Hi Everyone,
I have been tweaking the CD63KI – replaced all electrolytics, acouctica clock hack, lead damping on base and lid, shielded and earthed main processor chip and installed switch to kill display (courtesy of Martin at acoustica).
I have decided now is the time to add a new clock. The main suspects being:-
Audiocom clock being advertised on e-bay for £54
A Net Audio Clock MKII
Guido’s XO-2
Elso’s DIY clock
LCAudio
Audiocom - not a favourite company of mine.
Net Audio - looks good and would fit neatly inside the CD63; I would want to keep the board on the main PCB so I get the main board out without having to disconnect the clock board.
Guido - looks good and I like the fact that it has more than one output. Also have e-mailed Guido a few times and found him very willing to help the novice DIYer, although he will not supply kits.
Elso's - would be happy to have ago at his clock but I don’t have access to a scope, which I assume you would need to tune the crystal. Also there has been mention of a version 8. Wouldn’t make sense to make a version 7 now.
LC Audio - very professional looking but too expensive.
Views on the above would be welcome although it seems you end up having to “suck it and see”.
More importantly what would advice be for the power supply. Does anyone have a schematic for a straightforward supply you could use with any of the above clocks.
Elso suggests that the players own digital supply is best. I would intend to use this to start with; however there seems to be differing views on the best place to take the supply from.
Can anyone give me a definite answer. Do I take it from the 7812 reg at the back of the player or the 7805 in the middle. Elso says take the feed from the Digital supply which I think would mean the 7812 (+12v).
Last but not least, op amps. The choice is so bewildering. Once tried some Bur Brown’s in a CD80 (based on advioce from Audiocom) and was very disappointed. The LM6172 seems to be a favourite, although it needs careful bypassing. Loads of various Analogue Devices, although the AD8065 seems to stick out.
Have been recommended the following as a cost effective alternative. It’s the Elantec EL2244, a symmetrical video op amp, which you can get from Farnell for about five pounds each. Here’s the data sheet http://www.intersil.com/data/fn/fn7059.pdf
Apologies for the war and peace, but I would appreciate any views the forum might have.
I have been tweaking the CD63KI – replaced all electrolytics, acouctica clock hack, lead damping on base and lid, shielded and earthed main processor chip and installed switch to kill display (courtesy of Martin at acoustica).
I have decided now is the time to add a new clock. The main suspects being:-
Audiocom clock being advertised on e-bay for £54
A Net Audio Clock MKII
Guido’s XO-2
Elso’s DIY clock
LCAudio
Audiocom - not a favourite company of mine.
Net Audio - looks good and would fit neatly inside the CD63; I would want to keep the board on the main PCB so I get the main board out without having to disconnect the clock board.
Guido - looks good and I like the fact that it has more than one output. Also have e-mailed Guido a few times and found him very willing to help the novice DIYer, although he will not supply kits.
Elso's - would be happy to have ago at his clock but I don’t have access to a scope, which I assume you would need to tune the crystal. Also there has been mention of a version 8. Wouldn’t make sense to make a version 7 now.
LC Audio - very professional looking but too expensive.
Views on the above would be welcome although it seems you end up having to “suck it and see”.
More importantly what would advice be for the power supply. Does anyone have a schematic for a straightforward supply you could use with any of the above clocks.
Elso suggests that the players own digital supply is best. I would intend to use this to start with; however there seems to be differing views on the best place to take the supply from.
Can anyone give me a definite answer. Do I take it from the 7812 reg at the back of the player or the 7805 in the middle. Elso says take the feed from the Digital supply which I think would mean the 7812 (+12v).
Last but not least, op amps. The choice is so bewildering. Once tried some Bur Brown’s in a CD80 (based on advioce from Audiocom) and was very disappointed. The LM6172 seems to be a favourite, although it needs careful bypassing. Loads of various Analogue Devices, although the AD8065 seems to stick out.
Have been recommended the following as a cost effective alternative. It’s the Elantec EL2244, a symmetrical video op amp, which you can get from Farnell for about five pounds each. Here’s the data sheet http://www.intersil.com/data/fn/fn7059.pdf
Apologies for the war and peace, but I would appreciate any views the forum might have.
The digital supply is the 7805 in the middle. The 7812 is the supply for the opamps and the HDAM = analogue supply.
The "digital" supply also feeds the analogue supplies of the DAC and servo etc.
You could also use the +10V just below the 7805 and add a regulator from there.
Look at the Acoustica site for more on this...
If I would be you, I'd take the time to measure the 10k and 27k resistors before the opamp (and put 1% 120p caps ) and see if each balanced input is matched. If you match the values within 0,1% it will be a big difference, especially if they are like 1-2% matched now.
I made the Acoustica clock mod and when adding an LCClock2, there wasn't any big difference.
Believe you get more response if you clean up the 5V and the 12V supplies and check what to do over at the servo and motor side. There's obviously a lot of noise coming in to the 5V from there...
Cheers,
Tom
The "digital" supply also feeds the analogue supplies of the DAC and servo etc.
You could also use the +10V just below the 7805 and add a regulator from there.
Look at the Acoustica site for more on this...
If I would be you, I'd take the time to measure the 10k and 27k resistors before the opamp (and put 1% 120p caps ) and see if each balanced input is matched. If you match the values within 0,1% it will be a big difference, especially if they are like 1-2% matched now.
I made the Acoustica clock mod and when adding an LCClock2, there wasn't any big difference.
Believe you get more response if you clean up the 5V and the 12V supplies and check what to do over at the servo and motor side. There's obviously a lot of noise coming in to the 5V from there...
Cheers,
Tom
Tom.
Thanks for the info re which reg to use.
I'll definitely check out the op amp situation.
On supplies, do I take it that I would be better off adding a separate supply for digital and analogue, maybe in a separate box.
I've read that some have not got much improvement from adding a new clock after doing the the acoustica hack but surely it comes to a point where you’ve exhausted everything else and all that's left is to put a better clock in. I appreciate its the law of diminishing returns but as someone put it you could spend a lot more on just a mains or interconnect cable and not get much return.
I think I fall into that category of DIYer where a little knowledge can be very dangerous for the health. I can follow a schematic and use a soldering iron and meter but guessing at values is out of my league.
Thanks agian.
Thanks for the info re which reg to use.
I'll definitely check out the op amp situation.
On supplies, do I take it that I would be better off adding a separate supply for digital and analogue, maybe in a separate box.
I've read that some have not got much improvement from adding a new clock after doing the the acoustica hack but surely it comes to a point where you’ve exhausted everything else and all that's left is to put a better clock in. I appreciate its the law of diminishing returns but as someone put it you could spend a lot more on just a mains or interconnect cable and not get much return.
I think I fall into that category of DIYer where a little knowledge can be very dangerous for the health. I can follow a schematic and use a soldering iron and meter but guessing at values is out of my league.
Thanks agian.
Hi there - got your last email but lost it in a disc meltdown! Sorry for non-reply.
Others here will give you many opinions on opamps to use, but AD8620s are very, very good in this application. Whatever you chose, be sure to add local bypass caps across the pins - say 0.047 or 0.1uF ceramic types. The opamps are exposed to a lot of HF digital noise from the DAC (which has raw PWM output) so such bypass is critical to stability with fast opamps.
The 5v digital line is *very* noisy. Tap off the ~10.5V raw supply to the 7805 and use that to feed local (digital) regulators when required. A good idea is to add separate 5v regs to feed the DAC. The 5842 DAC has three 5v supplies, for the output stage, digital filter and oscillator gate stages. Feeding these from three separate regulators is thoroughly worthwhile. You can even do the same thing for the 7345 decoder if you really want - it has 'analogue' and 'digital' supply pins which can be fed separately. The decoder doesn't affect sound but here it distributes the clock signals to other parts of the player.
Oh, and don't use the analogue-side 7812 to feed digital circuits (including a new clock) - the digital noise will appear on the analogue side through the common impedance of the ground planes, even if your regulation was perfect.
Others here will give you many opinions on opamps to use, but AD8620s are very, very good in this application. Whatever you chose, be sure to add local bypass caps across the pins - say 0.047 or 0.1uF ceramic types. The opamps are exposed to a lot of HF digital noise from the DAC (which has raw PWM output) so such bypass is critical to stability with fast opamps.
The 5v digital line is *very* noisy. Tap off the ~10.5V raw supply to the 7805 and use that to feed local (digital) regulators when required. A good idea is to add separate 5v regs to feed the DAC. The 5842 DAC has three 5v supplies, for the output stage, digital filter and oscillator gate stages. Feeding these from three separate regulators is thoroughly worthwhile. You can even do the same thing for the 7345 decoder if you really want - it has 'analogue' and 'digital' supply pins which can be fed separately. The decoder doesn't affect sound but here it distributes the clock signals to other parts of the player.
Oh, and don't use the analogue-side 7812 to feed digital circuits (including a new clock) - the digital noise will appear on the analogue side through the common impedance of the ground planes, even if your regulation was perfect.
Thanks Martin, feel better that you weren't ignoring me.
By the way what wer your thoughts of using the 470uf Silmic to replace CD04 (which I have located in over CD05 as per instructions). I wasn't convinced to start with but now the sound seems to have clicked into placed. Could the the larger value cause any problems down the line.
I note the power supply hack on your site but was slightly confused in that the photo of the regulator included several resistors and a couple of caps. Is it simply a case of adding the requisite regulator to the supply track for the DAC and using a resistor to ground to draw sufficient current or do I need to make the fancy regulator in the photo.
I'd thought about the decoder and whether to give it its own supply and also whether anyone has fed it with a "clean" clock signal.
Does anyone have a regulated supply for cd clocks etc.
Gordon
By the way what wer your thoughts of using the 470uf Silmic to replace CD04 (which I have located in over CD05 as per instructions). I wasn't convinced to start with but now the sound seems to have clicked into placed. Could the the larger value cause any problems down the line.
I note the power supply hack on your site but was slightly confused in that the photo of the regulator included several resistors and a couple of caps. Is it simply a case of adding the requisite regulator to the supply track for the DAC and using a resistor to ground to draw sufficient current or do I need to make the fancy regulator in the photo.
I'd thought about the decoder and whether to give it its own supply and also whether anyone has fed it with a "clean" clock signal.
Does anyone have a regulated supply for cd clocks etc.
Gordon
Biskit said:
Hi Biskit
If the clock of your choice has its own reg, I'd suggest a small transformers, some nice Schotkky barier diodes and a decent lytic, as a front end power supply for the clock (make sure it is being switched of simultaneously with the IC the clock is feeding)
However, if the clock doesn't improve the situation when fed from one of the players' supplies, I wouldn't invest more in an additional supply
succes
Thanks Guido, I was hoping you’d join the fray.
Informative as ever and wise words. I think I've got to try the clock as it will always nag at the back of my mind what I am missing and is another one to tick off the list of the seemingly endless tweaks you can do.
For what its worth I have also damped the underside of the tray and mechanism wherever possible with clear resin. I wanted something that was more in tune with the plastic, if that makes sense. I also used the resin to fill the original feet.
I am lucky in that I have another 63 that I can practise on, I mullered that one having exploded a cap or two. But it’s useful for spares and trying out tweaks.
I would highly recommend Martin's tweak for the display. I managed to get a switch, which fitted the headphone socket. Looks good and the wife and kids can switch it back on easily. I also remove most of the gold lettering form the front
Gordon
Informative as ever and wise words. I think I've got to try the clock as it will always nag at the back of my mind what I am missing and is another one to tick off the list of the seemingly endless tweaks you can do.
For what its worth I have also damped the underside of the tray and mechanism wherever possible with clear resin. I wanted something that was more in tune with the plastic, if that makes sense. I also used the resin to fill the original feet.
I am lucky in that I have another 63 that I can practise on, I mullered that one having exploded a cap or two. But it’s useful for spares and trying out tweaks.
I would highly recommend Martin's tweak for the display. I managed to get a switch, which fitted the headphone socket. Looks good and the wife and kids can switch it back on easily. I also remove most of the gold lettering form the front
Gordon
The regulator in the photo was an LM317T, set to give 5V. The 317s have significantly better performance than a basic 7805. If you do this, you'll need to cut the track that supplies the power presently and insert your new supply, or the new and existing regs will be connected together...
A small separate supply for any clock is a nice bonus, as Guido has pointed out. However it does need to startup at the same time, or ahead of the main digital supply. Therwise you'll find the disc motor spinning up / out of control, which happens when the decoder is missing the clock signal.
The 470uF cap will cause no problems long term BTW.
A small separate supply for any clock is a nice bonus, as Guido has pointed out. However it does need to startup at the same time, or ahead of the main digital supply. Therwise you'll find the disc motor spinning up / out of control, which happens when the decoder is missing the clock signal.
The 470uF cap will cause no problems long term BTW.
James,
I'm going to have to appear thick here (no change some would say), good job I benefit from thick skin.
Thing is, however many times I go over it I'm still not 100% what the connections are to attach the +5 volt supply for the DAC.
Rather than make an idiot of myself trying to explain how I understand it could you possibly give me a simple A-B explanation. Apologies if this is teaching granny to suck eggs.
Gordon
I'm going to have to appear thick here (no change some would say), good job I benefit from thick skin.
Thing is, however many times I go over it I'm still not 100% what the connections are to attach the +5 volt supply for the DAC.
Rather than make an idiot of myself trying to explain how I understand it could you possibly give me a simple A-B explanation. Apologies if this is teaching granny to suck eggs.
Gordon
Tom,
Yes I have the schematic.
The thing I was on about was the new 5v supply for the DAC mentioned on the acoustica site.
Quote from site: "If you can, use build separate regulator to feed DAC pin 27; then use a bulk electrolytic of your choice (>100uF) over the position of CD05 together with the capacitor added above and remove RD01 and connect in your new local supply - ferrite beads at this point are recommended. You can take your raw voltage feed from the +10v rail feeding the main 5v regulator on the board (the one wearing the small heatsink near the transformer); or as we did, add a separate DC-in socket to the main case for a separate external supply and future expansion.....but that's a different story. If you use a 7805 or one of the better replacements (LT1086 or LM317AT offer lower noise etc) you'll need a small resistor on the output of your new regulator to ground - 500ohm or so - to draw at least 10mA, or regulation is not guaranteed; the clock gate itself draws a mere 3mA. The modified circuit digram shows where to connect the new supply".
The question was intended to get a more laymans explanation.
Gordon
Yes I have the schematic.
The thing I was on about was the new 5v supply for the DAC mentioned on the acoustica site.
Quote from site: "If you can, use build separate regulator to feed DAC pin 27; then use a bulk electrolytic of your choice (>100uF) over the position of CD05 together with the capacitor added above and remove RD01 and connect in your new local supply - ferrite beads at this point are recommended. You can take your raw voltage feed from the +10v rail feeding the main 5v regulator on the board (the one wearing the small heatsink near the transformer); or as we did, add a separate DC-in socket to the main case for a separate external supply and future expansion.....but that's a different story. If you use a 7805 or one of the better replacements (LT1086 or LM317AT offer lower noise etc) you'll need a small resistor on the output of your new regulator to ground - 500ohm or so - to draw at least 10mA, or regulation is not guaranteed; the clock gate itself draws a mere 3mA. The modified circuit digram shows where to connect the new supply".
The question was intended to get a more laymans explanation.
Gordon
Okay, to break it down a little further:
Use your multimeter to check the pins on the regulator in the middle of the player, the one with the heatsink. Relative to the ground plane you'll find one pin at 0v, one at +5V (output) and one at about +10v. You can, with care, connect to this +10v pin to get a raw feed for your new digital regulator(s).
If you check out how the leads are arranged for the powersupply to the DAC , you can find the links that feed +5v to the supply pins. So you can cut the links, and inject 'clean' 5V from your new regulator(s) to these pins directly. You'll need the NPC5872 dac datasheet, or the service manual to help (drop me an email and I can forward the datasheet).
All regulators perform better when loaded down a bit. This matters because some of the Dac supply pins only draw 1 or 2mA. We can't load the new regs heavily though, because the basic supply is only so big... hence suggestion to use a resistor to draw 10 or 15mA from the new regulators.
Finally, you can use an entirely separate supply to feed your new regulators (that's the reference to an offboard PSU) if you wish. I did for a while, but it's more hassle, doesn't add anything (if your regulators are any good!) and gave a noticeable 'warm up effect' - the player would take 10-15 minutes to come on song evey time . This was probably down to the quick lash-up implementation I did, but also why I didn't report further or recommend it on the webpage you found.
Hope this helps,
M.
Use your multimeter to check the pins on the regulator in the middle of the player, the one with the heatsink. Relative to the ground plane you'll find one pin at 0v, one at +5V (output) and one at about +10v. You can, with care, connect to this +10v pin to get a raw feed for your new digital regulator(s).
If you check out how the leads are arranged for the powersupply to the DAC , you can find the links that feed +5v to the supply pins. So you can cut the links, and inject 'clean' 5V from your new regulator(s) to these pins directly. You'll need the NPC5872 dac datasheet, or the service manual to help (drop me an email and I can forward the datasheet).
All regulators perform better when loaded down a bit. This matters because some of the Dac supply pins only draw 1 or 2mA. We can't load the new regs heavily though, because the basic supply is only so big... hence suggestion to use a resistor to draw 10 or 15mA from the new regulators.
Finally, you can use an entirely separate supply to feed your new regulators (that's the reference to an offboard PSU) if you wish. I did for a while, but it's more hassle, doesn't add anything (if your regulators are any good!) and gave a noticeable 'warm up effect' - the player would take 10-15 minutes to come on song evey time . This was probably down to the quick lash-up implementation I did, but also why I didn't report further or recommend it on the webpage you found.
Hope this helps,
M.
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