[angelo]

I bought this receiver about a week ago and took some pictures of the internals. I'm sure some people here are interested on them.

It uses (14) IRFI4024 MOSFET in conjunction with Texas Instruments TAS5182 (Digital Amplifier Power Stage Controller) and TAS5076 (Six-Channel Digital Audio PWM Processor)

http://focus.ti.com/docs/prod/folders/print/tas5076.html
http://focus.ti.com/docs/prod/folders/print/tas5182.html

I can't find any additional information about the IRFI4024 except it's mentioned from the TI site and International Rectifiers' Japanese website.


top view


rear view



Power Supply


PET 820uF Capacitor


Class D PWM Amplifier


IRFI4024 MOSFET


Texas Instruments TAS5182 and TAS5076


DTS DD decoder chip

angelo

[Jon L]

Thanks for the pics, but how does it Sound?  Have you tried the biamp feature?

[Feisal K]

wow is that a Yamaha chip

YSS944-V

[angelo]

i've used it for one week in my system (denon 2900 and onix ref3) and unfortunately i'm disappointed. i think it's too bright for my speakers, my system lost its balance bet. the high and low freq. that i get with my Hypex UCD400 amp, the highs are really bad (very harsh), bi-amp didn't help at all, the same result.

this receiver is going to a different system (HT) so i'm still keeping it, i watched some DVD movies with it and it's preety good for HT audio, for music listening i think it needs a warm/laid back speakers.

some people had good experience w/ it though.

angelo

[bikeman]

some people had good experience w/ it though.
angelo

I'm running it with Ascend 340's and I couldn't be happier.  The initial brightness that I experienced has faded.  I attribute that to listener break-in but I could be wrong.

David

[Feisal K]

As with any other gear, there are people who love it, and there are as always people who don't. it sounds great, and probably competes with receivers up to 3 or 4 times its price (like this HK7200 for example)

but it's $250 and while you get a lot, there's only so much you can reasonably expect from that.

[brj]

Ok, so compared to the SA-XR70, the 55 has the same bi-amp feature, an extra amp module, "real" binding posts on all channels instead of just one channel, yet still costs less.  What does it give up to the 70 besides the HDMI connectivity?

[daman]

I'm using mine for TV viewing and HT. Also use it in stereo mode thru Dishnetwork for music. I'm using Rocket 550's I think it sounds great. It replaced a Denon 3802.
     Later, Daman

[bikeman]

Ok, so compared to the SA-XR70, the 55 has the same bi-amp feature, an extra amp module, "real" binding posts on all channels instead of just one channel, yet still costs less.  What does it give up to the 70 besides the HDMI connectivity?

The biggest difference for me was the ability of the 55 to crossover to the sub @ 80hz instead of 100hz like the previous Panny models including the 70.  With my speakers and my preferences, 100hz is not acceptable.  

David

[tschanrm]

Thanks for those pictures; very nice and up close shots you took.  I'll try to post some pictures of what the other models look like on the inside tomorrow for a comparison.

As a side note, did you know that all of Panasonic's XR series line (xr10/25/45/50/70/55) can decode AAC?  Yes, its true, download the japanese owners manuals and look for yourself:

http://panasonic.jp/support/audio/manual/main_2.html#amp

AAC is the digital tv audio standard for Japan (like AC3 is here for Hdtv), so I can see why they include it.

[tschanrm]

Here's those pics:

XR10:


XR25:


XR45:


XR70:

[ABEX]

quote]

The biggest difference for me was the ability of the 55 to crossover to the sub @ 80hz instead of 100hz like the previous Panny models including the 70.  With my speakers and my preferences, 100hz is not acceptable.  

David[/quote]

I  have never used the XO of the reciever ,but the internal XO of the Sub itself .I do not see the logic of it due to the fact that my speakers go down to the 40Hz. range and I'd rather get  the full range of the speakers capabilities instead of the recievers dictation  of it.

It has always worked for me and I have read some engineers opinions on the merits for and against doing it that way. Music is my main interest.

I use a HSU VTF-3 MK.II with heavily Modified N.E.A.R's for speakers.

[AphileEarlyAdopter]

some people had good experience w/ it though.
angelo

I'm running it with Ascend 340's and I couldn't be happier.  The initial brightness that I experienced has faded.  I attribute that to listener break-in but I could be wrong.

David

I am running high-sensitivity Silverline Sonatinas with my XR55. Previously, I had the XR50. The XR55 fixes my gripe with the XR50 in terms of soundstage. The 50 had detail and dynamics but was little flat sounding. The XR55 greatly addresses this issue. Bi-amping adds little bit more clarity and surprisingly better bass as well - drums seem tighter.
With bi-amping and a good digital source, I think the Xr55 could be competitive with $1k Int. Amp and $500K players (my previous Int Amp was a Audio Refinement Complete) as long as the speakers are not very current hungry.

[enzo]

earlyadopter:
How does the high end of the XR55 sound on your Silverlines?? Was it harsh initially/currently?? TIA!

[AphileEarlyAdopter]

earlyadopter:
How does the high end of the XR55 sound on your Silverlines?? Was it harsh initially/currently?? TIA!

No not harsh at all. For the first week or so, the sound was not great. But after that it is very good. Listening to Vivaldi/Fabio Biondi (?) I hear the sweetest solo violins, I ever heard in a recording.

[jkeny]

Could somebody who has opened the XR55 check if the 110volt power module is usable on 230v by flicking a switch or jumper?

I am looking to import one from US into Ireland.

John

[dwc]

Ok, so compared to the SA-XR70, the 55 has the same bi-amp feature, an extra amp module, "real" binding posts on all channels instead of just one channel, yet still costs less.  What does it give up to the 70 besides the HDMI connectivity?

- you give up the xr70's feature of shutting down the video functions for audio-only output.  (never heard whether this makes a big diff or not)

as noted you gain a lower sub crossover point.

[dwc]

I  have never used the XO of the reciever ,but the internal XO of the Sub itself .I do not see the logic of it due to the fact that my speakers go down to the 40Hz. range and I'd rather get  the full range of the speakers capabilities instead of the recievers dictation of it.

Got me confused here... are you not using the "sub" rca output on the back of the receiver?  If you are then you must be using some crossover point, as iirc "none" is not an option for the sub's crossover.

Secondly, if you set front speaker size to "large" then you are still sending full-range sound to the fronts regardless of what freq you set the crossover "filter"  point in the sub settings.


-Dan

[Waaihoek]

.
Hi  guys,

This is a useful thread ...... have just bought a XR70 amp-reciever and a S97 DVD player plus a pair of Wharfedale Evo 30s. I'm a relative newby to quality audio although have always had an interest .......

The panny pair I bought because both have HDMI and the S97 will also upscale standard DVD to 720p and 1080i. Keen on HDMI because it seems to be the future ..... just one plug and lead does it all or nearly all ..... seems to me soon everything will have a HDMI, just like the USB is now almost the universal computer interface.

Also attracted to the digital amp in the XR70 .... and with the HDMI interface between the XR70 and S97 its a straight through digital process almost to the loudspeaker, excepting I think the final LC smoothing circuit. So no DAC's in the digital path and much more power efficient, less heat, smaller unit, more positioning options etc etc.

Interesting description of digital amps at:

http://sound.westhost.com/articles/pwm.htm#1

In the meantime have been setting up the panny pair and bi-wired and bi-amped the A and B channels to the hi and low frequency binding posts on the Evos. Results seem pretty wonderfully stunning .... but dont really have much experience to make an "audiophile" judgement.

But can say the base from the Evos feels to be well extended ..... I do have a small Aiwa sub, but for most listening the sub seems to quickly add too much base (room is about 17 x 13 feet), so mostly set the sub volume to about 0.35 FS and select 60 hz cut off. On the XR70 have of course selected "Large" for the two R and L front channels (so amp does not apply the 100hz cut off to the Evos). Then use the remote to set the sub-woofer to about 5/20 for classical music. So I am getting base from both the Evos and the sub as per previous posts re the XR70 set-up for subs etc.

Max sub setting on the XR70 is 20 units and in combination with the Evos thats way too much ..... terrible base booming, so have put the sub setting to about 5, and the opening to Also sprach Zarathustra then comes through with an impressive but well behaved basal line.

For pop music with the usual heavy base, the Evos seriously pump out the low end and the room shakes and I dont seem to need the sub at all, so mostly set the XR70 sub control to zero for pop/rock ...... but then I am not into heavy duty metal .....

The XR70 specs indicate the response is near flat out to plus 80khz ..... some digital amps are reputed as being too bright and clinical. However the trebble from the XR70 plus Evos is to my ear is detailed and textured but not shrill, hard or bright .... I read that Wharfedales are generally neutral to warm rather than bright re trebble, apparently the use of silk or textile tweeter material (rather than metallics) is part of the story. Anyhow the Wharfedale Evos seem to compliment the XR70 just fine.

The XR70/S97 were well priced here in Auckland, NZ ...... particularly compared to Denon analog equipment. OK Denon has a very solid name in quality audio ..... but I see from a bit of web surfing re digital amps that Denon are using TriPath digital amps in some of there smaller systems. Time will tell where the digital road is heading.

Waaihoek

[Mudjock]

I have never used the XO of the reciever ,but the internal XO of the Sub itself .I do not see the logic of it due to the fact that my speakers go down to the 40Hz. range and I'd rather get the full range of the speakers capabilities instead of the recievers dictation of it.

I've run some music-only systems this way also.  You can just set the Panny into party mode and run a set of L and R channels directly into the sub's amp and (with some care) set the crossover low enough to blend with the natural rolloff of the mains.  In my experience, that is the best way to maintain the overall character of the main speakers while just adding a little extra oomph to the bottom end.  Crossing this low completely eliminates any issues with sub localization.  

Based on basic principles, auditioning, and speaker-building, I think there can be considerable merit to using the receiver to cross higher to the sub.  If you set your mains on top of stereo subs that are forward-firing, then crossing as high as 300 Hz can really help clean up the mids and give lower frequencies extra body.  This only works if your sub is clean up to that point.  The Salk Veracity HT-3 is an excellent example of this approach.  In any event, if you need high SPL capability, then unloading the mains of deep bass duty via eq. of some sort will always help - and crossing at 80 Hz is quite a bit better than 100 Hz if you can't place your sub or subs close to your mains.