The danish magazine High Fidelity, 2003/6 has a very nice project based on the application note from National. It's a Gainclone with 4 pcs. of LM3886. Pcb's are for sale, surprisingly nice looking.
Can anyone explain why the designer not has chosen standing LM3886?? Much easier to get good cooling.
Can anyone explain why the designer not has chosen standing LM3886?? Much easier to get good cooling.
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pinkmouse said:
As far as I can see what's shown on the picture is the chips mounted to the L extrusion that would be attached to the main heatsink and also the mounting bar that presses the chips against the L extrusion. IMHO, if the project is aimed at the masses it is much better as the whole assembly of the amp channel can be done and then attached easily to the L extrusion and then you can fiddle as much as you want when attaching it to the main heatsink. This is the same way a great many projects ad kits do it in Elektor, ELV and many others. Standard issue it seems to me. Look at the app note and check the heatsinking for BPA-200. Not much needed in that config relatively speaking.
In designing my own bridge/parallell board I was always short on space for the supply rails and output. By laying the chips down you do two things which is to increase the space between board edge and chip to fit wide traces and you also make it possible to use that L extrusion. Pretty well implemented in my book. To bad the chip doesn't come that way in the first place (or I just missed that version).
peranders said:
Hi,
You can place some more tracks on bottom layout with horizontally placed IC's. Allu L profile is good choice if someone sells kits. This profile can be easily thermally coupled with any big heatsink or metal chassis.IMHO
(Rowland's and Linn's chips are horizontally mounted too)
Regards
(edit: I 'm slooow)
I think the cooling arrangements are for "musical" power.
The link is www.high-fidelity.dk and you have to get in contact with the editing staff. Price unknown.
When I write this I can reach the URL but I think it's the right one.
The link is www.high-fidelity.dk and you have to get in contact with the editing staff. Price unknown.
When I write this I can reach the URL but I think it's the right one.
Why is this project called "Das Modul"? The designer was tired of all fancy french names which noone can pronounce.
As a technical language german is wonderful!
Noise = Rausch (lovely!)
Apparatus = Gerät
Switch = Umschalter
What did you think of my swedish Gainclone spelling (see the subject line)?
As a technical language german is wonderful!
Noise = Rausch (lovely!)
Apparatus = Gerät
Switch = Umschalter
What did you think of my swedish Gainclone spelling (see the subject line)?
Das Modul
Hallo everybody
I am the author/constructor of "Das Modul". This is my first replay into this forum so please bare with me if I don't get the syntax 100 % right
First of all thanks for the nice comments and also for the not so nice comments on "Das Modul".
Feedback is always welcome, since this is the way to learn more. I take it that is why we all are here ??
I would like to take the opportunity to make a few points about the construction clear (UrSv have said a lot, but I will do it again):
1. There seems to have been some confusion/misunderstanding about the heatsink. The picture posted by "peranders" is just the Modul WITHOUT any heatsink. The two aluminium profiles you see are holding the LM3886 and for mounting the module onto a suitable heatsink of your own choice.
I have attached a picture that shows you this. Please notice that the PCB on that picture is NOT "Das Modul" but a prototype that used 6 x LM3886 and not 4 x LM3886 as "Das Modul". However I hope you understand the principle.
2. Some people are wondering why I didn't select the LM3886 to be standing up instead of lying down. UrSv got it almost spot on, but I will go through it anyway. There are 3 reasons for this;
A. Using a L-profile to mount the LM3886's onto allows you to make a complete final and functional module witch you can test (and trouble-shoot ) BEFORE you mount it on you heatsink.
You most remember that just 4 LM3886s have 30+ legs that need to be mounted which makes mounting/demounting very difficult if you didn't use the modul-approch.
B. If you use the "stand-up" approach your LM3886 get VERY close to the edge of the PCB. This makes is extremely difficult to run tracks to the LM3886 in a suitable size, if not impossible. If you insist using the "stand-up" approach you should use SMD components that will give you some extra space, but it will still be difficult.
The only way to use the "stand-up" approach IMHO is to leave some space on the PCB behind the LM3886. However this will not let you mount the LM3886 straight on to the heatsink, so you will either have to cut a deep slide into the heatsink or mount the PCB "under" the heatsink.
C. By having the LM3886 flat you can much easier mount the profile on top of them, to apply some pressure for better cooling. Again it can be done with the "stands-up" approach but easily becomes difficult to handle.
I would like to stress the importance of this "top-profile", in my case a small U-profile. Is gives a MUCH more even pressure on the LM3886 and therefore a much better cooling compared to just mounting the LM3886 with a screw through the hole.
Under "work" this top-profile get surprisingly hot, which just tells you how bad cooling you get if you are just using the hole.
3. About the LM3886. For "Das Modul" I use the LM3886 in a option that is already bend for flat mounting. The option is called LB14, so when you order your LM3886, you have to order LM3886T-LB14. Unfortunately not may suppliers that deal with DIY-people carries that option.
As you might already know, it is possible to bend the legs of a non-LB14 LM3886 so it will fit onto the "Das Modul" - PCB. Just be careful, they do break after couple of bendings. I can offer the LM3886-LB14 in a limited amount....see later.
4. "Das modul" construction have been published in the latest number (#6/03) of the Danish audio-magazine: High Fidelity.
If you don't read Danish or Swedish you are then a little bit in the dark.
However I do have a "informal agreement" with the magazine that I can put the article on the net at a later stage (½-1 year), which I very much hope to do. Translated to English and maybe German also.
But for now I can only talk about the article in very general terms...........sorry. They want to sell there magazine, which you really can't blame them.
5. I have put a few photos (some are also present in the article) on the net. You can see them at www.pbase.com/tlmadsen/das_modul
This will hopefully give you an idea about the construction. Feedback and comments are very welcome.
6. I have made a PCB for "Das Modul". It is 140 mm x 100 mm and have a cut-out as you can see. It is made in INDUSTRIAL STANDARD QUALITY, which basically means;
FR4, 1,6 mm thick and 35 um Cu.
The PCB is double sided and plated through. It also have a soldermask and a positionprint. I have tried to make the pads farley large and good space around the components so everybody can "swing there soldering iron" as much as they like. The value of each component is also printed on the positionprint.
However this should NOT be your fist solder-project. Since the PCB is plated through is makes it "non-trivial" to removes components from it (why should you ever have to do this.......)
I am selling this PCB for dkr.300,00 (=45 US$) including shipping. If you order 6 boards or more you will get each board for dkr. 250,00 (=38 US$).
The board comes with schematic, board layout of the component placement and a component list, with ref-# to Franell (see www.franell.com) for all the components.
You will need to make/get hold of the ALU-profiles yourselves.
IT DOES NOT COME with any kind of "how to put it al together-instructions", since they are all in the article. The article also deals with PSU and heatsink issues, with again don't come with the board.
However if you have be working with power op-amps before it should not be any problem for you to put together a working module.
7. I also have a limited amount of LM3886T-LB14 that I am selling. The price is dkr. 70,00 (=11 US$). This is WITHOUT shipping with have to be set on an individual basis. However it seems to be around 10 US$ regardless of the amount you order.
If you want yo buy the PCB or the LM3886-LB14, just send me an Email.
Looking forward to hear some input and feedback.
Thomas
Hallo everybody
I am the author/constructor of "Das Modul". This is my first replay into this forum so please bare with me if I don't get the syntax 100 % right
First of all thanks for the nice comments and also for the not so nice comments on "Das Modul".
Feedback is always welcome, since this is the way to learn more. I take it that is why we all are here ??
I would like to take the opportunity to make a few points about the construction clear (UrSv have said a lot, but I will do it again):
1. There seems to have been some confusion/misunderstanding about the heatsink. The picture posted by "peranders" is just the Modul WITHOUT any heatsink. The two aluminium profiles you see are holding the LM3886 and for mounting the module onto a suitable heatsink of your own choice.
I have attached a picture that shows you this. Please notice that the PCB on that picture is NOT "Das Modul" but a prototype that used 6 x LM3886 and not 4 x LM3886 as "Das Modul". However I hope you understand the principle.
2. Some people are wondering why I didn't select the LM3886 to be standing up instead of lying down. UrSv got it almost spot on, but I will go through it anyway. There are 3 reasons for this;
A. Using a L-profile to mount the LM3886's onto allows you to make a complete final and functional module witch you can test (and trouble-shoot ) BEFORE you mount it on you heatsink.
You most remember that just 4 LM3886s have 30+ legs that need to be mounted which makes mounting/demounting very difficult if you didn't use the modul-approch.
B. If you use the "stand-up" approach your LM3886 get VERY close to the edge of the PCB. This makes is extremely difficult to run tracks to the LM3886 in a suitable size, if not impossible. If you insist using the "stand-up" approach you should use SMD components that will give you some extra space, but it will still be difficult.
The only way to use the "stand-up" approach IMHO is to leave some space on the PCB behind the LM3886. However this will not let you mount the LM3886 straight on to the heatsink, so you will either have to cut a deep slide into the heatsink or mount the PCB "under" the heatsink.
C. By having the LM3886 flat you can much easier mount the profile on top of them, to apply some pressure for better cooling. Again it can be done with the "stands-up" approach but easily becomes difficult to handle.
I would like to stress the importance of this "top-profile", in my case a small U-profile. Is gives a MUCH more even pressure on the LM3886 and therefore a much better cooling compared to just mounting the LM3886 with a screw through the hole.
Under "work" this top-profile get surprisingly hot, which just tells you how bad cooling you get if you are just using the hole.
3. About the LM3886. For "Das Modul" I use the LM3886 in a option that is already bend for flat mounting. The option is called LB14, so when you order your LM3886, you have to order LM3886T-LB14. Unfortunately not may suppliers that deal with DIY-people carries that option.
As you might already know, it is possible to bend the legs of a non-LB14 LM3886 so it will fit onto the "Das Modul" - PCB. Just be careful, they do break after couple of bendings. I can offer the LM3886-LB14 in a limited amount....see later.
4. "Das modul" construction have been published in the latest number (#6/03) of the Danish audio-magazine: High Fidelity.
If you don't read Danish or Swedish you are then a little bit in the dark.
However I do have a "informal agreement" with the magazine that I can put the article on the net at a later stage (½-1 year), which I very much hope to do. Translated to English and maybe German also.
But for now I can only talk about the article in very general terms...........sorry. They want to sell there magazine, which you really can't blame them.
5. I have put a few photos (some are also present in the article) on the net. You can see them at www.pbase.com/tlmadsen/das_modul
This will hopefully give you an idea about the construction. Feedback and comments are very welcome.
6. I have made a PCB for "Das Modul". It is 140 mm x 100 mm and have a cut-out as you can see. It is made in INDUSTRIAL STANDARD QUALITY, which basically means;
FR4, 1,6 mm thick and 35 um Cu.
The PCB is double sided and plated through. It also have a soldermask and a positionprint. I have tried to make the pads farley large and good space around the components so everybody can "swing there soldering iron" as much as they like. The value of each component is also printed on the positionprint.
However this should NOT be your fist solder-project. Since the PCB is plated through is makes it "non-trivial" to removes components from it (why should you ever have to do this.......)
I am selling this PCB for dkr.300,00 (=45 US$) including shipping. If you order 6 boards or more you will get each board for dkr. 250,00 (=38 US$).
The board comes with schematic, board layout of the component placement and a component list, with ref-# to Franell (see www.franell.com) for all the components.
You will need to make/get hold of the ALU-profiles yourselves.
IT DOES NOT COME with any kind of "how to put it al together-instructions", since they are all in the article. The article also deals with PSU and heatsink issues, with again don't come with the board.
However if you have be working with power op-amps before it should not be any problem for you to put together a working module.
7. I also have a limited amount of LM3886T-LB14 that I am selling. The price is dkr. 70,00 (=11 US$). This is WITHOUT shipping with have to be set on an individual basis. However it seems to be around 10 US$ regardless of the amount you order.
If you want yo buy the PCB or the LM3886-LB14, just send me an Email.
Looking forward to hear some input and feedback.
Thomas
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Banned
Joined 2002
anyone want to arrange it?Banned
Joined 2002
Cool that you are a member here Thomas.
Of course I did understand that this L-profile was to be mounted on a big heatsink. Eventually some time in the future when I make my own Gainclone/Das Modul I may realize the pros and cons regarding standing/laying IC's. I gather that you will loose rather lot in cooling power with this arrangement but if it's for music at home it will probably be sufficient.
May I ask why you chose LF411, LF412? They are not bad at all but a little bit unusual and "old".
Once again, a nice CAD job.
I like also pcb's with groundplanes. I use groundplanes whenever I can (most of the time infact).
BTW: Are you related to Michael Madsen? I suspect that Madsen is a rather common name in Denmark.
Of course I did understand that this L-profile was to be mounted on a big heatsink. Eventually some time in the future when I make my own Gainclone/Das Modul I may realize the pros and cons regarding standing/laying IC's. I gather that you will loose rather lot in cooling power with this arrangement but if it's for music at home it will probably be sufficient.
May I ask why you chose LF411, LF412? They are not bad at all but a little bit unusual and "old".
Once again, a nice CAD job.
I like also pcb's with groundplanes. I use groundplanes whenever I can (most of the time infact).BTW: Are you related to Michael Madsen? I suspect that Madsen is a rather common name in Denmark.
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