Kurt von Kubik and Hurtig,
I can understand how pleased you are with the design and so on, I just think this is not the "market place" for this.
Correct me if I am wrong but I think you intend this preamp to built by the user going off your reply in post #41... and I suspect the smd technology aspect would put many off. Although many might like the overall idea, when it comes down to actually working with smt they won't or can't.
The folk on here that would work with smt like myself and Nico and several others are by our nature much more technically curious.
If this design is as good as you say then perhaps this isn't the right target audience for it. If it is a no profit venture and done for your satisfaction only (and that's absolutely fine) then you have to accept that this "being the forum that it is" that the more technical folk want to know all the ins and outs of the design. You have only to look to the Pass Labs forum and AKSA forums to see how designs can develop... and if that is what you want, then on a forum such as this you have to share.
If you want the design to have wide coverage perhaps you should look at supplying complete products that are ready to use and submitting them to dealers/magazines etc to start the ball rolling. I don't know how that side of things works though...
I can understand how pleased you are with the design and so on, I just think this is not the "market place" for this.
Correct me if I am wrong but I think you intend this preamp to built by the user going off your reply in post #41... and I suspect the smd technology aspect would put many off. Although many might like the overall idea, when it comes down to actually working with smt they won't or can't.
The folk on here that would work with smt like myself and Nico and several others are by our nature much more technically curious.
If this design is as good as you say then perhaps this isn't the right target audience for it. If it is a no profit venture and done for your satisfaction only (and that's absolutely fine) then you have to accept that this "being the forum that it is" that the more technical folk want to know all the ins and outs of the design. You have only to look to the Pass Labs forum and AKSA forums to see how designs can develop... and if that is what you want, then on a forum such as this you have to share.
If you want the design to have wide coverage perhaps you should look at supplying complete products that are ready to use and submitting them to dealers/magazines etc to start the ball rolling. I don't know how that side of things works though...
Welll. Then I guess yor are right. This is not the right place to show such a project, if www.diyaudio.com is all about schematics and tech specs, and absolutely no interest in sound quality....
Let's have some moderator shut down the thread.... Then I will post some op-amp design with perfect tech specs, and everyone will be happy.
Let's have some moderator shut down the thread.... Then I will post some op-amp design with perfect tech specs, and everyone will be happy.
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It is the right place if you are willing to discuss it...
diyAudio is very much about sound quality but there are folk on here happy to play around with a TDA2030 and think it's wonderful. At the other extreme there are folk who take their audio (music reproduction) very seriously indeed.
You have much to be proud of putting a design in front of the public gaze, but you haven't done your market research.
I put a design on here a while back that, last time I looked has had some 50,000 views and yet only a tiny handful have built it... and as I found out you can't just tell folk how good something sounds and expect them to build it on trust. Those that did were pleased and comments were very favourable... I just wish many more would have had a go.
So don't take it personally... it's a great achievment to present a fully worked design... but do your research as to your targeted audience.
diyAudio is very much about sound quality but there are folk on here happy to play around with a TDA2030 and think it's wonderful. At the other extreme there are folk who take their audio (music reproduction) very seriously indeed.
You have much to be proud of putting a design in front of the public gaze, but you haven't done your market research.
I put a design on here a while back that, last time I looked has had some 50,000 views and yet only a tiny handful have built it... and as I found out you can't just tell folk how good something sounds and expect them to build it on trust. Those that did were pleased and comments were very favourable... I just wish many more would have had a go.
So don't take it personally... it's a great achievment to present a fully worked design... but do your research as to your targeted audience.
Hi Mooly
As a matter of fact, we are not in for marketing anything, especially not the mounting work.
In the original thread, which I´ve linked to earlier, we were some 20 guys ordering PCB´s and Components altogether. We also offered those who did not have sufficient soldering skills to do the soldering for them for free. That changed the project from DIY to LSEDIFY (Let Someone Else Do It For You) in a few seconds. Therefor that offer was cancelled.
And there will not be anything like it in the future.
But anyway by now some 10 pcs. or so are singing, and some are underway, others decided to order components themselves and so forth.
But people are actually building them, and only one up until now did not work due to bad soldering.
So I do not think this project is for the very technical minded only. You just have to order things, and then keeping your workspace tidy, and your solder iron hot.
So this is IMHO not mission impossible, or technicians only.
Regarding Pass Labs I´ve listened to a few Pass designs, and they might be great, I don´t know for sure, but every time I´ve heard one, it sounds different. People are reworking them, doing things their own way, using other components etc. Exactly that is what we want to avoid.
We´ve spend a long time to design out components that we do not like.
I.e capacitors which I hate the sound of with all my heart. Some are better some are worse, but they all have their own sound.
That is actually the real achievement in this design. There is no patentable circuit details in it. Everything is known technology. But it is, as a result of the choices made, very transparent. Of course we knew that already, but it is much better to have independent feedback confirming this, and we do have that.
It has also been tested up against awesome preamps, with very good results.
We just thought that a DIY forum is the place to look, if you want to DIY.
Also to help solve problems, discus designs and so forth, but none of this exclusively.
We still hope that somebody will go on building it, in spite of all this quarrel. According to the mails, PM´s and number of downloads it seems as if the majority of people are very interested.
So I think these 10-15 pages are just a very narrow vision of what is going on.
Anyways we can only encourage people to do the project.
In DK we are by now working on doing a very nice enclosure for it.
We are trying to find an economical way to mill out the enclosure from a solid bar of aluminium. And then mount the amp from the bottom.
By now 14 people have ordered enclosures, which will be the same for both our upcomming DAC and poweramp exept for backpanels and holes for controls. This is a DK only thing though, but if anyone else would like to do the same, technical drawings can be mailed.
Also this could be an opportunity for you, if people are not confident with SMT.
Maybe you could help the nervous ones with soldering it for them. Maybe even they want to pay you for it.
I will say though that our design is for DIY, not for commercial use.
Maybe some day we will commersialize it, but that would never end up in here.
As a matter of fact, we are not in for marketing anything, especially not the mounting work.
In the original thread, which I´ve linked to earlier, we were some 20 guys ordering PCB´s and Components altogether. We also offered those who did not have sufficient soldering skills to do the soldering for them for free. That changed the project from DIY to LSEDIFY (Let Someone Else Do It For You) in a few seconds. Therefor that offer was cancelled.
And there will not be anything like it in the future.
But anyway by now some 10 pcs. or so are singing, and some are underway, others decided to order components themselves and so forth.
But people are actually building them, and only one up until now did not work due to bad soldering.
So I do not think this project is for the very technical minded only. You just have to order things, and then keeping your workspace tidy, and your solder iron hot.
So this is IMHO not mission impossible, or technicians only.
Regarding Pass Labs I´ve listened to a few Pass designs, and they might be great, I don´t know for sure, but every time I´ve heard one, it sounds different. People are reworking them, doing things their own way, using other components etc. Exactly that is what we want to avoid.
We´ve spend a long time to design out components that we do not like.
I.e capacitors which I hate the sound of with all my heart. Some are better some are worse, but they all have their own sound.
That is actually the real achievement in this design. There is no patentable circuit details in it. Everything is known technology. But it is, as a result of the choices made, very transparent. Of course we knew that already, but it is much better to have independent feedback confirming this, and we do have that.
It has also been tested up against awesome preamps, with very good results.
We just thought that a DIY forum is the place to look, if you want to DIY.
Also to help solve problems, discus designs and so forth, but none of this exclusively.
We still hope that somebody will go on building it, in spite of all this quarrel. According to the mails, PM´s and number of downloads it seems as if the majority of people are very interested.
So I think these 10-15 pages are just a very narrow vision of what is going on.
Anyways we can only encourage people to do the project.
In DK we are by now working on doing a very nice enclosure for it.
We are trying to find an economical way to mill out the enclosure from a solid bar of aluminium. And then mount the amp from the bottom.
By now 14 people have ordered enclosures, which will be the same for both our upcomming DAC and poweramp exept for backpanels and holes for controls. This is a DK only thing though, but if anyone else would like to do the same, technical drawings can be mailed.
Also this could be an opportunity for you, if people are not confident with SMT.
Maybe you could help the nervous ones with soldering it for them. Maybe even they want to pay you for it.
I will say though that our design is for DIY, not for commercial use.
Maybe some day we will commersialize it, but that would never end up in here.
oh, I didn't know you had been nominated to be new chief moderator
Mooly, you are not supposed to 'play' police/moderator
That is quite alright
A lot is going on behind the scene.
Just give the guys a little time to assemble it, maybe they will be back to write a bit about it.
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We do not measure succes in comments in this thread actually, but in people interested enough to use the links and download the gerbers and building instructions.
So far 647 people linked to the files from this great site alone already.
If just 1% of those will do the project, then we very soon will hear about their real life sonic impression of the finished project, and not just opinions of the schematics.
So far 647 people linked to the files from this great site alone already.
If just 1% of those will do the project, then we very soon will hear about their real life sonic impression of the finished project, and not just opinions of the schematics.
I am one of those that requested and received by email the full schematics. Obviously, I am not supposed to make these public without express permissions, however there are a few things that can be told about.
- First, the schematic posted here is the same with the signal chain schematic that I received. I'm not going to comment on the signal chain details (although there are lots of question marks regarding the design decision).
- The schematic I received has flagrant errors (like the negative power supply shorted to the servo opamp output, the negative supply parallel regulator current source having the pinout of a LM337 (which would, BTW, work fine as is) but claimed to be a LM317, etc...
- I've tried several times to discuss by email with the authors, but received nothing but pushbacks like "the schematic is correct as it is". Any common sense or simulation shows that implementing the schematic as distributed would lead to a pile of smoked silicon.
- There are some flagrant contradictions between the schematic, the BOM and the PCB pictures.
In conclusion, I wouldn't touch this design with a pole. I have no idea what are the authors after (certainly doesn't sound like DIY to me), I am not sure if the schematic was sent on purpose with flagrant errors (I am inclined to think so), or the authors have no idea what they are talking about, but I would warn anybody attempting to build this preamp to expect some significant troubles, both technical and in communication.
That's all folks, now back to my lurk mode...
You can try this. Its a voltage feedback amplifer and it sims at about 2.5ppm at unity gain, and 10ppm at a gain of 5 into 600 Ohms. Output is a simple emitter follower - so its designed to run class A. I have aboard layout, but I have not ordered or built any yet.
The pinouts are:-
1 = high output class A - link to -ve supply rail
2 = inverting input
3 = non inverting input
4 = -ve rail - up to 20V
5 = compensation cap
6 = Optional bypass for constant current regulator diodes.
7 = output
8 = +ve supply rail - up to 20V
To zero the output, you can use a servo as you would with a normal op-amp.
I'll do a bipolar input version in the next week or so and then a CFA version with the same pinouts
All dual bipolar transistors are 2% beta match from NXP.
R1 and R2 can be replaced with 0 Ohm links for lower noise, but this will require some adjustment of the comp cap value (which will typically lie between 22pF and 100pf depending on your gain setting.
The comp cap in this design is connected between the comp pin 5 and the output.
Happy experimenting!
(mods, you may want to move this to a separate thread - I leave it up to you to decide)
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For reference purpose or those who may be interested, attached please find my super linear dual complimentary symerty line amp and headphone driver. For those who are interested I have a full set of gerbers and boms. This pre-amp has been replaced in my commercial line-up with a newer version that improves the specs a tad more.
I started a write up for DIY Audio but did not find the time to complete it, sorry, but what is there may be useful.
Also the Pre-amp features a virtual earth thus is completely imune to earth loops and also needs no servo.
I started a write up for DIY Audio but did not find the time to complete it, sorry, but what is there may be useful.
Also the Pre-amp features a virtual earth thus is completely imune to earth loops and also needs no servo.
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