After using the Panasonic SA-XR55 class D receiver for almost three years, I wanted to upgrade to something very similar (with a class-D amplifier), but with DVD-Audio playback over HDMI connection. Ideally, it would have been even better if the receiver had HDMI switching and supported Super Audio CD (SACD) over HDMI as well, but Panasonic stopped selling class D receivers (and receiver overall for that matter) and I got addicted to Class D's price, performance, low power consumption and low heat.
Even before getting my XR55, I have read on several online forums that the Panasonic XR55 (and others from the XR line, e.g. the XR57) produce amazing sound. Some people claimed that they sold their previous (very expensive) gear, because the XR55/XR57 sounded as good or almost as good. Obviously, I was a bit skeptical at first, since the XR55 sold for only $230-250. But I decided to give it a try and never regretted it.
So now, I upgraded to the Panasonic SA-XR57, which is very similar to XR55, but adds DVD-Audio playback over HDMI, dual-amping for front speakers in surround sound mode and nicer remote control. I had to buy it on eBay since new Panasonic receivers are no longer sold in the US.
What is Unusual About the XR57?
The Panasonic SA-XR57 is among so-called Class D amplifiers. The major difference with amplifiers of other types (A, B, AB, H, H , etc.) is that the Class D is digital (the others are analog) and features very high efficiency (more than 90%). This translates into lower power consumption, less heat and smaller dimensions.
The signal from your DVD or CD player (or other device that has a digital out) is kept in digital domain longer, producing less noise and other sonic benefits (which I will describe later). This is especially true with DVD-Audio over HDMI connection.
What is Panasonic SA-XR57
The Panasonic SA-XR57 is a digital home theatre receiver, available in black or silver color. It uses a Class-D digital amplifier for sever channels to provide a 7.1 configuration. The receiver is rated to deliver 100 W into 6-Ohm speakers at 0.09% THD in stereo mode. It has (among others) two optical and two coaxial digital inputs, component video switching, S-Video switching as well as a multi-channel analog input.
It also has one HDMI input and one HDMI out. Although having only one HDMI input is a bit of a limitation, it is perfectly fine for my purposes as my TV has a bunch of HDMI connections and I intend to use this receiver's HDMI input for DVD-Audio only. The receiver also does not support SACD over HDMI, but supports it over its multi-channel analog input.
Update 10/2009: I am actually using an auto-sensing HDMI switch before the receiver's HDMi input so all of my devices (HD DVD player, Blu-Ray player and a universal DVD-Audio/SACD/DVD player) can be used with the receiver without any effort.
The HDMI part of the receiver supports signal pass-through when the receiver is off and control over Viera Link (HDMI-CEC).
The receiver has sturdy speaker binding posts for all speakers (unlike other inexpensive receivers that have spring clips). In addition to 7 channels, the receiver supports a separate set of stereo speakers (A/B switching available). It also supports bi-wired/bi-amped configuration, in which you run two separate connections to each of your two front speakers (if speakers support it): one for high frequencies, another for lows.
The receiver is rated to deliver a frequency response of up to 4-88,000 Hz from all sources aside from analog multi-channel input, which is rated 4-44,000. All of them are rated at /-3 dB. The rated Signal/Noise ratio is 85 dB (103 dB IHF 66).
The receiver supports Dolby Pro Logic IIx and DTS Neo:6.
Just as the XR55, it has 2 digital optical inputs and 2 coaxial digital audio inputs, with coaxial input #1 supporting up to 192 kHz and the rest up to 96 kHz. It has 2 component video inputs instead of the XR55's three. It also has a bunch of S-Video, composite and analog audio inputs and outs with a dedicated 5.1 analog audio input for DVD-Audio, SACD or DVD players.
The receiver I got is in silver color. It has the same width and depth as the XR55, but is slightly heavier. The XR57 has a modern look, which I like less than the look of classical receivers. But who cares about the way it looks if it sounds good?
Connectivity was easy. The receiver has large binding posts for all speakers. I connected my Athena AS-F1 towers to front left/right channels, Athena C.5 for center, Athena S.5 surrounds and Athena P200 subwoofer to form a 5.1 configuration. I do not have enough space for the complete 7.1 setup, but once I move, I will definitely us the two S.5 rear surrounds.
The setup was relatively easy, even without the manual. I set all speakers to Large and assigned the proper device to the digital inputs I used (e.g. assigned Optical 1 to DVD).
The remote control that came with this receiver is better than the one that came with the XR55, even though I expected the exact same one to be supplied. It can control many functions of my DVD player (menu navigation, etc.) and is powered by 2 supplied AA batteries. It has two separate power buttons (for the receiver and the AV component currently controlled). The buttons have a good tactile feel.
The XR57 is a 7.1-channel receiver, which can output 100 W into 6 Ohms (7 channels). It consumes only 135 W as opposed to my old Panasoinc SA-HE70, which consumed 320 W. The XR57 has no fan and it does not even get hot. At moderate listening volumes it gets only little warm. This is one of the advantages of digital amplification.
I find the receiver and its remote easy to use. The display is large and the buttons on the remote are clearly marked.
I have used the receiver mostly to listen to the music (in Stereo, 5.1 DTS Surround or converted from stereo DPL IIx/DTS Neo). I also watch movies with Dolby Digital/DTS soundtracks as well as the HD DVD with DD/DTS downconverted from DD and DTS true HD.
I have already ordered a universal Pioneer Elite DV-48AV, which plays DVD-Audio and SACD in addition to DVD video, CD-Audio, DivX and more. This player will be connected to the receiver through HDMI for the purpose of transmitting DVD-Audio in digital format over HDMI. The XR57 can pass through up to 1080i, so this is how I intend to set up the player once it arrives. And since SACD (DSD) decoding is not a part of the XR57's repertoire, I might also connect the Pioneer to the 6-channel analog inputs of the XR57.
I had to break the receiver in as at first it sounded very slightly harsh. The performance of the XR57 is nothing short of stunning, but that was expected from my experience with the XR55.
First of all, there is no noise in silent passages, whereas my older HE70 had some slight hiss. The sound is much more accurate overall, not as warm, but I would not call it bright either. Obviously, it also depends on your speakers.
All of my observations apply to a digital signal. I have not tried to critically evaluate the signal from the analog input yet. It should be a bit worse, since the signal has to be converted into the digital form before the amplification, but provided the ADC is good, the difference is going to be negligible. I believe I read that the ADCs in the XR57 are 192 kHZ/24-bit, but not entirely sure. That would provide excellent performance.
In stereo mode (no bi-wiring since the Athena F1 cannot be bi-wired), the sound is truly 3-dimentional. It is like if someone removed the barrier between me and the music. I can definitely hear more instruments in the familiar recordings, more detail (comparing to the HE70).
I listened to a variety of recordings, but mostly classical music. From classical like Ernest Bloch, Richard Wagner and John Williams to Hard Rock and Metal (Metallica, Dio). Doors, Aphex Twin, Telefon Tel Aviv, Dire Straits... All of them sound amazing. If you get this rciever and good speakers, be forewarned that you will be able to easily distinguish a poorly-recorded CD from the ones that are recorded well. For example some of my operas by Wagener sounded amazingly well, whereas the CD of preludes from his operas did not sound as good.
I heard that some people claimed that the sound was too bright for their taste. If you like very warm sound, the XR57 might be a less than optimal choice. Not for me. It does not sound too bright for me, just very accurate. I saw test results where the frequency response from the XR70 (similar hardware) was ruler-flat (20-20,000 Hz at /-0.1 dB). Obviously, you shouldn't compound the possible brightness by pairing it with bright speakers.
Same listening impressions as for the XR55 apply. On the "LA Woman" album of Doors, I could feel what kind of room some of the songs were recorded in. I could hear the small sounds I never knew were there before I got the class-D amp. In most of my recordings, I discovered something new. In fact, I could almost hear not only the horizontal position, but the distance to and the height at which each instrument was located. I know, sounds like a stretch, but it is true.
The sound, even from only two speakers, is three-dimensional and the imaging is amazing. I also tried the DPL IIx Music mode and DTS Neo Music. I liked DPL slightly better than DTS. The simulated surround gave some music even more spaciousness and was well-suited to electronic music. Things like Telefon Tel Aviv, Aphex Twin and Air sounded amazing in DPL IIx Music.
The receiver can be driven to high volumes with no signs of strain. At any volume, the dynamics are not compromised and the receiver sounds very responsive. Try as I might, I could hear no digital artifacts (in good-quality recordings). There are several modes of digital re-mastering to smooth the rough edges of MP3s and CDs that are not well-recorded. They work moderately well.
Update 10/2009: I since have gotten a lot of DVD-Audio disks and they sound amazing over the HDMI connection. There is a definite improvement over CD.
In summary, the XR57 provides amazingly good sound at very low price and I expect to save some money on my electric bill since it is so efficient. And this is also good for environment.
If you need more HDMI inputs and 1080p compatibility as well as decoding support for new high-res formats, you might have to look elsewhere.
Pros: Amazing sound, low power consumption, sturdy speaker connectors, features, price, HDMI
Cons: Could look better
I am stunned by the sound quality of this receiver. The XR57 is insanely cheap (now on eBay), has lots of useful features and amazing sound quality. It is even good for environment. I highly recommend it!