I think simple projects that folks might actually build have an educational purpose. As a ham radio friend told me no one actually builds those 500 component circuits except the author. Dsp or Bluetooth designs will end up with 100's of pin leadless IC's and/or a BOM full of custom inductors and SMT transformers. The harsh reality is that they have little DIY use.
Sorry for inserting this in Jans thread, but perhaps this can serve as inspiration. https://www.youtube.com/watch?v=N3k9lWz48rw
Cheers,
Mogens
Well to put it plainly no. No offense but I think you are 100% wrong.
There are already many people in this forum involved with smd components.
Have you ever taken a look into a bluetooth dongle? Where did you see 500 components?
How many components does a class ab amp or a phono stage have? And then take a look for example at the buffalo dac. How many components are there?
This technology becomes more and more available, included needed tools and people have the skills to build such boards.
I think you are generalising your personal point of view/abilities.
Well the good news is, people who have no interest in RIAA via DSP, or turntable dynamics, or OEO balanced interconnects, or soft recovery diodes, or minimalist amplifiers ... don't have to pay for those articles.
Now that Linear Audio makes each individual article available for download, you have the option to pay only for the things you really REALLY want. Not only does this save you money, it also provides the best possible kind of feedback -- economic feedback -- to the Editor.
Vote with your Euros; you will be heard, loud and clear.
Now that Linear Audio makes each individual article available for download, you have the option to pay only for the things you really REALLY want. Not only does this save you money, it also provides the best possible kind of feedback -- economic feedback -- to the Editor.
Vote with your Euros; you will be heard, loud and clear.
Yes, this is a way. Still I have bought all issues, even those that one article was of interest, to support the effort.
I just would like to some of those topics explored and maybe read the editor's thoughts on the matter after so many posts.
Nikitas, I would really welcome a good digital/DSP construction article, SMD or not. But there's not many that want to put in that big effort. I do pay an author fee but it is much too little for all the parts and especially the hours a typical article takes.
So the people who write for us do it as a hobby and of course they chose the subject they like and have experience with.
I think the young engineers that can do digital/DSP/SMD are still too busy making money to pay off their Lexus
Jan
So the people who write for us do it as a hobby and of course they chose the subject they like and have experience with.
I think the young engineers that can do digital/DSP/SMD are still too busy making money to pay off their Lexus
Jan
I think the young engineers that can do digital/DSP/SMD are still too busy making money to pay off their Lexus
Jan
Lexus' are leased, not purchased.
I find the article on TT dynamics to be among the most interesting in this issue. Terra incognita for me.
Your certainly entitled to your opinion. SMT is one thing bumped die is another, I've seen too many articles with 2 or 3 huge system level chips and then a firmware download. Seems more an exercise in software development not circuit design.
I assembled an all-discrete modular Elektor preamp design with >>500 parts.
Even today, 'no one' (*) is not accurate, in numbers not worth the ink and bother of writing.
But hey, I'm willing to pay for your dsp download.
(* such a pleasant sight, in these days of noone pain)
You mean Peter he is on our shopping channel selling "17 CD's of your favorite 60's memories by the original artists"?
Thank you Jan.
Here's a quick example. Audacity has a built-in FIR RIAA but it is linear phase only. Load the psuedo-random noise signal with inverse-RIAA applied and using the Nyquist prompt to run the two IIR filters from the table in this order:
(biquad-m s 1. 0.3655731 0.01499662 1. -0.66168391 -0.18158841)
(biquad-m s 1. -0.57552742 -0.37960478 1. -0.60450091 -0.39094593)
The result in the picture i(on the left) is flat 20-20k to <.005dB. Even at max length the built-in curve (right) is +-.3dB or so at the low end and the IIR solution is also the correct minimum phase answer. The holes in the spectrum are to check for spectral contamination either from numerical resolution or from an amplifier circuit that has passed this signal.
As an aside, I found the comment that, "when LP's were invented they did know about linear phase filters", rather silly. In fact the original RIAA spec specifically states that the response be exactly minimum phase, that is, exactly that of the three time constants.
Attachments
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Volume 11 hits the streets (figuratively)!
Volume 11 is out now! Another (the 12th!) Volume with lost of very interesting articles.
See for yourself:
RIAA Equalization for Displacement-Sensitive Phono Cartridges - Gary Galo
Gary’s interest in RIAA equalization for displacement-sensitive phono cartridges has been piqued in recent years by the revival of interest in strain-gauge phono cartridges and the claims made for them regarding playback equalization. Strain-gauge cartridges were once manufactured by Panasonic and Win Labs. In recent years new displacement sensitive cartridges have come on the market, where the required ‘RIAA’ correction is unusual or, some claim, not even required. Those claims have prompted his investigation.
Digging deeper into Error Correction - Hans Polak
Hans Polak read with great interest Giovanni Stochino’s articles addressing active feedback and error correction in LA Vol 7 and 8. Several implementations were given, illustrating how to translate a mathematical scheme into a practical solution, and exactly in the implementations it where Hans has a different view on things. He in particular feels that Balanced Error Feedback (BEF) is a version of Active Error Feedback and not a
separate concept that stands on its own; also, using two resistors in the context of Stochino’s article to form an adder is not at all a 1:1 replacement for a mathematical adder. This extended letter has led to an article, with a reply from Stochino in this same issue.
Error correction in power amplifiers – implementation issues and
reply to Hans Polak
Hans Polak very openly communicated his doubts on some issues in Giovanni’s Error Correction article and provided stimulating comments. Hans has touched on, among other things, implementation issues, and Stochino agrees that in the article not enough attention and time to some critical aspects of this matter was given. The gap between Polak’s and Stochino’s positions has not been fully closed even after intensive email correspondence, and a remaining difference of opinion remains. In this article, Stochino provides more implementation details and addresses Polak’s concerns.
Slewing in Audio Amplifiers of the Thompson Topology - Michael Kiwanuka
In a paper published in Electronics World and Wireless World in September 1994 Douglas Self gave an account of the slew asymmetry inherent in the most widely implemented audio amplifier topology: the two-stage Thompson circuit. However, in Michael Kiwanuka’s opinion this explanation was in error. In his article, Kiwanua addresses what he feels are deficiencies in the original analysis and provides his own views on the matter.
A high-performance single gain-stage Preamp - Dimitri Danyuk
There are many types of volume controls, from simple potentiometer to transformers (autotransformers) with switched taps, from light dependent resistors to multiplying digital to analog converters. However, in Dimitri’s views, the best volume control, for both technical and sound quality reasons, is a stepped very low impedance control.
In his article he goes into the design, testing and system performance of a high quality single transconductance gain stage preamp, loaded with a low-impedance stepped audio attenuator. The preamplifier has balanced inputs and a single ended output. The circuit is the basic JFET differential pair with folded cascode and current mirror. Each FET of the input differential pair is enhanced with PNP bipolar transistors in the well-known Sziklai configuration to allow higher output current.
The Devinyliser - Douglas Self
This investigation grew out of a letter that was published in HiFi News at the end of 2015, where Patrick Wallace points out that vinyl signals always come with a background of low-frequency noise due to pressing limitations and other causes; that some of this is vertical with respect to the stylus; and therefore appears out of phase and cannot be localised by the ears. He suggests it therefore is interpreted as 'surround sound' ambience on the recording. Douglas Self’s The Devinyliser is a device for removing this low frequency anti-phase material, suppressing rumble without attenuating wanted bass information. The idea is not a new one, but this implementation is.
Cathode followers: Love ‘m or hate ‘m - Guido Tent
Among tube designers, the cathode follower is always subject to debate. Most such discussions are initiated by perceived differences in sound quality, sometimes described as dull and lacking transparency, and Guido agrees that the classic cathode follower has a clear and substantial sound signature. Compared to other valve circuits, few measured results are available concerning cathode followers. However, offering low output impedance and the possibility for DC coupling makes cathode followers well suited to drive power triodes. Over the years Guido managed to optimize cathode followers to become more musically transparent. This article documents the distortion mechanisms in cathode followers and his measures to suppress them.
Low-cost superregs – design, performance and stability - Eugene Dvoskin
Eugene Dvoskin needed a pair of high performance voltage regulator to provide very clean power to one of his projects. An online search turned up the very his performance of the regulator family often indicated as ‘superregs’. However, Mr. Dvoskin decided to try to emulate the very high performance but using lower cost and more common parts. To that end it was necessary to delve into the details of the regulator circuits to find out what it was exactly that led to the exemplary performance, and how to reach it with simpler and lower cost means.
The Glowing NoiseMaker Reloaded - Burkhard Vogel
Burkhard Vogel had an article in the very first Linear Audio (Vol 0) about calculating the noise production of triode gain stages. In this article Burkhard develops simulation models using the fee LTspice IV simulator. By using data sheet numbers and a suitable 1/f noise corner frequency, Vogel develops models that lead to the same result as the calculation procedures explained in Volume 0.
Don’t put speakers in rooms & what happens if you do - Hannes Allmaier
It is often said that the listening room should be considered in the same way as any other component of your precious stereo setup. Easier said than done, room acoustics are not as easily handled as just another shiny new box. Shortcomings, limitations, ways to improve it and – yet more importantly – how much influence room acoustics actually have on the listening performance, are concepts rarely tackled. In this article Hannes gives this topic a new spin by providing a few hopefully interesting insights and tips for improvement.
The CoFusor — Quick! Call the patent office! – Bill Waslo
Bill Waslo has been impressed with what acoustic diffusion does in audio systems. In his view, power amplifiers, cables, DACs, for the moment are all just accessories by comparison. If you want to improve your sound stage by a lot, you should focus on the stage (i.e., the room) itself, not on all the doo-dads that get wired to the stage. That means enough absorption to tame down the boxiness and echoiness of a bare room. To go further in removing the walls as obvious sound sources, enough ambient energy should remain in the room but be diffused. In short: the room has to participate, but it has to be prevented from doing anything to disturb the stereo illusion. In this article, Bill gives some practical solutions to make all this happen.
Taking a Balanced View - Stan Curtis
It is fair to say that most hi-fi enthusiasts have paid little attention to the importance of their mains power supply and in part this is because of their ignorance of the impact of less than ideal supply wiring and of the various types of noise that creep into equipment via the mains plug. But, says Stan Curtis, L|A readers need make no apology as most of the amplifier designers he is aware of take a great deal of care in the design of everything after the IEC power socket - yet seem to assume that their equipment will be fed from a perfect supply direct from the power station turbines. This obviously is not the case, but Stan has some solutions to make it almost as if it is the case.
Self on Audio, 3rd edition; Douglas Self - Jean/Pierre Vanderreydt
If you have available the last edition of Audio Power Amplifier Design and Small Signal Audio Design from the Same author, you will not necessarily learn new approaches from this book, but you will enjoy to see how the techniques explained in these two books are applied in real designs. If you don’t; this collection of articles with the expanded prefaces brings you up to speed with less reading time albeit in a less didactical manner.
Self on Audio – The collected audio design articles of Douglas Self, 3rd Edition – Douglas Self.
Publisher: Focal Press; ISBN 978-1138854468, Amazon price: Hardcover ? 131; Paperback ? 42; Kindle ? 38;
Trans Tube Amplifiers; Menno Vanderveen - Stuart Yaniger
As Stuart notes, the circuit concepts in this book integrate several ideas in a synergistic way, yielding an amplifier with very good performance. Menno has done a nice job of explaining these circuit tricks, done in the form of a meandering design path to get to the right answer, experimentally verified. The cost/benefit ($35/100 pages) is an individual decision, but Stuart is quite happy having read it, admitting it got him thinking about a few alternative approaches.
Vanderveen Trans Tube Amplifiers – Menno Vandeveen.
Publisher: Elektor; ISBN: 978-1-907920-34-9, Elektor price: € 29.95; also available in German and Dutch.
Volume 11 is out now! Another (the 12th!) Volume with lost of very interesting articles.
See for yourself:
RIAA Equalization for Displacement-Sensitive Phono Cartridges - Gary Galo
Gary’s interest in RIAA equalization for displacement-sensitive phono cartridges has been piqued in recent years by the revival of interest in strain-gauge phono cartridges and the claims made for them regarding playback equalization. Strain-gauge cartridges were once manufactured by Panasonic and Win Labs. In recent years new displacement sensitive cartridges have come on the market, where the required ‘RIAA’ correction is unusual or, some claim, not even required. Those claims have prompted his investigation.
Digging deeper into Error Correction - Hans Polak
Hans Polak read with great interest Giovanni Stochino’s articles addressing active feedback and error correction in LA Vol 7 and 8. Several implementations were given, illustrating how to translate a mathematical scheme into a practical solution, and exactly in the implementations it where Hans has a different view on things. He in particular feels that Balanced Error Feedback (BEF) is a version of Active Error Feedback and not a
separate concept that stands on its own; also, using two resistors in the context of Stochino’s article to form an adder is not at all a 1:1 replacement for a mathematical adder. This extended letter has led to an article, with a reply from Stochino in this same issue.
Error correction in power amplifiers – implementation issues and
reply to Hans Polak
Hans Polak very openly communicated his doubts on some issues in Giovanni’s Error Correction article and provided stimulating comments. Hans has touched on, among other things, implementation issues, and Stochino agrees that in the article not enough attention and time to some critical aspects of this matter was given. The gap between Polak’s and Stochino’s positions has not been fully closed even after intensive email correspondence, and a remaining difference of opinion remains. In this article, Stochino provides more implementation details and addresses Polak’s concerns.
Slewing in Audio Amplifiers of the Thompson Topology - Michael Kiwanuka
In a paper published in Electronics World and Wireless World in September 1994 Douglas Self gave an account of the slew asymmetry inherent in the most widely implemented audio amplifier topology: the two-stage Thompson circuit. However, in Michael Kiwanuka’s opinion this explanation was in error. In his article, Kiwanua addresses what he feels are deficiencies in the original analysis and provides his own views on the matter.
A high-performance single gain-stage Preamp - Dimitri Danyuk
There are many types of volume controls, from simple potentiometer to transformers (autotransformers) with switched taps, from light dependent resistors to multiplying digital to analog converters. However, in Dimitri’s views, the best volume control, for both technical and sound quality reasons, is a stepped very low impedance control.
In his article he goes into the design, testing and system performance of a high quality single transconductance gain stage preamp, loaded with a low-impedance stepped audio attenuator. The preamplifier has balanced inputs and a single ended output. The circuit is the basic JFET differential pair with folded cascode and current mirror. Each FET of the input differential pair is enhanced with PNP bipolar transistors in the well-known Sziklai configuration to allow higher output current.
The Devinyliser - Douglas Self
This investigation grew out of a letter that was published in HiFi News at the end of 2015, where Patrick Wallace points out that vinyl signals always come with a background of low-frequency noise due to pressing limitations and other causes; that some of this is vertical with respect to the stylus; and therefore appears out of phase and cannot be localised by the ears. He suggests it therefore is interpreted as 'surround sound' ambience on the recording. Douglas Self’s The Devinyliser is a device for removing this low frequency anti-phase material, suppressing rumble without attenuating wanted bass information. The idea is not a new one, but this implementation is.
Cathode followers: Love ‘m or hate ‘m - Guido Tent
Among tube designers, the cathode follower is always subject to debate. Most such discussions are initiated by perceived differences in sound quality, sometimes described as dull and lacking transparency, and Guido agrees that the classic cathode follower has a clear and substantial sound signature. Compared to other valve circuits, few measured results are available concerning cathode followers. However, offering low output impedance and the possibility for DC coupling makes cathode followers well suited to drive power triodes. Over the years Guido managed to optimize cathode followers to become more musically transparent. This article documents the distortion mechanisms in cathode followers and his measures to suppress them.
Low-cost superregs – design, performance and stability - Eugene Dvoskin
Eugene Dvoskin needed a pair of high performance voltage regulator to provide very clean power to one of his projects. An online search turned up the very his performance of the regulator family often indicated as ‘superregs’. However, Mr. Dvoskin decided to try to emulate the very high performance but using lower cost and more common parts. To that end it was necessary to delve into the details of the regulator circuits to find out what it was exactly that led to the exemplary performance, and how to reach it with simpler and lower cost means.
The Glowing NoiseMaker Reloaded - Burkhard Vogel
Burkhard Vogel had an article in the very first Linear Audio (Vol 0) about calculating the noise production of triode gain stages. In this article Burkhard develops simulation models using the fee LTspice IV simulator. By using data sheet numbers and a suitable 1/f noise corner frequency, Vogel develops models that lead to the same result as the calculation procedures explained in Volume 0.
Don’t put speakers in rooms & what happens if you do - Hannes Allmaier
It is often said that the listening room should be considered in the same way as any other component of your precious stereo setup. Easier said than done, room acoustics are not as easily handled as just another shiny new box. Shortcomings, limitations, ways to improve it and – yet more importantly – how much influence room acoustics actually have on the listening performance, are concepts rarely tackled. In this article Hannes gives this topic a new spin by providing a few hopefully interesting insights and tips for improvement.
The CoFusor — Quick! Call the patent office! – Bill Waslo
Bill Waslo has been impressed with what acoustic diffusion does in audio systems. In his view, power amplifiers, cables, DACs, for the moment are all just accessories by comparison. If you want to improve your sound stage by a lot, you should focus on the stage (i.e., the room) itself, not on all the doo-dads that get wired to the stage. That means enough absorption to tame down the boxiness and echoiness of a bare room. To go further in removing the walls as obvious sound sources, enough ambient energy should remain in the room but be diffused. In short: the room has to participate, but it has to be prevented from doing anything to disturb the stereo illusion. In this article, Bill gives some practical solutions to make all this happen.
Taking a Balanced View - Stan Curtis
It is fair to say that most hi-fi enthusiasts have paid little attention to the importance of their mains power supply and in part this is because of their ignorance of the impact of less than ideal supply wiring and of the various types of noise that creep into equipment via the mains plug. But, says Stan Curtis, L|A readers need make no apology as most of the amplifier designers he is aware of take a great deal of care in the design of everything after the IEC power socket - yet seem to assume that their equipment will be fed from a perfect supply direct from the power station turbines. This obviously is not the case, but Stan has some solutions to make it almost as if it is the case.
Self on Audio, 3rd edition; Douglas Self - Jean/Pierre Vanderreydt
If you have available the last edition of Audio Power Amplifier Design and Small Signal Audio Design from the Same author, you will not necessarily learn new approaches from this book, but you will enjoy to see how the techniques explained in these two books are applied in real designs. If you don’t; this collection of articles with the expanded prefaces brings you up to speed with less reading time albeit in a less didactical manner.
Self on Audio – The collected audio design articles of Douglas Self, 3rd Edition – Douglas Self.
Publisher: Focal Press; ISBN 978-1138854468, Amazon price: Hardcover ? 131; Paperback ? 42; Kindle ? 38;
Trans Tube Amplifiers; Menno Vanderveen - Stuart Yaniger
As Stuart notes, the circuit concepts in this book integrate several ideas in a synergistic way, yielding an amplifier with very good performance. Menno has done a nice job of explaining these circuit tricks, done in the form of a meandering design path to get to the right answer, experimentally verified. The cost/benefit ($35/100 pages) is an individual decision, but Stuart is quite happy having read it, admitting it got him thinking about a few alternative approaches.
Vanderveen Trans Tube Amplifiers – Menno Vandeveen.
Publisher: Elektor; ISBN: 978-1-907920-34-9, Elektor price: € 29.95; also available in German and Dutch.
You mean "lots", sorry just the editrix-she-goddess getting hold of my keyboard.
She-goddes is right of course! Hopefully this wasn't a Freudian slip.
There's another nasty one in the writeup but I leave that as an exercise to the reader ;-)
Jan
