[timbley]

It's been noted before that the Panasonic's analog inputs aren't as good as their digital inputs.  I think it's also been mentioned that using an outboard A/D converter might be a good idea with the SA-XR receivers.

Well I'm here to report that indeed it is a good idea!  

Right now I'm listening to my record player by running the output from my phono stage into a M-Audio sound card. The sound card digitizes the analog signal at 96kHz 24 bit resolution and then sends the resulting digital signal off to my two Panasonic SA-XR50s. The sound is vastly better than running the phono output straight into the SA-XR50's analog inputs.

I'm loving it! I'm getting back into LPs big time!

I also tried running the analog output from my Denon 2200 into the soundcard while playing DVD-Audio and SACD discs. Awesome sound! These Panasonic receivers really like a good 96/24 digital source. Apparently their onboard A/D converters aren't that good, not as good as the amp's potential. An outboard A/D converter of good quality really moves the sound up to another level.

I think the SA-XR70 with it's HDMI might be stunning with SACD and DVD-Audio coming in directly digital, bypassing the D/A-A/D cycle that the darn copy protection inflcts upon us.

I really recommend to everyone who has a Panasonic digital receiver that they try using an external A/D converter for high quality analog sources. I'd love to know if anybody else finds it as big an improvement as I do.

[timbley]

Now this is enlightening. I'm listening to a Deutsche Grammaphon recording of Paganinin violin concerto No. 1 on LP right now, which was recorded in 1975, so I assume it's all analog. The phono output is being digitized by my computer's sound card and sent to my Panasonic digital receiver (XR-50.) I can switch the sample rate on the fly from 96khz to 44.1khz.
Listening to the violin in 96kHz, I'm remembering when I played the string bass, and performed in high school string orchestra concerts. The feel of the music hall is coming through and taking me there.  The sound isn't convincingly realistic on my system, but it's full of detail that tells me a lot about the recording venue, and gives me a spooky feel of being there. It's beautiful.  

So I switch over to 44.1 kHz. Instant change! Much of the ambient sounds  that were giving me spacial information before are now glued to the violin, giving me the impression that it is nasal sounding. Wow! I can still hear some reverb from the room, but it sounds more like some kind of echo effect is being applied artificially. Amazing! The sound is still quite listenable  and I can enjoy the music. All the instruments and all the notes are there. I wouldn't know anything was wrong if I hadn't just been hearing it at 96kHz. I would just assume it was the nature of the recording and the limits of my listening venue and equipment. I notice also that pizzicado notes seem to be coming from a different location than other notes, making the voilinist seem to be in two places at once. I've heard this effect a lot on my system while listening to CDs. At 96kHz it doesn't seem to be a problem. My ears can localize the sound easily.

This is not a double blind test, so this could all be in my imagination. But I find that really hard to believe.  I'm convinced 96kHz makes very important improvements. 44.1 kHz is really not enough, and you don't have to have super human hearing to tell the difference. I don't know why this is, since 44.1 kHz should be enough to cover the audible range.

Tim

[timbley]

After giving it some thought, I decided to try hooking up my Panny's in what I think is called a "bridged parallel" configuration. It occured to me that in the passive bi-amp mode, the receiver driving the horn tweeters was practically doing nothing, while the receiver driving the two 10" woofers was pretty much doing all the work.

In bridged parallel, both amps run the speakers full range at the same time, cutting the current demand from each amp in half, or making the impedance of the speaker look twice as large to each amp.

This works!

This produces the effect I was hoping for from biamping. The sound is smoother and fuller, with better dynamics and gutsy bass. The balance has changed. The speakers sound softer now.

If you've got speakers that present a difficult load, two, or maybe even 3 Pannies configured this way may be able to take control of the situation and provide some seriously impressive sound.

Now here's the sort of embarrasing part for me

All my ranting about how superior 96kHz sounds compared to 44.1kHz may have been due to equalization effects. Somehow the sound balance changes when I make changes in input setting on the sound card. It's clearly brighter sounding if I select "pro" mode compared to "consumer" mode. I think 44.1 kHz also sounds brighter than 96kHz. If everything were working 100 percent as it should, I wouldn't think these changes would happen.
With the amps in bridge parallel configuration, CDs sound different; smoother and warmer, with more apparent detail. The phono input into the audio card at 96 kHz now sounds too soft, almost muffled on some recordings.  

[timbley]

More embarassment.
The full, rich sound I claimed I got from doubling up SA-XR50s on my speakers was simply due to a tone control setting!

following is a quote from my post on the Klipsch forum about this:

"
I think overall I've just been confused. I'm a fool, a very enthusiastic one at that.
I didn't realize what was happening. One of the amps had somehow been set to +4 bass in the tone controls. Hence the "amazing" bass impact and full sound.
It's hard for me to admit to this foolishness.
Once I got all the settings matched on my two SA-XR50s, it became obvious that there was no difference in sound between running just one amp or two! Nothing! The RF-7s are getting plenty of juice from a single SA-XR50.
Man, the stuff I put myself through.

Everytime I think I've found something wonderful, it almost invariabley turns out to be something changing the EQ response of my system.

Passively bi-amping the RF-7s really doesn't add anything either. It changes the sound, but doesn't neccessarily improve it. I don't think the speakers were meant to be run this way. After trying it and listening for a number of months, I'd have to say I don't recommend passively bi-amping the RF-7s. It's not worth the trouble and expense. The double binding posts are made for bi-wiring I believe. I'm not sure if biwiring is worth anything either, but it surely doesn't hurt. And, I've got plenty of speaker cable lying around.

Active crossovers, now that may be worth trying. But I'd want to make sure I did it right, and I think it might be best to start from scratch with a speaker design optimized for that configuration. NHT's new system with the DEQX circuitry looks like the right idea. I'll let people who know what they're doing put something like that together for me.

So now I'm back to just running one single SA-XR50 for my entire system. It sounds great. I can play with the tone controls and get different responses if I want. I can run everything through my sound card on my computer if I want a softer, smoother sound.

 I've got a Panasonic SA-XR50 and an SA-XR25 available.
All you need is one for great sound!  
Anybody interested?

"

[AphileEarlyAdopter]

I think, the Panny sounds different with different digital cables. Try a different one and see how it sounds. I was using a Acoustic Zen Silver Photon, but now am using a  Zu Ash. I think the Ash is going to sound very good..I am beginning to like the sound already..while it is just burning in. I would have never believed in burn-in for a digital cable..But it sure does 'burn-in'..brand new it was unlistenable..it is getting better. Zu recommends 250hrs burn-in..hmm..I need to muster enough patience !!!

[timbley]

I think, the Panny sounds different with different digital cables. Try a different one and see how it sounds. I was using a Acoustic Zen Silver Photon, but now am using a  Zu Ash. I think the Ash is going to sound very good..I am beginning to like the sound already..while it is just burning in. I would have never believed in burn-in for a digital cable..But it sure does 'burn-in'..brand new it was unlistenable..it is getting better. Zu recommends 250hrs burn-in..hmm..I need to muster enough patience !!!

I must admit I am skeptical of digital cable burn in. I just can't see what would happen there. Does the frequency response change? I'm finding much of what I like or dislike has to do with a frequency response.

My newest item is a Behringer DEQ 2496. It has a real time analyzer on it that lets me see what the frequency response of different sources look like. I can see that I tend to like sources such as the LP and the radio played through my computer's sound card that have a slight downard slope across the audio spectrum. My CD player has a perfectly flat response on it's digital output, which due to my speakers and room, sounds too bright and lacking in midrange.

I also have the microphone for the Behringer, which lets me analyze pink noise played in my listening room. I can see that my room tends to have a buldge in the lower bass, followed by a bumpy slope downward through the midrange, transitioning to a flat response across most of the treble before finally tapering off, with a slight flare right before falling off.
Doing a little EQ to flatten the response across the audio spectrum, and provide a gentle room correction slope has made a big improvement to my ears.

 I guess if you have an awesome listening room that is working just right, you may be able to hear differences in digital cables. I've tried comparing digital cables. I couldn't hear it. I even did a crazy thing where I hooked over 100 feet of cheap patchcord together, ran the digital out from my DVD player through it, and then ran the digital signal through a fiber optic converter and finally ran it in to the Panny through a toslink cable. I was trying to find a way to make a discernably bad sounding digital connection. Unfortunately (or maybe fortunately), it worked flawlessly up to 96kHz, which is as high as I can test.

[timbley]

I think, the Panny sounds different with different digital cables. Try a different one and see how it sounds. I was using a Acoustic Zen Silver Photon, but now am using a  Zu Ash. I think the Ash is going to sound very good..I am beginning to like the sound already..while it is just burning in. I would have never believed in burn-in for a digital cable..But it sure does 'burn-in'..brand new it was unlistenable..it is getting better. Zu recommends 250hrs burn-in..hmm..I need to muster enough patience !!!

I must admit I am skeptical of digital cable burn in. I just can't see what would happen there. Does the frequency response change? I'm finding much of what I like or dislike has to do with a frequency response.

My newest item is a Behringer DEQ 2496. It has a real time analyzer on it that lets me see what the frequency response of different sources look like. I can see that I tend to like sources such as the LP and the radio played through my computer's sound card that have a slight downard slope across the audio spectrum. My CD player has a perfectly flat response on it's digital output, which due to my speakers and room, sounds too bright and lacking in midrange.

I also have the microphone for the Behringer, which lets me analyze pink noise played in my listening room. I can see that my room tends to have a buldge in the lower bass, followed by a bumpy slope downward through the midrange, transitioning to a flat response across most of the treble before finally tapering off, with a slight flare right before falling off.
Doing a little EQ to flatten the response across the audio spectrum, and provide a gentle room correction slope has made a big improvement to my ears.

 I guess if you have an awesome listening room that is working just right, you may be able to hear differences in digital cables. I've tried comparing digital cables. I couldn't hear it. I even did a crazy thing where I hooked over 100 feet of cheap patchcord together, ran the digital out from my DVD player through it, and then ran the digital signal through a fiber optic converter and finally ran it in to the Panny through a toslink cable. I was trying to find a way to make a discernably bad sounding digital connection. Unfortunately (or maybe fortunately), it worked flawlessly up to 96kHz, which is as high as I can test.

[timbley]

It's been noted before that the Panasonic's analog inputs aren't as good as their digital inputs.  I think it's also been mentioned that using an outboard A/D converter might be a good idea with the SA-XR receivers.

Well I'm here to report that indeed it is a good idea!  

Right now I'm listening to my record player by running the output from my phono stage into a M-Audio sound card. The sound card digitizes the analog signal at 96kHz 24 bit resolution and then sends the resulting digital signal off ...

Forget all that stuff I said earlier. It all had to do with settings and input levels. The analog inputs on the Panasonic sound very good indeed if you feed them a decent source at a reasonable input level, not attenuated for various reasons like mine were. Also, if you set it to DVD 6 channel analog input it wil not sound as good as if you feed it stereo analog inputs.

[soundboy]

I have read that the sampling rate is much higher using the stereo analog inputs than the 5.1 analog inputs.

[timbley]

I have read that the sampling rate is much higher using the stereo analog inputs than the 5.1 analog inputs.

Yes, it's 192kHz in stereo mode vs. 96kHz in multichannel. I feel fairly confident in saying the stereo mode sounds slightly better. I'm not sure if it's because of the sampling rate, or something specific about my system.

I did a comparison between the analog inputs and the direct digital listening to redbook CDs on my Denon 2200. Once I had the analog set to stereo, and the output on the Denon set to -0 db, (vs -9db I was using for the mains in surround mode,), the analog sound input was excellent. I think I'd have a hard time guessing analog from digital input.

[rhart]

I've also been listening to the differences between analog and digital inputs on my stock xr45.  Wayne at Bolder beleives that digital input is the way to go, while John Meyer of Newform Research has his clients use the analog inputs. He used this configuration at the Montreal audio show where his room was recognized as a "standout room" by Soundstage.com. (Wonder if Newform is using the xr45 this year?)

The digital connection is extremely detailed, but seems brights and a bit harsh (some of this harshness is probably in the recording and is simply being revealed). Running my 7volt, Peak-modded DI/O into the analog inputs (both 5.1 and cd) created a lot of work for the xr45. Even with the a/d attenuation circuit turned on, "Overflow" flashes constantly. Anyway, the sound of the modded DI/O with the xr45 was quite good: holographic and pinpoint soundstage. The mids were there, where they were lacking with the digital, but the resolution wasn't as good. Very close to my Passive Dact and Bryston set-up with the DI/O.

Maybe having a "hotter" than standard analog connection into the xr45 makes a difference. Anyone know what the voltage output of the Behringer DCX 2496 is?

[AphileEarlyAdopter]

timbley,
I am curious about your DEQ 2496. How is it working out ? I am mainly a soundstage kind of guy (after dynamics).  I dont want the DEQ 2496 to mess with the soundstage.
My room is not great. It is just the living room, and the whole floor is interconnected. So not much of reinforcement for bass. Especially, there is a open doorway next to one speaker.
Since I dont listen that loud and the music is mostly vocals I think I am getting by without any problems. But I would like to try out the DEQ. So if you could share more details it would be highly appreciated. I am concerned that equalisation would introduce some phase anomalies which might mess up the stereo image.

[timbley]

timbley,
I am curious about your DEQ 2496. How is it working out ? I am mainly a soundstage kind of guy (after dynamics).  I dont want the DEQ 2496 to mess with the soundstage.
My room is not great. It is just the living room, and the whole floor is interconnected. So not much of reinforcement for bass. Especially, there is a open doorway next to one speaker.
Since I dont listen that loud and the music is mostly vocals I think I am getting by without any problems. But I would like to try out the DEQ. S ...

Hi,

I got into the DEQ after hearing changes in my system that I liked or disliked and suspecting that it had a lot to do with frequency response of different components. Like you, I am concerned with adding things into the audiopath that will degrade the sound.

I'm listening to the DEQ through it's optical digital input and output, so I can't comment on the D/A A/D conversion quality. As I have it set up, I haven't been able to detect any bad effects on the sound from the digital processing. I've listened, switching back and forth from the DEQ to straight coaxial digital input into my SA-XR50, and as long as no EQ settings are applied, I can hear no difference. With proper EQ settings, I invariably prefer the EQ. The sound stage and imaging is the best I've ever had it in my small room now, largely due to room treatments and speaker placement changes inspired by the DEQ's real time analyzer. The EQ itself doesn't improve the soundstaging. But it provides some needed midrange boost,  and tames a bass spike in my room at around 40hz.  I also use it to smooth the treble roll off. I highly recommend you get the calibrated microphone to go with it. It's only 40 bucks, and can provide you with some interesting information about your room acoustics. If you're like me, the RTA and microphone will keep you busy trying things for a while. I've been thinking a lot about acoustic treatments lately.

I can assure you the DEQ will introduce no phase errors. That's the beauty of digital processing. The things to be concerned about are the quality of the A/D and D/A converters if you are using those functions. Others have said that the D/A conversion is  good on this unit, but that the A/D isn't so good. So, you're better off if you can feed it a digital signal.

[AphileEarlyAdopter]

timbley,
Thanks for the response, I will try DEQ with my XR50 soon.