Panasonic digital-amp receivers

[RichPA]

I've read some of the buzz about these both here on AK and elsewhere on the internet, so when I came across a very good deal on a lightly used XR55, I decided to go for it. My plan for it is to use it to power the center and rear channels in our HT setup, so I don't feel guilty about forgetting to turn off the amps for those channels after our twice-a-month or so movie watching (it draws 0.2 watts at idle!). Meanwhile, I though, I've got it hooked up in one of my two-channel setups, tuned in to FM (broadcast from the Ramsey FM transmitter in the main system). Also have a Marantz 110/Benchmark DAC1 CD front end hooked up. First impression: at first, it sounded coldly "digital," but after an hour or so it began to open up. At least, it sounds really good for the approximately $160 I spent on it. More later.

 

[tentoze]

For $160, I'd buy one any day, Rich. Be curious to hear more.

 

[whoaru99]

I'm very pleased with mine. However, if one is looking for a certain "sound" you won't find it in the Panasonic. IMO, what goes in is what comes out, only louder.

You really should try the CD player directly into the Panasonic via a digital optical or coax connection. After all, that receiver is essentially a DAC in and of itself.

All the analog inputs on the XRs get digitized, so feeding it from the Benchmark is really just adding another step of D/A conversion between the CD player and the Panasonic. IMO, it's at it's best when fed a digital signal. Although, I must admit I've never fed mine with a Benchmark DAC.

 

[RichPA]

You really should try the CD player directly into the Panasonic via a digital optical or coax connection. After all, that receiver is essentially a DAC in and of itself.

All the analog inputs on the XRs get digitized, so feeding it from the Benchmark is really just adding another step of D/A conversion between the CD player and the Panasonic. IMO, it's at it's best when fed a digital signal. Although, I must admit I've never fed mine with a Benchmark DAC.

Yes, that's a good point and I will try it. The only reason it's hooked up this way right now is that it was the quickest way to set it up. When I've got more time, I'll certainly try the direct digital connection.

 

[Cpt.Beaky]

I'm very pleased with mine. However, if one is looking for a certain "sound" you won't find it in the Panasonic. IMO, what goes in is what comes out, only louder.

You really should try the CD player directly into the Panasonic via a digital optical or coax connection. After all, that receiver is essentially a DAC in and of itself.

All the analog inputs on the XRs get digitized, so feeding it from the Benchmark is really just adding another step of D/A conversion between the CD player and the Panasonic. IMO, it's at it's best when fed a digital signal. Although, I must admit I've never fed mine with a Benchmark DAC.

There is a difference between PCM audio on a CD and PWM signals that the digital amps deal with, a significant enough difference that I wouldn't be surprised in Pana just used a normal D/A converter and then further down the line converts to PWM. It's worth trying something both ways, but it would be inaccurate to say that the receiver is a DAC any more so than any other HT receiver with built-in decoding of digital signals is. Even if the signal was going directly from PCM to PWM that is a significant enough change that it won't necessarily sound better than it would coming via the analog circuits after having been processed by an external DAC.

I still agree that it should be checked out both ways, though.

 

[Art K.]

The primary caveat for those switching amps is to make sure you use them with speakers that don't present a challenge with impedence swings. The speaker has to be stable or that amp gets in trouble and don't sound too shiny.

When I auditioned it my main gripe was what it did to the human voice. Your mileage may vary.

 

[whoaru99]

There is a difference between PCM audio on a CD and PWM signals that the digital amps deal with, a significant enough difference that I wouldn't be surprised in Pana just used a normal D/A converter and then further down the line converts to PWM. It's worth trying something both ways, but it would be inaccurate to say that the receiver is a DAC any more so than any other HT receiver with built-in decoding of digital signals is. Even if the signal was going directly from PCM to PWM that is a significant enough change that it won't necessarily sound better than it would coming via the analog circuits after having been processed by an external DAC.

I still agree that it should be checked out both ways, though.

Actually, the XR series are fully "digital" and don't have separate D/A conversion, in the sense of the typical HT receiver. They have A/D conversion for the analog inputs, but the digital inputs are fully digital PCM to PWM conversion.

 

[whoaru99]

The primary caveat for those switching amps is to make sure you use them with speakers that don't present a challenge with impedence swings. The speaker has to be stable or that amp gets in trouble and don't sound too shiny.

When I auditioned it my main gripe was what it did to the human voice. Your mileage may vary.

If you don't like it, that's cool. But it seemed to work fine with my Studio 100s and they dip all the way to 2.5 ohms in the upper bass, lower mid-bass region.

 

[Cpt.Beaky]

Actually, the XR series are fully "digital" and don't have separate D/A conversion, in the sense of the typical HT receiver. They have A/D conversion for the analog inputs, but the digital inputs are fully digital PCM to PWM conversion.

Thanks for the correction. I wish Panasonic would update these models, they seemed like a cool direction.

 

[RichPA]

Well, I've been listening off and on for a few days, and have several observations. First, the advice to use the digital inputs when possible is clearly on target - I think the A/D converters are a weak point, and easily overloaded besides. There is an A/D attenuator option, but it is not continuously variable, and drops level quite a lot. Second, the FM tuner is surprisingly for such a cheap modern receiver - not all that sensitive, but clean, with good stereo.

With a CD source, the sound is quite good, very clean with deep, pretty tight bass. Not as clean or detailed as the Bel Canto amps; the main shortcomings seem to be the very high end and depth of image. Inserting a Monarchy DIP 48/96 upsampler between CD source (a Marantz CD110) and the Panasonic goes a good ways toward correcting both of these issues.

So far, all of these impressions are with the Ohm Microwalsh Talls. I will give it a try with some other speakers, and update when I get a chance. So far, my bottom-line impression is that it is indeed remarkable for the price, but not the kind of thing I'd sell my other amps for.