Hi, i do not think it will be very easy to perform this test, even i understand that it should be done
I read of a company building AD-DA converters used to perform demo of their products switching between the direct signal and the signal gone through a stack of their AD-DA converters with minimal differences in sound quality i guess.
i will buy a sim software and i will start from the basic circuit
if i will be able to get a distortion like 0,01% this will be my definitive line stage. And i am sure that it will sound better than my current line stage, much more complex and musically uninvolving.
I am very curious to listen
Thanks again
Two things I take into consideration when I build something.
It needs to be something that I have most of the parts for, and something I have the knowledge to build (in reality I'm not that good with audio amps apart from basics).
It needs to be something that I have most of the parts for, and something I have the knowledge to build (in reality I'm not that good with audio amps apart from basics).
I agree, first we must specify the target. An engineer always tempted to optimize everything, if you not specifiy the target then you never finish it 😀
Listening test is always difficult. Everyone have different taste. Some people looking for enjoyable sound, others looking for accurate sound.
Listening test is always difficult. Everyone have different taste. Some people looking for enjoyable sound, others looking for accurate sound.
Hi and interesting even if worrying comment.
If measurements cannot tell about the sound, how do you normally proceed to evaluate the quality of a prototype ?
First issue i think is stability ... i played with some opamps and i had huge stability issue and the opamps sounded very very bad.
I guess here is where the instruments can tell something.
After having checked the stability how do you proceed ?
You listen for the effect of any modification to the circuit ?
This is really difficult i think but i am extremely interested if you could elaborate a little more
Thanks and regards, gino
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For a sim you might try LTspice. Takes some time to learn (although there's a very helpful user group) but is it free and very powerful.
Jan
Jan
Its a temptation well worth giving in to, in my experience. Optimizing everything is what allows me to learn what's important and what isn't. Also is there anything bad about never finishing a design?
BTW Ginetto, if you ever visit Helgi Joensen's studio in the Stavanger park, make sure you say 'Hi' to him for me.
If you are looking for absolutely unique amplifier front panels, ask him 😉
Jan
If you are looking for absolutely unique amplifier front panels, ask him 😉
Jan
Whatever I do, in the ending process I always have to tweak it and try various things, like feedback factor, ol gain BW changing etc. And It`s almost neverending game 🙂
Hi Jan and thanks a lot for the kind advice
Take some time for me means ages ... seriously. I am slow to learn.😱
I am willing to pay "some" cash for a more friendly software. 😉
I liked very much the Multisim screens ... i hope it is easier to use.
I need something easy ...
Then maybe with some more practise 🙄
Thanks again, gino
Thanks for the interesting advice
Speaking of boxes i like plain ones. But i have a strong preference for heavy ones. I have no explanation for this but i like them better than thin ones.
Very thick panels ... and big knobs.
Kind regards, gino
Hi and not a good news for me ...
I am looking for the most user friendly as possible
I do not know which one is actually
Regards, gino
No need for cash. I found the free version of Simetrix Simplis MUCH easier to learn and use than LTSpice, and it seems to be as good/accurate/useful.
I started getting into simulation software recently myself and I have been using ngspice. It's free and so far even though the owners manual can scare people away it's not that bad to use and it's very powerful piece of software.
LTSpice is easy to use and is very popular. This means that you will be able to get help, models, and full circuits from other people. Seems to be the most popular on this site and I often get circuits from other people. These are often by skilled people and these have taught me a lot.
Jim
Jim
het ginnetto61, check out this opamp. it's an LME49880, it has .00003% distortin, will drive a 2k or 600 ohm load and it's noise figure is 7nV square root of the Hz. look at the data sheet it has some designs along with there explanation.
The easiest Sim have ever used and still do is Circuitmaker 2000, it can be found if you search hard enough.
Its only draw back is that it is difficult to add models to it and support for it has ended some 15 or so years ago since it was bought out by Altium.
But, It has a very good selection of most all of the common components including a lot of LT ,TI and a few AD opamps, FET's and Bipolar's like the older IRF, Zetex and RCA devices.
A very well rounded set of selection's.
I mainly use it now just to create a PCB layout due to its ability to port the schematic in to a layout via Traxmaker program.
On that note the Sims are only as accurate as the models are.
LTspice is free and a very excellent sim program that has a ton of support and functions it is very easy to add models to if need be.
There have been some here that have even added more functions by the use of scripts as well.
Lately in the past I have been fighting with a few cheapo meters that aren't even self accurate from range to range.
Therefore I rely on my scope tremendously.
I did finally get a halfway decent inexpensive Sperry DMM and it works pretty good.
For everything else I use my sound cards (Creative X-FI and Gina24) for THD, Impedance Graphs, FFT's (RTA) and FR sweeps, of equipment,amps, preamp's and speakers.
All of the software do these things are free and can be found in these threads.
I have even showed how to measure as high as 5KV to 10KV ac voltages using my sound card without hurting my computer for those of whom are into ESL's and tube circuits.
A decent measurement mic such as the inexpensive Dayton Audio EMM-6 from Parts Express and a SPL meter should be on your list of valuable must have tools as well.
I set my goals typically for poweramps at no more than .1% THD and a goal of .01% completely acceptable and if it is better than that it is all good!!
Considering I am mostly limited by my sound card's specs at about .005% to .002% THD.
Noise?......Well I like to get at least down to -100db as the noise floor of my system is in the -110db to -120db range for the most part.
I use a Mackie 32-8 as my main Preamp, But rarely do I have any issues with equipment only as low as -90db or so.
THD and Noise is not really much of a problem with today's opamps, But board layout has the most effect on this at times.
My latest fascination is to measure extremely low voltages (Below 1mv) and I have to build my own apparatus's to do this, and, it is very hard just to get my surroundings electrically quiet enough to do so.
So, I haven't gotten very far with it lately, but still working on it. 😉
But, Messing with the latest precision opamp's is really something compared to just using the NE5534's and TL07x's that I have only used for the last 35 years or so!!!
The last thing is I am self taught.
But, I never claimed that I know it all and with the use of this forum and all of the people involved, I have learned more in the last 4 years than I have learned on my own in the last 40 years by myself by getting involved, rather than just lurking like I have for the last 15 years or so. 🙂
Especially the finer details of amplifier design and the how and why it works!!!
I already knew how to work with opamps, But poweramps were still a little bit of a mystery to me until recently.
Understanding the Solid State Current Source was the main key for me that "Turned On the Light" and put me in to the state of "Ahhhh...Haaaaaa....Now I see!!!". 😉
Transformers is another one, as most of you know...All thanks to this forum and the People that contribute to it, I now fully understand them.
FWIW
jer 🙂
Its only draw back is that it is difficult to add models to it and support for it has ended some 15 or so years ago since it was bought out by Altium.
But, It has a very good selection of most all of the common components including a lot of LT ,TI and a few AD opamps, FET's and Bipolar's like the older IRF, Zetex and RCA devices.
A very well rounded set of selection's.
I mainly use it now just to create a PCB layout due to its ability to port the schematic in to a layout via Traxmaker program.
On that note the Sims are only as accurate as the models are.
LTspice is free and a very excellent sim program that has a ton of support and functions it is very easy to add models to if need be.
There have been some here that have even added more functions by the use of scripts as well.
Lately in the past I have been fighting with a few cheapo meters that aren't even self accurate from range to range.
Therefore I rely on my scope tremendously.
I did finally get a halfway decent inexpensive Sperry DMM and it works pretty good.
For everything else I use my sound cards (Creative X-FI and Gina24) for THD, Impedance Graphs, FFT's (RTA) and FR sweeps, of equipment,amps, preamp's and speakers.
All of the software do these things are free and can be found in these threads.
I have even showed how to measure as high as 5KV to 10KV ac voltages using my sound card without hurting my computer for those of whom are into ESL's and tube circuits.
A decent measurement mic such as the inexpensive Dayton Audio EMM-6 from Parts Express and a SPL meter should be on your list of valuable must have tools as well.
I set my goals typically for poweramps at no more than .1% THD and a goal of .01% completely acceptable and if it is better than that it is all good!!
Considering I am mostly limited by my sound card's specs at about .005% to .002% THD.
Noise?......Well I like to get at least down to -100db as the noise floor of my system is in the -110db to -120db range for the most part.
I use a Mackie 32-8 as my main Preamp, But rarely do I have any issues with equipment only as low as -90db or so.
THD and Noise is not really much of a problem with today's opamps, But board layout has the most effect on this at times.
My latest fascination is to measure extremely low voltages (Below 1mv) and I have to build my own apparatus's to do this, and, it is very hard just to get my surroundings electrically quiet enough to do so.
So, I haven't gotten very far with it lately, but still working on it. 😉
But, Messing with the latest precision opamp's is really something compared to just using the NE5534's and TL07x's that I have only used for the last 35 years or so!!!
The last thing is I am self taught.
But, I never claimed that I know it all and with the use of this forum and all of the people involved, I have learned more in the last 4 years than I have learned on my own in the last 40 years by myself by getting involved, rather than just lurking like I have for the last 15 years or so. 🙂
Especially the finer details of amplifier design and the how and why it works!!!
I already knew how to work with opamps, But poweramps were still a little bit of a mystery to me until recently.
Understanding the Solid State Current Source was the main key for me that "Turned On the Light" and put me in to the state of "Ahhhh...Haaaaaa....Now I see!!!". 😉
Transformers is another one, as most of you know...All thanks to this forum and the People that contribute to it, I now fully understand them.
FWIW
jer 🙂
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Jer where have you documented those high voltage measurement methods? I'm into that right now and would like to see your ideas.
Jan
Jan
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