Panasonic SA XRS Digital amplifier/HT Receiver

_scotty_ · « **Reply #120 on:** 2 Nov 2003, 08:30 pm »

BenF, I haven't heard any problems from my DIY speakers. They are an 8ohm load from 100Hz to 30kHz. They also have a ribbon tweeter which would certainly show up any problem in this area. If your speakers tweeter does not have a zobel network on it the increased mid and upper frequency energy that a digital amp can deliver can make a non-zobeled tweeter sound harsh. Most loudspeakers were not designed with the performance potential of digital amps in mind. The zobel network that should be present on every conventional tweeter that has any voice coil inductance is frequently left off to save money or because the ill-informed speaker designer didn't think it was necessary. Sooner or later most speakers will probably have this $1.50 worth of parts included in their design. End of rant.

ABEX · « **Reply #121 on:** 3 Nov 2003, 12:14 am »

Looking at the Take5 Audio Site for the Adaptor I was about to buy one until I saw the cost for S&H. $16 for a $6 part is really just to much for my taste.

http://www.takefiveaudio.com/c8_to_iec_adapter.htm

Has anyone tried Cambridge Sounworks,Tweeter Etc.,BB or CC for the adaptor? Those are all the stores I have in my area.

Any other sources I might try for one online without paying that charge for S&H.

Just trying to save a $10-$16 and being cheap.

someidiot · « **Reply #122 on:** 3 Nov 2003, 12:47 am »

Quote from: ABEX

Looking at the Take5 Audio Site for the Adaptor I was about to buy one until I saw the cost for S&H. $16 for a $6 part is really just to much for my taste.

Any other sources I might try for one online without paying that charge for S&H.

Hey Abex,

Here's a few links that you might check out. I believe the first one is the original manufacturer, and they appear to have a contact point in CA:

http://www.yung-li.com.tw/EN/Products/Adptr/YL3213_side.htm
http://www.icecubeadapter.com/pages/1/index.htm
http://sphl.audiogon.com/cgi-bin/buy_cl.pl?cablpowr&1070632047
http://www.teklineaudio.com/dvd.htm
http://www.mr-cable.com/dvd%20power%20adaptor.htm
http://www.audiopartsinc.com/

(if this violates posting rules, please delete)

someidiot · « **Reply #123 on:** 3 Nov 2003, 01:10 am »

Quote from: Cens

Someidiot,

Thanks. I ordered an XR45 for $300. Could make up a decent and simple 2-channel HT with my Pioneer 656a feeding the digital signal directly into the XR45. Now if I can only make space for my speakers...

Regards,

Chris

Hope it works out well for you Chris! Let us know what you think after it's been on for several days?

BTW, the Panny defaults all speakers to "small". If your 2-channels are full-range, don't forget to adjust the speaker size for them.

ABEX · « **Reply #124 on:** 3 Nov 2003, 01:42 am »

Someidiot:
At those prices Take5 is looking lile a steal!

I will probably find something locally tomarrow. I might even find that Ratshack carries an adaptor.

Thanks!

Ears · « **Reply #125 on:** 3 Nov 2003, 03:11 am »

Just wondering if anyone has modified the power supply of the 45 yet?

For the small pricetag, you would think someone would at least modify the ps whith some Jensens or Blackgates.

Anyone?

killer5280 · « **Reply #126 on:** 3 Nov 2003, 03:25 am »

I just ordered an xr45 and can't wait to get my hands on it. I have a question that I don't think has been answered in any of the message boards I have been to in my research about this unit. I could be mistaken because my eyes are bloodshot and bleary.
I want to use the XR45 for both HT and two channel music listening. Has anyone determined if the front L/R speakers get a full bandwidth signal if they are set to large and a subwoofer is enabled? I like to listen to music with a sub, but I would prefer if my mains are not high passed at 100Hz, or at least I would like to have the choice of running them either full range or high passed.
Thanks for your help guys.

someidiot · « **Reply #127 on:** 3 Nov 2003, 05:06 am »

Quote from: killer5280

I just ordered an xr45 and can't wait to get my hands on it. I have a question that I don't think has been answered in any of the message boards I have been to in my research about this unit. I could be mistaken because my eyes are bloodshot and bleary.
I want to use the XR45 for both HT and two channel music listening. Has anyone determined if the front L/R speakers get a full bandwidth signal if they are set to large and a subwoofer is enabled? I like to listen to music with a sub, but I would prefer ...

Just tried that using the bass riff at the end of "Don't give up" on Peter Gabriel's "So"; and also switched the fronts between "small" and "large" to get a feel for the difference. These ears affirm that speakers set to "large" receive full bandwidth regardless of the subwoofer setting. Have fun!

_scotty_ · « **Reply #128 on:** 3 Nov 2003, 06:34 am »

Ears, there is a very small amount of room in the little box. If I manage to
get any Blackgates in there at all, and it helps, I will post the results.

killer5280 · « **Reply #129 on:** 3 Nov 2003, 06:34 am »

Quote

These ears affirm that speakers set to "large" receive full bandwidth regardless of the subwoofer setting. Have fun!

Thanks, Mr. Idiot.-) Now I'm really getting excited

ABEX · « **Reply #130 on:** 3 Nov 2003, 10:00 am »

WOW,next time I come up with a name I think I shall have to be more creative. When I see Some Idiot being addressed as a Mister in front of it I just have to respect that!

ABEX · « **Reply #131 on:** 3 Nov 2003, 11:17 am »

One of the thing that really made me always shy away from receivers were their inherent limitation to avoid the problem of interference along with numerous other traits like sterile sound,lack of dynamic and Bass ect..

The only Recievers I have heard lately are from Rotel and B&K which were not bad,but given the choice between having seperates for isolation, Damn I even avoided Intergateds,I always chose to use seperates.

Any how does anyone have any insights or opinions into the factors of RFI or IF rejection using Digital Switching amps used in receivers like this compared to standard types of receivers and amps?

I have been looking for answers at places such as the following site:
http://www.classd.org/

Just thinking!

cjr888 · « **Reply #132 on:** 3 Nov 2003, 12:30 pm »

To all the current Panny owners:

Does anyone have a relatively 'standard' pair of dynamic speakers -- average load, average sensitivity, and also a pair of speakers that either have an extremely friendly impedance and/or high sensitivity, and good feel for how both sets of speakers sound?

This would obviously require someone who has a very good grip on the characteristics of both speakers, but I'm curious to see if any of the Panny's described traits appear to change/disappear under vastly different speaker setups for better for worse.

Thoughts?

_scotty_ · « **Reply #133 on:** 3 Nov 2003, 12:50 pm »

ABEX, the proof is in the pudding. This thing sounds good at the end of the day. I think the fact that there is a functioning AM radio section in the receiver is a fair indication that the RF problem must have been dealt with fairly successfully in the end product.

ABEX · « **Reply #134 on:** 3 Nov 2003, 01:21 pm »

Scotty:
The ClassD Q&A section had some good info concerning the design.

http://www.classd.org/

The following I thought was intresting .At the bottom it mentions TI. I have been waiting for this chip to be implemented in a cost effective product. Of what I have been told by those following the chip wars many where not completely impressed with the Tripath implementation and as I noted in other post I would not and shall not buy a Digital amp for over $1K. But thats just me!

===========From ClassD Q&A Section===========

When is it a good idea to have a class-D amplifier with a digital input interface ?

In the case of real digital amplifiers the interface will be digital by default. This question concerns analogue class D amplifier subcircuits or modules with local D/A converters. This option would be considered mainly for cases where disturbances on analogue input signals are expected. Moving the D/A converter away from the DSP section and onto the amplifier indeed excludes any interference on the analogue signals. Care should be taken before deciding for digital input though. Transmitting the high-speed data and clock from the digital circuit to the amplifier section is likely to produce a fair amount of radiation. Coupling of data and other noise into the clock will cause jitter, making the option unsuitable for real high-quality audio.
Reducing the radiation would either require slowing down transitions (further degrading jitter performance) or moving to differential low-voltage signalling. The latter would probably both reduce radiation and maintain good jitter performance but is quite complicated and expensive. A more effective method seems to be to transmit the analogue signal together with its reference (D/A converter local ground) and use a simple op-amp+4 resistor circuit ("diff amp" or "translator") to translate the signal to the amplifier's local reference. It should be said that some analogue class D products (TI and Philips chips to name a few) actually sport differential inputs straight away.

ABEX · « **Reply #135 on:** 3 Nov 2003, 01:45 pm »

cjr888
If I had highly efficient speakers like Klipsch I think I might opt for the Sharp unit that is being touted on another thread here. Although I do not like the fact that it uses a 1-bit DAC. Hey for $130 and like $450 off list unless it is a defective piece it's good value.

Just thought that might help you.

Ears · « **Reply #136 on:** 3 Nov 2003, 01:53 pm »

Quote from: _scotty_

Ears, there is a very small amount of room in the little box. If I manage to
get any Blackgates in there at all, and it helps, I will post the results.

Thanks Scotty, I am looking forward to hearing of your results one way or the other.

Greg

BeeBop · « **Reply #137 on:** 3 Nov 2003, 02:31 pm »

Quote from: soundboy

So what happens with DVD-A or SACD, which only output in analog? If the analog 5.1 inputs on the XR is not quite the level of its digital inputs, is it still pretty good?

How about redbook? I have a lot of redbook CDs and would love to hear them in pure digital. If I output optical from my Denon 1600 direct to the Panny, would there be any Digital/Analog conversion for redbook CDs inside the Denon before going to the Panny?

Many thanks to anyone who can answer this question.

lcrim · « **Reply #138 on:** 3 Nov 2003, 02:51 pm »

I believe that the Panny would get a PCM bitstream from the digital connection to your cd player. This bitsream would then have to be converted (probably not the technical term) into Pulse Width Modulation (PWM) impulses to drive the speakers.
Perhaps someone with a more rigorous EE background can expand on this. MY Sony STR DA3000ES must accomplish the same thing.
What I am wondering is why PCM conversion to PWM seems to sound better in the Panny then analog to PWM? There is still processing (a change) taking place.

BeeBop · « **Reply #139 on:** 3 Nov 2003, 03:04 pm »

In fact the 1600 setup has the following options...

PCM Down Conversion (YES or NO)
Dolby Digital (Bitstream or PCM)
DTS Digital Surround (Bitstream or PCM)
D. Range Compression (YES or NO)

Whether any of this would apply when playing 2 channel as well as 5.1, I can't say