[Wayne1]

I do have two sheets of ERS on the top case of my modded unit.

[azryan]

Well maybe I missed it, but Wayne (or anyone who for sure knows...) is the XR-25 the same as the XR-45 soundwise and then modwise?

I have the XR-25 and it seemed like it's amps were the same and the only diff. was some meaniless features like onscreen set-up and more dig. inputs, etc...

Wondering if Wayne is modding the 25 too? Or if he is... if he thinks it'll be 100% the same sounding as the 45?

Also Wayne, do you think the 'Party' DSP mode does anything to damage the signal?

I know it's just sending a full range signal to each channel (rather than goofy HALL echo or something) but thought just having the DSP chip doing anything that it might smack up the signal somewhat?

Personally the stock XR-25 is not at all right on the top end compared to my eARTwo digital amp and certainly less than world class Outlaw prepro.

I was using the Pannie just as a stop-gap till I got something else, but the reports on these mods certainly have me reconsidering this unit.

What would happen if the modded unit failed? I'm guessing someone would just be out $1000 right?
Not that it wouldn't be worth the risk, but it IS a risk right? You wouldn't be able to repair a broken unit in most cases correct?
An AMAZING!!! $1000 slimline rec. that's dead is just $1000 gone right?
Nothing against your to pquality mods. Just a possible lack of faith in the quality of the rest of the unit. It is cheap in many respects beyond it's price.

I'd also like to know what the final exact mod is?

So far this seems like it's still an ever changing process and then connected to Bybee'd this and that beyond the actual Pannie -meaning possbily the modded Pannie on it's own might not quite do for me what it's doing for some of these other people?
Or maybe it would?

Did you decide to leave the POS binding posts as is or just replace the front L/R or the awful snap shut ones on the surround channels?

What about just popping off all those crappy speaker outputs and running speaker wire directly out bypassing any binding posts at all?

Ric S. had a good idea he posted recently about even using el cheapo binding posts in an amp but wrapping the output wire into it so that the quality of the bindging posts are irrelevent.

This seems like it'd be a perfect solution to getting then best signal out this little sucker.

Wayne, you seemed to feel the Pannie's fan is a total non-issue right?

In my system I found that it seems to come on when drawing a lot of current, but stops when it's not, so on most music you never know it's on, but on some Chinese drum tracks I have the start and stop of the drums lets you catch the fan just before it turns off.

This Pannie also runs pretty hot at idle here in AZ. I used it for a while just as surround amps where it did nothing 95% of the time and got REALLY warm 'cuz the fan doesn't turn on based on temp.

Any thoughts on popping that out and maybe putting a heat sink block out the back? Or somehow getting the fan to run based on temp?
Probably 'No' to both, but I had to ask.

Thanks!

People mentioned some other digital amp recs....

I also own the Sony 2000ES with it's 7 chan. 'S-Master Pro' digital amps and I found it to be a big smoother in the midrange than the Pannie (both stock of course), but neither is right on the top end. Brittle and edgy.

Supose to be $800 but got it for $500 but I'm returning it anyway.

Oh... and I thought HK was using Apogee, but looks like the HK DPR 2005 Rec. uses 'D2's 125W x 8 digital amp block (.05% THD+N -they claim). Saw 'em at the CES and picked up one of thier info sheets.

[Wayne1]

The Panasonic SA-XR25 and 45 receivers ARE NOT the same.

Here is a thread on another circle discussing them

http://www.audiocircle.com/index.php?topic=7653&start=10

I WILL NOT be offering mods for the SA-XR25.

I have not heard any difference when the PARTY mode is engaged. If you are bi-amping with PARTY mode, you do have to change the speaker output leads on the surround channels. PARTY mode is set up in a surround system so that it reverses left and right for the surrounds. For Bi-amp, you need to have the left surround channel connected to the right channel speaker, etc.

Panasonic offers a 1 year warranty on the unit. If it is modified by anyone, in any way, this will void the Panasonic warranty. All of the parts are avalable from Panasonic Service. Depending on what fails, I would repair a unit with just a parts charge, if it involved something other than what I changed.

The final, exact mod has not been determined. I am ALWAYS learning. I, hopefully. will always be learning. I learned some things listening to the modded Panny in Tyson's system tha caused me to want to change some of the things I have done. I have just received the last of the parts I needed to implement the changes. I will be working on my Panny early next week and let it burn in and hopefully listen to it again at Tyson's next weekend. After that listening session, I may be ready to finalize the mods and put them up on the BOLDER Cable website to accept reservations for the mods.

I have found that the fan on the SA-XR45 IS a non-issue in the four systems I have tried it out in. I have no experience with the SA-XR25 or the GR Alphas. There may be something with your system that causes it to run hot. I have not experienced any heat with the SA-XR45 unless it was running into load resistors with the FryKleaner plugged into it. When the fan came on it cooled down very quickly. In the real world, in the four systems it was used in, the Panny SA-XR45 was very cool to the touch even after very loud passages were played. I have no plans to modify the cooling of the SA-XR45.

The modded SA-XR45 is NOT for everyone. It may not work for every speaker and in every system.  It does not sound as good with an analog input as with a digital input. It's user interface is not very intuitive. It's crossover frequencies in HT use may be too high for some. It is not the be all, end all of home audio. It IS a very good sounding, one box solution for quite a few people and systems.

[zybar]

Well said Wayne.

I really wish I could be out there next week.  

If it wasn't for the Super Bowl being the next day, I probably would have come out.

I have my unit ordered and will have Sean bring it over to you once things get finalized.

GW

[Tyson]

One thing I thought of for people that need a lot of power, would be to use TWO of these units with a DVD player that has both coax and optical output.  Send the same signal to both Panny units, and simply use the one w/the coax input to it to amp the mids/highs, and the one with the optical input to it to amp the bass (this would be very useful if you have multiple towers like the rm40's which require a lot of power).  Just a crazy thought I had, but I think it would work pretty well.

[zybar]

Tyson,

I realize you won't have two modified units, but will you try that at the listening session?

Use the modified one on the mids/highs and the stock on the bass.

If that worked, I could possibly use the Panny for HT.

GW

[Tyson]

Definitely will give it a shot.

[azryan]

"-I have found that the fan on the SA-XR45 IS a non-issue in the four systems I have tried it out in. I have no experience with the SA-XR25 or the GR Alphas.-"

I'm sure it's not the GR Alphas as they're an easier load than any of the speakers you've seemed to have tested and much higher effi.

What I said was that 'at idle' like when I used the Pannie for surround amps that this is when it ran hot as the fan never kicked on to cool it at all.

The XR-25 and 45's act the same on this issue. The fan is not temp related.
It's really quiet though so i'm sure it totally is a non-issue for you.

When the unit is playing music and actually putting out some current the fan comes on and the unit does run cool because of the fan puffing out the heat.

Thanks for answering a lot of my questions. I'll go look up that link you posted now about the XR-25 and XR-45.

Same amp chips and power rating, same case, same manual even, and almost same price, but just some little features I mentioned that I could see them charging a small premium for.

It's wild that there'd be something else that's so totally diff. about these two units.

[ABEX]

From another post
==================
It looks like the following features are upgrades on the XR45 over the XR25

1. Multi-Source Re-Master*
Using 1/f algorithm technology, this original Panasonic feature compensates for the frequencies of the higher harmonics that are lost during recording due to compression technology such as AC-3, which is used for DVDs. Since these harmonics transmit subtle nuances of sound, this is a key technology for acheiving movie theater ambience with a Home Theater system. It's also effective during playback of CDs and other sources, particularly if the recording format is high-compression such as WMA or MP3.

2. Second-Room Output with Independent Selection*
Enables users in one room, for example, to use the receiver to watch a blockbuster film, while those in another room can use it for listening to their favorite CD or DVD-Audio disc.


3. DTS 96/24*
High-resolution 96kHz/24-bit sound on all 5.1-channels with full-quality full-motion video for music programs and motion picture soundtracks on DVD-Video. Sound quality equivalent to the original 96/24 master.

4. Gold Plated Terminals*
For high conductivity.

5. 4* Digital Inputs
4 digital inputs (3 optical, 1 coaxial) minimize electrical noise, assuring the reliable transfer of high-fidelity sound data to help provide a clear digital signal.

6. Deluxe Universal Remote Control with LED*
Gives you control over many brands of TVs, VCRs, and DVD players, letting you replace a pile of remotes with a single convenient all-in-one solution.
Actually, there is a BIG difference in the power supply. The back half of the PS board - back by the big inductor - is empty/bare in the 25 (it's marked 'xr45 only'). I can't say what this does, but since the main amp rails seem to come from here, I'd guess it's an extra level of regulation/filtering.
I was planning to get an XR45 which would have allowed a direct comparison, but I have an XR10 coming instead, since they appear to be MUCH easier to mod for direct digital input. The XR10 is somewhat different than the 25/45 - apparently it uses a variable output power supply to control the volume for part of the range. It'll be interesting to see what sonic differences there are

[azryan]

According to what I saw people post the only real thing diff. on the two units is the speculation that the two have diff. power supplies (and non sound quality related features that I've already mentioned twice here and in past threads).

You said you WILL NOT be modding the 25 as if you know they are vastly diff. (or that's the impression I got from your post) but you also say you have no exp. with the 25?

Do you actually know they are diff. in any criticla sound quality related way?
Like actually knowing that the two power supplies are diff. or something like that?

The only actual info on the diff. between the two seems to have been scotty saying the weight of the two is diff. and then thinking the power supply is then probably larger.... but is this based on him actually measuring the weight of the units or just reading their spec sheets claiming diff. weight?

The other info is from John Mayer (who is the man who kicked off this whole thing in the first place) who is selling the XR-45 and not the 25 (which is available in any Best Buy while the 45 isn't) and calling it 'upgraded' from the 25... but I see nothing that says how it's actaully 'upgraded' at all?

And his rave is not only about the 45 without any mods, but also not using the digital inputs but using the analog ones plus a digital x-over in front of the Pannie.

I just don't see why you wouldn't also mod the 25 unless you have tested it and KNEW it wasn't as good as the 45?

Even if it had a smaller power supply people like me who need less amp power than others shouldn't have a problem with this suposedly 'lesser' model.

I already have the XR-25 so of course that's why I'm making such an issue about it.
It'd suck to have to buy a 45 to send to you if the 25 turns out to be pretty much the same unit sound-wise.

Many people have comparedthe two in stock form and they seem to be straining to find diffs. in the sound and in the end calling the 45 better 'cuz it's only $50 more and 'must' be better 'cuz it's model number is higher?

I even double checked an 18+ page thread on AVS about this Rec. and still didn't see anyone who actual claimed that they knew for sure that the two actually were different, and no one who could say exactly how (beyond features).

I was thinking even if the 45 used some diff. slightly better parts too that maybe they'd just end up getting taken out and replaced with your mod anyway?

Sound and Vision (yes..., typically awful mag) tested the XR25 (I've got the issue) and it shows that it does deliver it's rated power (which is the SAME as the 45's rating) so the worse power supply rumor seems either bogus or not ness. a big issue to people who don't need as much power, and personally my speaker do only need half to a quarter (or less) power to hit the smae SPLs as some mentioned in the test (note- not mentioning this to plus my speakers).

Sorry if I'm being trouble for you. I'm really interested in getting this mod.

[azryan]

Thanks for the list of features ABEX,

I've seenthem many many times before though and having the XR-25/45 manual I already knew all these diffs.

Of the six you listed all six of them should be 100% meaningless to the actual sound quality of the two units and I couldn't see how any of these points would flat out bar the 25 from being an equal canidate to the 45 to mod.

If there's an actual reason I'd like to hear it.

It's not like I'm claiming the 25 and 45 are the same. I'm just saying they SEEM to be in all key sound quality ways and for all the threads I've read and links I've been told to look up nothing's been shown to me that changes that thought.

I'm totally open minded to actually learning whatever the truth is about these two units... I just think I've yet to hear it.

[JohnR]

In the thread that Wayne linked to, there's a photo showing clearly that the XR25 has less in the power supply. If it's not an issue of power output, then presumably it has some effect on sound quality. At any rate, it would be a different set of mods and there's only so much anyone can do in a day...

Having said that, if someone wants to sell an XR25 cheap, lemme know

[Brad]

Just sold mine today, John.....
Maybe you can turn the Dynaco into a digital amp?

[ABEX]

I was not trying to prove or disprove anything as far as sound quality I have a post that says they are basically the same in sound and I would need the 2 units to compare. The price difference of the 2  makes it worth it to myself. Iwould not think there would be a difference in order to mod the 25,but I have yet to open the 45 up.

Here is the post of someone that did compare the 2.From AA
=================================
Posted by ka7niq (A) on December 15, 2003 at 06:34:09

I am not going to beat around the bush on this , the 45 is better.
They both have great bass , with excellent pitch definition , and from Male voice on down , sound similar.
I think the 45 has a tad more punch , but its hard to tell.
But from Female voice up , the 45 walks away from the 25.
It is considerably more open and transparent , and dont seem to gloss over high frequency detail as the 25 does.
The image is larger and deeper in all dimensions on the 45.
At first, I didnt like the Digital Remaster feature of the 45 , but I do like it on some recordings.
For instance , listening to Rammstein's Engel track, The Digital Remaster places the Guitar clear back outside and behind the speaker , and allows you to hear the shimmer of the cymbals better.
Many of you who dont have speakers that image and reproduce extreme highs as well as 801's may not hear this , but the re master works well on some recordings , and you can simply turn it off on others.
The 25 dont have it at all.
So, I would overall reccommend the 45 over the 25 UNLESS you have Horns, or other bright speakers requiring some high frequency veiling.
Both the 25 , and the 45 drive the piss out of the 801's , not the worlds easiest speaker to drive.
We plan to try these out on VMPS RM 40's , just for shits and giggles , ha ha .
I havent drug out my horns yet , because the 801's sound so good and I am enjoying the overall sound so much.
The 45 has "Party Mode " that will allow you to bi amp your speakers, AND adjust the levels too !
My Klipsch CF 4 Horns are a two way , using 2 long throw 12's with a Neo Compression driver hooked to a Tractrix horn.
They were great in a larger room , but are a bit too much " in your face " in the smaller room I am now in.
I plan to hook em to the 45 , and simply reduce the gain to the tweeter amp , therby " revoicing " them.
Then perhaps I will be able to tolerate my beloved horns in the small room I now dwell in ?
I put the 25 in my bedroon on the KEF Q1's , its good enough for that , and provides a warm, mellow sound to go to sleep to.
Plus, its small , and fits easily on the dresser.

[Wayne1]

The biggest difference between the two units is in the power supply. As JohnR says, if you look at the picture on the link I reference, there are at least 8 large power supply capacitors, DC-DC convertors, switching mosfets and transistors and a serious amount of associated parts missing.

The TI Equibit chipset does like a very good, stiff power supply.

Part of the mod does involve work on this section of the power supply. I heard a noticeable difference in dynamics and impact when I worked on that section. The sound that the modded 45 offers is not possible without that section in place.

PeteG has agreed to bring his broken in SA-XR25 to the DAM's next get together. We will be able to compare it to Tyson's week old 45 and the modded 45.

[pjchappy]

Where's a good place online to get the 45?

thanks!

p

[ABEX]

J&R's Music World,but they only have it in Black just so you know. ABE's of Maine,which is not in Maine,but in Brooklyn,NY. is alittle more expensive because of S&H cost.

Good Luck!

[pjchappy]

I'm also still a bit confused on this digital technology. . .what is the signal going to the speakers?  I understand it remains digital throughout, but, when it hits the binding posts, what is going on?

Thanks again!

p

[azryan]

Dang, I wish you woulda just said -they have a totally diff. power supply and several associated parts so a 25 mod would 'not be possible' using the same parts I'm using for the 45 and I don't have time to work up a diff. solution for the 25.

I was thinking that even if the power supplies were diff. that you could still do the same mods and someone w/ high effi speakers might not care about the smaller PS.

My understanding this woulda stopped me asking about the 25.

At least it's cleared up here now for anyone else who might wonder the same thing.

The link you linked me to didn't have any pic. of the two power supplies, but I'll search again 'cuz it must be on a diff. page than the ones I saw. There's a LOT of pages though. hehe

Switching power supplies right? Both units are so tiny and there's obviously no torroid in there. Both must be really small even if ones bigger than the other.

Curious to see if they mention the actual V/A power diffs.

JohnR,

Looks like I'll be ordering the XR-45 and would sell the 25. Which is no big deal... I just didn't want to have to bother, but certainly a cheaper solution than any combo of 2 chan amp, preamp, and DAC I was looking at so I can hardly complain.

I don't think I'd need to take a lowball 'cheap' price though, but PM me an offer if you want and I'll take a look.

pjchappy,
Good to see that quote from a killer song that probably most Floyd fans have never even heard (but should).

You can't send a digital signal to speaker drivers 'cuz obviously they can't read ones and zeros so the last step in any digital amp converts the signal to analog before it shoots it out the speaker wire. It's always digital up until that last step though -not that there aren't digital to digital conversion steps too.
The incoming PCM signals and a dig. amp's radio freq. rate PWM processing are pretty dang diff.

The idea here I think is that 'cuz it's still ALL digital it's all just math to the chips and the signal comes out damn near perfect being unharmed by analog damage.

Other high end digital amps that you may have seen mentioned elsewhere (Jeff Rowland Group, Bel Canto, Acoustic Reality, Solar Hi-Fi, Spectron, Carver, PS Audio, etc...) take in an analog signal (hopefully from the output of a stellar DAC and preamp though) and convert that to digital.

Their stand seems to be that it's taken decades to get outstanding DAC's developed so take advantage of it then let the digital amp which is totally diff. type of digital do it's thing to that mint low level analog signal (often to rave reviews).

The digital amp chips in this Pannie are from Tex. In. who got the process from Toccata which is TacT Audio's Equibit amp chips. These take a digital signal and keep it digital.

You can find rave reviews on the TacT amps (which have been out for over a decade now), but I've seen many of the analog input digital amps called better too, so at least to me just saying 'it's 100% digital' isn't on it's own the be-all-end-all, but this Pannie in modded form should be stellar IMO at the very least in price/performance ratio, and certainly based on several work-in-progress reviews stellar in ultimate terms also.

There's gotta be someone who knows some links to where digital amps have already been greatly explained in detail on the forums.

[dm]

Where's a good place online to get the 45?

thanks!

p

Panasonic SA-XR45 $278.95 shipped...

I just purchased one from computers4sure.com. If you do a google search on computers4sure and coupon you will find a $20 off of $200 coupon for computers4sure. Free shipping and no tax in most states. Brings your price down to $278.95.

The site lists it as out of stock. But they get a few in every couple of days and ship them off as they come in to those on the wait list.  In my case I was on the wait list for 3 days, then got a "your package has shipped email".