TIC,
Yup, thats me, sillkk39 is my aol/ebay account, I use this one for all my college stuff. Anyway, somebody over at DIY audio asked about the differences between panasonics xr line and after a little research I came up with this. Its mostly just about internal stuff between the series, and for fairness I've only compared my xr10 to a tweaked vintage amp and some cheap fisher amp. Read up on stuff from Wayne from bolder cables, he has probably seen all these panasonic amps internals first hand.
I tried a different p/s cord, home built quad cat5 with iec adapter, no measurable difference from testing using RMAA and my emu 0404 sound card.
However, one thing that made a noticable difference, in fact a measureable difference using RMAA with my emu 0404 sound card for tesing, it was a computer surge protector/noise filter from radioshack that was originally $35, but they are clearancing out for $5! Plugging the xr10 to this made noise level go up from 84db to 88db and dynamic range 85 to 89db for digital in. This was repeatable, unplug, ~84, plug in radioshack special, ~88-89.
Power supplyDifferences between the xr10 and the 45 on the powersupply side are slim, I think the xr10 lacks one small transformer near the power cord that the 45 has. Also, xr10 uses two smaller main transformers, while xr45 uses only 1 bigger one. Xr70 is similar to the 45, but main transformer and smaller one right next to it is bigger and there are protection relays (which apparently degrade sound) for the speakers are on the p/s board as well according to wayne from Boulder cables on audiocircle. xr25 and 50 power supplies lack the extra filtering that the 10/45/70 have, and the 50 still has the protection relays for the speakers. The whole line uses the figure eight cord found on dvd players, xbox, ps2, etc. Lastly, xr10 uses a ferrite on the stock cord, all other models do not have this ferrite.
Amp section:45 and 25 use identical amp sections. XR10 uses the original TI equibit amp design, which used to be a $500 piece in itself if ordered through TI. The TI board is different from the 45/25 and 50/70. The xr10 has TAS5012 chips, xr 25 and 45 use I forget, i'll try and find it again. What I'm pretty sure is that the tas5012 was a higher end ti part, and just recently got surpassed by the newer tas5015 chip. 10 is rated differently (distortion wise) than 25/45 and 50/70 for stereo mode. XR10 has .9%, xr25/45 has .3%, and 50/70 have .09%, but they all have the same rated power (100wx2@6ohm).
Headphone and subwoofer are handled through a dac i believe for xr25/45/50/70(found if you search through one of the old xr10 posts on DIYaudio), xr10 uses straight from front channels for headphone, and not sure on sub-out. Only difference for 25/45 to 50/70 is that for the front two channels there are different ti power chips used, with the 50/70 having the better ti chips. From what I've read on avsforum and audiocircle, headphone out on the 45/25 and 50/70 are not good. I have the xr10 and I don't think it sounds bad at all, better than my Rio Karma (which sounds similar to an Ipod because they use the same DAC/headphone amp chip). JRC makes the headphone op-amp on the xr10, not sure what is used on the other units. When you plug in headohones on the xr10, main speakers are shut-off, confirming that it does use the front channels. Oh yeah, there is also copper grounding inside the xr10, I don't know whats in the other amps.
Analog/digital in's:nothing special about this, I know that the xr10 is rated 5db higher for analog s/n ratio, 90 instead of 85 for the rest of them. there is no digital out on the 10, but there is on the rest of the series.10 has 2 optical in and 1 coax in, 45 have 3 optical and 1 coax in, 25 only 2 optical in and 1 coax in. The 50 and the 70 add another coax in but loses an optical in (so 50/70 have 2 optical in and 2 coax in) and the 70 adds hdmi in/out. XR10 does not feature s-video switching, only composite. XR10 has input for tv, dvd (including 6 ch in), and VCR in/out. 25/45 has inputs for cd, tape, vcr, tv, and dvd (and 6ch in), and audio out, but its fixed and not a pre-out. 25/45 have s-video/composite video switching, no component switching. 50/70 add component switching and front a/v (composite) in.
miscXR70 has hdmi 1.1 input (audio and video) , but only 1.0 output (video ONLY). XR10 does not have any banana type connectors for main speakers, they are all spring clips. XR10 also features nichicon, elna, and even panasonic fm capacitors. Also, as far as speaker set up goes, subwoofer for xr10 is fixed at a 200hz low pass, and "small" setting only allows 100hz high pass, "large" is full spectrum. This is the same for 25/45, and I from looking at the 50/70 manual it is the same also. Some poeple have reported that they hear a small clicking noise when volume is changed on the xr25. Remote control for xr10/25/45 have more buttons on it than the xr50/70 remote, don't know if thats good or bad
. The xr10/25/45 use a small fan on the back of the unit, the xr50/70 do not. I have had my xr10 for two months now, and have not heard the fan turn on once yet. The screen on the xr10 is about the size of a TI solar calculator screen, and its hard to read from far away(8-10ft). I have not seen any other model so I can't compare. And one last note, my XR10 says its made in Japan, I don't know about the other models though.
I've compared this amp to an old sx-1010 of mine (110x2, .1% thd) . I'm using Mirage Omni260 speakers with a small Venturi 8' 150 watt sub. Analog source is a modified Technics SL-pd9, digital is emu0404.
SX-1010 vs. XR10These sound different, and I'm not sure which one I prefer. The sx-1010 defintely has more headroom, it should as it weighs 50lbs. Listening to Herbie Hancock's "Gershwin's World," my favorite jazz cd, the sx-1010 is deep, everything sounds like it has an echo to it, but mostly the lady singer and the piano solos. I think this is do in part that the 1010 needs caps replaced and rolls off like -1.5 or 2db at 20khz when measured in RMAA, but it still sounds real nice. The xr10 analog is actually kinda close to the 1010, but I can sense that depth isn't as good, its much more forward. I can tell this with the ladies voice again and with trumpets- both seem much more closer and present, like 6 feet away, while the 1010 makes them feel like 30ft away. If I use the 0404 analog with the xr10 and low pass shelf to simulate the 1010 freq response, I get some of that nice echo back, not the same, but similar. Using the digital out on the emu, xr10 is much more detailed. Again, with the womens voice, I can more accurately sense she varies the loudness in her long standing notes. Ok, very difficult to explaning, but here's my best way of describing it: instead of hearing a long winded "eeaassyy," you hear "eeaasyeayeay." I would say overall its a tie because with the digital out on the 0404 eq'd to similar freq. response of the 1010 the xr10 and the 1010 are close sounding. Ambience, 1010 wins out, details xr10 wins out. If it was an analog source only, I'd say 1010.
I've also compared the two with faster music, like The New Deal, and Sound Tribe Sector Nine. XR10 easily beats out the 1010, no contest even when fed analog to both. The 1010 just can't match the speed of the digital amp, and the high end of the xr10 really shines with this music.
If you listen to classical, jazz or any other slow deep music, I think xr10 is an ok source IF it is a digital source, but its really a toss up for me which amp I prefer more for this style of music. If you listen to rock, techno, any other fast music, by all means give a digital amp a try, I think you'll be surpised how accurate they are.
From what I've read on various forums, some people feel that the high end freq. are less detailed on the xr10, but also less harsh when compared to the xr25/45. Also, the xr50/70 may be able to handle lower ohm loads better than the 10/25/45 (a user claims to be able to use MMG's no problem with xr50), but this is only by the account of one user.
I think digital amps will
eventually (who knows when) surpass Solid state amps for digital sources (cd, dvd, sacd, etc) in terms of sound quality, but I think tubes will always have a place in audio due to its pleasing sonic characteristics, and also because I love the simplicity of some vintage tube gear
