we do not have any commercial interests in this project.
We did it for the fun of it. We haven´t been selling it, we just bought parts and PCB´s along with around other people.
We are sorry not to be able to arrange something likely, because that should be done locally. So if one of you guys could take an initiative for doing so, you´re welcome.
I´ve been enjoying this hobby for more than 35 years now, and I also learned a few things.
One thing is, that if you look at a project like ours, it is obvious, that a lot of work has been put into it. The PCB is a beauty, and it is also an important part the amps performance to.
Anyways its performance is very close to transparent, meaning no sound added. Give it a shot and report about it, or do another.
Then you are right.
I missed the point.
I thought DIYA also was a forum, where you could find projects and do them yourself.
If you wan´t the schematics you can mail me, but they are not to be published.
You can read almost anything else about this project in the original thread.
The reason for not publishing the schematics is, that we do not want any discussion about the design. It is closed, working well, the layout is done, a lot of components has been evaluated in just as many combinations.
So you can do it, or you can not do it. Your choise.
Wow
The building instructions have now been downloaded more than 800 times.
I´m very impressed. We did not think of interest in this magnitude at all.
We look forward to hearing from the first ones to get hole through.
The building instructions have now been downloaded more than 800 times.
I´m very impressed. We did not think of interest in this magnitude at all.
We look forward to hearing from the first ones to get hole through.
So what you're saying is it's a perfect design that can never be excelled or improved upon in any way? 😉
Mike
Mike
I don´t think I said that.
But still more than 800 did download building instructions.
More than 400 the last five days.
Some one must be interested.
Well regardless of numbers (millions believe UFOs are space aliens afterall), I'll say it agian; the main reason for the exitstance of forums like this is to share information, not hide behind unsubstantiated claims. I'm out.
Mike
Mike
well, the usual proceedure is to have schematic only
then someone build and test
then make gerbers
order proto boards to test again
and then a GB can be arranged
hmm, here we have a tested design, and production gerbers
which to prefer I suppose depends on who you are
but noone have problems with other members selling kits, or boards
and a few may even be without schematic published
seems like our small world may be changing
looks great
then someone build and test
then make gerbers
order proto boards to test again
and then a GB can be arranged
hmm, here we have a tested design, and production gerbers
which to prefer I suppose depends on who you are
but noone have problems with other members selling kits, or boards
and a few may even be without schematic published
seems like our small world may be changing
looks great
I wish to know why LM317 type regulators were used as a current sources in shunt regulators
They tend to pass some high frequency garbages which is no good for any line pre
I wish to get some feedback from the author of this pre -comparitions to which other line amps let him to conclude about music reproduction quality level of his "toy"
There are couple of well reputated preamps ( Pumpkin , Aikido , No26 tube pre , B1 , DISPRE (PMA)
They tend to pass some high frequency garbages which is no good for any line pre
I wish to get some feedback from the author of this pre -comparitions to which other line amps let him to conclude about music reproduction quality level of his "toy"
There are couple of well reputated preamps ( Pumpkin , Aikido , No26 tube pre , B1 , DISPRE (PMA)
As other people already said - the primary reason for existence of this forum is to learn and understand, not just to own stuff.
Treating people that way: "You don't need to see or understand because I did it already, you just need to accept my infinite wisdom and build it, I will tell you what's best for you" is disrespectful and insulting.
I'm sad to see a moderator approving this kind of misbehavior...
Treating people that way: "You don't need to see or understand because I did it already, you just need to accept my infinite wisdom and build it, I will tell you what's best for you" is disrespectful and insulting.
I'm sad to see a moderator approving this kind of misbehavior...
maybe it is
and its also about just constructing something you need
its about everything related to DIY
and every single project presented here doesn't have to fit the 'primary' ideal of ultimate DIY
and every member has the right to present what he think is OK
there is no rule saying that only the best possible is allowed
nor is there a rule saying that you have a right to be part of the design process
if its a well functioning and reliable design, what can there be to complain about
can't get enough of that
if you want a designers project, I guess its a different thing
but I think you may realise they are a minority
and that many never reach the finish line
so yeah, a ready to go project, what's there not to like about it
We don´t have any problems with noise what so ever in this preamp.
Actually in normal use, you cannot hear any difference in noise level regardles of position of the volume control.
Also the PSU has been measured, no noise is present.
The LM317 current source solution was chosen, because of its enormous ripple and noise rejection, theoretically it is more than 160 dB.
Regarding comparisons, we´ve mostly compared it to high end preamps of different makes. But I don´t really think that has any relevance any longer.
If you read in the original thread about the project, then you can find pretty much feedback about the sound. I can mention a few things from the feedback for you, which has been consistent throughout.
Several builders have said, that "there really isn´t much to say about it. It seems as if it has little or no sound of its own."
Exactly that has been our goal. So mission accomplished on that.
Another thing that everyone has remarked is the bass reproduction, which they say "is very lively compared to their own preamps, and much deeper and controlled."
I hope this was what you needed.
Enjoy
But not a impressive way just as a part of the music
About the need for schematics and maybe a discussion of it, and a short or long process going through every single point once again.
Obviously this is not necessary, we are now close to a thousand downloads of the BOM and building instructions, but only 4 people asked for schematics.
They all had them by mail.
So we will accept that this project is a "GO" for the lot and a "NOGO" for a few.
And if anyone should get the thought of somebody wanting to sell kits, just forget it. We will not sell you anything. You´ll have to do it yourself.
We helped as much as we think we could, in building a preamp that works and is stable.
Send the Gerber files to i.e. Olimex (OLIMEX LTD ARDUINO MAPLE PINGUINO ARM AVR MAXQ MSP430 PIC LOW COST DEVELOPMENT BOARDS), and in a few days you´ll have your PCB.
Choose your vendor for the components and order for yourself and friends. But do not change anything. Every component has been evaluated thoroughly already.
You can freely choose between the Suncon electrolytics and Panasonic FM.
It is also possible to change the relays from Omron to Panasonic, probably this will save you money. But you also can leave them out, if you just need a single input, which will give you extra performance.
The footprint for the potentiometer can of course be used as solderpoints for a remote pot. The Alps pot can of course be replaced by P&G or likely.
But they are mostly unavailable and costly.
I really cannot see why anybody should feel bad about this.
But if you hear about anyone selling KITs please notify us.
Obviously this is not necessary, we are now close to a thousand downloads of the BOM and building instructions, but only 4 people asked for schematics.
They all had them by mail.
So we will accept that this project is a "GO" for the lot and a "NOGO" for a few.
And if anyone should get the thought of somebody wanting to sell kits, just forget it. We will not sell you anything. You´ll have to do it yourself.
We helped as much as we think we could, in building a preamp that works and is stable.
Send the Gerber files to i.e. Olimex (OLIMEX LTD ARDUINO MAPLE PINGUINO ARM AVR MAXQ MSP430 PIC LOW COST DEVELOPMENT BOARDS), and in a few days you´ll have your PCB.
Choose your vendor for the components and order for yourself and friends. But do not change anything. Every component has been evaluated thoroughly already.
You can freely choose between the Suncon electrolytics and Panasonic FM.
It is also possible to change the relays from Omron to Panasonic, probably this will save you money. But you also can leave them out, if you just need a single input, which will give you extra performance.
The footprint for the potentiometer can of course be used as solderpoints for a remote pot. The Alps pot can of course be replaced by P&G or likely.
But they are mostly unavailable and costly.
I really cannot see why anybody should feel bad about this.
But if you hear about anyone selling KITs please notify us.
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For those assembling the pre-amplifier.
To do it right, you must connect the power supply board to the main board as follows:
When placed just towards one another, the leads from the PSU board should be crossed when connected to the main board.
This along with the polarity of the wall outlet, that produces the smallest potential from amplifier ground to local earth, will produce by far the best sound quality.
So keep that in mind.
Also be shure to chose the right power voltage. The building instruction will only show you the 230VAC connection. But that should quite logical anyway.
Anyways it would be nice if some of the downloaders who actually are building the amp, would write us some feedback.
Please do so.
To do it right, you must connect the power supply board to the main board as follows:
When placed just towards one another, the leads from the PSU board should be crossed when connected to the main board.
This along with the polarity of the wall outlet, that produces the smallest potential from amplifier ground to local earth, will produce by far the best sound quality.
So keep that in mind.
Also be shure to chose the right power voltage. The building instruction will only show you the 230VAC connection. But that should quite logical anyway.
Anyways it would be nice if some of the downloaders who actually are building the amp, would write us some feedback.
Please do so.
What exactly is this pre-amp used for? Is it to amplify the output of a moving coil pick-up or is it to modify the output from a CD player or other high level playback device.
Why would one want to put this thing between a CD player and an amplifier, to adjust the volume or to modify "distort" the sound somewhat. I see the bass is very impressive according to you thus it must be modifying the original signal, increase/shape/distort the bass (and possibly all other signals). I cannot see how otherwise it would make an original signal coming out of a CD player better than what it is without adding distortion or character that is not in the original output.
Just the fact that it sounds different from what comes out of the original source means that you are listening to something that changes or distorts the original signal.
If it was pure and added or subtracted nothing from the original signal then why would need one of these at all?
Why would one want to put this thing between a CD player and an amplifier, to adjust the volume or to modify "distort" the sound somewhat. I see the bass is very impressive according to you thus it must be modifying the original signal, increase/shape/distort the bass (and possibly all other signals). I cannot see how otherwise it would make an original signal coming out of a CD player better than what it is without adding distortion or character that is not in the original output.
Just the fact that it sounds different from what comes out of the original source means that you are listening to something that changes or distorts the original signal.
If it was pure and added or subtracted nothing from the original signal then why would need one of these at all?
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Why do you use BFR90/BFT92 in your amplifier. It is typically used for oscillators in garage door key-fobs, UHF TV antenna boosters, and the like. Is there a need to amplify RF signals in your design, it is not particularly suitable for low frequency.
Well
You´l have to study the output of i.e. a DAC and a CD player then.
A preamplifier has the job to drive cables and load, and thus protect the source against it. that´s just about it.
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They are used in the shunt regulator, and is particularly intended for HF. The shunt has a cut of frequency around 10 MHz.
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What you are saying is that my CD player cannot be connected to the interconnection cables. My goodness, I must have stuffed up my CD player completely over the years connecting it through wires to my amplifier.
Where can I study DACs because I do not work in the insurance industry.
Where can I study DACs because I do not work in the insurance industry.
@Nico Ras
If you open your CD player you will most probably find a standard arrangement of opamps. A single opamp is in many situations incapable of driving high capacitance loads (interconects with high parasitic capacitance). This will result in series of problems and of course will give the snake oil pseudo high-end cable dealers a way to drain some money from you.
Now, whether a preamplifier is needed in a particular system is a completely different issue and is a pure matter of a personal taste. One thing is for sure - some power amps represent a non easy to drive load(having a signal conditioning networks at the input) and that is where a preamp really helps.
Of course if a simple system is implemented (CD player -> integrated amplifier, or a high sensitivity power amp) and no signal switching is required, nor any other "bells and whistles", a simple high current output buffer is always an option. A CSS loaded emitter follower stage with about 20mA standing current would do just fine in driving almost any capacitive load. Another option is Burr Brown's BUF634.
Regards,
Venci
If you open your CD player you will most probably find a standard arrangement of opamps. A single opamp is in many situations incapable of driving high capacitance loads (interconects with high parasitic capacitance). This will result in series of problems and of course will give the snake oil pseudo high-end cable dealers a way to drain some money from you.
Now, whether a preamplifier is needed in a particular system is a completely different issue and is a pure matter of a personal taste. One thing is for sure - some power amps represent a non easy to drive load(having a signal conditioning networks at the input) and that is where a preamp really helps.
Of course if a simple system is implemented (CD player -> integrated amplifier, or a high sensitivity power amp) and no signal switching is required, nor any other "bells and whistles", a simple high current output buffer is always an option. A CSS loaded emitter follower stage with about 20mA standing current would do just fine in driving almost any capacitive load. Another option is Burr Brown's BUF634.
Regards,
Venci
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