I think it is always healthy to have multiple books in one broad and relevant subject matter, especially when they are of a different writing style and selection of topics and ways of explaining those topics. In reseraching my books, I found that I had to obtain many engineering books in order to put the material together in a more cohesive and complete way. Often the needed material is scattered all over the place. There is a tremendous amount of good material out there, but it is in many different places. I found this to be the case with switching power supplies and class D amplifiers when I wrote my power amplifier book.
Cheers,
Bob
Cheers,
Bob
Hi AnalogJoe,
What Bob says is so true! The information is out there, but you have to dig and gather it. You also have to work in the field to help sort out misinformation and see what is true in application.
Douglas has a perspective born from his education and professional experience as does Bob. They disagree in some areas and that's fine. I would never suggest one or the other is wrong. I also don't think asking either to comment would be fruitful.
Both men are professional and courteous in my experience. Hat's off to both for compiling the information in a way that others can learn from.
What Bob says is so true! The information is out there, but you have to dig and gather it. You also have to work in the field to help sort out misinformation and see what is true in application.
Douglas has a perspective born from his education and professional experience as does Bob. They disagree in some areas and that's fine. I would never suggest one or the other is wrong. I also don't think asking either to comment would be fruitful.
Both men are professional and courteous in my experience. Hat's off to both for compiling the information in a way that others can learn from.
I do not disagree that the information is out there. I have a circa 3000 book technical library on electronics. That and papers in journals from the AES, IEEE, Jan Didden's Linear Audio, AudioXpress, Elektor, Electronics World, etc.... definitely make up a great pool of information in which you can find what you are looking for. However, when it comes to a single book in the matter that gathers high-end pro audio circuitry and that it is still relevant today (I'm discarding those books about "pro audio" circuits that use 2 germanium pnp transistors and a single negative supply), my opinion still stands. I still believe that, until now, Doug's Small Signal Audio Design was the only book out there of the kind. And as Bob very well puts it, I also believe it was badly needed for another author to publish something similar, but with a different approach.
By the way, Bob, if you have any good book recommendations that you've found during your search, I would love to hear them. (Hint: I am a book buff who is always on the hunt for good books, which is why I found yours and pre-ordered it a month ago)
By the way, Bob, if you have any good book recommendations that you've found during your search, I would love to hear them. (Hint: I am a book buff who is always on the hunt for good books, which is why I found yours and pre-ordered it a month ago)
Mr. Self's latest book is already wrong, as far as I'm concerned. He talks about phase perception as though Ohm's Acoustic Law as formulated by Helmholtz is beyond question. Even when Helmholtz was considering it, other people expressed concerns. In more recent times, W. Dixon Ward was an outspoken critic of the so-called Law.
A part of Dixon Ward's critique can be found in the wiki page on the subject: https://en.wikipedia.org/wiki/Ohm's_acoustic_law#:~:text=Ohm's acoustic law, sometimes called,physicist Georg Ohm in 1843.
More details in the attachments
A part of Dixon Ward's critique can be found in the wiki page on the subject: https://en.wikipedia.org/wiki/Ohm's_acoustic_law#:~:text=Ohm's acoustic law, sometimes called,physicist Georg Ohm in 1843.
More details in the attachments
Attachments
Last edited:
Self says: Phase perception. You don’t have any."
Then he goes on to explain that most audio equipment (there are a few exceptions) these days won't produce any audible phase shift.
Okay, he just started out with a little exaggeration, then sorta corrected it. But what do you think readers are left with? The strong and absolute claim at the beginning, or the all the details about when and where you do or don't hear phase. What I don't like about it is the basic impression it leaves for many readers.
Then he goes on to explain that most audio equipment (there are a few exceptions) these days won't produce any audible phase shift.
Okay, he just started out with a little exaggeration, then sorta corrected it. But what do you think readers are left with? The strong and absolute claim at the beginning, or the all the details about when and where you do or don't hear phase. What I don't like about it is the basic impression it leaves for many readers.
I honestly don't care. I bought his book to read about Small Signal Audio Design, not for psychoacoustics. Self has always been very outspoken about his measurement-driven philosophy when it comes to audio. I care about his circuits, not about his opinions on what the ear can perceive or not. I haven't read that portion, but, in my opinion, that shouldn't even be in the book; it is completely off-topic.
Last edited:
That is an amazing technical library that you have! One of the things I have done is to provide a generous helping of references, including books, at the end of each chapter. Some of those were a bit difficult to find, and in fact some are long out of print and no longer available. It can indeed take a lot of digging. I am greatly indepted to all of those brilliant authors out there. Another source of important information for very smart people in a given field is application notes, such as for integrated circuits. Another example is the numerous Rane Notes authored by Dennis Bohn.
Cheers,
Bob
Sigh..... I remember the days when we used to keep like 100+ books on our shelves at work. Hundreds of technical application books from Motorola, Intel, TI, Toshiba, etc, etc, etc,
Complete book sets also from Wind River, Green Hills, HP, all kinds of Unix, DEC....
Then we had the technical libraries at work.
I was working at a place where they got rid of their microVAX. So I offered to buy the books, 100 bucks I said. The next day the computer guy approached me and told me to "bring the truck"... they were including the computer and tape drives into the 100 bucks. I didn't want that! ;-)
I threw them books all away. That boat sailed off and it ain't coming back.
Complete book sets also from Wind River, Green Hills, HP, all kinds of Unix, DEC....
Then we had the technical libraries at work.
I was working at a place where they got rid of their microVAX. So I offered to buy the books, 100 bucks I said. The next day the computer guy approached me and told me to "bring the truck"... they were including the computer and tape drives into the 100 bucks. I didn't want that! ;-)
I threw them books all away. That boat sailed off and it ain't coming back.
Hi Bob,
Completely agree! Application notes are a fantastic source of information. I've recommended them as the best source of accurate information. Not white papers, application notes.
Markw4,
Not the venue for raising your disagreements with measurement based engineering and truth. The subject you raised is an entire thread you are welcome to open, not here. You basically introduced noise into this discussion.
Completely agree! Application notes are a fantastic source of information. I've recommended them as the best source of accurate information. Not white papers, application notes.
Markw4,
Not the venue for raising your disagreements with measurement based engineering and truth. The subject you raised is an entire thread you are welcome to open, not here. You basically introduced noise into this discussion.
Focal Press, a division of Routledge, is a powerhouse in publishing books like this.
Rick has played a crucial role in making my new book better than it would have been without his input. I also owe a lot to numerous other great developers and authors in this and related fields.
Cheers,
Bob
Hey Tony,
I would have died and gone to heaven with those books. I have several book cases full of technical documentation starting from the 1920's on up. The books from Toshiba would have been very interesting as they are rare, I only have a couple things from Japanese manufacturers.
I would have died and gone to heaven with those books. I have several book cases full of technical documentation starting from the 1920's on up. The books from Toshiba would have been very interesting as they are rare, I only have a couple things from Japanese manufacturers.
Any engineer doing hardware and/or embedded firmware from the 70s through the 90s had lots of those things.
The sales and support guys would come by and unload cases.
The Motorola office in Irvine used to have an open door policy towards engineers. We'd show up, show our badge and they'd give us whatever we wanted.
I had four shelves full of Motorola CPU32 -and related- application books.
Your best bet nowadays would be to search for old guys like me... or older like Nelson... they might have the books in their garage.
Around '94 it all changed. The widespread adoption of the WWW and html saw all of that data moved online and easily searchable. By '00 even stuff subject to NDAs moved to the public domain ( like operating systems books ).
Stuff like Bob's books is different. It's more like a User's Manual whereas the Application books were Reference Guides. User's guides are much easier when you want to learn, a Reference is better when you are already an expert in the field.
The sales and support guys would come by and unload cases.
The Motorola office in Irvine used to have an open door policy towards engineers. We'd show up, show our badge and they'd give us whatever we wanted.
I had four shelves full of Motorola CPU32 -and related- application books.
Your best bet nowadays would be to search for old guys like me... or older like Nelson... they might have the books in their garage.
Around '94 it all changed. The widespread adoption of the WWW and html saw all of that data moved online and easily searchable. By '00 even stuff subject to NDAs moved to the public domain ( like operating systems books ).
Stuff like Bob's books is different. It's more like a User's Manual whereas the Application books were Reference Guides. User's guides are much easier when you want to learn, a Reference is better when you are already an expert in the field.
Last edited:
I honestly don't know the extent to which phase perception plays a role in sound quality, and I don't take a position on it. I would be happy if everything was minimum phase across the audio band, but that is not always the case.
An example is in loudspeakers and their crossovers. Consider the Linkwitz-Riley family of crossovers. They act like all-pass filters, which are way not minimum phase or free of group delay distortion, yet they are very widely used in a great many great-sounding loudspeakers. I've often wondered a lot about this.
Most electronic equipment is largely minimum phase, with relatively low phase delay and group delay within the audio band. However, there are cases where digital audio processors are not minimum phase. For example, filters in DSP functions can be FIR (finite impulse response) or IIR (infinite impulse response), the latter being of a minimum phase nature. Finally, there are minimum phase filters that also can create large amounts of phase distortion and group delay deistortion in the region near their low-pass cutoff frequency, and these attract controversy as well. Consider anti-alias and reconstruction filters in digital audio.
If you implement two DSP RIAA phono preamps with IIR and FIR filters, will you hear a difference? I don't know.
Cheers,
Bob
Still, the entire goal of electronic amplification is to pass and reproduce the signal with minimal changes except for voltage and current levels. Any discussion about how we perceive sound after passing through the chain and air into our ears is really confusing the real issues and of no value.
We worry and do the best for anything we have control over. We can't worry about a speaker's response, or the ability of the person to hear. That falls out of the equation since they original sound would have produced (hopefully) the same sound pressure variations. That is the goal of the entire system. The goal of the electronics is to reproduce the signal, not correct for the uncorrectable and undefinable.
On phase. My belief is that we are designed to determine direction from phase and loudness of a sound at the same frequency between the ears. We are pretty good at that (survival). What we don't detect well is phase between widely separated frequencies since this does not provide directional cues, really not important for our survival. This was one of Harmon Kardon's sales pitches, and they ran their stuff very hot trying to achieve constant phase to tiny differences where it didn't matter. If it did matter, all manufacturers would have followed suit. So I think this is a point of argument for the sake or arguing. A red herring.
We worry and do the best for anything we have control over. We can't worry about a speaker's response, or the ability of the person to hear. That falls out of the equation since they original sound would have produced (hopefully) the same sound pressure variations. That is the goal of the entire system. The goal of the electronics is to reproduce the signal, not correct for the uncorrectable and undefinable.
On phase. My belief is that we are designed to determine direction from phase and loudness of a sound at the same frequency between the ears. We are pretty good at that (survival). What we don't detect well is phase between widely separated frequencies since this does not provide directional cues, really not important for our survival. This was one of Harmon Kardon's sales pitches, and they ran their stuff very hot trying to achieve constant phase to tiny differences where it didn't matter. If it did matter, all manufacturers would have followed suit. So I think this is a point of argument for the sake or arguing. A red herring.
Hi Tony,
Yes, I was able to walk into any sales office and come out with the entire year of tech data. But we are in Canada and not everyone was present, certainly not the Japanese firms. As soon as they put their stuff up on BBS's (I had an account) it became tougher. Never mind a several hour download at night or on a fax line.
That petered out. I also remember being able to grab some semiconductor samples freely out of bins, some carded in blister packs. Those were the good old days.
Yes, I was able to walk into any sales office and come out with the entire year of tech data. But we are in Canada and not everyone was present, certainly not the Japanese firms. As soon as they put their stuff up on BBS's (I had an account) it became tougher. Never mind a several hour download at night or on a fax line.
That petered out. I also remember being able to grab some semiconductor samples freely out of bins, some carded in blister packs. Those were the good old days.