Pioneer SC-07 Overview & Set-Up
Someday they're going to have the technology to build a fully functional A/V receiver on a single chip the size of your thumb that will run on solar power. If you believe that, then you probably think we will also be traveling at warp speed and fighting Klingons in a few hundred years. Pioneer, on the other hand, is attempting to take the next evolutionary step in A/V receivers by employing Class D amplifier technology which not only runs more efficiently (> 90% vs 50% of classic linear AB designs), but can also deliver more available power to your loudspeakers. The question remains, however: Can it do it with the same level of finesses and poise as yesterday's amplifiers? Read on to find out.
The SC-07 is the second in line from flagship status for Pioneer Elite and decodes virtually every known audio format in existence. This 40lbs metal beast houses a highly efficient Class D power amplifier that is rated for 140wpc x 7. Video processing and scaling is accomplished by Faroudja DCDi, proving 1080p support and analog to HDMI video upconversion. There's also the new Precision Quartz Lock System (PQLS) which, according to Pioneer, re-clocks 2-CH PCM CD audio from the HDMI digital output of a compatible Pioneer Blu-ray disc player to reduce jitter and improve fidelity. Since I didn't have a Pioneer Blu-ray player on hand, I was unable to confirm this feature's benefit.
The Pioneer SC-07 build quality is typical of what I've seen in past Elite products: a nice glossy faceplate, big chassis to house all of the electronics, and a clean and simple front panel as far as the bridge of a Starship goes. Seriously, could they or any other Japanese receiver company figure out how to squeeze more poorly marked buttons on a front panel of a receiver? Removing the top panel was no small task and Pioneer would surely win the award for "most screws in a single chassis" (count 'em, there's 22).
The SC-07 is missing one key element bestowed upon its predecessors: a large heatsink on which to mount the power devices. Instead, the ICE amplifier module is located in an isolated compartment on the bottom of the receiver which I was unable to get to for photos. I was a bit perplexed as to why they located the parts that generate the most heat towards the bottom of the receiver but it seemed to be more a real estate issue than one of preference. Make no mistake, despite this is a highly efficient Class D amplifier, the module gets hot to the touch when this amp is running at high levels for long periods of time. This is a fact that I learned after my multi-channel listening test was done and I was packing it back in the box. The top of the chassis is cross beam braced for increased rigidity and reduction of mechanical vibration. This is a welcome feature I am seeing offered on the latest flagship receivers from other brands as well.
Where's the beef?
Although the SC-07 contains an ICE amplifier module, Pioneer chose to stick with a linear power supply, which in my opinion was a good call on their part. SMPS (Switch Mode Power Supply) , although more compact and efficient, can be more costly to design properly and still result in less overall headroom and higher power supply ripple during heavy demands. This can lead to power sag and sonic nasties. The E-core power transformer utilized in the SC-07 was a bit small for a receiver in this price class, about 10-15% smaller than what I observed in the Yamaha RX-Z7 which I also had under review at the same time. What was even more surprising to me was the meager 2 x 10,000uF power supply capacitors. I've reviewed $400 Yamaha and $850 Denon receivers with more juice than this. I also noticed that they employed 80V capacitors, which is a way larger Vrating than is needed for the 140wpc rating on this receiver. I started to suspect that maybe Pioneer was using a lower current high voltage power transformer to yield more impressive dynamic power measurements at the expense of sustained low impedance continuous power delivery. I would confirm this later on the bench.
System Setup & Configuration
I set up the SC-07 for 5.1 but biamped my front channels full range which consisted of RBH Sound T-30LSE towers that dip into the 3-ohm range to really give the ICE amplifier modules a workout. I used the matching RBH T-1SE/R center channel and MC-6C bookshelfs on stands for the rears and one of my Velodyne DD-15's for the subwoofer channel. The transports were the Denon DVD-5910, Toshiba HD-A2 HD DVD player (yea I know, dead format) and the Yamaha MusicCAST MCX-2000. All of my cables were Sonicwave by Impact Acoustics / Cables to Go with the exception of my front speakers which were wired with Rivercable Starflex.
Back Panel View of the Pioneer SC-07
The back panel of the SC-07 is a bit crowded like all other receivers in this price range. There are seven speaker connections where two of them can either be used as Speaker B, Surround Backs, Zone2 or Biamp depending on how you assign them in the OSD. There are 4 HDMI inputs and 2 outputs, 3 component inputs and 2 outputs (1 for Zone2), 4 TOSlink ins / 2 outs, and 3 coax inputs. The power cord is not detachable which is disappointing at this price, and there are no provisions for switched or unswitched outlets.
Choosing the Speaker Impedance?
Um, well not really. In fact, this is the first UL rated receiver that has no impedance markings on the back panel or the user manual. Pioneer gives zilch as far as recommending a minimum impedance speaker to use with this receiver sans the small blip on page 64 of the user manual about recommending 6 ohm yo 16 ohm speakers when using the Speaker B amp configuration. Instead of a silk screen with impedance markings, my unit had a removable thin film plastic faceplate over the speaker terminals. I have no idea what that was for. As far as I know, Pioneer has no issue connecting up a fork on the outputs, but I wouldn't recommend it.
Back in the 70's and 80's linear amps were doing some very similar things as the ICE power module unit in question. What was found was this caused slew rate limitations giving what is still known as slewing induced distortion. This was observed on in band impulse response testing. Contrary to some beliefs one does not need a DC to light bandwidth to NOT have slewing induced distrotion but one must have a near flat response to 20 kHz independent of power for the load the amp is designed for.
Too see audio go back in history and make the same mistakes all over again is just a bit disheartening.
Even though a lot of people there disagree with you (and still do) they (like I) appreciate your review and your posts there.
What I did not agree with is how you announced your last post on that thread and said you were done with it. Why not continue to defend your review? You never got any personal attacks or insults.
I don't need to "defend" my review that has objective measurements done by the most advanced and industry standard Audio Analyzer with a test in accordance to how the FTC has measured amplifiers for the last 30 years. There are people that would like to believe full bandwidth power tests are irrelevant and I'd say more power to them (no pun intended), but there are those that also believe in testing products to their limits and ensuring they are getting an amplifier that can deliver maximum full bandwidth power into low impedance loads. I am not on a quest to change peoples minds. I do however test all amplifiers under the same test conditions and hold the same criteria regardless of amplifier classification. You will see soon a review of a Class D amp that can deliver full power bandwidth into 8, 4 and 2 ohm loads as an example as well as a series of articles on this very topic.