Panasonic class D amps

jkeny

Banned
2007-02-06 12:43 am
Dublin
How come there is nothing of note posted here about these amps (SA-XR55,57,59) - the sound, mods, etc? In the US they are very inexpensive & seem to sound good out of the box (with a bit of burn in) with potential for tweaks - so why no DIYA users?

I know there are lots of posts over on AVS forum but a most of these posters are interested in home theatre sound and are not DIY types. They talk about crystal clear sound which is important for movies but is it tiring for music listening? I would be happier with a sonic evaluation from posters here as I know you guys and where you're coming from.

I'm interested in one for stereo use (fed digitally from a music server) with future potential for surround sound or digital crossover use. My current speakers are Rogers LS3/5as & Jordan JX92s (to be boxed)

I'm tempted to spring for an SA-XR57 but all stockists, here in Ireland, would have to order one in (stockists eh!) so I can't get one for home trial and the price is €500 ($740), not something just to take a punt on.

Any of you guys listen to one of these and have an opinion about sonics for stereo music listening & any mods?
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
The other question I have is - is it possible to use a US model (120V) in Europe (240V) by using a suitable step down method which could also have the side benefit of cleaning up the mains feed to the amp?

I'm tempted by the price in the US of $250 http://www.jr.com/JRSectionView.pro...h&lastSearch=&search.x=0&search.y=0&search=GO

compared to the $750 being charged over here, gives me $500 for shipping & step down trafo - seems like it could be done!
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
OK, I'm probably being impatient but seeing as there are no replies, I reckon a punt is in order at the US price.

So, now I have a number of other questions
- has anybody imported electrical equipment into EU from US? What is the best way to do this to avoid crippling duties?
- Apart from the voltage difference & the AM/FM radio diferrences is there anything else I'm missing? What about freq of internal clock being affected?
- What is the best solution for down-conversion from 240V to 120V for a 7*100Watt amplifier?
 
I haven't heard these but they look like nice units. If I was looking for a receiver I would seriously be taking a look. It's hard to believe the features to price.

The life of a receiver for me is years and years. For me it's best to try something for a few weeks in my home before I make a hard decision. The shopping for price isn't so important as being able to return it and try something else.


Warranty may not be valid in a different country.
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
Thanks for replying Raintalk, I think the warranty would be an issue also but at these prices $250 it's probably worth a risk.

Ok, here's my final attempt at getting some feedback - I'm wondering what some of the inmates here think of Panasonic's implementation of TI's TAS5076 and TAS5182 chips?

I know BWRX & STEngineering have designed pcbs for these chips, but I don't think there are any boards left? Maybe you guys have an opinion of the Panny amps?
 
FWIW,

I have 2 SA XR55s. I am using Jordan XR92s in a slim 6"x6"x36" transmission line enclosure. I paid USD$170 each.

The sound is very clear. On certain recordings where there is a bit of sibilence, it is...sibilent. It can be harsh at times. With the Jordans it makes a great 2.1 system for TV. I stream internet radio thru a USB DAC from Peter Daniels (www.audiosector.com) and it sounds better than other DACs I have used. Running a CDP via coax digital to the panny, the sound is very good.

Check out Audio Circle (www.audiocircle.com) and search fot the Panasonic - there are threads for mods. Mostly cap changes, cutting traces for unused stuff, replacing connectors and internal wiring swaps.

t

Boulder Cable used to do mods on the pannys...if you mod warranty is gone...
 
There is no shortage of reviews and opinions on these units. Many, many people are thrilled with them, but there is a dissenting group and I think I'm in it. I was intrigued a few months ago by the chatter (latecomer, they have been around awhile) and went ahead and got an SA-XR55 from jr.com. It was around $200 shipped. I did only spend a couple of hours running familiar material through it on Paradigm Titans-- the unit failed in less than 24 hours. The clarity and detail is quite stunning and initially very captivating, but voices were not natural in my opinion. I've been listening to Mark Knopfler for 25 years on a number of different systems and I just did not like how he sounded with this amp, but maybe I was looking for something not to like. I typically make my mind up very quickly when I hear a new amp and, for two channel listening as I was doing, I concluded it was not up to par. I left the unit on overnight for burn-in and the following day after work it was off and refused to come back on, broadcasting an "overload" message then immediately switching off. There are some posts on this failure mode, it was not an isolated incident. I packed the unit, shipped it out, and haven't thought about it much til now. I do think its clarity and detail qualities would make it a great surround sound amp, but I think I would not have been happy with it as a main two channel system for critical listening. But we all have different tastes and expectations, your conclusions may very well differ.
 

john65b

Member
Paid Member
2005-01-09 2:32 am
Chicago
I too had got wrapped up in the hype a few years back and have had a XR25, XR50, XR45, and the XR55 in my possession.

I recently put the XR45 in place of my homebuilt - UCD400 and a modded ESP-101 amp on my Magnepan MGIIIa and there really was no contest. Power may have had something to do with it...

I still have an XR50 upstairs that's my everyday Plasma TV, the XR45 in the basement (with old B&W220) in a home theater. They work fantastic in my theater and daily setup, and never really mess with it, but just didn't cut it on two channel with the maggies.

Never really tried biamping the MGIIIa's with the panny, maybe someday... It is very clear and quiet (great for HT dialogue), but juts didn't sound as nice as the P101 or UCD400 on the maggies.

Of course I didn't mod it - all stock. Also the speakers may have been a bit tough for the XR45...
 

lousymusician

Member
Paid Member
2005-11-24 4:10 am
NorCal
My HT receiver is an XR55. It's been running reliably for a couple of years now. It sounds better to me now than when it was new, either it's mellowed some or I've adapted to it. Its sound is on the lean'n'clean side, no hint of tube-like lushness, so I wouldn't pair one with an excessively bright speaker.

For the US street price, I think it's a very good deal. I like it well enough that I bought one for my son for Christmas.

At $740, I'd expect you could do better though.
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
One thing that comes through from these posts is that in two channel use maybe the amp is underpowered & perhaps has to be turned up into it's high wattage/high distortion area to achieve decent output?

Has anybody listened to the bi/tri-amping mode of the XR55 and up models and compared it to single channel use? t-head?

Another potential weakness of the amp is the fact that there is only about -30db PSRR at 20KHz. As the amp works as a power DAC and the PS could be looked on as it's reference voltage, the PS quality is more important than most other amps.

I have a stock of 12V SLA 7aH batteries and wondered had anybosy tried to use a bank of batteries? If this worked it would solve the voltage conversion problem US to Ireland and allow me to purchase from US!
 
jkeny,

I presently use the 55 in dual-amp mode for 2 channel use. It is running Jordan JX92S in FR (88dB eff with dip to 5ohm or so at low end). I do not find the amp clipping or operating into distortion, although depending on speaker efficiency and presence of crossovers etc it is possible. Using the signal from USB DAC, I operate at -24dB setting and have gone to limit of pot - 0dB (full out). Distortion is not obvious, though the shouts of neighbor to turn the darn thing down are...not to mention the damage to my ears, etc...5mx5mx2.5m room.

No exp with batteries...a step-down transformer should work fine. I have not checked, but it is possible that jumpers inside may be present to switch input voltage...have to check with tech guys at Panasonic (lol).

t
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
Thanks t-head,
I'm interested in your set-up as I will be running this amp with JX92S speakers also, so no crossover to worry about!

What other amps have you listened to with these speakers and could you give me some sonic reference?. Sorry to ask you all these questions!

I have built/modded & listened to gainclone, sonic t-amp, SKA amp & Rogers Cadet III tube amp (rebuilt to Baby Huey circuit). All these I like in one way or another but they don't have the WAF so remain outside the main living quarters.

A couple of things I hope to achieve with this amp are:
- avoid a lot of ugly boxes, DAC, preamp,etc (I'm not the best at good finishes)
- avoid a lot of boxes DAC, preamp, etc each of which has potential to introduce, jitter, distortion into signal
- Have a good sounding system in the living room
- Use Music server to send lossless files over Ethernet and connect to amp via SPDif (or better I2S)

Thanks for the replies!
 
looks nice

I thought would add a picture for those that connect visually...

gychang
 

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jkeny said:
Thanks t-head,
I'm interested in your set-up as I will be running this amp with JX92S speakers also, so no crossover to worry about!

What other amps have you listened to with these speakers and could you give me some sonic reference?. Sorry to ask you all these questions!

I have built/modded & listened to gainclone, sonic t-amp, SKA amp & Rogers Cadet III tube amp (rebuilt to Baby Huey circuit). All these I like in one way or another but they don't have the WAF so remain outside the main living quarters.

A couple of things I hope to achieve with this amp are:
- avoid a lot of ugly boxes, DAC, preamp,etc (I'm not the best at good finishes)
- avoid a lot of boxes DAC, preamp, etc each of which has potential to introduce, jitter, distortion into signal
- Have a good sounding system in the living room
- Use Music server to send lossless files over Ethernet and connect to amp via SPDif (or better I2S)

Thanks for the replies!


I purchased the SA XR55 specifically for my JLMs ('Jordan Lean Monitors') I purchased from Carolina Audio. I had a Trends 10.1 modded by Michael Mardis. Ronnie Thackery (builder of the JLMs) suggested that I would need at least 50w-100w to get the JX92S singing. He was the one who suggested the Panny. I found the price to be good ($170) so I got one. I have tried a set of 7 watt 300B monoblocks with a nice tube pre and though they work, I agree that the Jordans need watts (current) to function well. The Trends didn't cut it. Twice the power of the Panny would not hurt...but it works well. I have also used a KingRex amp, but still not enough power on its own. With a tube pre/King Rex it was better, but so far the panny stays and is the best solution so far. I was thinking of a gainclone from Peter Daniels (AMP1) with 3 source selector, but it is $1200...no remote...

I like the Panny for just the reasons you mention...It is one box, has remote, internal DAC (oversampling) and multiple in/outputs. The internal DAC can be connected via Toslink or Coax digital input. There are also analog inputs for external DAC, CDP, DVDP, TV, VCR, etc. Its brightness out of the box mellows with use and can be adjusted by cable choice. You can adjust internally via HF tone control at first if necessary, and go back to nothing later...It has the approval of my wife, FWIW...

Some love it, some hate it...Mine is streaming www.radioparadise.com from my laptop right now at -16 dB volume...nice...

t
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
Thank you t-head,
That's exactly the sort of info I need to try & make an informed decision about these amps in the absence of a home audition! It sounds to me like it's very good value at $170!

Now to see how possible it is to import from US? Has anybody looked inside the amp? Is there a 120/240 mains voltage switch? (Those Panasonic tech guys are not forthcoming with info from what I hear)

Has anybody imported something around this size/weight into Europe? What duty applied or how did you avoid duty altogether? Would customs declaration of "equipment for repair" work or is this too obvious? (I have a company name that could be used)
 
jkeny said:

Has anybody imported something around this size/weight into Europe? What duty applied or how did you avoid duty altogether? Would customs declaration of "equipment for repair" work or is this too obvious? (I have a company name that could be used)

Yes often, and duty averages around 5% for most electronics. Depending on the courier a brokerage fee of order EUR 15 will be charged (if you have a company it will definitely be cheaper to use your own courier and have them collect, and they'll get the VAT right too - i.e. you won't pay it if you are registered).

Incorrect customs declaration = fraud.

I'd expect shipping, duty, fees (and VAT on all of that) to roughly double the price, possibly a little more depending on the size of the box. Much the same to Ireland, I suspect.

Ken
 

john65b

Member
Paid Member
2005-01-09 2:32 am
Chicago
I have heard a thing or two about Onkyo's Class D integrated Amp - the A-9555.

Unlike the Panny, it is analog in, no digital in (as fas as I know)

What made the Panny so interesting is the straight thru digtal amplification before the DAC out to speakers, not a "digital amplification hybrid" like the others...
 

jkeny

Banned
2007-02-06 12:43 am
Dublin
Hey John65b,

I have modded the SI t-amp and although the sound is great for the price, ultimately it's tiring. So I was interested in a pure digital amp i.e. a PowerDAC that avoids analogue input and uses digital straight through.

I know this no-feedback type amp has it's own issues to overcome (PSRR 0db rejection - I said 30db before but I've seen 0db also) but I believe that avoiding an external DAC avoids all the potential areas for introducing jitter, noise, distortion & all the boxes needed for this.

I'm guessing your take on the sound of the panny amp with the Magnepan MGIIIa speakers was based on using the analogue in rather than digital in? Was it also based on single channel rather than bi-amping?