But, it does allow you to get mighty close. If the model of the circuit element is not accurate enough, as is, for the particular situation then there is nothing stopping you, or anyone else from adding a higher level of complexity to the modelling, by creating subcircuits and arbitrary behaving elements which can have a level of sophistication, to as far as you want to push the maths. If that's what it takes to get accurate behaviour, then go for it - LTspice has the flexibility to do all of that ...
When I did my modelling of power supply behaviour, taking into account some of the "funnies", and compensated to suit, I was pleased to see multimeter readings which agreed pretty well with what LTspice reckoned would then happen.
If the tool does the job well enough to get a useful result, then that's all that matters ...
Frank
When I did my modelling of power supply behaviour, taking into account some of the "funnies", and compensated to suit, I was pleased to see multimeter readings which agreed pretty well with what LTspice reckoned would then happen.
If the tool does the job well enough to get a useful result, then that's all that matters ...
Frank
Sorry, that should be 'second VOLTAGE' breakdown. Damn!.... You can not understand that until you have taken a TO3 metal device to pieces and checked out the thickness of the leads that go from the pins to the chip on the substrate. Some devices are filled with heat conducting paste too, where as others aren't. LT Spice wont tell you which devices can be pushed or even meet spec, and which don't or can't.
Fair enough in the sense you're asserting, that can only be found out via unpleasant experience, or wise words passed on. But once you know, and if you're stuck with using the "baddies", then there's nothing stopping you creating a variation, a "lesser" sibling, in the program with the poorer behaviour tacked on.
Everyone knows a dodgy connection, anywhere, is not going to help sound quality. What the world needs is a comprehensive Spice model for that particular, infinitely variable, nasty ... anyone got one?
Frank
Now that I've mentioned Spice a few times, it's worthwhile pointing out further why this will take a little time. By some strange means a couple of circuit diagrams which supposedly strongly resemble what the schematic of such a beast is, now reside on my hard disk. They, of course, disagree so the real thing is some variation of what they detail.
Now, my general way of working is to fully understand what the impact of a change made is electronically, which is where LTspice comes in. It tells me the theoretical implications, assuming perfect or controlled imperfect behaviours, of doing things. In the old days I willy nilly added cap's and suchlike in the hope that there would be some benefit, now I aim to have much more ammunition from a simulation to know where I can do real damage, in a positive sense. I'm after a ten-fold improvement, not a mere 10%.
So, I need, or better put, I want to know how the monitor works. Electronically. And this is tedious, unless someone knows a magic means of transcribing real circuits into a capture program. Some time back, I looked around and there was no falling off a log solution. So, at the moment I working on using a screen version of the tracing paper technique, and need to rev myself up to get on with doing this.
Of interest, pick up a classic el cheapo Casio scientific calculator. That's a perfect match in size and bulk of the total circuitry, apart from the transformer and the odd switches! A couple of smoothing caps are chimneys on the board, but that's it - scary, eh? Yet, in the pro shop where I bought it this fellow was pounding out a sound level that would shame a great deal of high end gear ... will wonders never cease?
Frank
Now, my general way of working is to fully understand what the impact of a change made is electronically, which is where LTspice comes in. It tells me the theoretical implications, assuming perfect or controlled imperfect behaviours, of doing things. In the old days I willy nilly added cap's and suchlike in the hope that there would be some benefit, now I aim to have much more ammunition from a simulation to know where I can do real damage, in a positive sense. I'm after a ten-fold improvement, not a mere 10%.
So, I need, or better put, I want to know how the monitor works. Electronically. And this is tedious, unless someone knows a magic means of transcribing real circuits into a capture program. Some time back, I looked around and there was no falling off a log solution. So, at the moment I working on using a screen version of the tracing paper technique, and need to rev myself up to get on with doing this.
Of interest, pick up a classic el cheapo Casio scientific calculator. That's a perfect match in size and bulk of the total circuitry, apart from the transformer and the odd switches! A couple of smoothing caps are chimneys on the board, but that's it - scary, eh? Yet, in the pro shop where I bought it this fellow was pounding out a sound level that would shame a great deal of high end gear ... will wonders never cease?
Frank
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Of interest, pick up a classic el cheapo Casio scientific calculator.
That's a perfect match in size and bulk of the total circuitry, apart
from the transformer and the odd switches! A couple of smoothing
caps are chimneys on the board, but that's it - scary, eh?
Yet, in the pro shop where I bought it this fellow was pounding out a sound level
that would shame a great deal of high end gear ... will wonders never cease?
Frank
Hi, What on Earth are you talking about ? rgds, sreten.
Of interest, pick up a classic el cheapo Casio scientific calculator. That's a perfect match in size and bulk of the total circuitry, apart from the transformer and the odd switches! A couple of smoothing caps are chimneys on the board, but that's it - scary, eh? Yet, in the pro shop where I bought it this fellow was pounding out a sound level that would shame a great deal of high end gear ... will wonders never cease?
Frank
I do not know what are you smoking or taking but that must be very, very powerful stuff...
Salvia divinorum?
Gee whiz, do I have to spell it out?
. Bought a small Behringer active monitor, ie., all the circuitry, input side, active filters, power amps, power supply sits on the back of the carcase under a metal cover. Took the cover off, and laughed - pick up a calculator, or a decent remote. That's the size of the one and only circuit board, and the only components of any height were the twin power supply main capacitors. The whole lot would easily fit into a 70's hand held trannie. Or a couple of stacked smart phone ...But, this miniscule lot of circuitry was pumping out pretty clean dB's, enough to give you hearing damage after 5 minutes or so ...
Frank
Gee whiz, do I have to spell it out?
Frank
Your allusion is immensely and stupidly obscure, so yes you do.
Which actual model would be a useful place to start a discussion. Modern
surface mounted technology, switching supplies, class D amplifiers etc as
far as I can tell means you haven't a hope in hell of improving anything.
So nothing remotely related to this threads original premise.
And still no remotely useful insight from your re-engineering
of all and sundry to claimed perfection for the last 25 years.
Do I have to spell it out ? This thread is self-egotistic nonsense.
rgds, sreten.
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Okay, B2030: yes, not even a B2031, which is nominally going to do better bass, from a bigger bass driver and bigger carcase. I heard both, and preferred the lesser fellow, a key element is that the smaller box is intrinsically more structurally rigid, will enable better damping of vibration. What I particularly liked is that the bass driver behaved itself when driven hard -- none of this flopping around at very visually discernable frequencies so beloved by makers of ads -- which indicates to me the bass amplifier was working correctly.
The circuit design is very standard -- I don't want to get in trouble from Behringer, so won't mention specifics of parts used, unless I get the OK that that's all right to do -- and there are schematics out there of B2031, Mackie, Phonics: all use the same concepts.
Which is, normal rectifier, smoothing cap main supply, going through very basic regulators to supply the filtering subcircuit. ST chip amps, on amazing small heatsinks. A nice touch, well overspecified units used, these are capable of 100W if fed the right voltages, etc. Down the track I might explore adding an extra transformer to up the supply rails and get there, there's tons of room under the metal lid to put extra goodies in. Which means, if I do everything right, real 200W per side active monitors, I should be able to push 120dB peak SPL at 1 metre, for a pair - just what the pro manufacturers do!!
Frank
The circuit design is very standard -- I don't want to get in trouble from Behringer, so won't mention specifics of parts used, unless I get the OK that that's all right to do -- and there are schematics out there of B2031, Mackie, Phonics: all use the same concepts.
Which is, normal rectifier, smoothing cap main supply, going through very basic regulators to supply the filtering subcircuit. ST chip amps, on amazing small heatsinks. A nice touch, well overspecified units used, these are capable of 100W if fed the right voltages, etc. Down the track I might explore adding an extra transformer to up the supply rails and get there, there's tons of room under the metal lid to put extra goodies in. Which means, if I do everything right, real 200W per side active monitors, I should be able to push 120dB peak SPL at 1 metre, for a pair - just what the pro manufacturers do!!
Frank
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I don't know what you were expecting or thought you would find inside a B###ringer product but that's what they are fas42.....cheap built knock off electronics designs, parts and labor.
They cater their products to people who don't know any better and think $150 will buy you a pair of reference monitors! There not even good enough to be hi-fi at half that price!
Anyone who is involved in the professional audio field knows that fact...LOL
I would highly recommend you go buy a pair of Bowers &Wilkins Diamond Series 800's. You should tear those apart and modify them!
Listen to them first though before you "fix" the power supply..
They cater their products to people who don't know any better and think $150 will buy you a pair of reference monitors! There not even good enough to be hi-fi at half that price!
Anyone who is involved in the professional audio field knows that fact...LOL
I would highly recommend you go buy a pair of Bowers &Wilkins Diamond Series 800's. You should tear those apart and modify them!
Listen to them first though before you "fix" the power supply..
Okay, just being cautious. First time I've done this sort of thing, so don't want to step on company toes. Plus, my photo'ng days are well behind me, I have zero interest in doing such things unless if it serves a very direct, immediate purpose. Just had a look around, and there appears to to be plenty of other Behringer material exposed as such, so I shouldn't cause a bother here.
This is a roughie, as said, was done some weeks ago for a purpose, but gives the picture:
TDA7293Vs at each end of board, mounted on small pieces of aluminium. Note the fattest components are the rectifier diodes, on top ...
Frank
This is a roughie, as said, was done some weeks ago for a purpose, but gives the picture:
TDA7293Vs at each end of board, mounted on small pieces of aluminium. Note the fattest components are the rectifier diodes, on top ...
Frank
Of interest, and taking a somewhat extreme example, assume some financially comfortable person bought a D'Agostini Momentum amp, then hired a technically competent chap to complete dismantle it, taking pics of every aspect of its construction; and complete trace and capture the schematic, and record the details of every part. Then, because he was quite an eccentric, generous of spirit, he started a thread here and posted every last fragment of that information. So what would the story be then ...??
Curious ...
Frank
Curious ...
Frank
If you're not in a position to give anything away what the hell are you posting for? donations? The only thing you've done comprehensively so far is waffle on for post after post with very little fact or evidence to back up anything - not even a 'little subtle' fact or two. But then your not in the position to give any away - thats a great circular, self fulfilling argument, preventing any useful, factual debate while you continue to pontificate ad nausem
So you're saying that after all this, your changes make very little change at all but we are supposed to believe the sound is better? You should start a tv evangelical church - at least that way your financial worries would be over
Just a couple more posts and your hot air balloon will be ready
I have "given away" the most important fact already: eliminate every weakness in your system. I could name 5 typical weaknesses -- in fact I have done at least that many already -- which match exactly what one person's problem are. He fixes them, voila, gets great sound and thinks I'm a hero. Another has a quite different set of problems, tries what I suggest, ends up with worst sound, and thinks I'm talking total rubbish.
Again, you won't get the point unless you understand that it is the attitude with which you approach getting better sound that is the answer.
This may be of benefit, I've been rabbiting on about this sort of thing for a while, chucked out a bit on another forum: http://forum.audiogon.com/cgi-bin/fr.pl?ymisc&991962314&openflup&306&4#306 , but it fizzled out quickly ...
Frank
Again, you won't get the point unless you understand that it is the attitude with which you approach getting better sound that is the answer.
This may be of benefit, I've been rabbiting on about this sort of thing for a while, chucked out a bit on another forum: http://forum.audiogon.com/cgi-bin/fr.pl?ymisc&991962314&openflup&306&4#306 , but it fizzled out quickly ...
Frank
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Do you SERIOUSLY think that with 226,234 Members, 206,869 threads and 3,058,239 posts that no one has ever come up with that BLINDING GLIMPSE OF THE OBVIOUS?!?!?!? Its old hat around here, its been done and being done to of thousands of products, thousands of times by thousands of members
No one is going to get the point??? WHAT POINT????? You are trying to sell ice to Eskimo's - unless a total noob we've ALL been there before. What are you going to do thats new? write it on parchment, wrap it in a sheeps scrotum and only give it away to to disciples with the right attitude? It matters not what you do or describe because unless you can show us all around the globe with measurements we aren't likely to take your word for it!
How about you build one of planet10's fullrange speakers, a chip amp and a Opus 3 Cantus parallel tracking arm for your record deck? (all available here via search facility) Unless you see what a MASSIVE body of work exists here already and respect the community "you won't get the point" because YOU don't/wont/can't understand that we ALREADY KNOW your 'secret' - Its not secret!!!!!!! Thats why its called DIYAUDIO DO IT YOURSELF
We want to see a speaker taken from new with measured results, then taken apart so see whats inside, parts upgraded and observational comments as well as measurements along the way until it can be improved no more without some impractical upgrade with a sprinkling of photos along the way. Thats the only way you are going to get support here because your reputation is writen in stone already - mumbo jumbo horse cr@p wins no friends here
As you can see, the power supplies are pretty ridiculous, from my point of view: the level of crosstalk, once the bass driver is starting to work hard, on the voltage rails would be dreadful. If I was starting with a clean sheet, and wasn't worried about costs, and fitting it into the space, I would use 3 separate transformers, and 3 following, dramatically more independent, power supplies. One for the treble power amp, one for the mid/bass, and one for the filtering and other circuitry: this alone would lift the dynamics to a whole new level.
But, that wouldn't the "smart" way, so the trick will be to isolate voltage rail fluctuations in the various areas from impacting each other. This is where something like LTspice can really help, by showing you what actually happens in real circuits -- no pretending you have pure voltages just because a schematic has a neat symbol, like V+, claiming such.
As far as I'm concerned, a voltage rail is a varying input, just as much as the wire marked <In>. This is the sort of thinking that has allowed me to make good progress over the years -- don't assume anything!!
Frank
But, that wouldn't the "smart" way, so the trick will be to isolate voltage rail fluctuations in the various areas from impacting each other. This is where something like LTspice can really help, by showing you what actually happens in real circuits -- no pretending you have pure voltages just because a schematic has a neat symbol, like V+, claiming such.
As far as I'm concerned, a voltage rail is a varying input, just as much as the wire marked <In>. This is the sort of thinking that has allowed me to make good progress over the years -- don't assume anything!!
Frank
Sorry to upset you, but my "blindingly obvious" has been treated as nonsense elsewhere, or dismissed as useless. So, there must be different audio planets ...
But there in the quoted section is where the great failure of vaunted measurements takes place. A fixing of the power supplies will have zero impact on the FR. Zero impact. Phase response, impedances, waterfall, impulse response, zilch. What's left? The miserable standard of normal distortion testing will also reveal nothing, as the power drain conveniently shifts 100% from one chip amp to the other. Only the most sophisticated of the current test regimes will show anything worthwhile, and will be very expensive. So, I use the best tools of all, my ears ...
Frank
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