6h5c said:
Hi avr,
Good one. I use a CD57 to compare my CD67SE-XXXL with.
Does the 63SE have an improved chassis, like the CD67SE?
Then I would say, use the SE for modding.
If there's no difference, use the standard for modding and the slightly better SE to compare it with. The PCB's are the same, and you're gonna take out all the parts anyway.
Regards,
Ray.
Hi Ray..
Yes it has, mainly a thicker baseplate. I think bluetag and bitumen are gonna do the job just nicely.
I just start unsolder the standard.
btw, ok picture
/avr
Hi all,
I tend to go for the multipcb offering:
Their toroid is 70mm dia. / 37mm height and specified with 35VA.
Even their 50VA toroid is only 75mm dia. / 38mm height (and probably only € 2-3 more)...
Right now, we are only using 27VA with our specifications. Should we change this?
OK, I'll ask for the additional costs.
Still, until now no one from the US seems to be interested...
Please forgive me when I come up with the voltage thing once again:
I understand that 17V AC secondaries turn into something around 23V DC
when you consider ripple and diode drop. But since we load the 200mA windings with only 35mA,
I would still expect the DC voltage to be higher:
A toroid this size has a regulation of 16% when unloaded.
How much of this regulation remains when it is only partially loaded?
(I have no idea...)
I tend to go for the multipcb offering:
Their toroid is 70mm dia. / 37mm height and specified with 35VA.
Even their 50VA toroid is only 75mm dia. / 38mm height (and probably only € 2-3 more)...
Right now, we are only using 27VA with our specifications. Should we change this?
6h5c said:
OK, I'll ask for the additional costs.
Still, until now no one from the US seems to be interested...
6h5c said:
Please forgive me when I come up with the voltage thing once again:
I understand that 17V AC secondaries turn into something around 23V DC
when you consider ripple and diode drop. But since we load the 200mA windings with only 35mA,
I would still expect the DC voltage to be higher:
A toroid this size has a regulation of 16% when unloaded.
How much of this regulation remains when it is only partially loaded?
(I have no idea...)
AVR300 - SE as the reference cd player. mmmm.
The SE has quite a lot of improvements over the standard player,
most caps around the dac ,op amps and Hdam are elna silmics and cerafine.
and the 4.7 ohm resistors are changed to 5% types on power rails etc.
The tx is also improved with better caps on psu
The hdam has copper shield and there is the chassis braise + extra damping plate on the bottom of player.
So you can use this as a reference or mod it. It will be easy to get the standard 63 past these levels by changing a few critical components, so I would change these bits on the SE and get bigger gains
I often do very simple mods (output caps , opamps , hdam , a few caps and resistors) to SE players and they become sooooo much better than the KI in standard form, infact you would think the SE was twice the price.
The SE has quite a lot of improvements over the standard player,
most caps around the dac ,op amps and Hdam are elna silmics and cerafine.
and the 4.7 ohm resistors are changed to 5% types on power rails etc.
The tx is also improved with better caps on psu
The hdam has copper shield and there is the chassis braise + extra damping plate on the bottom of player.
So you can use this as a reference or mod it. It will be easy to get the standard 63 past these levels by changing a few critical components, so I would change these bits on the SE and get bigger gains
I often do very simple mods (output caps , opamps , hdam , a few caps and resistors) to SE players and they become sooooo much better than the KI in standard form, infact you would think the SE was twice the price.
Michi124 said:Hi all,
I tend to go for the multipcb offering:
Their toroid is 70mm dia. / 37mm height and specified with 35VA.
Even their 50VA toroid is only 75mm dia. / 38mm height (and probably only € 2-3 more)...
Right now, we are only using 27VA with our specifications. Should we change this?
Please forgive me when I come up with the voltage thing once again:
I understand that 17V AC secondaries turn into something around 23V DC when you consider ripple and diode drop. But since we load the 200mA windings with only 35mA, I would still expect the DC voltage to be higher:
A toroid this size has a regulation of 16% when unloaded.
How much of this regulation remains when it is only partially loaded?
(I have no idea...)
Hi Michael,
This is the reason I pleaded for a smaller tranny in the first place, instead of a 50VA. As we don't really need the power, the voltages are going to be a bit higher. How much is going to be a guess.
Let's assume that if we load it with half the power, the regulation is going to be like 10%?? Then we would get 18.7VAC from the 17VAC winding. The peak value is 18.7*1.4142 = 26.4VDC. Minus two diode drops (1.4V) leaves 25VDC. But since there's always a load connected it's going to sag, and will probably say below 24VDC. It's a theoretical value, if your mains voltage is a bit higher, it could be above 24V, if you use smaller caps it will be lower.
Personally I don't have a problem with it, since my regulators can handle 35...40VDC input. We could tune the voltages down a bit to be sure. How do the others feel about this?
I don't think we should change the tranny to 35VA, since that will only make this effect worse. It's not a problem to have a slightly more capable core.
Regards,
Ray.
hi.
Bigger VA, Lower Off-load voltage =
Better Regulation = Better PSU
If a bigger VA toroid is available for a few cents more and it will fit, then this is the better option.
It does not matter whether discrete or 7805-type regulators are used, the whole idea of a psu is to provide a stable output voltage, regardless of the load conditions. The psu will not perform to its best if an inadequate Tx is used ( like the oem!!!)
The idea or replacing the Tx must be considered to be part of the rebuilding of the PSU section along with diodes, caps, pre-regulator if required etc.
For those worried about the offload voltage, you can always use an (extra) preregulator - it will NOT degrade performance.
Andy
PS Lower noise is a beneficial by-product of PSU regulation!
Bigger VA, Lower Off-load voltage =
Better Regulation = Better PSU
If a bigger VA toroid is available for a few cents more and it will fit, then this is the better option.
It does not matter whether discrete or 7805-type regulators are used, the whole idea of a psu is to provide a stable output voltage, regardless of the load conditions. The psu will not perform to its best if an inadequate Tx is used ( like the oem!!!)
The idea or replacing the Tx must be considered to be part of the rebuilding of the PSU section along with diodes, caps, pre-regulator if required etc.
For those worried about the offload voltage, you can always use an (extra) preregulator - it will NOT degrade performance.
Andy
PS Lower noise is a beneficial by-product of PSU regulation!
Ehm,
Guys...are you sure? The tranny is already oversized. A bigger tranny will have better regulation, but that's the off-load voltage compared to the FULL LOAD, which we won't be using. The difference in regulation between a 30VA and a 50VA is not that big. You must realize that if you make the windings even higher current, with the small load we draw from it, it will make the voltages even higher and more unpredictable. We really should stick with the configuration we have.
Regards,
Ray.
Guys...are you sure? The tranny is already oversized. A bigger tranny will have better regulation, but that's the off-load voltage compared to the FULL LOAD, which we won't be using. The difference in regulation between a 30VA and a 50VA is not that big. You must realize that if you make the windings even higher current, with the small load we draw from it, it will make the voltages even higher and more unpredictable. We really should stick with the configuration we have.
Regards,
Ray.
Simon . In Amps where there is a big current demand you are more right but the cdp only demand mA and therefore needs very little headroom.
The KI TX appears to have it about right interms of headroom.
Making a custom version of this seems to be the way to go, with extra windings for 5v circuits etc
The KI TX appears to have it about right interms of headroom.
Making a custom version of this seems to be the way to go, with extra windings for 5v circuits etc
Hi all,
Sorry for posting so late in this thread, only recently registered.
I've been modding my cd63 for a little over a year now, thanks to all on the forum for the help.
Basically the work consisted of:
Kwak clock
BB2107 opamps
silver mica caps and 0.1% resistances around output stage
upgrading of reservoir caps generally around the CDP
removed muting
removed output caps
deadsheeting and caulking of main board (I did this on a friends cd63, will do on mine soon)
etc, etc
I have had the chance to compare the cdp to a micromega stage 2, and was pleased to find them comparable, despite the micromega having a slight edge in the instrument seperation stakes.
Since then, and from this thread, I have bypassed the HDAM (though haven't completely disabled it yet, hope that will help too!) and added a regulator per power line on the DAC. I'm amazed by these two mods alone and can't wait for a rematch
I haven't done anything deliberate with the servo driver circuitry or around the decoder. Has anybody made any great improvements in this field?
Also, I haven't tried browndogs yet (the 2107 on paper is cracking, but perhaps not quite a 627), Is cost the main reason, or maybe lower bandwidth of the lesser opamp (can't remember what was recommended, was it the 2134?), the reason to use only one 627 per adaptor?
Anyway, thanks to you all for your help. Very much appreciated!
Cheers,
Phil
Sorry for posting so late in this thread, only recently registered.
I've been modding my cd63 for a little over a year now, thanks to all on the forum for the help.
Basically the work consisted of:
Kwak clock
BB2107 opamps
silver mica caps and 0.1% resistances around output stage
upgrading of reservoir caps generally around the CDP
removed muting
removed output caps
deadsheeting and caulking of main board (I did this on a friends cd63, will do on mine soon)
etc, etc
I have had the chance to compare the cdp to a micromega stage 2, and was pleased to find them comparable, despite the micromega having a slight edge in the instrument seperation stakes.
Since then, and from this thread, I have bypassed the HDAM (though haven't completely disabled it yet, hope that will help too!) and added a regulator per power line on the DAC. I'm amazed by these two mods alone and can't wait for a rematch
I haven't done anything deliberate with the servo driver circuitry or around the decoder. Has anybody made any great improvements in this field?
Also, I haven't tried browndogs yet (the 2107 on paper is cracking, but perhaps not quite a 627), Is cost the main reason, or maybe lower bandwidth of the lesser opamp (can't remember what was recommended, was it the 2134?), the reason to use only one 627 per adaptor?
Anyway, thanks to you all for your help. Very much appreciated!
Cheers,
Phil
Hi philpoole
I have also seperated the rails to the decoder, it as 2 digital 5v rails and one analogue rail.
There is an error you have to rectify on the 5v rail to the decoder as it is wired the wrong side of the 4.7 ohm resistor but the diagram shows otherwise. The track need cutting and wiring to correct place.
Use the output of the correct regs you already have powering the DAC and drop in some nice caps (I used 16V 470uf Black Gates).
You need to fully remove the HDAM from the signal and supply line, not sure what effect it will have but it certainly wont benefit you!!
Also with the muting and HDAM removed the only thing using the +/- 12V rails are the op amps. What I did was remove the 12v regs from their location and fit some Audiocom regs right next to the opamps. Doing this removes any noise being picked up on the rail from it winding across the pcb (IMHO).
You can see here http://www.diyaudio.com/forums/showthread.php?s=&threadid=54009&perpage=10&pagenumber=22
I have also fitted bigger caps around servo etc, I did this so there is always enough juice if needed.
The next mod for me is to upgrade the components in the HF amp stage to the decoder.
I have browndog pcbs with OPA132 and OPA627 and previously had OPA2134 fitted. The 2134 was brilliant especially for the cost but the new browndog combo is utterly amazing.Save up and go for this combo much more air and openness.
Also before I stop ranting on..... change the diodes in the unit to HexFRED's or schottky
I have also seperated the rails to the decoder, it as 2 digital 5v rails and one analogue rail.
There is an error you have to rectify on the 5v rail to the decoder as it is wired the wrong side of the 4.7 ohm resistor but the diagram shows otherwise. The track need cutting and wiring to correct place.
Use the output of the correct regs you already have powering the DAC and drop in some nice caps (I used 16V 470uf Black Gates).
You need to fully remove the HDAM from the signal and supply line, not sure what effect it will have but it certainly wont benefit you!!
Also with the muting and HDAM removed the only thing using the +/- 12V rails are the op amps. What I did was remove the 12v regs from their location and fit some Audiocom regs right next to the opamps. Doing this removes any noise being picked up on the rail from it winding across the pcb (IMHO).
You can see here http://www.diyaudio.com/forums/showthread.php?s=&threadid=54009&perpage=10&pagenumber=22
I have also fitted bigger caps around servo etc, I did this so there is always enough juice if needed.
The next mod for me is to upgrade the components in the HF amp stage to the decoder.
I have browndog pcbs with OPA132 and OPA627 and previously had OPA2134 fitted. The 2134 was brilliant especially for the cost but the new browndog combo is utterly amazing.Save up and go for this combo much more air and openness.
Also before I stop ranting on..... change the diodes in the unit to HexFRED's or schottky
Or.....try a tubestage!
Whooohoooo!!!!!
SOUNDSTAGE!
DYNAMICS!
EMOTION!
....MUSIC!
No opamp can compete with this. I even dare to say that it sounds more....ANALOG
.
This is the first attempt to get Thorstens Delta-Sigma circuit working and see what it does. So I mostly built it out of components I had laying around (especially notice the ugly blue ceramic suppression caps, since I didn't have 100n film caps...).
Ray.
Whooohoooo!!!!!
SOUNDSTAGE!
DYNAMICS!
EMOTION!
....MUSIC!
No opamp can compete with this. I even dare to say that it sounds more....ANALOG
.This is the first attempt to get Thorstens Delta-Sigma circuit working and see what it does. So I mostly built it out of components I had laying around (especially notice the ugly blue ceramic suppression caps, since I didn't have 100n film caps...
).Ray.
