Panasonic class D amps - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th January 2008, 12:02 AM   #11
diyAudio Member
 
Join Date: Nov 2005
Location: 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.
__________________
The difference between theory and practice is that in theory there is no difference between theory and practice, but in practice there is.
  Reply With Quote
Old 13th January 2008, 01:13 PM   #12
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: 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!
  Reply With Quote
Old 13th January 2008, 02:05 PM   #13
t-head is offline t-head  United States
diyAudio Member
 
Join Date: Jul 2007
Location: Key Largo
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
__________________
trust, but verify...
  Reply With Quote
Old 13th January 2008, 02:37 PM   #14
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: 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!
  Reply With Quote
Old 13th January 2008, 02:51 PM   #15
gychang is offline gychang  United States
diyAudio Member
 
Join Date: Feb 2005
Location: Davis, California
Default looks nice

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

gychang
Attached Images
File Type: jpg saxr55.jpg (9.7 KB, 4219 views)
  Reply With Quote
Old 13th January 2008, 03:24 PM   #16
t-head is offline t-head  United States
diyAudio Member
 
Join Date: Jul 2007
Location: Key Largo
Quote:
Originally posted by jkeny
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
__________________
trust, but verify...
  Reply With Quote
Old 13th January 2008, 06:57 PM   #17
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: 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)
  Reply With Quote
Old 13th January 2008, 08:15 PM   #18
kstrain is offline kstrain  Scotland
diyAudio Member
 
Join Date: Apr 2006
Location: Glasgow
Quote:
Originally posted by jkeny

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
  Reply With Quote
Old 13th January 2008, 09:32 PM   #19
john65b is offline john65b  United States
diyAudio Member
 
john65b's Avatar
 
Join Date: Jan 2005
Location: 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...
__________________
All right, but apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the Romans ever done for us? Life of Brian
  Reply With Quote
Old 13th January 2008, 10:14 PM   #20
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: 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?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale: Tube Amps, Class-A Amps, BG Ribbons, Chassis and Other Goodies! opc Swap Meet 23 2nd November 2009 06:04 PM
FS - Class D Panasonic SA XR55 HT Receiver t-head Swap Meet 2 29th December 2008 01:12 AM
New Panasonic AVR is it class D? evad Digital Source 0 2nd July 2008 06:19 PM
panasonic SA-XR10 vs Tripath amps jkeny Class D 0 9th August 2005 02:49 AM


New To Site? Need Help?

All times are GMT. The time now is 03:07 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2