Spooky , Leach , HK990 , all the dayton audio AB plate amps for sub ,
those old rush AB amps , at least 1/3 of all my schematic collection ....
All the same - 4 device symmetric input stage as the symetri. Some last
a full 20+ years clipping away with musicians.
(popular with musician SS amps , even cheap ones).
OS
I understand your point, but i have also built amplifiers since i was Young and built most of the same kind of circuits here ,not simulated but from books and service manuals..
The thread here has allready been very informative far more than i could ask for...
OS,
I think you also have to discriminate between the truly digital amps and the analog switch mode amps. I'm not recommending either but I think people confuse that fact.
What you are saying about these classic circuits and using discrete output devices is a major factor in why I haven't just jumped on the monolithic power amp chips, I don't think they sound nearly as good as your discrete designs. It would be so easy and cheap to just use the NI3886 chips now sold by TI or some of the other chip amps, I just don't want to do it. As long as we can still get quality discrete output transistors that is what I am going to do.
I don't know for sure yet but I think I have someone who is going to come on board with me who can sort out all the digital side of things. I hopefully should know in the not to distance future. First response was encouraging. No it is not JC! I am still set on using your amp designs.
I think you also have to discriminate between the truly digital amps and the analog switch mode amps. I'm not recommending either but I think people confuse that fact.
What you are saying about these classic circuits and using discrete output devices is a major factor in why I haven't just jumped on the monolithic power amp chips, I don't think they sound nearly as good as your discrete designs. It would be so easy and cheap to just use the NI3886 chips now sold by TI or some of the other chip amps, I just don't want to do it. As long as we can still get quality discrete output transistors that is what I am going to do.
I don't know for sure yet but I think I have someone who is going to come on board with me who can sort out all the digital side of things. I hopefully should know in the not to distance future. First response was encouraging. No it is not JC! I am still set on using your amp designs.
Ohh, classD has come a long way, what is good for effiency also gradually does away with the limitations, now class D can be as good as most AB. One has to remember that while the last complementary chipsets for AB amps are 30 or so year old, we se better and better chipsets for class D most every year, lower capacitance means faster rise time and great reduction of the dreaded dead time, faster switching and better performance. As good as the Best AB... Don't see that, but cool, compact and high power in one package is hard to beat.
You mean LC ? JC says his 30 YO designs are best (and won't sell them)?
I did look around this forums commercial sector -
Two "camps" - high power LFET designs (LC and the "wizard") and
Hybrid "voiced" lower power designs (the "Guru").
3 real options for really good , well implemented amp "kits". LC's seems
to the best value , the other two want 300-600$ (or more) for a pre-built
stereo pair (just the parts/PCB !! )
At least LC is affordable !
I could effortlessly reverse engineer either , I just know what
they are and see nothing inferior in the slewmaster's.
I know the secrets. But , I would not go there - these are not
my "secrets".
EDIT - if I refined and put all my effort into one or two complete amps with
IPS/OPS - one PCB , It would be quite competitive.
OS
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OS,
I did mean to say JC, I was just saying it isn't him but somebody who I think is at least at his level and may be willing to get on-board with my speaker designs and do the digital circuit design. He's done a bunch of work for JBL/Harmon and others and knows his stuff. It is just going to take me to long to come up to speed on the circuit implementation and the software side to do a dsp xo and also allow for usb input and even a simple Bluetooth or WiSA wireless connectivity. I also want to allow for a simple analog input for those who still have a preamp or other analog sources. I'd love to do a bunch of other digital functions but I think that is best left outside the enclosure. Also there is the power supply to think of, that I am leaning towards an external smps. Space is at a premium so smd is going to be a requirement where it can be used. i can dream about what I want to do forever, you and a few others can actually implement all of this and make it work. I have nothing against LC, but if I have to implement all the other things for the digital I might as well have someone consolidate as much of this as possible in as small an area as is reasonable. I saw some consumer active speakers the other day for less than $200.00 per pair, I don't want to make something that uses the cheapest and lowest quality components, that would just ruin the quality of the sound that I know my speakers are capable of.
I did mean to say JC, I was just saying it isn't him but somebody who I think is at least at his level and may be willing to get on-board with my speaker designs and do the digital circuit design. He's done a bunch of work for JBL/Harmon and others and knows his stuff. It is just going to take me to long to come up to speed on the circuit implementation and the software side to do a dsp xo and also allow for usb input and even a simple Bluetooth or WiSA wireless connectivity. I also want to allow for a simple analog input for those who still have a preamp or other analog sources. I'd love to do a bunch of other digital functions but I think that is best left outside the enclosure. Also there is the power supply to think of, that I am leaning towards an external smps. Space is at a premium so smd is going to be a requirement where it can be used. i can dream about what I want to do forever, you and a few others can actually implement all of this and make it work. I have nothing against LC, but if I have to implement all the other things for the digital I might as well have someone consolidate as much of this as possible in as small an area as is reasonable. I saw some consumer active speakers the other day for less than $200.00 per pair, I don't want to make something that uses the cheapest and lowest quality components, that would just ruin the quality of the sound that I know my speakers are capable of.
OS, i do not fully agree with your analysis. From my point of view, there are two tracks we can follow in order to design the best amp you can. One is to achieve the best distortion numbers by design. It had complexity, and increase the price. The other is to make-it as simple as possible, and optimize-it. It takes more time, but, well, do a simpler circuit preserve more details ?
I believe the best is in the middle, as always.
The other thing is what we are looking for, when designing. I mean, on what are-we concentrating, speed (slew rate), or harmonic distortion ? Not an easy thing to answer, as nobody has an idea of the thresholds and their effects on listening experience.
Too the quality of the boards and parts are very important on the sonic signature. On my side, I tend to prefer SMDs, as it reduce the path lengts and parasitics, and most efforts of the manufacturers are focused on this kind of components, nowadays.
About BJTs VS Laterals for power devices, i tend to prefer laterals for their safety and simplicity (no temps compensation needed, no secondary breakdown).
I believe the best is in the middle, as always.
The other thing is what we are looking for, when designing. I mean, on what are-we concentrating, speed (slew rate), or harmonic distortion ? Not an easy thing to answer, as nobody has an idea of the thresholds and their effects on listening experience.
Too the quality of the boards and parts are very important on the sonic signature. On my side, I tend to prefer SMDs, as it reduce the path lengts and parasitics, and most efforts of the manufacturers are focused on this kind of components, nowadays.
About BJTs VS Laterals for power devices, i tend to prefer laterals for their safety and simplicity (no temps compensation needed, no secondary breakdown).
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Thoughts and Ideas...
When looking at making products you definitely don't want to be on the
bleeding edge...
Use the one design that makes the most bang for the buck!
Then simplify, test, simplify, test. Then abuse it to see how
it lasts. You've got a great core group here use it.
The NEW financial model is collaborative and distributed payments.
That is if you are going to do this as a business then you set up
some type of payment for people's contributions and efforts.
Hard to figure it all out but you have to try, so people will do
more than help a little bit.
Don't let the bean counter's run things. Let them count the
beans. But know they can help you get the numbers.
Then get your process down of how your going to make or buy
parts, boards, amps etc. The most important job a manager has is to differentiate between causes with in the process and those causes out side the process.
For everyone who's not familiar with these processes it goes somethink
like this:
A. You have a bus driver who picks up kids and drops them off at school.
Within a few days we know it takes 20 mimutes + or - 5 mins to pick up
and drop off kids at school. This is your process, it is in
statistical process control...don't freak out because of the words.
B. ON day ten the bus arrives 15 minutes late.
1. Do give the driver a warning and threaten him to hurry up?
2. Do you look for the root cause and find out the door handle
broke and it will take a week for the new part so the schedule
is adjusted. Then resume back to normal schedule.
C. ON day 35 the bus arrives 8 minutes late.
1. Do you write up the driver and threaten a loss of pay?
2. Do you look for the root cause and find out the school
changed the route because of an accident.
D. On the rest of the days the bus arrives as scheduled.
Also, if you want it to succeed it has to be delegated to a few
people. No one person can do it all really well now days. Find
the folks who will help you succeed.
Finally, if you want this thing to really succeed, you have to make
it sexy. Don't name the thing a quark, or some obsure non sexy
thing. It has to look good and function. It has to be elegant,
streamlined, and in good form...even if it incrementally a bit
more....IT WILL PAY OFF.
They didn't name that car a "sheep" or an arschloch17.
The called them Mustang's, Z28s, Corvettes, SSs, etc.
not and Edsel either.
Ya'll get what I mean with this post. None of this is trival,
and if it gets screwed up many people will have a lot of parts
that won't sell. You can do everything right also and not
make it. What everyone wants though is to get lucky.
Doing all the back ground work helps you get lucky.
Oh and one more thing...follow R. Sutton's guiding words here - L I N K.
Cheers,
When looking at making products you definitely don't want to be on the
bleeding edge...
Use the one design that makes the most bang for the buck!
Then simplify, test, simplify, test. Then abuse it to see how
it lasts. You've got a great core group here use it.
The NEW financial model is collaborative and distributed payments.
That is if you are going to do this as a business then you set up
some type of payment for people's contributions and efforts.
Hard to figure it all out but you have to try, so people will do
more than help a little bit.
Don't let the bean counter's run things. Let them count the
beans. But know they can help you get the numbers.
Then get your process down of how your going to make or buy
parts, boards, amps etc. The most important job a manager has is to differentiate between causes with in the process and those causes out side the process.
For everyone who's not familiar with these processes it goes somethink
like this:
A. You have a bus driver who picks up kids and drops them off at school.
Within a few days we know it takes 20 mimutes + or - 5 mins to pick up
and drop off kids at school. This is your process, it is in
statistical process control...don't freak out because of the words.
B. ON day ten the bus arrives 15 minutes late.
1. Do give the driver a warning and threaten him to hurry up?
2. Do you look for the root cause and find out the door handle
broke and it will take a week for the new part so the schedule
is adjusted. Then resume back to normal schedule.
C. ON day 35 the bus arrives 8 minutes late.
1. Do you write up the driver and threaten a loss of pay?
2. Do you look for the root cause and find out the school
changed the route because of an accident.
D. On the rest of the days the bus arrives as scheduled.
Also, if you want it to succeed it has to be delegated to a few
people. No one person can do it all really well now days. Find
the folks who will help you succeed.
Finally, if you want this thing to really succeed, you have to make
it sexy. Don't name the thing a quark, or some obsure non sexy
thing. It has to look good and function. It has to be elegant,
streamlined, and in good form...even if it incrementally a bit
more....IT WILL PAY OFF.
They didn't name that car a "sheep" or an arschloch17.
The called them Mustang's, Z28s, Corvettes, SSs, etc.
not and Edsel either.
Ya'll get what I mean with this post. None of this is trival,
and if it gets screwed up many people will have a lot of parts
that won't sell. You can do everything right also and not
make it. What everyone wants though is to get lucky.
Doing all the back ground work helps you get lucky.
Oh and one more thing...follow R. Sutton's guiding words here - L I N K.
Cheers,
Sync,
That sounds like you have been in the trenches and understand both Lean and 6-sigma concepts along with some simple business concepts of collaboration. I am very much in that camp, it has taken a long time to understand the nuances of many different fields to be able to do that.
On the other hand I would say that though OS has done the real lifting here it has been the builders such as Terry, Bimo and Thimios who have found some real issues that between them all have seemed to be worked out. Now which of the many designs to use is going to come down to personal preferences at this point I think.
Esperado has just stated his preference for lateral mosfet output devices and others may not want that for a particular reason but OS has allowed for those to be used and has given some variables to be able to do that. I can't imagine this thread being more open or more collaborative in the non commercial sense.
I am the outlier here, I want to use these amps in a commercial product, I can't expect to hijack this thread for my purposes. I can simply offer to renumerate OS for using his designs in the end. That is my plan, I would feel the thief if I just copied his work and sold it as mine. On the other hand I do need to change things, I need much less power for a dome tweeter and even my high power needs would never use over 3 pairs of output devices. I need smd devices to make this all small enough but I don't consider that a true design change in the sense that it isn't still using the same topology, it is just another way to do the same thing.
I really hope that the person I asked to collaborate with me will come on board, if not I will find someone else willing to do that and get me to where I am trying to go. The offer was real and we live close enough together that it would make things much simpler. I need major help on the digital side of things, otherwise I could just make an active xo and use OS's designs as is and just run with it.
I don't want to take OS away from what he is doing, he has offered and given a real service here for all the diy community. I wouldn't be surprised in the least if we don't see some other commercial amps based on this work coming from somewhere in Asia before we even know it has happened, many people who will never post here are watching, that is obvious from the numbers who have viewed this thread.
That sounds like you have been in the trenches and understand both Lean and 6-sigma concepts along with some simple business concepts of collaboration. I am very much in that camp, it has taken a long time to understand the nuances of many different fields to be able to do that.
On the other hand I would say that though OS has done the real lifting here it has been the builders such as Terry, Bimo and Thimios who have found some real issues that between them all have seemed to be worked out. Now which of the many designs to use is going to come down to personal preferences at this point I think.
Esperado has just stated his preference for lateral mosfet output devices and others may not want that for a particular reason but OS has allowed for those to be used and has given some variables to be able to do that. I can't imagine this thread being more open or more collaborative in the non commercial sense.
I am the outlier here, I want to use these amps in a commercial product, I can't expect to hijack this thread for my purposes. I can simply offer to renumerate OS for using his designs in the end. That is my plan, I would feel the thief if I just copied his work and sold it as mine. On the other hand I do need to change things, I need much less power for a dome tweeter and even my high power needs would never use over 3 pairs of output devices. I need smd devices to make this all small enough but I don't consider that a true design change in the sense that it isn't still using the same topology, it is just another way to do the same thing.
I really hope that the person I asked to collaborate with me will come on board, if not I will find someone else willing to do that and get me to where I am trying to go. The offer was real and we live close enough together that it would make things much simpler. I need major help on the digital side of things, otherwise I could just make an active xo and use OS's designs as is and just run with it.
I don't want to take OS away from what he is doing, he has offered and given a real service here for all the diy community. I wouldn't be surprised in the least if we don't see some other commercial amps based on this work coming from somewhere in Asia before we even know it has happened, many people who will never post here are watching, that is obvious from the numbers who have viewed this thread.
Every time I built an amp, it sound differently (may be just a little bit). Some topology have sonic signature like symmetry/leach, CFA, and Lin/Blameless.
I tried Hugh Dean's design philosophies (H2 or monotonic harmonic profile and high slew rate), too. And it sound different and it has some fans here.
In my experiment, Lin/Blameless topology can sound "airy" if it have enough slew rate. I made Lin/Blameless amp using +-45VDC PSU. In first simulation, it have about 40V/uS slew rate and can not sound "airy". Then, I modified the compensation to get around 72V/uS... yes! it sound "airy".
Can someone explain these sonic signatures? Or, it just "unmeasurable"?
I tried Hugh Dean's design philosophies (H2 or monotonic harmonic profile and high slew rate), too. And it sound different and it has some fans here.
In my experiment, Lin/Blameless topology can sound "airy" if it have enough slew rate. I made Lin/Blameless amp using +-45VDC PSU. In first simulation, it have about 40V/uS slew rate and can not sound "airy". Then, I modified the compensation to get around 72V/uS... yes! it sound "airy".
Can someone explain these sonic signatures? Or, it just "unmeasurable"?
Yes , A hands down salute to Thimios,Terry,and both JK/JW !!
(and others)...
Heatsink USA is sending me my extrusions this morning , forgot to
tell them my house # ... 😱 .
Messed up my chinese ones 😱 - 70$ mistake will make me stronger.
I really am going to make a small amp with combo smd/through-hole.
Our commercial vendors are a good place to look for "style".
I think a 76 X 76-100mm full amp with caps/coil - everything is possible.
The design will be the Kypton ND ! I "revisited" that design last night.
I DID NOT optimize it when I first designed it.
- Run the diamond (collectors) from a better regulated 12V supply , instead of the rails.
-lowering my dual current FB node resistances.
- Just 1ma diamond / 1.6ma NFB stage - 5.3ma Ivas.
-C5 = 1uF ( 2-3ppm was the servo FB !!)
What did I get (below) -
A IPS that even beats the "blameless" -
IN EVERY metric (pssr , THD , definitely slew -350v/us , offset).
I'm quite amazed , even.
Sub PPM <10K any power (below 2) !
At 20K , it scales from 2ppm to 12ppm ( 10W - 100W)
(Below 3) are the changes - original PCB is unchanged. I'll do a
new updated one to match the new OPS. This is the one I'll
also send to RN Marsh when he gets back from Thailand.
Bet it beats most forum amps !!!
OS
Attachments
Nice to see your housekeeping, that is clearly pusling performance up, you can even make it DC coupled and loose the input caps, another possibility is to have base stoppers at the output of the diamond and some C to GND for the RF filtering, this will also make it possible to stick a volume control in front of the amp, with out changing bandwidth with volume setting.
Pete,
Check your wife's mail tomorrow, you should receive a package with the diptrace and the other software. Sorry it took so long I couldn't for the life of me get my laptop to burn a disk, I think it is time for a new dvd burner for it though I hardly ever used the damned thing. I finally went to my old desktop and fought with that. Then I realized that for some reason many of the blank DVD+R disks would not format, no rhyme or reason to it, some would format and other would just tell me there was no disk in the drive, very frustrating for sure. I got it done finally. I'm sure you will have lots of questions about that software, it is not intuitive in the least. I have multiple books and took two semesters of college level classes to get it down and that was just the basics.
I appreciate what you are doing and I surely didn't mean to leave our two Canadian friends off the list of people who have helped to get all these amps sorted out and working on your Pitchfork pre. That Pre is just way more than I want to do inside my speaker and I don't want multiple boards and all the Arduino way of doing things, it doesn't need to be that complicated for my usage. I'll let someone else who understands all this figure out how to do this simply. The only other thing I am considering is a simple RIAA TT preamp board so someone could hook a turntable up directly but that may be to much to ask, how you would do any volume control could just be a PITA. It would be cool though as I don't see anyone doing anything like that on anything commercial in a self powered speaker. Vinyl seems to be alive and well and having a resurgence. A simple opamp based RIAA circuit would be as far as I would take that, not worth chasing high quality with vinyl I don't think.
A mini Blowtorch with Bybee devices oh my! Just kidding on that one!
Check your wife's mail tomorrow, you should receive a package with the diptrace and the other software. Sorry it took so long I couldn't for the life of me get my laptop to burn a disk, I think it is time for a new dvd burner for it though I hardly ever used the damned thing. I finally went to my old desktop and fought with that. Then I realized that for some reason many of the blank DVD+R disks would not format, no rhyme or reason to it, some would format and other would just tell me there was no disk in the drive, very frustrating for sure. I got it done finally. I'm sure you will have lots of questions about that software, it is not intuitive in the least. I have multiple books and took two semesters of college level classes to get it down and that was just the basics.
I appreciate what you are doing and I surely didn't mean to leave our two Canadian friends off the list of people who have helped to get all these amps sorted out and working on your Pitchfork pre. That Pre is just way more than I want to do inside my speaker and I don't want multiple boards and all the Arduino way of doing things, it doesn't need to be that complicated for my usage. I'll let someone else who understands all this figure out how to do this simply. The only other thing I am considering is a simple RIAA TT preamp board so someone could hook a turntable up directly but that may be to much to ask, how you would do any volume control could just be a PITA. It would be cool though as I don't see anyone doing anything like that on anything commercial in a self powered speaker. Vinyl seems to be alive and well and having a resurgence. A simple opamp based RIAA circuit would be as far as I would take that, not worth chasing high quality with vinyl I don't think.
A mini Blowtorch with Bybee devices oh my! Just kidding on that one!
I had the C to earth , took it off to see if I retained the >300v/us.
(See the empty lines near R1).
You are right on that this amp could lose the input cap. Still , that would
expect a very low DC (offset) source or a capacitor coupled output.
I'll try the basestoppers at Q3/4 , what would this do ? more stability ?
It seems mighty stable now.
The ultimate new layout of this CFA will determine those last few PPM,
for sure. Symetri's style I think is best.
OS
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I got it. I also got it from JW , as well.
Everybody is so helpful - I must match or exceed those commercial offerings.
But that is scary .... would they be mad if I offered better stuff for
a song (like the asians - sort of ??).
What I mean , some of these creations could take "candy" away from
a commercial interest.
This CFA most definitely outperforms the "simple CFA" (you know the one).
No matter what else is said (commercially) - it does in every way.
OS
IMHO people buying the commercial product are after a different experience then the folks here. Using a product that is that much "done", at least for me, is much less satisfying.
Yes , If I "ace" diptrace and make a SMD/through-hole hybrid -
The input stage/VAS would most likely be "done". To still have it as
a "kit" , the end user could solder the caps/outputs in.
Would just have to make a "jig" to loopback from an external OPS ,
test the IPS , package it. (with a test paper - "born on 7/10/15"). 🙂
OS