In the late 1970's or early 1980's Bob Stewart is said to have given a lecture approximately called " Causes of distortion in audio amplifers due to loss of imformation ". Bob seemed to say if an amplifier could be made in the simplest way possible and met a design spec it should sound better in a way not easy to prove against typical designs. If nothing else new types of distortion were said to exist and perhaps due to his ideas. For some reason fashion now says the views of the 1960's are in fact more true. I am very unhappy with this. Almost the doctrin of those who want to make money from audio rather than spending it on research to my mind in typical tone circuits.
Tone controls seemed number one thing we could live without. Many had systems so well balanced we seldom used them. Most of the 1980's amps without tone controls did sound better. The reason most likely being a circuit better suited to a car stereo being used.
Recently I had to use a tone control with my baffle speakers. Instantly the advantages were sonically greater than any loss. The speaker being usable in the flat position so not just need over predudice. It made me look at the 1970's Quad 33/303 and ask was it considerably better engineered? I think it is. It is also very fussy so will dissapoint any who want to simply buy and use one.
In the past we humans were considered a mixture of body and soul. That would almost be laughed at now. Hi fi is the same. Some hi fi that should sound good doesn't and the opposite. Looking at the tube active circuit in this link below I like how it tries to address the problems. Very like the circuits I usually dislike. This one looks that I might like it.
A renewed interest in tone controls might be the future. Michael Gerzon wrote plenty on this. He might have read a book by Gilbert Briggs claiming seemingly indentical tone controls can sound different writen in the 1960's ( and observed in the 50's I think on 78's). Michael very much made it one of his early quests. Not an easy man to know. I think he called it " flutter echo ". If I understood, the circuit Q being a sound quality factor I suspect. Perhaps open verses closed loop which the passive " might " side step.
Simple Tome Controls.
Tone controls seemed number one thing we could live without. Many had systems so well balanced we seldom used them. Most of the 1980's amps without tone controls did sound better. The reason most likely being a circuit better suited to a car stereo being used.
Recently I had to use a tone control with my baffle speakers. Instantly the advantages were sonically greater than any loss. The speaker being usable in the flat position so not just need over predudice. It made me look at the 1970's Quad 33/303 and ask was it considerably better engineered? I think it is. It is also very fussy so will dissapoint any who want to simply buy and use one.
In the past we humans were considered a mixture of body and soul. That would almost be laughed at now. Hi fi is the same. Some hi fi that should sound good doesn't and the opposite. Looking at the tube active circuit in this link below I like how it tries to address the problems. Very like the circuits I usually dislike. This one looks that I might like it.
A renewed interest in tone controls might be the future. Michael Gerzon wrote plenty on this. He might have read a book by Gilbert Briggs claiming seemingly indentical tone controls can sound different writen in the 1960's ( and observed in the 50's I think on 78's). Michael very much made it one of his early quests. Not an easy man to know. I think he called it " flutter echo ". If I understood, the circuit Q being a sound quality factor I suspect. Perhaps open verses closed loop which the passive " might " side step.
Simple Tome Controls.
So what's best -- conventional simple bass / treble tone controls, graphic equaliser, parametric equaliser? The latter take a lot more care to use, perhaps...
To side step that slightly. My brother always liked tone controls in the power amp section. His reasoning being that the power amp ideal to drive the circuit without extra complexity. If you like the amp is a big higher voltage op amp. They were low distortion designs so no obvious trade off. Kenwood / Trio being one.
I like controls that give simple lift and cut at as many flequenices as possible. I never found a graphic as useful as I hoped for except on cheap TV's. The Quad 33 with a few more bass EQ's would suit. I have a hunch phase shift is important and might be a factor in fatigue. Keeping it simple might matter. A warning. The brain will process an EQ'ed sound and say " that's better ". 10 minutes later fatigue sets in. As so much EQ has been used in recordings it is impossible to know what is best. I suspect a speaker ( including amplifer if active ) that produces a square wave at 1 kHz might help . Some do quite well. One problem seems stereo image spread can suffer to get it square. It's how and where you cross.
One point hi fi people never seem to get. Recordings we buy were never aimed at the hi fi user. Ones that are seldom have good musical quality. Pink Floyd's dark side of the Moon might be the exception and might have invented 1980's audio. ELO and others a " me too " product. I watch plenty of low fi. The system I own is no worse than a TV and often better. That has taken me 40 years to get right. On Audiophile recordings it is Audiophile. I was watching UK version of Wallender. Whilst it seems to loose the story compared with the original the sound is stunning. Were it not for me taming low fi I doubt it would be so good. The production is still made for standard TV's.
I like controls that give simple lift and cut at as many flequenices as possible. I never found a graphic as useful as I hoped for except on cheap TV's. The Quad 33 with a few more bass EQ's would suit. I have a hunch phase shift is important and might be a factor in fatigue. Keeping it simple might matter. A warning. The brain will process an EQ'ed sound and say " that's better ". 10 minutes later fatigue sets in. As so much EQ has been used in recordings it is impossible to know what is best. I suspect a speaker ( including amplifer if active ) that produces a square wave at 1 kHz might help . Some do quite well. One problem seems stereo image spread can suffer to get it square. It's how and where you cross.
One point hi fi people never seem to get. Recordings we buy were never aimed at the hi fi user. Ones that are seldom have good musical quality. Pink Floyd's dark side of the Moon might be the exception and might have invented 1980's audio. ELO and others a " me too " product. I watch plenty of low fi. The system I own is no worse than a TV and often better. That has taken me 40 years to get right. On Audiophile recordings it is Audiophile. I was watching UK version of Wallender. Whilst it seems to loose the story compared with the original the sound is stunning. Were it not for me taming low fi I doubt it would be so good. The production is still made for standard TV's.
Hello,
I think that would be the complete demoltion of everything related to audio on the internet so people will spend their time sitting in a good chair listening to music and having a snack and/or a homebrew coffee instead of reading opposite opinions regarding diy audio with some music playing in the background.
Greetings, Eduard
I think that would be the complete demoltion of everything related to audio on the internet so people will spend their time sitting in a good chair listening to music and having a snack and/or a homebrew coffee instead of reading opposite opinions regarding diy audio with some music playing in the background.
Greetings, Eduard
In Pro Audio these things are hot topics and always were. Imagine. You arrive already having driven for 3 hours. You unpack the rig. Then as best you can do a sound check. The skill is getting it right when the musicians turn up with their various ideas of what is best. The skill is making it sound as if it was right from the word go. Often if over three days the hard work done on day one pays off.
I did some work in Ibiza at a TV studio. The guy had been deserted and the crew took equipement as payment. What was left didn't look ideal. We made a pile of audio gear to sell and kept one 4 chanel mixer which seemed to sound better than any other he had. The others had far more inputs, all very lo fi. The Electrovoice michrophones very good. His Apple computer seemed to hum like crazy. it was vital to being able to run alas. The lights excellent so they were the prime part of the plan. I built him a 1960's TV studio. He is very happy and it makes him an expert in this simple format. All the other gear went on eBay and made a nice bit of money. He adapted his style to the realities of what he had. The staff thought they had shafted him. No, they proved how much is hype. They had made it seem he could not work without them. I doubt the results I got would have been so good if I had tried to make the original plan work and it would have cost plenty. Funny thing is no one told me I was doing this. No one asked me if I knew how! I did it for 23 years and never had said about it. Video was not my cup of tea, my old boss loved it and roped me in to help. I had remembered enough. It was a holiday gone wrong. A number of Farnell 110 V isolation transformers sent as the majority of gear was USA voltage. The yellow types used for building sites. I suspect these were a good move. Again the staff taking the 230 V stuff might have done him a favour.
Taking TV as part of audio I suspect is the reality of most peoples future needs.
I did some work in Ibiza at a TV studio. The guy had been deserted and the crew took equipement as payment. What was left didn't look ideal. We made a pile of audio gear to sell and kept one 4 chanel mixer which seemed to sound better than any other he had. The others had far more inputs, all very lo fi. The Electrovoice michrophones very good. His Apple computer seemed to hum like crazy. it was vital to being able to run alas. The lights excellent so they were the prime part of the plan. I built him a 1960's TV studio. He is very happy and it makes him an expert in this simple format. All the other gear went on eBay and made a nice bit of money. He adapted his style to the realities of what he had. The staff thought they had shafted him. No, they proved how much is hype. They had made it seem he could not work without them. I doubt the results I got would have been so good if I had tried to make the original plan work and it would have cost plenty. Funny thing is no one told me I was doing this. No one asked me if I knew how! I did it for 23 years and never had said about it. Video was not my cup of tea, my old boss loved it and roped me in to help. I had remembered enough. It was a holiday gone wrong. A number of Farnell 110 V isolation transformers sent as the majority of gear was USA voltage. The yellow types used for building sites. I suspect these were a good move. Again the staff taking the 230 V stuff might have done him a favour.
Taking TV as part of audio I suspect is the reality of most peoples future needs.
As long there is no analog signal (phono, FM-tuner, etc.) I would vote for a completely digital, DSP based solution. Filtering, room-correction, equalization, all in one. I don't understand, how anyone would discuss conventional tone-controls in the digital era, where it's simple to route/replay anything with a computer, and be it just an embedded development board, like the RPi or the BeagleBone and the likes.
Sometimes it is the right solution. As in RIAA as you make an inverse phase shift solution ( if only ). Otherwise 100 % agree. TV sound is complex and I would welcome the facilities you say. My Pro Audio friend says I can have a short lone of his box of tricks. He says I won't want to give it back. It even has digital RIAA on it.
Nigel, have you been following these guys?
Remarkable results not easy to do without DSP.
http://www.diyaudio.com/forums/mult...lti-way-point-source-horn-25.html#post4644522
Remarkable results not easy to do without DSP.
http://www.diyaudio.com/forums/mult...lti-way-point-source-horn-25.html#post4644522
Simpler. Just do the EQ in the audio player. IIR and FIR filters are easy these days.
Digital EQ can have its own problems, the biggest one being that there is considerable time delay involved in many cases. Last time I worked with them (which was many years ago), I found that an FIR filter producing corrective EQ at, say, 100 Hz, would also involve a signal delay of the order of 10 milliseconds (that's roughly one period at 100 Hz).
That delay seemed to be tied to the physics of wave motion (there is a fundamental theorem there that relates time and frequency changes to each other.)
Now, if you have gone to considerable trouble to time-align the drivers in your speaker system to within the equivalent of a fraction of an inch of path length, you are not going to be thrilled to have a corrective FIR filter then introduce a delay equivalent to ten feet of path length!
This can also be a problem in speakers designed for live music use - stage monitors, say. Too many milliseconds of delay there can be confusing for the musicians who are playing along with the sound through the monitors.
Since there are plenty of active monitors/P.A. speakers with onboard DSP for live use these days, the manufacturers must have found ways to manage the excessive time delay; possibly by using IIR (rather than FIR) filters for the lower frequencies, or only using DSP at higher frequencies, where the necessary delays are shorter (at 1 kHz, you only need 1 mS of delay, which is acceptable to just about anyone, even critical musicians with finely honed musical ears.)
Additional time delays rear their heads with this sort of processing, too. Not only does A/D conversion take some time, there is invariably some buffering going on, so that signals have to fill up the buffer before they come out of the other end. We usually hear about this when the conversation turns to DAWs (Digital Audio Workstations), where audio latency can be a major concern.
-Gnobuddy
Very interesting and and so good that the idea seems to attract only helpful observations.
Samson D2500 31 Band Graphic EQ - DM Music for Churches
This comes close to a product I would want. Picked at ramdom from eBay and now obsolete. I like the idea of delay and the optional noise gating. It even has HF synthisis which could be fun.
One way of using this product on my system would be to EQ the bass ( 30 Hz to 250 Hz ) and the treble ( 6 kHz > ). This would be via three amplifiers of differnent types. I would attempt to keep the main unit ( 100 to 8 kHz ) pure. If I could find an ideal curve using the graphic that could be cloned in a fixed circuit in the main amplifier.
As to the time delay. Alas one has to delay the main amp to get the benefit. I suspect with how my system works it wouldn't be a big issue.
I think that a unit with even more features for the domestic market would be a winner. It sould have a first class phono stage built in with flat EQ for a microphone, parts $3 to do an OK job, adds about $20 retail, Could be better than typical D Self / Denon type circuits despite low cost. Driven from existing clean PSU . The humble MC33078 would suit very well. Also basic peramp out and mini headphone amp built in. If that amp could offer 5 watts 8R it would be useful. If so and me designing it I would avoid class D and SMPS. If I had to use them they would be designed as a whole unit. I would lock the SMPS to the class D using a sub harmonic. For example 400 kHz for the amp and 100 kHz via a ripple counter for the PSU. If self oscillating I suspect the SMPS would still be happy enough to follow the amp. That way no radio band harmonics are generated except the unavoidable, this is not a specualtion as I have measured this idea. The DACS would need a clean supply. Chokes still work very well for that.
This comes close to a product I would want. Picked at ramdom from eBay and now obsolete. I like the idea of delay and the optional noise gating. It even has HF synthisis which could be fun.
One way of using this product on my system would be to EQ the bass ( 30 Hz to 250 Hz ) and the treble ( 6 kHz > ). This would be via three amplifiers of differnent types. I would attempt to keep the main unit ( 100 to 8 kHz ) pure. If I could find an ideal curve using the graphic that could be cloned in a fixed circuit in the main amplifier.
As to the time delay. Alas one has to delay the main amp to get the benefit. I suspect with how my system works it wouldn't be a big issue.
I think that a unit with even more features for the domestic market would be a winner. It sould have a first class phono stage built in with flat EQ for a microphone, parts $3 to do an OK job, adds about $20 retail, Could be better than typical D Self / Denon type circuits despite low cost. Driven from existing clean PSU . The humble MC33078 would suit very well. Also basic peramp out and mini headphone amp built in. If that amp could offer 5 watts 8R it would be useful. If so and me designing it I would avoid class D and SMPS. If I had to use them they would be designed as a whole unit. I would lock the SMPS to the class D using a sub harmonic. For example 400 kHz for the amp and 100 kHz via a ripple counter for the PSU. If self oscillating I suspect the SMPS would still be happy enough to follow the amp. That way no radio band harmonics are generated except the unavoidable, this is not a specualtion as I have measured this idea. The DACS would need a clean supply. Chokes still work very well for that.
I have not heard of this before - https://en.wikipedia.org/wiki/Super_High_Material_CD
shmcd
I have experimented with different CD blanks and gotten differing subjective PB results...IIRC the dark/black discs were the best of what I tried.
Dan.
shmcd
I have experimented with different CD blanks and gotten differing subjective PB results...IIRC the dark/black discs were the best of what I tried.
Dan.
Green felt tip pen around the edge??
Or, seriously, data is data, If the disk plays without error, it's design is not important.
The second part of the Apple business plan, get you to pay again for what you already have.
Next big thing : without doubt will be Entangled reality.
Sort of creepy but its coming.
I would dump any stocks depent on 3d , virtual reality.
SiFi flicks get storylines from cutting edge science white papers.
anyway I'm following it.
Bruce
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Sort of creepy but its coming.
I would dump any stocks depent on 3d , virtual reality.
SiFi flicks get storylines from cutting edge science white papers.
anyway I'm following it.
Bruce
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Can we hold you to this, whatever it means? The scientists who did the early QE experiments laugh their a$$es off at the extrapolations of the pop science press.
Here is a basic concept test you can do quickly with common substances.
There are many many published but don't go there. Wait until the all clear sounds and the biophysics are fully understood.
For example you may unknowing link with a carcengin.
Its a really exciting new field of research.
Just don't assume safety even not being in physical contact.
https://patentimages.storage.googleapis.com/pdfs/US20090114526.pdf
Bruce
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I listen to some good old school recordings from RCA & EMI.
You can hear from the recordings that it took a lot of time & set up
to record with minimum editing. Perhaps this generation of engineers
can take a look back & might learn something from it. Off course with
modern day equipment everything can be done in a snap but what are the
results like ? Pointless to have Hi Res audio equipment when recording
itself is only so so. Short of being shot, perhaps red book playback should
be given another look as much has been learned about digital since.
Why do I say this, cause I've done comparisons & frankly I don't know
what the fuss is all about. for me I don't feel that I'm missing anything
when listening to good Red Book recorded CD's
cheers
You can hear from the recordings that it took a lot of time & set up
to record with minimum editing. Perhaps this generation of engineers
can take a look back & might learn something from it. Off course with
modern day equipment everything can be done in a snap but what are the
results like ? Pointless to have Hi Res audio equipment when recording
itself is only so so. Short of being shot, perhaps red book playback should
be given another look as much has been learned about digital since.
Why do I say this, cause I've done comparisons & frankly I don't know
what the fuss is all about. for me I don't feel that I'm missing anything
when listening to good Red Book recorded CD's
cheers
Didn't get what you mean. The three time constants of 3180 uS, 318 uS and 75 uS are the RIAA specified equalisation curves that all discs that conform to RIAA use. That makes it all vinyl that we normally use.
Why do you call the 75uS eq a tone control ? Of course you can change it but then you will no longer be playing the disc as it was mean to be played ( flat freq response !)
It isn't a good idea altering this in the preamp as it has implications regarding signal levels and over load capability. Better to use an external tone control. 75uS corresponds to a pole at 2,120 Hz.
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