jkeny said:
Hi Jkeny
See the thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7754&perpage=25&pagenumber=1
Cheers 😎
Thanks Tube_Dude,
I read through that thread a long time ago (2002) and it was very interesting but too advanced for me with BGA chip soldering, etc.
What I'm hoping here is to re-invigorate investigation of mods to these amps which are within the capability of ordinary Jo's like me, and not just digital amp design experts. Although I'm hoping they might drop in to give some expert advice!
BTW, I've sent you the service manual! Let me know your thoughts
I read through that thread a long time ago (2002) and it was very interesting but too advanced for me with BGA chip soldering, etc.
What I'm hoping here is to re-invigorate investigation of mods to these amps which are within the capability of ordinary Jo's like me, and not just digital amp design experts. Although I'm hoping they might drop in to give some expert advice!
BTW, I've sent you the service manual! Let me know your thoughts
eld, I'm no expert and maybe some experts will jump in here and answer this - the C707 is listed as 820p 200V on the schematic & 820p 400V on the parts list?. Is this a PS smoothing cap? Increasing this to 6600uF seems like a huge jump! I'm not sure where the appropriate application of a larger PS smoothing cap would be in this switching PS? Maybe the experts could have a look?
Can I post this part of the schematic here without violating copyright?
Can I post this part of the schematic here without violating copyright?
edl,
The other cap mods (C717 & 718 are 1uF/50V) seem OK, adding 6000uF, as long as they don't stress the transformer or surrounding devices.
Does anybody know what Boulder mods they applied to these amps - don't think they still do these mods? I seem to remember mention of a 4 pole Jensen cap(s)?
Edit: Because the service manuals for the XR55 & 57 are 10MB & 16MB I hosted them on the following site for download: http://www.4shared.com/dir/5422093/4db6362a/Panasonic_Service_Manuals.html
Let me know if there is any problem assessing them!
The other cap mods (C717 & 718 are 1uF/50V) seem OK, adding 6000uF, as long as they don't stress the transformer or surrounding devices.
Does anybody know what Boulder mods they applied to these amps - don't think they still do these mods? I seem to remember mention of a 4 pole Jensen cap(s)?
Edit: Because the service manuals for the XR55 & 57 are 10MB & 16MB I hosted them on the following site for download: http://www.4shared.com/dir/5422093/4db6362a/Panasonic_Service_Manuals.html
Let me know if there is any problem assessing them!
Adding 6000uF to C717 & C718, which are both 1uF/50V seems more reasonable as long as they don't cause any strain on the transformer or surrounding components?
Again, I'm no expert but these are the questions I'd ask myself before doing these mods!
What is the best way to extract an image from a pdf file for posting here? I can copy into the clipboard the image part of the pdf page but how can I post it here? As a rtf doc?
Again, I'm no expert but these are the questions I'd ask myself before doing these mods!
What is the best way to extract an image from a pdf file for posting here? I can copy into the clipboard the image part of the pdf page but how can I post it here? As a rtf doc?
eld said:
i've modded my xr45 ( which has a regulated smps )
i've replaced the 6x1000uF of the power amplifiers with 1x12000uF Elna Cerafine and replaced the speakers internal wirings
the result depends on which caps you choose , a Elna has not the same sound than a Blackgate or other , especially with class D
rha61 said:
Was the change worthwhile?
Do you mean the 6*1000uf caps in the output stages just after the 6 * toroid inductors? In the later models XR55 & up these have been replaced by special? Panasonic water? electros, so I don't know if there is much mileage in replacing these - maybe bypassing with high quality PP caps?
Again, in latter models the output from here goes through relays which provide Dual/triamping function so I don't know how amenable this is to rewiring?
yes the change was worthwhile
strangely caps have their own sound and it's obvious with power supply for classD amps
after trying some different caps , i choosed Elna because of more bass and nice midrange
bypassing with film caps creates resonance
strangely caps have their own sound and it's obvious with power supply for classD amps
after trying some different caps , i choosed Elna because of more bass and nice midrange
bypassing with film caps creates resonance
Thanks rha61!
I will look into upgrading the caps at the output stage once I have the wires and binding posts updated. Is the Elna Cerafine a 12,000uF-50V cap? I'm having a hard time finding one on the net.
What are your opinions of adding more capacitance to the input power board, is this a wasted effort or could it help in providing a more stable power to the entire unit?
Thanks, Jkeny, for your help.
This is my first unit modification, so you are definitely a step ahead of me. I noticed that the C707 cap has actually gotten smaller in the SAXR57 vs. SAXR55. The positive lead looks like it goes directly from the diodes to the transformer. I thought it might play a dual role of filtering and be a high current power tank, but I'm just guessing.
I think there is definitely room for improvement as far as upgrading the wires in the speaker circuit. The existing ones are tinned and look about 18 gauge wires if not smaller. I plan on changing these to 12 gauge OFC wires and maybe removing some connection sockets and hardwire them to the boards.
I will look into upgrading the caps at the output stage once I have the wires and binding posts updated. Is the Elna Cerafine a 12,000uF-50V cap? I'm having a hard time finding one on the net.
What are your opinions of adding more capacitance to the input power board, is this a wasted effort or could it help in providing a more stable power to the entire unit?
Thanks, Jkeny, for your help.
This is my first unit modification, so you are definitely a step ahead of me. I noticed that the C707 cap has actually gotten smaller in the SAXR57 vs. SAXR55. The positive lead looks like it goes directly from the diodes to the transformer. I thought it might play a dual role of filtering and be a high current power tank, but I'm just guessing.
I think there is definitely room for improvement as far as upgrading the wires in the speaker circuit. The existing ones are tinned and look about 18 gauge wires if not smaller. I plan on changing these to 12 gauge OFC wires and maybe removing some connection sockets and hardwire them to the boards.
eld said:
i found my Cerafine in an old Kenwood amp but all the Elna for audio are well-known for big bass and "euphonic " midrange
just be careful with the size
for the cap in the input power board , i dont know
ask to Wayne at Bolder Cable , he used an expensive Jensen 4 poles
rha61,
did you replace 6*1000uf caps with one 12,000uF - how does this work?
I don't have a unit here to open up so I'm just working off service manual - forgive me if my comments are obviously wrong!
eld,
I don't think C707 at 820pF is a PS smoothing or tank cap! - I'm not sure what it's role is? Maybe if I could post here an image capture from a PDF file others would be able to pitch in.
Changing the internal wire to the speaker pcb sounds like a good idea.
We need to focus on the internal PS changes for increased sonic benefit.
I had posted earlier about a step-down transformer (from 240 to 110V- if import a US model) as possibly giving some PS advantage (isolation, PS filtering, etc)? Has anybody got an opinion on this?
did you replace 6*1000uf caps with one 12,000uF - how does this work?
I don't have a unit here to open up so I'm just working off service manual - forgive me if my comments are obviously wrong!
eld,
I don't think C707 at 820pF is a PS smoothing or tank cap! - I'm not sure what it's role is? Maybe if I could post here an image capture from a PDF file others would be able to pitch in.
Changing the internal wire to the speaker pcb sounds like a good idea.
We need to focus on the internal PS changes for increased sonic benefit.
I had posted earlier about a step-down transformer (from 240 to 110V- if import a US model) as possibly giving some PS advantage (isolation, PS filtering, etc)? Has anybody got an opinion on this?
jkeny said:
the cap is simply lying between the + ang Gnd rails
you can also replace each 1000uF cap with 2200 ones but , again be careful with size
Sorry eld,
I don't understand, is the 12,000uf cap in PS rather than in the output stage? Which cap in the PS did you replace then?
I thought the 6*1,000uF caps were on each output to the speaker just after the output toroid inductors!
I don't understand, is the 12,000uf cap in PS rather than in the output stage? Which cap in the PS did you replace then?
I thought the 6*1,000uF caps were on each output to the speaker just after the output toroid inductors!
Jkeny,
Did you mean to address the last post to rha61?
I have order the upgrades to C717 and C718, will let you know how it goes. I'm pretty sure they will be helpful since it looks like they are in parallel to all the "water" caps and are shared by all channels.
The Cardas CCGG binding posts are on the way, this and rewiring should really help as well.
Cheers,
Eld
Did you mean to address the last post to rha61?
I have order the upgrades to C717 and C718, will let you know how it goes. I'm pretty sure they will be helpful since it looks like they are in parallel to all the "water" caps and are shared by all channels.
The Cardas CCGG binding posts are on the way, this and rewiring should really help as well.
Cheers,
Eld
I believe both the PS caps and the large smd cap should be replace.
Not sure if Panasonic has any really high quality caps, I would prefer to use Rubycon ZL or Za instead and definitely Oscon for those SMD type.
Not sure if Panasonic has any really high quality caps, I would prefer to use Rubycon ZL or Za instead and definitely Oscon for those SMD type.
Yes sorry eld,
Last post should have been to rha61!
Good work, eld - let us know how the mods work out!
I have just heard of some fully working APC UPS (uninterruptible Power Supplies) boxes being disposed of and I wondered if they could be easily modified to provide 120V output instead of 240V? This might be a useful power conditioner - what do people think?
WIll probably post this accross in Power Supplies section
Last post should have been to rha61!
Good work, eld - let us know how the mods work out!
I have just heard of some fully working APC UPS (uninterruptible Power Supplies) boxes being disposed of and I wondered if they could be easily modified to provide 120V output instead of 240V? This might be a useful power conditioner - what do people think?
WIll probably post this accross in Power Supplies section
eld said:
Originally posted by ChuckT
Thank you very much, ChuckT! Are there any values you would recommend? I was thinking of going as large as I can within the space constraint.
Jkeny,
If you can easily modified the APC UPS to run at 120V and function also as a power conditioner that would be awesome.
Will keep you posted on any mods.
Thank you very much, ChuckT! Are there any values you would recommend? I was thinking of going as large as I can within the space constraint.
Jkeny,
If you can easily modified the APC UPS to run at 120V and function also as a power conditioner that would be awesome.
Will keep you posted on any mods.
Panasonic FC & FM are rated as excellent low ESR caps at very good prices! Are Oscons made in smd size?
I have tried both FC & Fk and I would say Rubycon ZL & ZA are better.
The spec on ZL & ZA are better too.
For the price of the panny, don't expect them to use really high grade cap, even if their marketing say so.
Use Oscon around the digital chips, they are very good, that's why they are use in top end video cards.
The spec on ZL & ZA are better too.
For the price of the panny, don't expect them to use really high grade cap, even if their marketing say so.
Use Oscon around the digital chips, they are very good, that's why they are use in top end video cards.
Thanks Chuckt,
I will try & get some Rubycon's. Did you add Oscons on all the PS lines of the digital chips?
I'm about to order the SA-XR59 from an on-line supplier - it will probably take 3-4 days. I have 10 days to see if it suits my speakers. I will take some photos of the innards even if I'm not going to keep it. One thing I noticed about the spec for the XR59 is that it specifies 125W per channel so maybe this model is using a different TI chip?
Thinking about these amps, some areas that would most likely show the best return from modifications are:
- the clock or clock recovery stage - I think these amps use a PLL clock recovery scheme - I don't know if anybody has looked at this - I guess adding Oscons to the PS bypass may help! Has anybody checked into this area?
- The PS - external conditioners, beefing up the Capacitance & improving the wiring are possible improvements - moving to battery DC supply to ouput stage would be excellent but then difficult to retain PS vol control.
- The output stage is probably the most sensitive to mods, The PS, ouput inductors & caps are all critical. I know Panasonic make some excellent output inductors & wonder if these are in this amp? Anybody tried changing these?
Bypassing or changing the output caps might reap benefits!
One thing that always worried me when I looked at photos of the innards is that all the toroid inductors are parrallel & close together. I always thought that this would lead to channel cross-talk (I think I read that the crosstalk was 55dB). Would it be physically possible to remove each odd inductor & reposition it under the board? Has anybody tried it - is it worth it.
My idea with modding this amp would be to do one channel only & compare!
I will try & get some Rubycon's. Did you add Oscons on all the PS lines of the digital chips?
I'm about to order the SA-XR59 from an on-line supplier - it will probably take 3-4 days. I have 10 days to see if it suits my speakers. I will take some photos of the innards even if I'm not going to keep it. One thing I noticed about the spec for the XR59 is that it specifies 125W per channel so maybe this model is using a different TI chip?
Thinking about these amps, some areas that would most likely show the best return from modifications are:
- the clock or clock recovery stage - I think these amps use a PLL clock recovery scheme - I don't know if anybody has looked at this - I guess adding Oscons to the PS bypass may help! Has anybody checked into this area?
- The PS - external conditioners, beefing up the Capacitance & improving the wiring are possible improvements - moving to battery DC supply to ouput stage would be excellent but then difficult to retain PS vol control.
- The output stage is probably the most sensitive to mods, The PS, ouput inductors & caps are all critical. I know Panasonic make some excellent output inductors & wonder if these are in this amp? Anybody tried changing these?
Bypassing or changing the output caps might reap benefits!
One thing that always worried me when I looked at photos of the innards is that all the toroid inductors are parrallel & close together. I always thought that this would lead to channel cross-talk (I think I read that the crosstalk was 55dB). Would it be physically possible to remove each odd inductor & reposition it under the board? Has anybody tried it - is it worth it.
My idea with modding this amp would be to do one channel only & compare!
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