SACD is similar to one of the PCM high rez formats. With DSD, the recording engineers can choose a preferred balance between bandwidth and dynamic range, even during the production stage. Also, since the data are handled one bit at a time, there is no processing delay, as there is with handling them 16 bits or 24 bits at a time. Third, decimation and interpolation filters are not necessary with the DSD signal. Fourth, there is more tolerance to bit errors, and fifth, downsampling to a PCM format is easy.
So, what are the problems? Well, for one thing, like all Delta-Sigma modulations, there is quite a bit of noise. However, using certain techniques, the noise is pushed far into a high range of frequencies that are inaudible. But, that noise is there, nonetheless, with the possibility of interacting with frequencies in the audible band. If SACD were perfect, everyone would be using it. Funny that there are notes here and there on forums saying that Sony has abandoned its support of the format, but new SACDs still are arriving on music shelves. What I have noticed is that SACDs tend to be classical music, while popular music favors DVD-As.
The rear panel of the SA-7S1 has the unit's outputs. It has one pair of XLR and RCA analog outputs, one coax and one Toslink optical digital output, and an external clock input, if you so choose to control the unit with a clock in some other component.
The remote control is spartan compared to a receiver's remote control, but there are not as many functions to deal with. It's quite narrow, maybe a bit too narrow for my large hands, but should be fine for most people.