Hi Farncois, I am sure you are just trying to make sense of things.
Where do I start...
The majority of the bypass caps will go under the boards... so the thickness is not realy a problem... Unfortunatley there is no eagle package for a capacitor lying on it's side..
On top of the boards the spaceing from hole to hole is on average 5mm, meaning a 5mm part will extend 2.5mm each side of the hole... in theory you should be fine then...
Those measurements are fromthe wima library so as long as you can get Wima's they should fit, no problem... and most of the other brands are even smaller...
I have never had a problem getting a .25W resitor in 7mm holes... just bend the lead against the desk to form a 90 degree angle right at the body... where it was possible, I allowed the leads to extend a bit, but to go up a size in the resistors would seriously affect the board size...(cost).
I think you found the answers to your other questions allready...
Regards
Nico
Where do I start...
The majority of the bypass caps will go under the boards... so the thickness is not realy a problem... Unfortunatley there is no eagle package for a capacitor lying on it's side..
On top of the boards the spaceing from hole to hole is on average 5mm, meaning a 5mm part will extend 2.5mm each side of the hole... in theory you should be fine then...
Those measurements are fromthe wima library so as long as you can get Wima's they should fit, no problem... and most of the other brands are even smaller...
I have never had a problem getting a .25W resitor in 7mm holes... just bend the lead against the desk to form a 90 degree angle right at the body... where it was possible, I allowed the leads to extend a bit, but to go up a size in the resistors would seriously affect the board size...(cost).
I think you found the answers to your other questions allready...
Regards
Nico
Jaycee.... i was thinking about you and i decide
To post some informations that may help a little.
Your amplifier using 48 volts will not need 3 output transistors as you already know, but you may use despite that to make boards seems pretty... will not be bad to use three transistors, but i could perceive in my home that when you reduce them the audio quality increases a little bit.... maybe they interact because differences they have as normally they are not from the same factory "waffer"... difference is small and can be inside my "illusions of perceptions"....maybe more connected to my own fears than to the real audio modifications...very subjective and i do not guarantee this informs i am posting here as something real...i would tell you i have perceive some...but i can be wrong.
What i mean with that.... a simple test is to you make audio recording using some wavepad program you have as freeware into the web, and them you make a post processing after recording, you add some echo... that means your audio repeated with smaller level.... then you adjust the delay to be almost nothing to your ears.... well, the sound turns more rich, as each tone seems a little bit longer, and in the reality it is longer because repeated... this effect is what i have perceived when i have installed 6 pairs of transistors in my home...i was very shocked, already had some fear about and when i listen was confirmed and i start to swet, fear to be suggesting things into the forum that sounds worse than the best possible.... responsability..that moment i could see in my mind as i was inside the Roman Coliseu and all forum folks with the fingers down to cut my neck into the gladiator's battle field..... and people screaming...lyer!...lyer!...lyer!...... yes.... i accept that this could be illusion, a product of my fears, the same way when i miss my mum (died many years ago) i can listen her voice inviting me to a coffee with a nice piece of cake....illusions from my broken heart only.
You amplifier may put out 98 watts into 8 ohms and near 170 into 4 ohms, but this if your transformer keep that voltage of 48 and if you arrange zeners to have 45 into the input circuitry voltage..... 30 volts zener if exists this value and 15 volts zener or other combination of zener diodes.
In the reality, the 500 VA transformer will not be able to hold 2 channels without loose a big voltage under hard load conditions, into 4 ohms you gonna have 3 amperes each rail (around 1.55A to 8 ohms loads)... and this may result your voltage fell down to 42 volts... this means your zeners should be "adjusted", in this case, to 40 volts.
This will be more real sittuation to a 500VA transformer i think..... and your gain resistor (R4), the sensitivity one, will need replacement to a value around 750 ohms (more or less)... your power will go down because supply voltage dropped (I believe it will under continuous tone, steady sinusoidal tone, maximum undistorted power) and will result into 75 watts to 8 ohms and something near 120 watts into 4 ohms.... this way, you can even remove one more pair to operate into 8 ohms and may use into 4 ohms if do not go full volume for too long....R6 will go to 2K7, and your current will be around 1.4A into 8 ohms and 2.5A into 4 ohms.
What this means..... the HRII big brother related power, off course sonics is different, but so many parts and work to have small difference in power....you will not perceive this as huge advantage, as we perceive more clear when the power is multiplied by 4, and this is the 64 volts version.
Well dear Jaycee, we do what we can.... we love to use the parts we have, that missed transformer into our junk box...i know the need to use those things, bothers a lot to watch those transformers daily without use....... i suggest you, really, to sell into a garage sale, that small transformer you have, or to make a gift to your nearest electronic freak you have around and to have a big monster transformer..because despite very special sound quality, the interesting point you have into Precision I (one here is ROMAN LETTER) is the earthquake astounding sound..the room shacking undistorted bass..... a beautifull voices too... i feel treble fair, good, but do not make me fell down from the chair!
I just could not make it astounding into trebles...i just could not!
More treble i could not..but i could have EFFECT.... reducing input condenser, removing C10 (changes sound stage too) and adjusting C13 to smaller value....very carefully, monitoring the output to AC voltage and when finished your reduction, while playing music observe heat, as some High frequencies of audio can trigger oscilations that goes following high frequency peaks...and this only into scope and using Finger-o-meter, as the amplifier will be hot, consumption will be high and treble may seems enormous...you may say ...NOW I HAVE IT...but this is result of distortions that increases the level we listen...you may see quality of trebles goes away when this happens.
I could have 39 picofarads in my home..... but i think it goes to threshold... Mmmmmm not very safe dear Jaycee.
Do you know how to dance?.... ahahahaha will learn while listening room shaking levels.
regards,
Carlos
To post some informations that may help a little.
Your amplifier using 48 volts will not need 3 output transistors as you already know, but you may use despite that to make boards seems pretty... will not be bad to use three transistors, but i could perceive in my home that when you reduce them the audio quality increases a little bit.... maybe they interact because differences they have as normally they are not from the same factory "waffer"... difference is small and can be inside my "illusions of perceptions"....maybe more connected to my own fears than to the real audio modifications...very subjective and i do not guarantee this informs i am posting here as something real...i would tell you i have perceive some...but i can be wrong.
What i mean with that.... a simple test is to you make audio recording using some wavepad program you have as freeware into the web, and them you make a post processing after recording, you add some echo... that means your audio repeated with smaller level.... then you adjust the delay to be almost nothing to your ears.... well, the sound turns more rich, as each tone seems a little bit longer, and in the reality it is longer because repeated... this effect is what i have perceived when i have installed 6 pairs of transistors in my home...i was very shocked, already had some fear about and when i listen was confirmed and i start to swet, fear to be suggesting things into the forum that sounds worse than the best possible.... responsability..that moment i could see in my mind as i was inside the Roman Coliseu and all forum folks with the fingers down to cut my neck into the gladiator's battle field..... and people screaming...lyer!...lyer!...lyer!...... yes.... i accept that this could be illusion, a product of my fears, the same way when i miss my mum (died many years ago) i can listen her voice inviting me to a coffee with a nice piece of cake....illusions from my broken heart only.
You amplifier may put out 98 watts into 8 ohms and near 170 into 4 ohms, but this if your transformer keep that voltage of 48 and if you arrange zeners to have 45 into the input circuitry voltage..... 30 volts zener if exists this value and 15 volts zener or other combination of zener diodes.
In the reality, the 500 VA transformer will not be able to hold 2 channels without loose a big voltage under hard load conditions, into 4 ohms you gonna have 3 amperes each rail (around 1.55A to 8 ohms loads)... and this may result your voltage fell down to 42 volts... this means your zeners should be "adjusted", in this case, to 40 volts.
This will be more real sittuation to a 500VA transformer i think..... and your gain resistor (R4), the sensitivity one, will need replacement to a value around 750 ohms (more or less)... your power will go down because supply voltage dropped (I believe it will under continuous tone, steady sinusoidal tone, maximum undistorted power) and will result into 75 watts to 8 ohms and something near 120 watts into 4 ohms.... this way, you can even remove one more pair to operate into 8 ohms and may use into 4 ohms if do not go full volume for too long....R6 will go to 2K7, and your current will be around 1.4A into 8 ohms and 2.5A into 4 ohms.
What this means..... the HRII big brother related power, off course sonics is different, but so many parts and work to have small difference in power....you will not perceive this as huge advantage, as we perceive more clear when the power is multiplied by 4, and this is the 64 volts version.
Well dear Jaycee, we do what we can.... we love to use the parts we have, that missed transformer into our junk box...i know the need to use those things, bothers a lot to watch those transformers daily without use....... i suggest you, really, to sell into a garage sale, that small transformer you have, or to make a gift to your nearest electronic freak you have around and to have a big monster transformer..because despite very special sound quality, the interesting point you have into Precision I (one here is ROMAN LETTER) is the earthquake astounding sound..the room shacking undistorted bass..... a beautifull voices too... i feel treble fair, good, but do not make me fell down from the chair!
I just could not make it astounding into trebles...i just could not!
More treble i could not..but i could have EFFECT.... reducing input condenser, removing C10 (changes sound stage too) and adjusting C13 to smaller value....very carefully, monitoring the output to AC voltage and when finished your reduction, while playing music observe heat, as some High frequencies of audio can trigger oscilations that goes following high frequency peaks...and this only into scope and using Finger-o-meter, as the amplifier will be hot, consumption will be high and treble may seems enormous...you may say ...NOW I HAVE IT...but this is result of distortions that increases the level we listen...you may see quality of trebles goes away when this happens.
I could have 39 picofarads in my home..... but i think it goes to threshold... Mmmmmm not very safe dear Jaycee.
Do you know how to dance?.... ahahahaha will learn while listening room shaking levels.
regards,
Carlos
Attachments
Funny that I never really thought of 500VA as being small! I've a feeling it uses an oversized core as it's bigger than some other 500VA's i've seen. It's pretty solidly wound too. I picked it up from eBay a few years ago, I think it was actually used in some industrial power supply.
When I knew less about amps. I figured it'd be good for some 100W/8 ohm amp with 2 pairs. I've been fiddling with designs but never gotten around to building anything yet. The main reason I'd like to use it is that transformer prices have gone up rather sharply since.
To be honest, I doubt I will require full power - I just like to have it in reserve. Currently I'm using a Gainclone with 25V rails and a 160VA transformer, with 2x4700uF capacitance per rail and with music, it's OK - films is another matter 🙂
Transistors - I had thought to use the MJL4281/4302 pair from On Semiconductor, but I have noticed Fairchild's FJL4215/4315 pairs - they are now advertising them as second source for the 2SA1943/2SC5200's too. Even better - they will let me buy them directly from them 🙂 Pity they don't seem to do a good driver transistor!
When I knew less about amps. I figured it'd be good for some 100W/8 ohm amp with 2 pairs. I've been fiddling with designs but never gotten around to building anything yet. The main reason I'd like to use it is that transformer prices have gone up rather sharply since.
To be honest, I doubt I will require full power - I just like to have it in reserve. Currently I'm using a Gainclone with 25V rails and a 160VA transformer, with 2x4700uF capacitance per rail and with music, it's OK - films is another matter 🙂
Transistors - I had thought to use the MJL4281/4302 pair from On Semiconductor, but I have noticed Fairchild's FJL4215/4315 pairs - they are now advertising them as second source for the 2SA1943/2SC5200's too. Even better - they will let me buy them directly from them 🙂 Pity they don't seem to do a good driver transistor!
Well, maybe it is not small... try to use it and you may be happy
If you are using a chip amplifier with that small voltage, for sure you will have power enougth even if you transformer, under hard load conditions, start to have drop of voltage.
Maybe not into normal listening levels.
Regards,
Carlos
If you are using a chip amplifier with that small voltage, for sure you will have power enougth even if you transformer, under hard load conditions, start to have drop of voltage.
Maybe not into normal listening levels.
Regards,
Carlos
Carlos and Nico,
great pcb layput.
As I want to start building your precision amplifier...
I'm wondering whether you will post precisioon 1 pcb file-pdf?
thanks and best rgds,
great pcb layput.
As I want to start building your precision amplifier...
I'm wondering whether you will post precisioon 1 pcb file-pdf?
thanks and best rgds,
I have asked Nordic not to publish pcboard data, or gerber files, or board image into
the forum threads.... if you really want board image, not needing the boards he is producing into the group buy, no problems, but he will send you into your direct mail adress.
If posted here, my people (Brasil) will copy as it is a tradition and i will see hundreds of Precision Clones beeing sold in my country.
The will be competing with me, as i will sold them in Brasil, into my country, to the Brazilian people that visit my Orkut and Home Page.... Brazilian people that is living in Brasil only.
Forum is for free....no business...but forum open to everybody around the world, including my own people, and my people can have the board image reading forum, some of them can read in English badly as i can, and others can use google translator.
Not a very good idea, to my own personal interests, as in my place there's nothing with this quality, so they may run to have this board alike bees catching honey....not having copies here i will have the advantage to protect my work.... they have schematic to prepare their own boards in Brasil, as also HRII and Dx Standard.... to standard they have even the board layout image for free, and 60 guys already started their own boards in those last 12 days.
Of course, i will ask you and all folks, that will have those informs directly form Nordic, to keep those informs to yourself and avoid to publish or mail those images... use them to your own needs and be happy with this nice board Nordic have made... excelent job!
Not to publish the pdf files containing images here, in our lovely forum, those informations will not be opened and free to whole world.
So, i have asked Nordic just to feed our forum folks needs, directly to their personal mail adresses... and if possible, to feed them with boards made, without the need to give them board images.
To stimulate, to help, to motivate folks to obtain boards by the production costs plus mail costs, he is ordering boards and he made a very pretty board that we really think will be good enougth to the highest standards.
Gerber to anyone!....board image all rigth.
regards,
Carlos
the forum threads.... if you really want board image, not needing the boards he is producing into the group buy, no problems, but he will send you into your direct mail adress.
If posted here, my people (Brasil) will copy as it is a tradition and i will see hundreds of Precision Clones beeing sold in my country.
The will be competing with me, as i will sold them in Brasil, into my country, to the Brazilian people that visit my Orkut and Home Page.... Brazilian people that is living in Brasil only.
Forum is for free....no business...but forum open to everybody around the world, including my own people, and my people can have the board image reading forum, some of them can read in English badly as i can, and others can use google translator.
Not a very good idea, to my own personal interests, as in my place there's nothing with this quality, so they may run to have this board alike bees catching honey....not having copies here i will have the advantage to protect my work.... they have schematic to prepare their own boards in Brasil, as also HRII and Dx Standard.... to standard they have even the board layout image for free, and 60 guys already started their own boards in those last 12 days.
Of course, i will ask you and all folks, that will have those informs directly form Nordic, to keep those informs to yourself and avoid to publish or mail those images... use them to your own needs and be happy with this nice board Nordic have made... excelent job!
Not to publish the pdf files containing images here, in our lovely forum, those informations will not be opened and free to whole world.
So, i have asked Nordic just to feed our forum folks needs, directly to their personal mail adresses... and if possible, to feed them with boards made, without the need to give them board images.
To stimulate, to help, to motivate folks to obtain boards by the production costs plus mail costs, he is ordering boards and he made a very pretty board that we really think will be good enougth to the highest standards.
Gerber to anyone!....board image all rigth.
regards,
Carlos
Ahahahahha Fardo.... não foi por causa de você amigo
Ahahahahahhaah!
Was not because of you.... you know we have different culture levels in our country... you are not that one that will be the one to reproduce.
You can have the informs Fardo.
Tem muita gente oportunista por aqui... essa gente é um "fardo" difícil pra carregar amigo.
I have a lot of "eagle minds" around... people sniffing something alike hunting dogs, to own an easier money robbering schematics, ideas and boards.. those guys are heavy to put them into our backs, and to carry them for too long... this is hard my friend.... they do not want to make efforts..they let you develop and them they copy and start to sell with another brand...very normal here.
We have not the "copyrigth" culture... our mind is free, and my father wrote a letter for a music called "ninguém é de ninguém".. that means that nobody belongs to nobody... the culture here say that schematic has no owner... the owner is the one that have it..also boards, gerber, layouts and all stuff.
regards,
Carlos
Ahahahahahhaah!
Was not because of you.... you know we have different culture levels in our country... you are not that one that will be the one to reproduce.
You can have the informs Fardo.
Tem muita gente oportunista por aqui... essa gente é um "fardo" difícil pra carregar amigo.
I have a lot of "eagle minds" around... people sniffing something alike hunting dogs, to own an easier money robbering schematics, ideas and boards.. those guys are heavy to put them into our backs, and to carry them for too long... this is hard my friend.... they do not want to make efforts..they let you develop and them they copy and start to sell with another brand...very normal here.
We have not the "copyrigth" culture... our mind is free, and my father wrote a letter for a music called "ninguém é de ninguém".. that means that nobody belongs to nobody... the culture here say that schematic has no owner... the owner is the one that have it..also boards, gerber, layouts and all stuff.
regards,
Carlos
Attachments
Oh no ma, that old "fardo" joke again... 😀 😀
It´s all right
But dito is. Power to Nordic.
Carry on.
It´s all right
But dito is. Power to Nordic.
Carry on.
Great!... thank you very much to test boards, very nice you care to
give folks guarantee related your boards.
I see no flange, and good that you are showing a stable amplifier even having long wires connecting board to heatsink... this is one of the Myths people use to believe.
I see i gave you a hard time because of those boards, and i thank you very much to tollerate the bad mood i had in many moments, you behave kindly all time long... a very nice man you are, and also very competent, now very skilled with boards.
Aussie friends sent me mails and have complained the way i was talking with you..... you see that good friends do not let things goes wrong and you have a lot of friends into my aussie friends too.
Lovely those aussies, despite i know i had good reasons to be upset, i see i was not kind... they called me rude... and i have to thank them to say to me:
- Hey Carlos, Hold on!.... calm down!
Those folks from Australia are just lovely... i see i could be very happy living there.... Greg Erskine said clearly do not agree with my behavior, also my dear Friend Hugh Dean said do not like the way i have made some posts... i see dear Rabbitz not happy too.
I am not a bad man...but i am very distant to be perfect..i use to make lot of ship too.... ship carried with a lot of bad behavior... I thank moderators that have tollerated me..... i see i was reaching the limits.
Thank you very much for this great job you have done dear Nordic.
regards,
Carlos
give folks guarantee related your boards.
I see no flange, and good that you are showing a stable amplifier even having long wires connecting board to heatsink... this is one of the Myths people use to believe.
I see i gave you a hard time because of those boards, and i thank you very much to tollerate the bad mood i had in many moments, you behave kindly all time long... a very nice man you are, and also very competent, now very skilled with boards.
Aussie friends sent me mails and have complained the way i was talking with you..... you see that good friends do not let things goes wrong and you have a lot of friends into my aussie friends too.
Lovely those aussies, despite i know i had good reasons to be upset, i see i was not kind... they called me rude... and i have to thank them to say to me:
- Hey Carlos, Hold on!.... calm down!
Those folks from Australia are just lovely... i see i could be very happy living there.... Greg Erskine said clearly do not agree with my behavior, also my dear Friend Hugh Dean said do not like the way i have made some posts... i see dear Rabbitz not happy too.
I am not a bad man...but i am very distant to be perfect..i use to make lot of ship too.... ship carried with a lot of bad behavior... I thank moderators that have tollerated me..... i see i was reaching the limits.
Thank you very much for this great job you have done dear Nordic.
regards,
Carlos
Hi Carlos,
I just did a THD spice analysis of your your latest amplifier schematic (see below). It's good from 300Hz - 20kHz (under 0.003%), but there's a peak of 0.03% at around 40Hz. Do you have any idea whats causing that?
I used Helmut Sennewald's perl THD script attachment to LTSpice
Murray
I just did a THD spice analysis of your your latest amplifier schematic (see below). It's good from 300Hz - 20kHz (under 0.003%), but there's a peak of 0.03% at around 40Hz. Do you have any idea whats causing that?
I used Helmut Sennewald's perl THD script attachment to LTSpice
Murray
Attachments
Is it now a good time to propose a DX group hug? 
(This forum is amazing in so many levels... almost a therapy at times.)
Great job Carlos and Nordic!
(This forum is amazing in so many levels... almost a therapy at times.)
Great job Carlos and Nordic!
Carlos
thanks for yr reply.
Please send the pcb and layout (hopefully in pdf files ) to my email address dexter@telkom.net
many thanks.
best rgds,
thanks for yr reply.
Please send the pcb and layout (hopefully in pdf files ) to my email address dexter@telkom.net
many thanks.
best rgds,
No... i do not know the reasons of this peak
You may not know me.... i am not a real designer...i use to make the Dc design only and to join sub circuits together...and them i go tuning using the best top modern instrument... the Spectrum Superb Harmonically sensitive wave meter THD sensitive instrument ever made.... EARS!
So... things goes this way... i found bass huge.... was an accident, nothing desired or previously decided into a working bench, simulator or calculator...i have accepted as interesting, as people loves this frequency (also sharks love this frequency).
I am sorry to say... i have no idea how i could get there.
I would say that i am protected by all the Gods...they love me and everything i do sounds nice...big magic.
regards,
Carlos
.........................................................................................................
Dexter
I am already waiting those informs from Nordic...he is the board designer and your mail will be informed to him about.
He is busy now a days testing board.
As soon as i have those files i will send to you mail adress.
regards,
Carlos
You may not know me.... i am not a real designer...i use to make the Dc design only and to join sub circuits together...and them i go tuning using the best top modern instrument... the Spectrum Superb Harmonically sensitive wave meter THD sensitive instrument ever made.... EARS!
So... things goes this way... i found bass huge.... was an accident, nothing desired or previously decided into a working bench, simulator or calculator...i have accepted as interesting, as people loves this frequency (also sharks love this frequency).
I am sorry to say... i have no idea how i could get there.
I would say that i am protected by all the Gods...they love me and everything i do sounds nice...big magic.
regards,
Carlos
.........................................................................................................
Dexter
I am already waiting those informs from Nordic...he is the board designer and your mail will be informed to him about.
He is busy now a days testing board.
As soon as i have those files i will send to you mail adress.
regards,
Carlos
Re: Great!... thank you very much to test boards, very nice you care to
Who said I'm not happy? I find your posts fine and part of the Australian culture is ribbing (making fun or teasing) each other. If a friend doesn't take take a swipe at you at least once a day, you feel something is wrong.
destroyer X said:
Who said I'm not happy? I find your posts fine and part of the Australian culture is ribbing (making fun or teasing) each other. If a friend doesn't take take a swipe at you at least once a day, you feel something is wrong.
I am glad to know that.
I could see that when i was starting a good friendship with Hugh Dean...the first day he called me - astard i perceived that i had a real friend.... we do the same here... exactly the same.
But we do not do that with the ones we do not like.... we have enormous respect...exactly to keep them very distant from us.
Great!
Fine!
Excelent culture.
regards,
Carlos
I could see that when i was starting a good friendship with Hugh Dean...the first day he called me - astard i perceived that i had a real friend.... we do the same here... exactly the same.
But we do not do that with the ones we do not like.... we have enormous respect...exactly to keep them very distant from us.
Great!
Fine!
Excelent culture.
regards,
Carlos
Carlos and Nordic.
I think you should consider, to people you send gerbers for free, the possibility to retrive some kind of donation, to help you with your website -if they want to, so nobody gets offended-
It´s a lot off work you have putted on it and for the DIYers.
Best regards to both and congratulatios.
I think you should consider, to people you send gerbers for free, the possibility to retrive some kind of donation, to help you with your website -if they want to, so nobody gets offended-
It´s a lot off work you have putted on it and for the DIYers.
Best regards to both and congratulatios.
We cannot.... not allowed to use forum for those purposes
The group buy is for free..so we can make the publicity we want, as this is not a business...if for forum folks, for free, without any payment of profit.
If we start to own money we will broke forum rules and our group buy will be immediattelly closed... as will be doing publicity, non paid publicity, to own money.
This kind of publicity, publicidade, anúncios, advertising, propaganda is something we can have, off course paid, in this forum.
So..if we do that,.we will be using a trick to not obbey forum rules.... we gonna be trying to be more clever than the forum management..not decent with them..we cannot and for sure they will counter react and i think they will be rigth and i will be wrong and ashamed.
But i understand what you mean... i do think this is fair..but this cannot work using forum the way we are using... group buy..for free.
Group buy is a space they give us, to help one each other, to allow folks to have a nice communitty operating..everybody working to allow friends to have free things... price cost things, without tricks.
I would like to have some small return by my work, in special Nordic would be happy, as he is is paying to produce boards to test..he paid three.... 30 dollares gone from his pockets!... and he cannot see this money back once more... i said him to include this into the people price... some cents to each one, as this was the cost to be sure the board is fine...but Nordic is honest and he do not accept this method anyway.... so.... you are kind to suggest... we just cannot do those things.
I said Nordic that i will paid him sending some free boards to him... Classic boards, as he is working with me, for free, and paying from his own pockets..i will try to compensate him, giving him for free, and sending him, a lot of boards to make this nice guy very happy.
He is a lovely person!
Obrigado, gracias!
regards,
Carlos
The group buy is for free..so we can make the publicity we want, as this is not a business...if for forum folks, for free, without any payment of profit.
If we start to own money we will broke forum rules and our group buy will be immediattelly closed... as will be doing publicity, non paid publicity, to own money.
This kind of publicity, publicidade, anúncios, advertising, propaganda is something we can have, off course paid, in this forum.
So..if we do that,.we will be using a trick to not obbey forum rules.... we gonna be trying to be more clever than the forum management..not decent with them..we cannot and for sure they will counter react and i think they will be rigth and i will be wrong and ashamed.
But i understand what you mean... i do think this is fair..but this cannot work using forum the way we are using... group buy..for free.
Group buy is a space they give us, to help one each other, to allow folks to have a nice communitty operating..everybody working to allow friends to have free things... price cost things, without tricks.
I would like to have some small return by my work, in special Nordic would be happy, as he is is paying to produce boards to test..he paid three.... 30 dollares gone from his pockets!... and he cannot see this money back once more... i said him to include this into the people price... some cents to each one, as this was the cost to be sure the board is fine...but Nordic is honest and he do not accept this method anyway.... so.... you are kind to suggest... we just cannot do those things.
I said Nordic that i will paid him sending some free boards to him... Classic boards, as he is working with me, for free, and paying from his own pockets..i will try to compensate him, giving him for free, and sending him, a lot of boards to make this nice guy very happy.
He is a lovely person!
Obrigado, gracias!
regards,
Carlos
Re: No... i do not know the reasons of this peak
I've looked into it a bit further Carlos, and what causes the increase in distortion at low frequencies is the 470R/470uF filter on the feedback connection. If you lower the frequency of this filter (make C7 larger for example), it shifts the distortion peak lower into the inaudible frequencies. Whether this has a bad affect on the performance of the amp in other areas or not, I don't know.
By the way, I must compliment you on an excellent design - it performs very nicely in simulation, and I'm very interested in building it.
Cheers,
Murray
destroyer X said:
I've looked into it a bit further Carlos, and what causes the increase in distortion at low frequencies is the 470R/470uF filter on the feedback connection. If you lower the frequency of this filter (make C7 larger for example), it shifts the distortion peak lower into the inaudible frequencies. Whether this has a bad affect on the performance of the amp in other areas or not, I don't know.
By the way, I must compliment you on an excellent design - it performs very nicely in simulation, and I'm very interested in building it.
Cheers,
Murray
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