I know the DVD963SA, the modded "Van Medevoort" version, and it doesn't even come close to my '67. I have a DVD763SA myself and modded the filter, analog stage and PSU. It got better, but no-where near my '67. These are not even cheapo's. Most of those players have crappy DAC's and switch-mode PSU's, and clock distribution is horrible. But for some people lots of jitter sounds very pleasant. Just my $ 0.02 😀.
Regards,
Ray.
CD 67 HDAM bypass
Hi,
It seems to me that if I bypass the HDAM by removing the jumpers U216/7 and connecting direct from there to the output sockets I also take the muting and DC blocking sections out in the process and save a lot of desoldering.
Is there anything else I need to beware of if I do this?
Pete
Hi,
It seems to me that if I bypass the HDAM by removing the jumpers U216/7 and connecting direct from there to the output sockets I also take the muting and DC blocking sections out in the process and save a lot of desoldering.
Is there anything else I need to beware of if I do this?
Pete
I think Naim do a nice DVD player with a lovely toroidal based psu. However, at that price I feel it defeats the object!
Seriously though, for nearly ten years I've professionally worked on DVB STBs, which are essentially DVD players with tuners and/or HDD instead of the transport.
Having seen the schematics of platforms I've worked on, and having sometimes had to rework software so that a few pennies can be saved removing a single component at times to drive down costs (do you think they'll splash out on black gates?) I can assure you that these mass consumer products are not well built.
The really cheap ones use the onchip dac in the main DVD chip. Nice.
I totally agree that the 21st century is all about mass production and maximised profits.
Seriously though, for nearly ten years I've professionally worked on DVB STBs, which are essentially DVD players with tuners and/or HDD instead of the transport.
Having seen the schematics of platforms I've worked on, and having sometimes had to rework software so that a few pennies can be saved removing a single component at times to drive down costs (do you think they'll splash out on black gates?) I can assure you that these mass consumer products are not well built.
The really cheap ones use the onchip dac in the main DVD chip. Nice.
I totally agree that the 21st century is all about mass production and maximised profits.
Re: CD 67 HDAM bypass
Also remove the 12v feed to the HDAM thus removing any noise from this circuit polluting the 12v which the op amps uses. Also just cut away the 4 muting transistors and R659 and R660.
Brent
Chivvyp said:
Also remove the 12v feed to the HDAM thus removing any noise from this circuit polluting the 12v which the op amps uses. Also just cut away the 4 muting transistors and R659 and R660.
Brent
Talking about transformers ...
Some important transformer properties to us CDP-mothers are regulation, common mode noise rejection and the stray magnetic field.
Toroidal transformers posses as a function of their fysical design only a small stray magnetic field. This is helpfull when components or wires are within a few cm so they won't be coupled to the 50Hz (60Hz) pulsating magnetic field. The coupling effect keeps regulators busy and might manifest in audible hum, depending on the affected circuit.
'Old' style transformers can have better common mode noise rejection than torroids while parasitic capacitance between primary and secundairy is small by supplying two seperate wound coils. Better rejection against voltage spikes, noise and HF-pollution is noticable in the end quality of the DC. This is only important to circuits depending on the PSU-quality (clock, discrete out).
Regulation is the voltage alternation occuring when the load changes while the mains voltage is held constant. This property can be expressed in percents as the difference between the full load and the no load secundary voltage, divided by the no load secondary voltage and multiplied by 100.
Although the current drawn by the DAC, Servo and Clock is quite small (100mA?, someone?) this property might explain audible differences among transformers (CD63 vs CD63ki) with regards to dynamics. You must understand dynamics are important to the perceived 'naturalness' of the reproduction.
Every cycle loading the reservoir capacitor the transformer is cut of and connected twice. Applying Schottky diodes reduces the switch current but larger caps automaticaly lead to larger currents (especially low ESR type). Larger currents mean a larger load to the transformer...
Jaap
Some important transformer properties to us CDP-mothers are regulation, common mode noise rejection and the stray magnetic field.
Toroidal transformers posses as a function of their fysical design only a small stray magnetic field. This is helpfull when components or wires are within a few cm so they won't be coupled to the 50Hz (60Hz) pulsating magnetic field. The coupling effect keeps regulators busy and might manifest in audible hum, depending on the affected circuit.
'Old' style transformers can have better common mode noise rejection than torroids while parasitic capacitance between primary and secundairy is small by supplying two seperate wound coils. Better rejection against voltage spikes, noise and HF-pollution is noticable in the end quality of the DC. This is only important to circuits depending on the PSU-quality (clock, discrete out).
Regulation is the voltage alternation occuring when the load changes while the mains voltage is held constant. This property can be expressed in percents as the difference between the full load and the no load secundary voltage, divided by the no load secondary voltage and multiplied by 100.
Although the current drawn by the DAC, Servo and Clock is quite small (100mA?, someone?) this property might explain audible differences among transformers (CD63 vs CD63ki) with regards to dynamics. You must understand dynamics are important to the perceived 'naturalness' of the reproduction.
Every cycle loading the reservoir capacitor the transformer is cut of and connected twice. Applying Schottky diodes reduces the switch current but larger caps automaticaly lead to larger currents (especially low ESR type). Larger currents mean a larger load to the transformer...
Jaap
Some reference material for newbies
Hi Folks,
In my search for some background understanding of the technical discussions in this thread (and not to look like a fool when asking simple - and what to some may seem stupid - questions), I have come across a link that may help some newbies like myself decipher some of the posts and gain a little technical knowledge (a requirement to get the most benefit from this thread) in the process.
To the untrained eye it looks like a handy reference to have and maybe one of the more senior techs can give it a review to see if it can be of use to others.
http://sound.westhost.com/articles.htm
Hope this is of some assistance.
Cheers
Justin
PS This is off topic I know but I found some terminals that looks similar to that used on some Kimber speaker cables at the link below so if anyone is building up the TNT U-Byte speaker cable it may be helpful.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=292&CFID=2621439&CFTOKEN=68549184
Hi Folks,
In my search for some background understanding of the technical discussions in this thread (and not to look like a fool when asking simple - and what to some may seem stupid - questions), I have come across a link that may help some newbies like myself decipher some of the posts and gain a little technical knowledge (a requirement to get the most benefit from this thread) in the process.
To the untrained eye it looks like a handy reference to have and maybe one of the more senior techs can give it a review to see if it can be of use to others.
http://sound.westhost.com/articles.htm
Hope this is of some assistance.
Cheers
Justin
PS This is off topic I know but I found some terminals that looks similar to that used on some Kimber speaker cables at the link below so if anyone is building up the TNT U-Byte speaker cable it may be helpful.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=292&CFID=2621439&CFTOKEN=68549184
Re: Some reference material for newbies
There is some handy and useful info on that web site.
And yes Kimber do use WTB connectors
Brent
JustIN8 said:
There is some handy and useful info on that web site.
And yes Kimber do use WTB connectors
Brent
I found this low cost clock upgrade while surfing the net. What do you all think?? Here is the pricing.
3ppm crystal with PCB $37 10ppm $22
�PCB + all parts 3ppm $45 10ppm $30
diy clock upgrade
It looks as though you simply add a transformer and your done, total cost would be around $50! It seems much less expensive than many of the clock upgrades Ive seen and the parts quality looks to be pretty good. What do you guys think I was thinking of trying one in the cd53 i just picked up. Any opinions, what do you guys think?
3ppm crystal with PCB $37 10ppm $22
�PCB + all parts 3ppm $45 10ppm $30
diy clock upgrade
It looks as though you simply add a transformer and your done, total cost would be around $50! It seems much less expensive than many of the clock upgrades Ive seen and the parts quality looks to be pretty good. What do you guys think I was thinking of trying one in the cd53 i just picked up. Any opinions, what do you guys think?
Re: Some reference material for newbies
Justin,
When you intend to learn more about electronics this might be a good start. On the other hand highscool physics is enough to understand a voltage results from a current running through resistance.
I have the idea some new readers are shy trying to do some research of their own (reading datasheets and the Service Manual). Parts as 'Servo', 'HF Amp' etc are spoken of frequently and their function should be clear before mixing in a discussion about improving their operation. A good source might be Grant Ericksons paper on the technical aspects of the CDplayer.
Regards, Jaap
JustIN8 said:
Justin,
When you intend to learn more about electronics this might be a good start. On the other hand highscool physics is enough to understand a voltage results from a current running through resistance.
I have the idea some new readers are shy trying to do some research of their own (reading datasheets and the Service Manual). Parts as 'Servo', 'HF Amp' etc are spoken of frequently and their function should be clear before mixing in a discussion about improving their operation. A good source might be Grant Ericksons paper on the technical aspects of the CDplayer.
Regards, Jaap
imperfectcircle said:
I think the LM317T has a RMS outpout Noise far greater than 0.003% at 100KHz 😀
But seriously, give the $45 set a try. It's much cheaper than the $250 Tent Clock.
Regards, Jaap
Re: Re: Some reference material for newbies
Hi Jaap,
Thanks for the links. The Grant Erickson paper is great for people like me who have heard many of the terms used in this forum but not put them into context. 😀
Thanks also to Brent for his input. 🙂
Cheers
Justin
disco said:
Hi Jaap,
Thanks for the links. The Grant Erickson paper is great for people like me who have heard many of the terms used in this forum but not put them into context. 😀
Thanks also to Brent for his input. 🙂
Cheers
Justin
Very true, but it should still be far better than the stock clock circuit?? what about power for this clock, do I just need a small tranny with a 12v secondary? The regulator couild always be upgraded with a LT317 or even a super reg?
imperfectcircle said:
What clock are you referring to? 😕
The clock upgrades I know consist of a small PCB carrying a high precision crystal and a dedicated voltage regulator / current source. In Europe these sell for $100 - $125. For best results they are powered from any clean DC source within certain limits, not shared with 'noisy' circuits.
Jaap
disco said:
You can get a superclock for not alot more on ebay!!
And you are guaranteed a good clock.
Just a thought
Brent
rowemeister said:
I guess you ment that $45 clock Brent?
The high price for the Tent is with its 230-15V supply (overrated, I know).
Regards, Jaap
NB You need luck when buying of Evilbay: sometimes you receive the goods offered, sometimes not, sometimes nothing at all
disco said:
I guess you ment that $45 clock Brent?
The high price for the Tent is with its 230-15V supply (overrated, I know).
Regards, Jaap
NB You need luck when buying of Evilbay: sometimes you receive the goods offered, sometimes not, sometimes nothing at all
I've had 100+ good experiences and one bad (but it was a cd, could've been worse) that I can remember.
Simon
pics coming 😉
I was talking about this clock
clock
It looks as though the smaller pcb is the clock circuit and the larger is the power supply. According to the schematic the rectifier and regulator is on the power supply board so you just need a raw 12v from a tranny? Am i looking at this correctly?
thanks
Frank
clock
It looks as though the smaller pcb is the clock circuit and the larger is the power supply. According to the schematic the rectifier and regulator is on the power supply board so you just need a raw 12v from a tranny? Am i looking at this correctly?
thanks
Frank
imperfectcircle said:
I think so, at least that's how I see it at a glance.
It looks very nicely done with the floating crystal section!
An externally hosted image should be here but it was not working when we last tested it.
Simon