You may know that is not only the increasing of capacity of the filtering caps important when is to improve filtering of a switching PSU. The caps it may have very low ESI/ESR, paralleled with very good low capacity (film/ceramics) capas, short or not at all terminals (SMD types), and some other precautions to minimise the HF noises out of that PSU. I will recommend to use many smaller capacities caps (right working tension) paralleled to get the desired capacity on the output of that PSU. If you parallel f. ex. 5 - 10 caps to get a 1000µF on output, it will be more effective filtering than using one 1000µF cap... And it could be enough only that 1000µF... There is not necessary to replace the original caps, but only add some more...
There is not a benefit for that type PSU to have very big capacities on its outputs. This it may increase quite much the start up currents, and may block or even damage the PSU. A rational balance in this area is recommended.
If you own a 93 model, then you may pay attention to the +/- 15v too. I will recommend to try to find an analogue solution to deliver these tensions, which it will be used in analogue stages/opamps of the player. There is not about important currents here, so a such analogue PSU for +/-15v it may be quite small. In such case you need a transformer, with synchronized start up with the rest of the player...
There is not a benefit for that type PSU to have very big capacities on its outputs. This it may increase quite much the start up currents, and may block or even damage the PSU. A rational balance in this area is recommended.
If you own a 93 model, then you may pay attention to the +/- 15v too. I will recommend to try to find an analogue solution to deliver these tensions, which it will be used in analogue stages/opamps of the player. There is not about important currents here, so a such analogue PSU for +/-15v it may be quite small. In such case you need a transformer, with synchronized start up with the rest of the player...
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Yes, you can!
I think you have already a relay into the switching PSU of the player. So, if you will connect your (toroid) transformer primary just after that relay, which it connect 220v AC to the PSU, than you have done it.
If one use a quite powerful toroid transformer, than the clue is to have it connected all the time to the main, and place a relay to connect (on device power on) its AC secondary to the rectifiers/regulators. In this way one may prevent the start-up important current spikes of a toroid... A fuse it may be placed in primary (but you have such already in that PSU...).
You can use quite large capacities for the analogue stage. Here is not any problem if the caps take large currents on start up. The transformer will limit that current anyway. You can use few tens thousands µF just/only after the rectifier bridges (before regulators). I have 33000µF on -/+15v. It is a matter of place this... The same rule: many paralleled caps is better, than one big.
I think you have already a relay into the switching PSU of the player. So, if you will connect your (toroid) transformer primary just after that relay, which it connect 220v AC to the PSU, than you have done it.
If one use a quite powerful toroid transformer, than the clue is to have it connected all the time to the main, and place a relay to connect (on device power on) its AC secondary to the rectifiers/regulators. In this way one may prevent the start-up important current spikes of a toroid... A fuse it may be placed in primary (but you have such already in that PSU...).
You can use quite large capacities for the analogue stage. Here is not any problem if the caps take large currents on start up. The transformer will limit that current anyway. You can use few tens thousands µF just/only after the rectifier bridges (before regulators). I have 33000µF on -/+15v. It is a matter of place this... The same rule: many paralleled caps is better, than one big.
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An Earth Question
Is it ok to add an Earth connection to audio parts that have no earth connection?
I had crackles on the sound from a HD Dvd player.I ran the ground part of the hdmi cable across the chassis of my Denon 3808(No earth cable).
There were sparks.I measured the voltage between the hdmi ground and the Denon chassis and it came up 110v AC.
But no sparks or voltage from the hdmi from the BDP93.I will check the freesat box later.
Any help would be appreciated.
Thanks
Smiffy
Is it ok to add an Earth connection to audio parts that have no earth connection?
I had crackles on the sound from a HD Dvd player.I ran the ground part of the hdmi cable across the chassis of my Denon 3808(No earth cable).
There were sparks.I measured the voltage between the hdmi ground and the Denon chassis and it came up 110v AC.
But no sparks or voltage from the hdmi from the BDP93.I will check the freesat box later.
Any help would be appreciated.
Thanks
Smiffy
If you are measuring 110V AC - sounds scary.
Generally speaking, If part of an audio system is not 'mains' grounded, it often gets grounded any by the cables that connects the system together, by the interconnects etc. There are not too many exceptions. I have often seen grounds removed or isolated so as not to ground it directly to mains earth, to sort out hum loops. This especially when using phono/turntables, but can also happen when only line stage signals are involved.
From my way of understanding, disconnecting a ground is a legal question too, or a grey area, yet many do it. But adding a ground, at least that should be legal, as it means you are at least touching metal/chassis that is grounded and that can surely be considered 'safe'. Must be a 'mains' ground.
Anyone else have an opinion on this, I would be interested.
Cheers, Joe
PS: I have seen small sparks connecting HDMI cables. Not sure why.
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WRT grounding I recommend Rod Elliot's very informative web page
Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
There is absolutely *NO* reason not to have safety ground capacity on
a device even whilst avoiding earth loops. Refer to diag with 35A bridge rectifier.
The rectifier connected as such will have a peak fault current capacity of many
hundreds of amps, yet still leave the device floating.
The standards these days are pretty tough WRT earth connection lugs. Last full
time design job I had we were using copper plated / welded studs to chassis.
Back in diy land, what Rod has shown is a very effective and practical
solution.
cheers
T
Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
There is absolutely *NO* reason not to have safety ground capacity on
a device even whilst avoiding earth loops. Refer to diag with 35A bridge rectifier.
The rectifier connected as such will have a peak fault current capacity of many
hundreds of amps, yet still leave the device floating.
The standards these days are pretty tough WRT earth connection lugs. Last full
time design job I had we were using copper plated / welded studs to chassis.
Back in diy land, what Rod has shown is a very effective and practical
solution.
cheers
T
Thanks for the help Joe and Zenelecto.An good artice from Rod Elliot.
I measured the freesat box.99 volts ac.I remember years ago I had a JVC S video recorder.
I use to get shocks when I touched the JVC chassis and the radiator together,I measured it and it was 134v ac.Yikes.
In terms of earth would the radiator pipe be ok or would a 4 ft copper pipe driven into the earth outside be better?
Ta for any help.I think i'll make a star earth unit.
Smiffy
I measured the freesat box.99 volts ac.I remember years ago I had a JVC S video recorder.
I use to get shocks when I touched the JVC chassis and the radiator together,I measured it and it was 134v ac.Yikes.
In terms of earth would the radiator pipe be ok or would a 4 ft copper pipe driven into the earth outside be better?
Ta for any help.I think i'll make a star earth unit.
Smiffy
Hello,
I have to connect two card in my 93.
A CBC Lab 3D map I2S to exit EBU (XLR) and the other a USB card (native DSD).
For I2S is good but for the USB I need you.
On the analog board, there are specific to different signals.
I need: DSD Flag (DSD-1 PCM-0); MCLK, PCM & DSD BCLK; PCM LRCLK/DSD SDATA 1 and PCM SDATA/DSD SDATA2.
The names used by OPPO are different.
If someone can help me?
In advance thank you, Johann.
I have to connect two card in my 93.
A CBC Lab 3D map I2S to exit EBU (XLR) and the other a USB card (native DSD).
For I2S is good but for the USB I need you.
On the analog board, there are specific to different signals.
I need: DSD Flag (DSD-1 PCM-0); MCLK, PCM & DSD BCLK; PCM LRCLK/DSD SDATA 1 and PCM SDATA/DSD SDATA2.
The names used by OPPO are different.
If someone can help me?
In advance thank you, Johann.
An externally hosted image should be here but it was not working when we last tested it.
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My suggestion is to get a licensed electrician to check the ground consistency in your house from each individual AC outlet back to the main switchboard. Also, make sure the ground is connected to the neutral properly.
You can also do few checks while waiting for the electrical checks to be finilised:
- Interconnects shield consistency
- Check grounding inside the equipment
- Check if the PCB ground (inside an individual unit / component) is AC or DC coupled to the chassis.
Nick
Smiffy, I would have your mains checked as a matter of urgency.
The only safe and reliable (and get out of jail free when something does go wrong) is a direct metal to metal link to protective earth, anything else is dangerous and may be illegal depending on your country.
Removing the earth connection from any earthed equipment is illegal in most country's is dangerous, life risking and STUPID.
This one area of DIY that is best left alone cos most don't really know what they are doing.
Some reading matter:
http://www.celectronics.com/seminar/sample/IEEE11-9-05.pdf
The only safe and reliable (and get out of jail free when something does go wrong) is a direct metal to metal link to protective earth, anything else is dangerous and may be illegal depending on your country.
Removing the earth connection from any earthed equipment is illegal in most country's is dangerous, life risking and STUPID.
This one area of DIY that is best left alone cos most don't really know what they are doing.
Some reading matter:
http://www.celectronics.com/seminar/sample/IEEE11-9-05.pdf
Thanks Nick
I will check the bits.I have an electrician coming round soon the replace the main fusebox for a more up to date one with circuit breakers.I have also pluuged into all the sockets a mains tester which checks they are all wired correctly and no earth is missing or earth is swapped with Neutral etc.
All check fine.
Smiffy
It will not be a dramatic improvement, but this it should be done (in the factory actually...). The metal parts of the transport bay are not grounded as default, and this is not a very proof approach I may say...
You can just solder a wire on the edge of that plate and connect the wire to a ground somewhere near. There are some screws around which are a good grounding...
Just read this as I think you have a very common error in your home regardless of where you are living this an often occurring phenomenon.
If you have devices that need Safety Ground/PE and they are plugged in a wall outlet that has no PE contact then the caps and resistors that are in the switched PSU for leading RF/garbage to Ground are "hanging in the air" so the voltage at the metal chassis/case to which they're connected as well is approx. half the mains voltage (voltage divider).
Now if you touch something that IS connected to Safety Ground/PE then you will be awake very fast as you are the "part" that makes the circuit... Please reread to understand exactly what is going on. Think of a resistor from L to PE and a resistor from N to PE. Now disconnect the connection of their middle point from PE. Indeed, that is a voltage divider with half the mains voltage.
Just check if you have devices that need PE but are connected to a non PE socket... Any device that has a PE contact in the plug MUST be connected to a wall outlet that has a PE contact. Any disruption of the PE connection may lead to unwished shocks.
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Here is something interesting about the video aspect of these players if you are a videophile. Once you have done your mods and upgrades, try using HDMI 2 (Mediatek) instead of HDMI 1 (Marvel QDEO).
You may actually find the standard video processor is more natural, less artificial and less processed. A better picture all round than the Marvell.
My theory as to why this happens; with a standard player you have much noise throughout the digital part of the system, causing jitter in the data timing streams and clocks, which results in more grain and noise in the picture. So in this standard player, the extra processing of the Marvell QDEO improves things and helps the picture quality.
But once you get rid of the SMPS, start doing some clean power treatment, use a power conditioner, custom LPS e.t.c e.t.c then you will find the extra processing just gets in the way of the image quality and makes it worse.
It makes sense, the Marvell QDEO takes the data and reprocesses it after the Mediatek video output. Why not do it right first time (by using clean power and custom clocks) and avoid a second stage of manipulation?
Coris it would be cool if you or others could try this so I can be sure Im not imagining things, but I have done quite a few tests on an ISF calibrated full backlit LED Sony.
At first it may seem the HDMI 2 output is a bit softer, but what you are seeing is the image without Marvells sharpening and manipulation for the first time. Contrary to what some of the reviews may say, the Marvell QDEO has undefeatable processing applied to the image, even when all settings are set to 0 in the menu.
You may actually find the standard video processor is more natural, less artificial and less processed. A better picture all round than the Marvell.
My theory as to why this happens; with a standard player you have much noise throughout the digital part of the system, causing jitter in the data timing streams and clocks, which results in more grain and noise in the picture. So in this standard player, the extra processing of the Marvell QDEO improves things and helps the picture quality.
But once you get rid of the SMPS, start doing some clean power treatment, use a power conditioner, custom LPS e.t.c e.t.c then you will find the extra processing just gets in the way of the image quality and makes it worse.
It makes sense, the Marvell QDEO takes the data and reprocesses it after the Mediatek video output. Why not do it right first time (by using clean power and custom clocks) and avoid a second stage of manipulation?
Coris it would be cool if you or others could try this so I can be sure Im not imagining things, but I have done quite a few tests on an ISF calibrated full backlit LED Sony.
At first it may seem the HDMI 2 output is a bit softer, but what you are seeing is the image without Marvells sharpening and manipulation for the first time. Contrary to what some of the reviews may say, the Marvell QDEO has undefeatable processing applied to the image, even when all settings are set to 0 in the menu.
Your theory about video quality is quite interesting. It make also sense...
I never thought to try the so called inferior (low quality) HDMI output 2. But I will do it for sure.
After the necessary mods, one remark quite well the improvements in video (HDMI1), as in audio. I have connected the TV display as standard on HDMI1, and I use the another video out to drive a little monitor.
Oppo use now Darbeee on some of the last models, to even more "improve" the picture...
I have expressed already my opinion that Darbee is fully unnecessary for improvements, if they should take more care about the actual design, and do something more to lower the general noise in the device...
Someone may like the Darbee real time manipulation of the image, but I do not. I think is horrible, and it give an unreal picture...