[rsc]

Just wondering if anyone has had the chance to compare the JVC RX-F10 using it's DVD-Multi input to a full digital Panasonic XR50?

Some info, I'm currently using the JVC in a (limited budget) 2.1 setup with my source being a Sony dvp-nc685 CD/SACD/DVD player.  The bass management in the Sony allows me to feed 2.1 channels into the JVC's DVD-Multi input. I recently have been shopping for interconnects to use between the Sony & JVC and I've realized that a couple decent pairs of cables almost cost half as much as the Panasonic.

I'm not unhappy with the JVC, in fact I really like the soundstaging & depth it has but I'm intrigued by the DAC-less full digital signal path of the XR50 and wonder how it sounds compared to the F10.

Thanks for reading, anyone have any comments?

[Horizons]

Just wondering if anyone has had the chance to compare the JVC RX-F10 using it's DVD-Multi input to a full digital Panasonic XR50?

Some info, I'm currently using the JVC in a (limited budget) 2.1 setup with my source being a Sony dvp-nc685 CD/SACD/DVD player.  The bass management in the Sony allows me to feed 2.1 channels into the JVC's DVD-Multi input. I recently have been shopping for interconnects to use between the Sony & JVC and I've realized that a couple decent pairs of cables almost cost half as  ...

I have compared the F10 to the XR45. The answer is that it depends on your speakers. The full digital path is great in the Panny, but not so good in the JVC. But the JVC can drive difficult loads. When presented with low impedance or hard to drive speakers, the Panny starts to sound strident and bright. I believe this is why opinions vary so much on the Panny but not so much on the JVC.

If you have easy to drive and fairly efficient speakers,  I would try the Panny via the all digital route. If not, the JVC is killer in my opinion as I feel the JVC with analog ins is awesome with my non-oversampling, filterless DAC powered by batteries. The Panny just couldn't drive my Maggies. The JVC does.

YMMV.

[pekar]

I own both, and vastly prefer the JVC for music, slightly prefer the Panasonic for home theater. I'm selling the Panasonic.
The Panasonic has this incredibly clean sound with no presence.  The Jvc has presence.
Full digital may be overrated-

http://www.audioholics.com/techtips/audioprinciples/amplifiers/digital_classD_amplifiers.html

[TheChairGuy]

Hey pekar, great link - it mirrors my own informal findings. The author has some serious credo.

In case some of you don't want to cut n' paste the link...it's well worth reading:

http://www.audioholics.com/techtips/audioprinciples/amplifiers/digital_classD_amplifiers.html

[Dmason]

RSC,

I agree with Horizons in that the biggest diff with the JVC is that it seems to be a True Music Maker. It has real presence, and communicates dynamics and emotive content effortlessly.

 I write this because I also have a battery driven non-OS type DAC paired with it, which seems not to be very picky about transports etc., and the combination is reeelly nice. A better overall effect might not be had in spending a whole lot more in some cases. I also prefer the ES1 over the F10, and only own fairly sensitive speakers. With outstanding drivers, it offers a stand out quality. I am a big fan of this JVC "hybrid dual digital feedback" architecture, whatever that is...

[AphileEarlyAdopter]

First, let me state the weaknesses of XR50.
It is unable to drive certain speakers (which have too big a dip of impedence).
One recording engineer posted on avsforum, it kills the backwall reflections. Another person said, the XR50 is less detailed and less dynamic than the XR45, which he places in the company of Krell, CJ.

As you will know ChairGuy, Dmason and many friends here are taken by the JVC's sound. I am only hesitating to go for it because it seems to have only one usable analong input. It also has a fan, which may not be an issue. But the main thing is I need to get a good DAC.

So the XR50, seems to satisfy me for now. The sound is very dependent on the quality of digital input. I use a Acoustic Zen Silver Photon coax (I think it is better than a 'glass toslink') with a Philips 963SA . Put the player on a shelf on spikes (instead of the MDF shelf just resting on the frame) provided a very nice improvement in sound. I also use a balanced power conditioner and a Furman power factor pro. Yes, I have good soundstage and presence. But then gain, it is all relative.

It would be a good idea to get the XR70 and use it to biamp and check out its sound.

[CSMR]

Do you really think that quality of digital input is important on the Panasonic? Given that it there is digital processing to convert to a DSD signal, which shouldn't be dependent on the quality of input?

One other thing, I'm not sure that biamping is a good idea with the panasonics because of the time-delay between the front and surround outputs - unless this delay can be used to compensate for the crossover phase change.

[CSMR]

But the JVC can drive difficult loads. When presented with low impedance or hard to drive speakers, the Panny starts to sound strident and bright.
If you have easy to drive and fairly efficient speakers,  I would try the Panny via the all digital route.

Just wonder if you could explain what "easy to drive" means. Since I'm likely to get a Panasonic, I will need easy to drive speakers. Also is efficiency important, or power: do you imagine the panasonics will be OK with inefficient speakers at low volumes?

[JoshK]

Do you really think that quality of digital input is important on the Panasonic? Given that it there is digital processing to convert to a DSD signal, which shouldn't be dependent on the quality of input?

One other thing, I'm not sure that biamping is a good idea with the panasonics because of the time-delay between the front and surround outputs - unless this delay can be used to compensate for the crossover phase change.

Wow, didn't know there was a latency in the surround channels for the Panny digital amps.  That is good to know.  What is the cause of the latency, do you know?  

I, for one, am a believer that digital signals are not all the same. You can see this on a scope if you know someone with one. So for any digital input that doesn't buffer or receive the clock there is difference in digital inputs, wish it were as easy as 1's and 0's.

[JoshK]

But the JVC can drive difficult loads. When presented with low impedance or hard to drive speakers, the Panny starts to sound strident and bright.
If you have easy to drive and fairly efficient speakers,  I would try the Panny via the all digital route.

Just wonder if you could explain what "easy to drive" means. Since I'm likely to get a Panasonic, I will need easy to drive speakers. Also is efficiency important, or power: do you imagine the panasonics will be OK with inefficient speakers at low volumes?

This has a bit to do with the power supplies of the JVC's or Panny's. However, the 'digital' amps are quite efficient and therefore do quite well at driving many speakers.  How big is your room?  This makes a big difference.   How loud do you listen, also a big factor.  Inefficient speakers themselves aren't the problem, it is how loud and how far away you listen that also matter.   Although I think you should be ok with the exception of maybe Apogees and some of the Magneplanar speaks.

[CSMR]

Wow, didn't know there was a latency in the surround channels for the Panny digital amps.  That is good to know.  What is the cause of the latency, do you know?  

I got the info from this thread:
http://www.audiocircle.com/index.php?topic=12853
10ms delay it seems - long enough to make biamping unuseable I should think.
I don't know why it's there.

I, for one, am a believer that digital signals are not all the same. You can see this on a scope if you know someone with one. So for any digital input that doesn't buffer or receive the clock there is difference in digital inputs, wish it were as easy as 1's and 0's.

Sure digital signals are not the same. The question is when does the difference matter. I get the feeling that people assume that since it matters for DACs it will matter for these digital amps.
My basic idea of how the Panasonic must work is:
digital PCM spdif input
->converted to a digital DSD signal
->which controls the switching of the power
Will jitter result in an alteration in the DSD signal? It seems unlikely to me. I also can't imagine how the whole thing would work without a buffer. However I have little understanding of all this.

[AphileEarlyAdopter]

Do you really think that quality of digital input is important on the Panasonic? Given that it there is digital processing to convert to a DSD signal, which shouldn't be dependent on the quality of input?

One other thing, I'm not sure that biamping is a good idea with the panasonics because of the time-delay between the front and surround outputs - unless this delay can be used to compensate for the crossover phase change.

The time delay is there only in the Party Mode on the XR50. The XR70 supports a true biamp mode in stereo.
Like Josh says, if the digital input is not buffered and reclocked, quality of digital input matters and thats been my experience
4ohm speakers are okay, but with low efficiency speakers overall output will be low.  What speakers do you have or thinking of ? Maybe, I can check if the impedence curves are available and will probably give you my opinion. I know some are having problem with the Ascend Acoustics.

[CSMR]

This has a bit to do with the power supplies of the JVC's or Panny's. However, the 'digital' amps are quite efficient and therefore do quite well at driving many speakers.  How big is your room?  This makes a big difference.   How loud do you listen, also a big factor.  Inefficient speakers themselves aren't the problem, it is how loud and how far away you listen that also matter.   Although I think you should be ok with the exception of maybe Apogees and some of the Magneplanar speaks.

Thanks for answering.
Not so large room, 14'*16', not so loud music, Classical mostly chamber music, listening reasonably close. Thinking about getting Spendor monitors. Hopefully I'll be OK.

[Red Dragon Audio]

By the way fellas, I just got word back from the custom tranny company and they said the EI core autoformers ("RyanFormers" as some have affectionately dubbed them), are goind to be about $85 each.  If the Toroid version works to specs, then it will be slightly cheaper.  They're working on both types for me now as prototypes and the testing phase is going to be underway soon enough.

As my order is rather small (just a pair to start with) they're obviously not rushing it along though they have been more than gracious in answering my emails etc.

If you have any questions you'd like me to pass on, let me know.

I hope these are done in the next month or so as I'd really like to try them out with the XR45 I've got.  Right now it's making sweet melodious tunes in our master bedroom with my Diapason Adamante III's.  I hope the autoformer can take it up a notch.  

[TheChairGuy]

Bring on my Ryanformer!!  The 'Little Wonder' is looking for additional tweeks to confirm and build on it's giant killing status. It likes $85 ones better than $450 ones...if they work as well  

[psonic]

My exerience with the XR-25 was one of big disappointment. I have a tough load for it, Dynaudio Audience 60, and it sounded bright, hard and clinical. Not a good match at all for these speaks. I sold the Panny. Now suprisingly, the 15wpc Sonic Impact Tripath amplifier sounds decent running these at low to moderate levels. Very odd.

[AphileEarlyAdopter]

I think the Tripath's Class-T is  better at handling difficult loads than TI's Equibit. This is probably because, there is some sort of feedback in the architecture (the whitepaper says, "the architecture understands the characteristics of the switching transistor and according generates signals").
Panasonic has started using the Tripath's digital input processor in car audio. Hopefully, they will switch the receivers also to Class-T with digital input. It would sound fantastic. If not for Panasonic somebody else is bound to come out with a Class-T digital input solution soon.

(CSMR, the Spendors are a little bit difficult to drive, best bet is the XR70 than the XR50).

[Horizons]

My exerience with the XR-25 was one of big disappointment. I have a tough load for it, Dynaudio Audience 60, and it sounded bright, hard and clinical. Not a good match at all for these speaks. I sold the Panny.

This was EXACTLY my experience with the Panny XR-45 driving my Maggie 1.6QRs. I can't comment on what is "easy to drive" for the Panny receivers because I didn't try anything other than the Maggies on the Panny.  The JVC F10 drives the Maggies with ease.

Seems that all of the users who really like the Panny receivers are driving speakers in the 4-8 ohm range with above average efficiency.

FWIW, I think the all-digital route is overrated. YMMV though...

[epsilon]

I know some are having problem with the Ascend Acoustics.

Pardon the hijack but I was ready to order the CBM-170s and this caught my attention. Could you please point me to relevent info? I have the XR50.

[Rob H]

I am powering a pair of the (Ed Frias) AR.com DIY speakers with a Panasonic XR25 with phenomenal results.  Prior to this, I was powering them with a  Denon DRA685 stereo receiver. The Denon sounded good, but the DIY's tended to be bright with certain source material. I'd had some concerns, prior to hooking it up, that the Panasonic might be too bright, based on comments I had read on this forum and others. What I found, was that the DIY's now have a much more balanced sound. Not bright at all (yet very detailed) and better bass. This particular combination of speakers and receiver sound great

Here is a link to my system gallery:

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=246