As far as I can tell, there is a third divider on this board for the audio clock into the Philips SAA7893HL SACD chip at pin 29. Taking a quick look at the manual, it may be storing the DSD and audio data in a nearby (opposite side of the processor board) 64mbit sdram module, and pulling the data at the needed times. The divider and the memory sdram are beside eachother, and the tech manual seems to indicate that this NEW DESIGN, second generation SACD multi-process capable chip can take a variety of clocking frequencies and dividers.. so maybe the PLL is not needed? It may just use the master 27mhz clock?
The chip usage block diagram shows a PLL, but there is none that I can see on the Pioneer board. there is apparently a possible spot for it, as the silkscreened numbers on the board itself seems to indicate it (the Pioneer processor board) is an other Pioneer models as well, like the 565 and 566 (if they even exist).
Not knowing anything about all this modern Digital Stuff I will ponder out loud: ....Also, since it is SACD/DVD-A/CD all in one chip.. it may be doing a upsample-process-DAC-downsample trick of some sort, and may not need or use the expected clock frequencies. At least the CD 44.1k and DVD-A 96k stuff may be upsampled, is what I mean,and then fed to the BB1791 at upsampled levels. Why bother with any other configuration?
Philips SACD SAA7893HL tech manual
The chip usage block diagram shows a PLL, but there is none that I can see on the Pioneer board. there is apparently a possible spot for it, as the silkscreened numbers on the board itself seems to indicate it (the Pioneer processor board) is an other Pioneer models as well, like the 565 and 566 (if they even exist).
Not knowing anything about all this modern Digital Stuff I will ponder out loud: ....Also, since it is SACD/DVD-A/CD all in one chip.. it may be doing a upsample-process-DAC-downsample trick of some sort, and may not need or use the expected clock frequencies. At least the CD 44.1k and DVD-A 96k stuff may be upsampled, is what I mean,and then fed to the BB1791 at upsampled levels. Why bother with any other configuration?
Philips SACD SAA7893HL tech manual
KBK said:
Correct me if I am wrong here, but all I see is the 27MHz circuit, and it splits to feed 27MHz into IC701 (SACD IC) and 27MHz intoIC601 (back end IC). I believe that any freq. dividing needed is done inside these chips. All the clocking info used by the DACs is sent to them by IC701. And based on what I see on the schematics, there is NO DSD to PCM conversion. The L/R DAC is IC201, labeled DSD1791, and it inputs DSD or a PCM signal (depending on the format being played). IC601 outputs the SPDIF, along with video output signals.
In terms of clock jitter, like it was mentioned above, I think this is pretty much limited by IC701 and IC601's internal PLLs and such. I'm not sure how much improvement would come about if a really precise 27MHz clock was installed.
Also, I don't see where to beef up the power supply feeding the 27MHz clock circuit. The supply is V+3D, and for the 27MHz signal feeding IC601, it goes through L604 and then directly into pin 8 of the hex inverter type IC (used for buffering I believe). For the signal feeding IC701, the V+3D goes through L606 in a similar fashion to pin 8a different hex inverter IC (only one buffer is used on this IC). Did you add a cap from the pin 8;s of these ICs to GND to make this supply more stable?
Konnichiwa,
I have amused myself extensively with Chip Datasheets. Interesting. Can anyone who has the unit and ideally service manual check if the SAA SACD Chip is used to oversample all PCM to a DSD Datastream and to reclock or if PCM runs on a simple "passtrough"?
If the formaer, you can simply pick up the SACD Datastreams prior to the DAC Chip's for all signals and send them through a basic Bufferamp/Filter. This reputedly sounds pretty good (see Allan Wright) though I was underwhelmed by a machine modified in similar manner, for whatever reasons.
Secondly, for all europeans, the differences bewteen the 563 and 565 seem cosmetic, I have found several references suggesting that the 565 uses the same chipset as the 563 and I would guess mostly identical PCB's too... So all mods should translate well.
Sayonara
I have amused myself extensively with Chip Datasheets. Interesting. Can anyone who has the unit and ideally service manual check if the SAA SACD Chip is used to oversample all PCM to a DSD Datastream and to reclock or if PCM runs on a simple "passtrough"?
If the formaer, you can simply pick up the SACD Datastreams prior to the DAC Chip's for all signals and send them through a basic Bufferamp/Filter. This reputedly sounds pretty good (see Allan Wright) though I was underwhelmed by a machine modified in similar manner, for whatever reasons.
Secondly, for all europeans, the differences bewteen the 563 and 565 seem cosmetic, I have found several references suggesting that the 565 uses the same chipset as the 563 and I would guess mostly identical PCB's too... So all mods should translate well.
Sayonara
I could very much use that schematic myself, although at this point is is nearly not needed at all.
BTW, I have done my proprietary clock mod and the SACD chip responds as well as a regular 44.1 CD unit to such ministrations. It does indeed improve the machine dramatically when it comes to harshness and overall coherency. Before anyone asks, I cannot share it. I do apologize. After the patent is applied for, feel free. I will share then.
BTW, I have done my proprietary clock mod and the SACD chip responds as well as a regular 44.1 CD unit to such ministrations. It does indeed improve the machine dramatically when it comes to harshness and overall coherency. Before anyone asks, I cannot share it. I do apologize. After the patent is applied for, feel free. I will share then.
Re: Re: Re: Yes, me toos.
Gee, do I detect some rudeness?
I was just trying to confirm what it exactly was that you did, for my and everyone elses benefit (if they are interested). Unless I am misinterpreting your intentions, you seem to be a little edgy. Are you working in a well ventilated area?
Getting back on track here, I just ordered a pair of Black Gate NX Hi-Q non-polarized caps (6.3V, 47uF) to replace the stock electrolytic output coupling caps. I've done the same thing a while back on a Sony NS500V and noticed a nice improvement in bass control. Has anyone else swapped out these caps with something else? I have to measure how much DC bias is before the cap to see if it can be completely bypassed. There is also a 200 ohm resistor in series with the output after the cap (used for the muting transistor circuit). I have bypassed these before in my DV-45A but got annoying popping sounds when opening/closing the door and changing tracks, and the 45A uses the same muting topology. A better solution would be using a relay instead of the muting transistors. I may do this, but I want to work on other things first that will probably yield a better improvement.
Regards,
Vinnie
KBK said:
Gee, do I detect some rudeness?
I was just trying to confirm what it exactly was that you did, for my and everyone elses benefit (if they are interested). Unless I am misinterpreting your intentions, you seem to be a little edgy. Are you working in a well ventilated area?
Getting back on track here, I just ordered a pair of Black Gate NX Hi-Q non-polarized caps (6.3V, 47uF) to replace the stock electrolytic output coupling caps. I've done the same thing a while back on a Sony NS500V and noticed a nice improvement in bass control. Has anyone else swapped out these caps with something else? I have to measure how much DC bias is before the cap to see if it can be completely bypassed. There is also a 200 ohm resistor in series with the output after the cap (used for the muting transistor circuit). I have bypassed these before in my DV-45A but got annoying popping sounds when opening/closing the door and changing tracks, and the 45A uses the same muting topology. A better solution would be using a relay instead of the muting transistors. I may do this, but I want to work on other things first that will probably yield a better improvement.
Regards,
Vinnie
KBK said:There was no rudness intended. None at all. Humor was the desired effect. I'm just not good at remembering to put smilies in my posts. I saw that this was probably the wisest course to follow for the BB DACs, and that thought came when I read your post again. that's all.
No problem, that's the thing with communication over chat forums. It's hard to get a reading on what people may be feeling because you don't hear their tone of voice. Anyway, I shouldn't give you a hard time because you are working on that clock tweak patent and I want to learn about it when the time comes
I just ordered a bunch of Panasonic FC electrolytics that I will use on the power supply along with the audio out board. I should finally be able to start tweaking next week. I've been listening to this player stock and getting a feel for its sound, and to be honest, it isn't bad at all
I don't find it to be that harsh, it has plenty of detail, bass is okay (needs to be tightened somewhat, but isn't that bad), and vocals are pretty good sounding too. I look forward to trying different tweaks and letting everyone know the results. This player definitely has a lot of potential. Did anyone check out: http://www.aplhifi.com/Pioneer563a.html
-Vinnie
KBK said:Now that I've properly created friction and then kissed and made up, can I have copy of that manual too?
Well, I guess
When I get home tonight, I'll start scanning and will email it.
-Vinnie
Vinnie, et al.:
I one instance, I replaced the coupling caps at the outputs of the op amps with Black Gates as you suggest, removed the muting transistors, and removed the filter caps around the op amps.
I'm not so sure this was an improvement. And, frankly, I'm not sure wasn't worse. My "Why" follows. First, and I'm speaking generally to all the mods I've done on players, the coupling caps probably helped. Nothing I would call earth shattering; but, they help. Second, removing muting transistors helps, and moreso than the coupling caps just mentioned, at least to my ears. When they're are not driven, they act like caps that are modulated by the music. Removal eliminates this. So, frankly I can't see either of these things making the sound worse. As to the filter, generally removing such filters has helped. However, in this case, I'm not so sure. Frankly, I think I come down with the filters being necessary. Perhaps, this is all the HF in there? But, I was playing redbook, so who knows.
In isolation from the above mods, and on an otherwise stock player, I installed an IEC power socket recently, eliminating the wimpy little fuse on the power supply board in the process. This changed things; but, again, I'm not so sure for the better. Seems to allow adjustment of the width of the soundstage with different power cords. I think I preferred the way things were in my system.
I also poked around with eliminating the output coupling caps mentioned above. Due to the single supply for the op amps, I don't think it is possible. There is always dc voltage at the outputs. And I tried messing with the voltage ref., eliminating the voltage ref, and referencing the op amps to various pins on the dacs. All in all, a no go. Any ideas here?
So, where's that leave us? Perhaps, tx coulping.
I one instance, I replaced the coupling caps at the outputs of the op amps with Black Gates as you suggest, removed the muting transistors, and removed the filter caps around the op amps.
I'm not so sure this was an improvement. And, frankly, I'm not sure wasn't worse. My "Why" follows. First, and I'm speaking generally to all the mods I've done on players, the coupling caps probably helped. Nothing I would call earth shattering; but, they help. Second, removing muting transistors helps, and moreso than the coupling caps just mentioned, at least to my ears. When they're are not driven, they act like caps that are modulated by the music. Removal eliminates this. So, frankly I can't see either of these things making the sound worse. As to the filter, generally removing such filters has helped. However, in this case, I'm not so sure. Frankly, I think I come down with the filters being necessary. Perhaps, this is all the HF in there? But, I was playing redbook, so who knows.
In isolation from the above mods, and on an otherwise stock player, I installed an IEC power socket recently, eliminating the wimpy little fuse on the power supply board in the process. This changed things; but, again, I'm not so sure for the better. Seems to allow adjustment of the width of the soundstage with different power cords. I think I preferred the way things were in my system.
I also poked around with eliminating the output coupling caps mentioned above. Due to the single supply for the op amps, I don't think it is possible. There is always dc voltage at the outputs. And I tried messing with the voltage ref., eliminating the voltage ref, and referencing the op amps to various pins on the dacs. All in all, a no go. Any ideas here?
So, where's that leave us? Perhaps, tx coulping.
larry moore said:
Hi Larry,
I think to get away with not using Vref, you need to use a +/-12V supply instead of the +12V and GND supply that is in there. Doing things this way should reduce the DC on the output.
For now I am going to leave the Vref circuit alone and just replace the output caps with the BG's. I've done this with a NS500V and the improvement was definitely noticeable and worth it.
As far as removing the muting transistors, if you do this, you can also remove the 220 ohm resistors that are in series with the signal path which are used to bias the transistors. I have bypassed these resistors and muting transisors on my DV-45A in the past, but get pops when pressing eject, and skipping tracks and such. Besides that, the sound quality did improve as well. A better approach that I might implement will be using a high quality reed-relay instead. Sure, you get a relay in the signal path, but thats better than the 220 ohm resistors. A lower output impedance is best.
I was also planning on installing an IEC connector, but before I even do that I plan to install a 1uF 275V X2 rated cap across the mains on the input. There already is a 0.1uF X2 cap in there, but I find that not to be enough. These switching power supplies really dump a lot of hash back out of the player onto the mains. The cap is $3.25 on digikey (part number P10530-ND). I will also replace the large 250V 82uF electrolytic after the diode bridge with a 250V 150uF Panasonic FC cap, and probably bypass that with an Auricap. This cap smooths the DC that gets 'chopped up' by the switching power supply. One may ask, then why bother? Well, the switcher addes noise no doubt, but it is at a different frequency. It's worth a try and isn't expensive.
BTW, the opamps are Rohm BA4560's (dual opamp IC). Has anyone tried or is considering replacing them. Maybe with a
burr-brown OPA2604??? I am going to leave them alone for now, but may revisit this in the future. The stock opamps aren't that bad to me.
I should get parts in next week and then I'll start modding. I will report my findings of each tweak (doing one tweak at a time).
Konnichiwa,
First thanks to Vinnie for sending me the scans from the manual. I am still looking at Universal players to use as "Mod" Platform and the mostly identical 565 is high on my list. Here is what I noticed on the 563 Schamtics.
The first thing I was looking for was the SACD Decoder chip.
Now this has theoretically the option to "upsample" any PCM input to DSD. This would allow us to simply take a pair of inverter buffer C-MOS Gates per signal to geterate a differential signal we can lowpassfiler (LC) and apply to an Output Transformer (all channels).
However, this function is strictly under software control, for anyone who own the 563 or 565, is there a hidden menu that allows you to switch this upsampling option on? Otherwise it would require a firmware update, a bit beyound my abilities I'm afraid....
Moving forward from the SACD IC, the "B.E. LSI" IC is clearly a "DVD-Player on a Chip" and seems to generate all clocks etc. from the 27MHz main clock, except the SACD clock which goes direct to the SACD Chip. This mean the PSU noise on this chip will affect the clock precision for DVD-Audio & CD, maybe the reasons for the sometimes noted less than stellar performance of this box with PCM Audio. An Upgrade of the 27MHz will improve SACD Playback and MAY improve CD/DVD-A playback, but I think more milage for CD/DVD-A is in cleaning up the B.E. LSI Ic supplies.
Moving on to the DAC's. They are all pretty dire, by todays standards, consumer Junk, especially LFE/Center & Rear Channels. Luckily all clock and data lines can be tapped, so one could engineer a "daughterboard" 6-Channel DAC using anything one likes really, including non-oversampling or just better oversampling Chips for PCM and LC lowpass filters for SACD plus a suitable switching logic.
Replacing the Analog Stage Op-Amp's is an obvious choise, the AD8620 would seem the hottests ticket in town for the job and comes in a suitable SMD Case. The signle rail nature of the circuit means you need to deal with coupling Capacitors and the capacitors on the "voltage reference" Pins, maybe BG N/Nx Types would work, or polarised ones like Elna Silmic, or if there is enough space Film Cap's, following the formula of 47/Rload (in KOhm) = C (in uF).
The L/R DAC offers a differential Output of 3.2V P-P @ 0dbfs which is around 5db below the normal CD/DVD-A 0dbfs Level, the outputs are load tolreant to around 3K4 differential. This means that as long as the load does not get lower than 10k you could use a 1:2 Audio Transformer directly attached to the DAC as sole output stage, getting an output slightly above the usual 0dbfs levels. The surround sound channels cannot be treated thusly though as they have DC offset single ended outputs and low output levels and definitley need post-amps.
The switching supply is pretty basic, I'd think an external Liear Supply with 12V, 6V & 3.3V plus -28V (Display Anode Voltage) and the Display Heater Voltage (not stated, needs to measured, often around 2V) might be a good idea. The 12V, 6V & 3.3V can be generated from one 12V+12V torroid with suitable regulators, the display heater winding could be handwound on the same winding and the -28V could be generated by a voltage doubler.
You then apply these voltages to the actual supply filter cap's on the SMPS Board (to keep all switching logic in place during powerup) and simply do not power the SMPS Input. Using a 6-Pole lockable plug/socket the external linear PSU can be made optional, with the actual SMPS remaining fully functional if used. The whole linear PSU could be build into a "Seismik Sink" support for the player and also inlcude optional added supply voltages for analog stages and clock.
Such things as mechanical re-inforcement of the Chassis (ideally with Spruce solid- or ply-wood), the rounding off or PCB corners and C37 Lacquering PCB's address other performance areas (obviously) but have their own rewards as well.
Sayonara
First thanks to Vinnie for sending me the scans from the manual. I am still looking at Universal players to use as "Mod" Platform and the mostly identical 565 is high on my list. Here is what I noticed on the 563 Schamtics.
The first thing I was looking for was the SACD Decoder chip.
Now this has theoretically the option to "upsample" any PCM input to DSD. This would allow us to simply take a pair of inverter buffer C-MOS Gates per signal to geterate a differential signal we can lowpassfiler (LC) and apply to an Output Transformer (all channels).
However, this function is strictly under software control, for anyone who own the 563 or 565, is there a hidden menu that allows you to switch this upsampling option on? Otherwise it would require a firmware update, a bit beyound my abilities I'm afraid....
Moving forward from the SACD IC, the "B.E. LSI" IC is clearly a "DVD-Player on a Chip" and seems to generate all clocks etc. from the 27MHz main clock, except the SACD clock which goes direct to the SACD Chip. This mean the PSU noise on this chip will affect the clock precision for DVD-Audio & CD, maybe the reasons for the sometimes noted less than stellar performance of this box with PCM Audio. An Upgrade of the 27MHz will improve SACD Playback and MAY improve CD/DVD-A playback, but I think more milage for CD/DVD-A is in cleaning up the B.E. LSI Ic supplies.
Moving on to the DAC's. They are all pretty dire, by todays standards, consumer Junk, especially LFE/Center & Rear Channels. Luckily all clock and data lines can be tapped, so one could engineer a "daughterboard" 6-Channel DAC using anything one likes really, including non-oversampling or just better oversampling Chips for PCM and LC lowpass filters for SACD plus a suitable switching logic.
Replacing the Analog Stage Op-Amp's is an obvious choise, the AD8620 would seem the hottests ticket in town for the job and comes in a suitable SMD Case. The signle rail nature of the circuit means you need to deal with coupling Capacitors and the capacitors on the "voltage reference" Pins, maybe BG N/Nx Types would work, or polarised ones like Elna Silmic, or if there is enough space Film Cap's, following the formula of 47/Rload (in KOhm) = C (in uF).
The L/R DAC offers a differential Output of 3.2V P-P @ 0dbfs which is around 5db below the normal CD/DVD-A 0dbfs Level, the outputs are load tolreant to around 3K4 differential. This means that as long as the load does not get lower than 10k you could use a 1:2 Audio Transformer directly attached to the DAC as sole output stage, getting an output slightly above the usual 0dbfs levels. The surround sound channels cannot be treated thusly though as they have DC offset single ended outputs and low output levels and definitley need post-amps.
The switching supply is pretty basic, I'd think an external Liear Supply with 12V, 6V & 3.3V plus -28V (Display Anode Voltage) and the Display Heater Voltage (not stated, needs to measured, often around 2V) might be a good idea. The 12V, 6V & 3.3V can be generated from one 12V+12V torroid with suitable regulators, the display heater winding could be handwound on the same winding and the -28V could be generated by a voltage doubler.
You then apply these voltages to the actual supply filter cap's on the SMPS Board (to keep all switching logic in place during powerup) and simply do not power the SMPS Input. Using a 6-Pole lockable plug/socket the external linear PSU can be made optional, with the actual SMPS remaining fully functional if used. The whole linear PSU could be build into a "Seismik Sink" support for the player and also inlcude optional added supply voltages for analog stages and clock.
Such things as mechanical re-inforcement of the Chassis (ideally with Spruce solid- or ply-wood), the rounding off or PCB corners and C37 Lacquering PCB's address other performance areas (obviously) but have their own rewards as well.
Sayonara
Please could you briefly explain what benefits this would have to a PC motherboard? I mentioned it to a friend who's very interested in overclocking and performance, and he believes it is stupid to change caps, if they perform adaquately already. Please educate usKBK said:
(Sorry its off-topic)
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.