Originally Posted by castaban
I am a little bit confused. Everybody seems to be so hot on this Receiver. Maybe somebody can shed some light into these questions. I am gonna make some comparison with Yamaha RX-V550, but any decent analog receiver will serve same purpose.
1. Why would a pure digital receiver be so much better. As speakers need Analog, the signal need to be converted to Analog at one point anyway. Analog ones do it when the signal is low, digital ones do it just before it is output to speaker. Isn't that the same?
2. I thought the power supply was one of the most important piece in the receiver. How can a 135W power consumption adequetely drive this amplifier. Although people say the two power ratings are different and they are but they are certainly related. RX-V550 has close to 400W power supply (Sorry, actually I mean power consumption). I have serious doubts Pana having enough dynamic power. I don't buy that digitals are more power efficient. A huge percentage of the power is consumed at the output power amp and both analog and digital have to have similar consumption there.
3. Again the weight. Pana weighs less than half of Yamaha. The big percentage of a Receiver weight is the Power supply and the cooler. Power amp portion being similar on both receivers how come this Pana can adequetely cool itself
4. Pana has a THD about 0.09. Isn't that high? (Yamaha has 0.06)
5. Pana has a S/N Ratio of 85 DB's. I again find that too little. (Yamaha has over 100db)
If somebody can answer these question, I will be very happy as I am trying to decide between these two receivers
I'm going to oversimplify a bit just to keep the post length under control:
1. Non-digital receivers use digital/analog conversions before they do amplification. The analog amplification also has a side effect of distortion, and even though different designs work to minimize this distortion, it still exists. Digital avoids the degradations that happen in the conversion stages and also the distortions. Now the end product that goes to your speakers is not 100% distortion free, but two of the main forces that act to lower the sound quality have been bypassed with new methods.
2. This method of amplification requires much less power. In the final product this translates into smaller power supplies, cooling sinks, chassis, and weight. I guess I would compare it to Honda and a Buick. How is the Honda quicker and higher top speed with its 165 HP versus the Buick's 300 HP? It's a stretch, but similar concept.
3. Power stage for this design does not have to be as overbuilt as on the big iron analog amplifiers. Remember, the Honda doesn't need a 300 HP power plan to easily outperform the Buick. Thus you end up with lower size and weight.
Personally I wonder when Panasonic or another maker is going to put a 3 inch thick 20 pound slab and an internal heating element in the bottom just to win over the old school audiophiles, but luckily it hasn't come to that yet.
4. & 5. The stats between different manufacturers are pretty irrelevant. One company's idea of 0.09 THD is totally different than the next. This irrelevance becomes even more dramatic when comparing against two pretty different types of technology.
There's a sound & vision article around where they measured real world results against the manufacturer's spec sheets, I believe pushing 5 channels hard at 6 ohms or thereabouts.
Although Yamaha's spec's weren't that much higher than actuals, the most interesting part is that the lowly old XR25 they used for their testing came out to a real world 85 Wpc (??) out of a claimed 100 W.
Consider that the Panasonic amps we yak about today (XR45, XR50, XR70, XR55) all are considered higher power than the old XR25.
Luckily for you these things are super cheap and available practically everywhere. Unless you are looking for tons of user controls, size, weight, and lots of binding posts, it's worth your while to check one out for yourself.