Hi James 
Dear Dady, your email doesn't work for me...message rebounds.
It seems I won an oscilloscope, two channels, 60MHz bandwidth.
2012 will see my return to the fields
Best wishes to all.
M.
PS: the two Kingston SD cards I own are very annoying to work with...
I hope newer ones are more reliable...perhaps we will have to a Wiki with tips on SD cards...
Dear Dady, your email doesn't work for me...message rebounds.
It seems I won an oscilloscope, two channels, 60MHz bandwidth.
2012 will see my return to the fields
Best wishes to all.
M.
PS: the two Kingston SD cards I own are very annoying to work with...
I hope newer ones are more reliable...perhaps we will have to a Wiki with tips on SD cards...
PS: the two Kingston SD cards I own are very annoying to work with...
I hope newer ones are more reliable...perhaps we will have to a Wiki with tips on SD cards...
Kingston have given no trouble in my SD player; I've had to return a couple of Sandisk 16GB. I like the KomputerBay 32GB Class 10: Reliable so far, fast and cheap.
Perhaps if others are going to chip in we should start a new thread?
Thank you jonners,
I wonder if it is not a basic mistake I am making...even if I re-format them and record WAV 16b/44,1Khz files I get some problems like a high freq. sound on the middle of a track or not detecting the card at all... I will try to load them on another laptop.
Sorry for this little OT.
I wonder if it is not a basic mistake I am making...even if I re-format them and record WAV 16b/44,1Khz files I get some problems like a high freq. sound on the middle of a track or not detecting the card at all...
I will try to load them on another laptop.Sorry for this little OT.
hi studiostevus,
Voltage regulators have limited bandwidth, this means that output impedance is likely to rise above this bandwidth. The inductance of wiring between regulator and load is likely to further reduce effective bandwidth.
These effects can be compensated with a correctly dimensioned decoupling cap. If the decoupling cap value is too high or too low, bumps or dips are created in regulator output impedance. This in turn can lead to undesired effects in connected loads and can lead to different perceived sound quality.
The coupling cap properties are also important here, two caps with exactly the same value can still have different impedance properties.
I use large bandwidth voltage regulators with approx. 7 MHz bandwidth (LM78xx has around 10 KHz bandwidth), so decoupling cap values can be relatively low. This enables the use of film caps.
I made some mistakes in common mode capacitance multiplier and pre-regulator. Here I used 470uF decoupling caps, this value is too high of course, so I replaced these with 1uF film caps for now.
I use a sweep generator and a scope to check voltage regulator impedance between 10 Hz and 10 MHz. I connect the sweep generator (50 Ohm output impedance) to the regulator output using a 180R series resistor.
The scope is triggered by the sweep generator by connecting sync out with the scope external trigger input. The scope input is connected to the voltage regulator output.
The scope now displays a real-time scan of the regulator impedance over approx. 10 MHz bandwidth.
The decoupling cap was tuned for flattest frequency response and lowest ringing / overshoot. Fine tuning was done using listening tests.
The DEM decoupling caps are part of a RC filter (R is located inside the TDA1541A), here C will also determine filter response.
Compromise has to be chosen between maximum capacitor value and capacitor impedance at the DEM clock frequency that is used. The impedance of caps with larger value / size is likely to increase with increasing frequency.
The 1uF film decoupling caps I am using offer low impedance (small size / stacked film) and relatively high value (1uF).
The wiring between cap and TDA1541A DEM decoupling pins increases impedance and reduces filter efficiency. That's why I soldered the SMD film decoupling caps directly to the TDA1541A decoupling pins as close to the chip package as possible.
Voltage regulators have limited bandwidth, this means that output impedance is likely to rise above this bandwidth. The inductance of wiring between regulator and load is likely to further reduce effective bandwidth.
These effects can be compensated with a correctly dimensioned decoupling cap. If the decoupling cap value is too high or too low, bumps or dips are created in regulator output impedance. This in turn can lead to undesired effects in connected loads and can lead to different perceived sound quality.
The coupling cap properties are also important here, two caps with exactly the same value can still have different impedance properties.
I use large bandwidth voltage regulators with approx. 7 MHz bandwidth (LM78xx has around 10 KHz bandwidth), so decoupling cap values can be relatively low. This enables the use of film caps.
I made some mistakes in common mode capacitance multiplier and pre-regulator. Here I used 470uF decoupling caps, this value is too high of course, so I replaced these with 1uF film caps for now.
I use a sweep generator and a scope to check voltage regulator impedance between 10 Hz and 10 MHz. I connect the sweep generator (50 Ohm output impedance) to the regulator output using a 180R series resistor.
The scope is triggered by the sweep generator by connecting sync out with the scope external trigger input. The scope input is connected to the voltage regulator output.
The scope now displays a real-time scan of the regulator impedance over approx. 10 MHz bandwidth.
The decoupling cap was tuned for flattest frequency response and lowest ringing / overshoot. Fine tuning was done using listening tests.
The DEM decoupling caps are part of a RC filter (R is located inside the TDA1541A), here C will also determine filter response.
Compromise has to be chosen between maximum capacitor value and capacitor impedance at the DEM clock frequency that is used. The impedance of caps with larger value / size is likely to increase with increasing frequency.
The 1uF film decoupling caps I am using offer low impedance (small size / stacked film) and relatively high value (1uF).
The wiring between cap and TDA1541A DEM decoupling pins increases impedance and reduces filter efficiency. That's why I soldered the SMD film decoupling caps directly to the TDA1541A decoupling pins as close to the chip package as possible.
Hi maxlorenz,
When you are experiencing problems with SD-cards in SD-players, the card could have too low throughput (it is not able to provide sustained high data rate), or it is a fake SD-card.
Major brands are often copied, these fake cards cause a lot of problems. I have already tested some of these fake cards that looked almost identical to the original.
Original SD-cards from Kingston for example have (bar) codes printed on them that can be used to check (Kingston website) if the card is original.
I use 32GB (rating 4) Kingston SDHC cards that are assembled in Japan. These work excellent and offer room for up to 54 CDs in WAV.
I lost my brand new Hameg 1500-2 scope (it ceased functioning correctly after few times of use). Over two months after returning it for repair I was told by the dealer that it couldn't be repaired and this type is already taken out of production.
I also lost my older Hameg scope (loud bang in the power supply, resulting in a very bright, 1cm wide trace). It couldn't be repaired either.
So that basically left me without suitable analogue scope. I lost my confidence in new measuring instruments for now, so I bought a second hand Philips/Fluke PM3065 (2 x 100 MHz) scope on ebay and that one works fine.
When you are experiencing problems with SD-cards in SD-players, the card could have too low throughput (it is not able to provide sustained high data rate), or it is a fake SD-card.
Major brands are often copied, these fake cards cause a lot of problems. I have already tested some of these fake cards that looked almost identical to the original.
Original SD-cards from Kingston for example have (bar) codes printed on them that can be used to check (Kingston website) if the card is original.
I use 32GB (rating 4) Kingston SDHC cards that are assembled in Japan. These work excellent and offer room for up to 54 CDs in WAV.
I lost my brand new Hameg 1500-2 scope (it ceased functioning correctly after few times of use). Over two months after returning it for repair I was told by the dealer that it couldn't be repaired and this type is already taken out of production.
I also lost my older Hameg scope (loud bang in the power supply, resulting in a very bright, 1cm wide trace). It couldn't be repaired either.
So that basically left me without suitable analogue scope. I lost my confidence in new measuring instruments for now, so I bought a second hand Philips/Fluke PM3065 (2 x 100 MHz) scope on ebay and that one works fine.
Hi John, thanks for your elaborate reply.
Are you replacing all 470uF electrolytes with SMD film caps? So the only large cap is the 4700uF electrolyte....
-edit: just re-read...I gather that only the "last" cap is replaced (the decoupler)...
Could you share a picture of your power supply board?
I lack the equipment and, more importantly, the skills and knowledge to go as deep and thorough as you do on the design. I will just shut up and listen (and probably ask some questions as usual....)... this is all about the learning for me...
Thanks very much!
Are you replacing all 470uF electrolytes with SMD film caps? So the only large cap is the 4700uF electrolyte....
-edit: just re-read...I gather that only the "last" cap is replaced (the decoupler)...
Could you share a picture of your power supply board?
I lack the equipment and, more importantly, the skills and knowledge to go as deep and thorough as you do on the design. I will just shut up and listen (and probably ask some questions as usual....)... this is all about the learning for me...
Thanks very much!
Last edited:
I have my email on service
Dear Mauricio (Max Lorenz) my email is on service. Thanks for your salutations.
For the excelent team of this eminent forum.
Best Wishes for Christmas time and Happy New year.
Hi James
Dear Dady, your email doesn't work for me...message rebounds.
It seems I won an oscilloscope, two channels, 60MHz bandwidth.
2012 will see my return to the fields
Best wishes to all.
M.
PS: the two Kingston SD cards I own are very annoying to work with...
I hope newer ones are more reliable...perhaps we will have to a Wiki with tips on SD cards...
Dear Mauricio (Max Lorenz) my email is on service. Thanks for your salutations.
For the excelent team of this eminent forum.
Best Wishes for Christmas time and Happy New year.
Best Wishes to All on DIY Audio!
Although we see a lot of barbs traded and a few heated discussions from time to time, the spirit of giving and sharing is evident all over on this forum. Love, peace and joy are the messages of Christmas, and I hope it finds each of you at this time and in the New Year.
Merry Christmas, all the best in 2012!
Gary
Although we see a lot of barbs traded and a few heated discussions from time to time, the spirit of giving and sharing is evident all over on this forum. Love, peace and joy are the messages of Christmas, and I hope it finds each of you at this time and in the New Year.
Merry Christmas, all the best in 2012!
Gary
I am working on a shopping list to try your power supply concept.... 16v caps right after rectified 12v ??
Hi Ecd
Consider a smps power supply.
I still be some confused about the next,
first, De-emphasis, is there anyone who can explane what this mean?
second, In the data-sheet is stated that the system clock is X time Fs.
For example, the system clock is 22,5792 Mhz ( 512 Fs. Fs=44.1Khz).
But one can play cd's both with 44.1or 48 Khz data. Here is the point why I am confused. Because 512 x 48 Khz = 24.576 Mhz. Is there anyone who can explane?
Regards,
Zjaakco
Consider a smps power supply.
I still be some confused about the next,
first, De-emphasis, is there anyone who can explane what this mean?
second, In the data-sheet is stated that the system clock is X time Fs.
For example, the system clock is 22,5792 Mhz ( 512 Fs. Fs=44.1Khz).
But one can play cd's both with 44.1or 48 Khz data. Here is the point why I am confused. Because 512 x 48 Khz = 24.576 Mhz. Is there anyone who can explane?
Regards,
Zjaakco
Last edited:
Such a word .....leimotiv...
Richard Wagner
Hi Galeb,
Very good. Altruism is the leitmotiv of the next age.
Merry Christmas and wonderful audio newyear.
M.
Richard Wagner
Hi zjaakco,
It is already extremely difficult to design an ultra low noise linear power supply without switching noise and ripple produced by a SMPS.
The noise needs to be so low to ensure low masterclock jitter and prevent modulating the masterclock jitter spectrum with more noise. It is also required to minimize interference in the DAC and connected equipment.
In general the SMPS mains filter performance is very limited in order to save cost, so first the mains and all connected (audio) equipment get polluted with RF interference. Rf interference has no problems passing power supplies (stray capacitance) and safety earth.
So my personal tip, never ever use SMPS in or anywhere near high performance audio equipment.
De-emphasis - Wikipedia, the free encyclopedia
Emphasis was used in few early CD recordings, and is rather seldom.
The system clock is usually the highest clock frequency present in a (DAC) circuit.
system clock equals fs * oversampling factor * number of bits / frame * fixed factor.
fs equals the sample rate, the fixed factor is usually 1 but could also be a different number depending on clock distribution system and standard crystal frequencies.
So a CD player with 44.1 KHz sample rate, 8 times oversampling and 48 bits / frame would require 44,100 * 8 * 48 = 16.9344 MHz system clock. The system clock would be 16.9344 / 44,100 = 384fs.
NOS DAC running on 44.1 KHz and 64 bits / frame would require 44,100 * 1 * 64 = 2.8224 MHz system clock. The system clock would be 2.822,400 / 44,100 = 64fs.
Digital audio source with 44.1 Khz sample rate, 8 times oversampling and 64 bits / frame would require 44,100 * 8 * 64 = 22.579 MHz. The system clock would now be 22,579,000 / 41,100 = 512fs.
Digital audio source with 48 Khz sample rate, 8 times oversampling and 64 bits / frame would require 48,000 * 8 * 64 = 24.576 Mhz. The system clock would now be 24,576,000 / 48,000 = 512fs.
The amount of bits / frame determines the number of bits that can be processed. With 32 bits / frame 16 bits for L channel and 16 bits for R channel. With 48 bits / frame 24 bits for L channel and 24 bits for R channel, and with 64 bits / frame 32 bits for L channel and 32 bits for R channel.
SAA7220 digital filter for example uses 32 bits / frame, together with 4 times oversampling and 44.1 KHz sample rate. Required system clock would be 44,100 * 4 * 32 = 5.6448 MHz. But the SAA internal circuits require a higher system clock of 11.2896 MHz, this means the fixed factor is now 2.
It is already extremely difficult to design an ultra low noise linear power supply without switching noise and ripple produced by a SMPS.
The noise needs to be so low to ensure low masterclock jitter and prevent modulating the masterclock jitter spectrum with more noise. It is also required to minimize interference in the DAC and connected equipment.
In general the SMPS mains filter performance is very limited in order to save cost, so first the mains and all connected (audio) equipment get polluted with RF interference. Rf interference has no problems passing power supplies (stray capacitance) and safety earth.
So my personal tip, never ever use SMPS in or anywhere near high performance audio equipment.
De-emphasis - Wikipedia, the free encyclopedia
Emphasis was used in few early CD recordings, and is rather seldom.
The system clock is usually the highest clock frequency present in a (DAC) circuit.
system clock equals fs * oversampling factor * number of bits / frame * fixed factor.
fs equals the sample rate, the fixed factor is usually 1 but could also be a different number depending on clock distribution system and standard crystal frequencies.
So a CD player with 44.1 KHz sample rate, 8 times oversampling and 48 bits / frame would require 44,100 * 8 * 48 = 16.9344 MHz system clock. The system clock would be 16.9344 / 44,100 = 384fs.
NOS DAC running on 44.1 KHz and 64 bits / frame would require 44,100 * 1 * 64 = 2.8224 MHz system clock. The system clock would be 2.822,400 / 44,100 = 64fs.
Digital audio source with 44.1 Khz sample rate, 8 times oversampling and 64 bits / frame would require 44,100 * 8 * 64 = 22.579 MHz. The system clock would now be 22,579,000 / 41,100 = 512fs.
Digital audio source with 48 Khz sample rate, 8 times oversampling and 64 bits / frame would require 48,000 * 8 * 64 = 24.576 Mhz. The system clock would now be 24,576,000 / 48,000 = 512fs.
The amount of bits / frame determines the number of bits that can be processed. With 32 bits / frame 16 bits for L channel and 16 bits for R channel. With 48 bits / frame 24 bits for L channel and 24 bits for R channel, and with 64 bits / frame 32 bits for L channel and 32 bits for R channel.
SAA7220 digital filter for example uses 32 bits / frame, together with 4 times oversampling and 44.1 KHz sample rate. Required system clock would be 44,100 * 4 * 32 = 5.6448 MHz. But the SAA internal circuits require a higher system clock of 11.2896 MHz, this means the fixed factor is now 2.
Hi Ecd
Thank you very much for your explanation.
The point for a smps was as follow.
A few months ago I read again the review of the linn cd12 on the side of stereophile .One of the remarkable points was the use of a smps. If a professional use it. why don't a diy'er use it?
The nice thing of audio is in my opinion one must make choices, like real life. With a result one like it, another don't like it. And you explane your choices.
Ecd, again, thanks.
Regards
Zjaakco
Thank you very much for your explanation.
The point for a smps was as follow.
A few months ago I read again the review of the linn cd12 on the side of stereophile .One of the remarkable points was the use of a smps. If a professional use it. why don't a diy'er use it?
The nice thing of audio is in my opinion one must make choices, like real life. With a result one like it, another don't like it. And you explane your choices.
Ecd, again, thanks.
Regards
Zjaakco