Guys,
We've been talking and giving advice without listening to geolemon.
There are people that like watching different activities on TV(watchers) and people that like DOING them. Most people on this forum are from the second group (doers) and don't understand the thinking of the people from the first group (the watchers). They are fine. That's what they LIKE to do. There’s nothing wrong with that. But don't expect them to go DO the things they like watching. Just try to understand them (doesn't mean agree with them either). And don't try to judge them please.
Thanks for reading my rant.
/Greg
We've been talking and giving advice without listening to geolemon.
There are people that like watching different activities on TV(watchers) and people that like DOING them. Most people on this forum are from the second group (doers) and don't understand the thinking of the people from the first group (the watchers). They are fine. That's what they LIKE to do. There’s nothing wrong with that. But don't expect them to go DO the things they like watching. Just try to understand them (doesn't mean agree with them either). And don't try to judge them please.
Thanks for reading my rant.
/Greg
I had similar thoughts this morning and almost wanted to aplogize to geomelon for making him feel insulted. He has the right to choose any approach he wishes in his quest for knowledge and it shouldn't be any of my concern.
I just find it difficult to comunicate in that sort of situations (or inquiries). So, once again, I'm sorry for my previous misbehaviour.
I just find it difficult to comunicate in that sort of situations (or inquiries). So, once again, I'm sorry for my previous misbehaviour.
Just another illustration, that everyone's brain work differently.
I had a programmer working for me and he used to write programs out by hand on paper. I couldn't believe it. A thousand lines of code written by hand on paper and not tested. He was reasonably inexperienced in programming but read all the books on how to program and digested hundreds of example code. Well, when he typed it all in the program actually worked first time as designed. Unbelivable!
Although this chap "appeared" to be slow and only average intelligence, once given a task he would always do the research and produce outstanding results. The ideal employee! I learnt a lot from this experience. You have to let people do things their way. Encourage them and offer advice by all means, but remember your "right" way may not be their "right" way.
I had a programmer working for me and he used to write programs out by hand on paper. I couldn't believe it. A thousand lines of code written by hand on paper and not tested. He was reasonably inexperienced in programming but read all the books on how to program and digested hundreds of example code. Well, when he typed it all in the program actually worked first time as designed. Unbelivable!
Although this chap "appeared" to be slow and only average intelligence, once given a task he would always do the research and produce outstanding results. The ideal employee! I learnt a lot from this experience. You have to let people do things their way. Encourage them and offer advice by all means, but remember your "right" way may not be their "right" way.
well, thank you, and believe me I do appreciate it... and it's no skin off my back, because I'll forget all about it by next tuesday or so at any rate... I tend to do that...Peter Daniel said:
My reason for being insulted were the misconclusions and judgements.
I'm very much someone who does, not an observer (I even wrote an article called "doers and viewers" once
)... I think if you click the "www" button and spent a little time on my webpage, you'll see I do experiment quite a bit...I like to experiment where others have not, though.
I've become literally drawn into the audio industry behind the scenes (even pondering leaving my DBA career fully) as the result of a hobby gone out of control... In fact, I was initially tapped on the shoulder because of the projects I've done... someone who was just participating on some other forums with me (things have come a long way since my old TI 99/4A I'll tell you...
).The reason we are where we are in history, technologically speaking, is because one person learned from those who came before them.
Heck, that's what school and college are for, fundamentally. That's what learning is.
Like a big tower of Lego blocks... previous knowledge laying the foundation for the tower to rise higher.
I'm just trying to find that foundation.
It's probably also worth noting that I'm very committed to building one of these. Make that a few...
I'm not sure where the impression came from, if one was out there, that I'm not.
Since I can't start a project right now (too many other projects converging), but since I am interested, I figured at least mentally I can get prepared.
Bear in mind, previous to coming here, I didn't know what componentry was involved, how much of the overall amplifier circuit was encompassed in "the chip", what could be tweaked and manipulated for specific applications... much less what chips were for what applications, whose schematics to use and why, what components to select for the build, etc.
Even being probably the least experienced, least informed person on this forum with regard to chip amps, my level of knowledge on the topic has increased already by orders of magnitude since reviewing information in this thread... many thanks.
My mind is still somewhat in shock, also, regarding the whole concept...
It's amazing to see the benefit of these designs apparently coming from an intentional reduction of components.
But when I look inside something like say... a 25" long 150x2 Alpine car amplifier, with a completely loaded circuit board within... just a [relatively] massive number of parts contained within... or a QSC MX1450, likewise... it certainly begs the question "why?", doesn't it?
I'm all for simplicity.
It's been a while since I read it... but I found my original Word draft, so I thought i'd attach it.GregGC said:
I thought you might be interested, and upon reviewing it, I think there's a lot that relates to this thread... even though otherwise it's just a tad OT...
(I've never attached anything here, so hopefully it will work!)
(edit: oop, had to zip it)
geolemon said:
But when I look inside something like say... a 25" long 150x2 Alpine car amplifier, with a completely loaded circuit board within... just a [relatively] massive number of parts contained within... or a QSC MX1450, likewise... it certainly begs the question "why?", doesn't it?
I'm all for simplicity.
You might find some explanation to that here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=9270&perpage=15&highlight=&pagenumber=1
especially by checking the post of one Kuei Wang Yang
Thanks, that's a great link...
As is the link you posted on the first page of that page.
I've got a set of 6.5" Vifa mids and some brand new Focal T90K tweeters sitting around here, and I believe I have the proper caps, coils, and resistors sitting around to do a 2.5Khz Xover for them with any L-padding that might be desired...
I'm going to whip up a small pair of simple, oversized "not much effort" sealed and stuffed bookshelves, so that I've got something to use for testing with, when I build my first one...
It really doesn't look like there's a lot to get wrong, but I've seen a few comments here and there about potentially frying the load... I'd rather fry something I don't care much about, I think...
btw... do you think it's wise to build the prototype on a breadboard, or is that asking for trouble?
I just made a Parts Express order, and I had a pair of small breadboards in my cart.. and then I thought that itself sounded risky.. if the chip would even fit, what happens if a jumper comes loose, etc...
And I haven't seen anyone do it that way here.
But on the other hand, I would like to experiment swapping out things... particularly things like the same value components, "cheap" to "high-end", things like that... even fundamentally seeing what these different schematics are all about.
If no breadboard... are you just desoldering components to try another?
Which brings me to another concern... my soldering iron is rather large, and I have the worst little desoldering sucker I've ever seen... I'm sure I'll need to pick up a better small soldering/desoldering station... any suggestions for good value?
As is the link you posted on the first page of that page.
I've got a set of 6.5" Vifa mids and some brand new Focal T90K tweeters sitting around here, and I believe I have the proper caps, coils, and resistors sitting around to do a 2.5Khz Xover for them with any L-padding that might be desired...
I'm going to whip up a small pair of simple, oversized "not much effort" sealed and stuffed bookshelves, so that I've got something to use for testing with, when I build my first one...
It really doesn't look like there's a lot to get wrong, but I've seen a few comments here and there about potentially frying the load... I'd rather fry something I don't care much about, I think...
btw... do you think it's wise to build the prototype on a breadboard, or is that asking for trouble?
I just made a Parts Express order, and I had a pair of small breadboards in my cart.. and then I thought that itself sounded risky.. if the chip would even fit, what happens if a jumper comes loose, etc...
And I haven't seen anyone do it that way here.
But on the other hand, I would like to experiment swapping out things... particularly things like the same value components, "cheap" to "high-end", things like that... even fundamentally seeing what these different schematics are all about.
If no breadboard... are you just desoldering components to try another?
Which brings me to another concern... my soldering iron is rather large, and I have the worst little desoldering sucker I've ever seen... I'm sure I'll need to pick up a better small soldering/desoldering station... any suggestions for good value?
I don't think a breadbord would be a problem. Break off all unnecessary pins from a chip (so it's easier to work with) and attach small extention wires to the pins (so it fits the breadboard better). Make sure that feedback resistor is closest to the chip. The heatsink requirement is not big and for normal listening a 5" x 5" aluminum plate should is enough.
I absolutely love my Weller. It heats up within 10 - 15 seconds after power up and is very responsive to temp changes. I had a Radioshack 45W one before this and it took 2 - 3 minutes to fully heat up. The tip lasted maybe two weeks. It only did cost me $15 though.
Even though the nice ones will set you back a few dollars, I'd still say they're the better value. With proper care, tips can last a long time and there are a wide variety available for the station-type irons. I can see myself using it many years down the road, so thats how I justified it. That and it doesn't nearly test my patience like that old heat stick.
grege said:
I don't quite see why people seem so surprised and amazed at
this. Yes, if the code actually worked immediately, that is very
unusal. However, as a methodology, it is largely what I would
call "the right" approach and similar to how we teach our
university students to approach programming. It is usually very
pointless to start programming haphazardly. It typically leads
to longer development time and inferior end results. Many
companies force their programmers to work in a different way,
usually because the bosses don't understand programming and
software project management, they have unrealistic deadlines
and are more interested in getting something done than getting
something in particular done or the design spec. is so unclear
that the programmers have to start writing code and ask "is
this what you want?"
Matjans agrees with many here, that doing is better than theorizing BUT he parenthetically mentions a very important point. The guys that ski and sail etc. beautifully, not only spend huge amounts of time actually doing their activity, but the BEST invariably have taken lessons or have a mentor. I've seen lots of skiers that think they are great, but their form is poor in ways that limit their advancement. Sailing racing is also tricky-it looks easy but is almost infinately difficult. Without some instruction it takes 10 times as long to advance in many activities. So, I think it is generally a good strategy in life to ask some questions and get a theoretical background before setting out- especiallyif one doesn't have a mentor or teacher close by.
Geolemon may have made the assumption that many who play with chipamps have profound understanding of exactly what happens inside the chip-that they are choosing ancillary parts based on some in depth understanding of exactly what's in the chip.
Now this should be somewhat sobering to some here, but a lot of the appeal of the chip amps is that you can come up with great sounding amps and "play" at being a designer by just treating the chip as a black box with the only knowledge you have being what the external traces are for from the spec sheet. The currently popular gainclones are wired up exactly as the manufacturer suggests. Merely swapping 4 components in and out of a design isn't a very profound level of electronic expertise, no matter how good it sounds.
Perhaps Geolemon is interested in electronics, not just making a good sounding amp. In that case he is going to eventually surpass those that don't aspire to greater depth of knowledge.
In case I've irritated some here- I admit freely I'm in the "play" designer camp. Few are as ignorant here as I, yet having spent a lot of time at this forum , I have picked up a lot of knowledge. If in ADDITION to spending 6 hours a week here, I'm sure I would have been better served by studying some books and taking an electronics class a couple of hours a week at the local junior college than spending those same 2 hours here.
On the other hand- what is really cool about electronics is that making stuff is an essential part to learning. MAN do I have lot of questions when I actually have to order parts, and hook 'em up.
Geolemon may have made the assumption that many who play with chipamps have profound understanding of exactly what happens inside the chip-that they are choosing ancillary parts based on some in depth understanding of exactly what's in the chip.
Now this should be somewhat sobering to some here, but a lot of the appeal of the chip amps is that you can come up with great sounding amps and "play" at being a designer by just treating the chip as a black box with the only knowledge you have being what the external traces are for from the spec sheet. The currently popular gainclones are wired up exactly as the manufacturer suggests. Merely swapping 4 components in and out of a design isn't a very profound level of electronic expertise, no matter how good it sounds.
Perhaps Geolemon is interested in electronics, not just making a good sounding amp. In that case he is going to eventually surpass those that don't aspire to greater depth of knowledge.
In case I've irritated some here- I admit freely I'm in the "play" designer camp. Few are as ignorant here as I, yet having spent a lot of time at this forum , I have picked up a lot of knowledge. If in ADDITION to spending 6 hours a week here, I'm sure I would have been better served by studying some books and taking an electronics class a couple of hours a week at the local junior college than spending those same 2 hours here.
On the other hand- what is really cool about electronics is that making stuff is an essential part to learning. MAN do I have lot of questions when I actually have to order parts, and hook 'em up.
Inverting amp
Hi Geolemon,
On page 19 of the datasheet of the LM4780 I've found that a inverting amplifier has less distortion than a non-inverting amplifier. What do you think about this. There is also a lot of good to learn information in this datasheet. (look with Google)
Best regards
Kurt
Hi Geolemon,
On page 19 of the datasheet of the LM4780 I've found that a inverting amplifier has less distortion than a non-inverting amplifier. What do you think about this. There is also a lot of good to learn information in this datasheet. (look with Google)
Best regards
Kurt
geolemon,
i think you are right about gaining understanding about something before you actually does it. this is true, as i myself do not follow blindly any schematics without pondering about 'what makes it so good?'
but i believe moderate knowledge with trial & error experience is more effective than 100% knowledge alone. when i first started building amps, i read and read and read the datasheets, and figured out how to get the juiciest sound from a chip. However, the books dont tell me certain (practical) things, like using star grounding, using thick wires in certain places, etc..
Books wont tell me that certain types of components will 'colour' my sound in a particular way, for example, the values for my power supply capacitors. Common knowledge is to use >2200 uF per ampere load current, and as in the case of LM3886, that shout be more than 10,000uF. however, by experimenting, people found out that 2200uF is the best value, as it gives the best blah-blah-blah. (you get the idea)
another example is experimenting with the types of op-amp. on paper, an opamp might look good, but when tested in reality, it sounds 'dead'. do you know that a very old, noisy, obselete, lousy opamp (JRC4558D) is one of the best opamps to be used in a distortion device? changing it with a modern opamp will not give that sweet crunch, no matter how good is it on paper. and i certaintly do not want to waste my time looking at the chips under the microscopes....etc.
this is a DIY forum. we experiment with different stuffs, and we share the knowledge we have learned with everybody else. what we lacked with theories, we compensate with experience. I am not an electronics student, but believe me, I can make better amps than most of my friends in electronics courses. They may know more than me, but i have the fullfilment of building something good and listening to it.
if i offended you in any way, im sorry, im just sharing you my thoughts.
i think you are right about gaining understanding about something before you actually does it. this is true, as i myself do not follow blindly any schematics without pondering about 'what makes it so good?'
but i believe moderate knowledge with trial & error experience is more effective than 100% knowledge alone. when i first started building amps, i read and read and read the datasheets, and figured out how to get the juiciest sound from a chip. However, the books dont tell me certain (practical) things, like using star grounding, using thick wires in certain places, etc..
Books wont tell me that certain types of components will 'colour' my sound in a particular way, for example, the values for my power supply capacitors. Common knowledge is to use >2200 uF per ampere load current, and as in the case of LM3886, that shout be more than 10,000uF. however, by experimenting, people found out that 2200uF is the best value, as it gives the best blah-blah-blah. (you get the idea)
another example is experimenting with the types of op-amp. on paper, an opamp might look good, but when tested in reality, it sounds 'dead'. do you know that a very old, noisy, obselete, lousy opamp (JRC4558D) is one of the best opamps to be used in a distortion device? changing it with a modern opamp will not give that sweet crunch, no matter how good is it on paper. and i certaintly do not want to waste my time looking at the chips under the microscopes....etc.
this is a DIY forum. we experiment with different stuffs, and we share the knowledge we have learned with everybody else. what we lacked with theories, we compensate with experience. I am not an electronics student, but believe me, I can make better amps than most of my friends in electronics courses. They may know more than me, but i have the fullfilment of building something good and listening to it.
if i offended you in any way, im sorry, im just sharing you my thoughts.
Inverting has lower distortion
GreqCk:
Indeed the capacitor and resistor can be changed for a lower roloff frequentie.
But the question is: Why National says in the application note that the distortion has better perfornance when you use an inverting amplifier? Is there anyone who knows this?
Regards
Kurt
GreqCk:
Indeed the capacitor and resistor can be changed for a lower roloff frequentie.
But the question is: Why National says in the application note that the distortion has better perfornance when you use an inverting amplifier? Is there anyone who knows this?
Regards
Kurt
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