color coded BOM and assembly instructions
there really is very little magic. The basic idea in stuffing the boards is to do it so that smaller lower lying things get done before bigger things that overshadow them for purely matters of convenience. So: all the little resistors first, then all the small caps. One suggestion that's been made is that putting in the very caps after you mount the amp chip because you might have a hard time otherwise to get the screw driver in there. For the soldering, if you don't have much experience, you might practice on something else first. Basic rule is to go in quick. Nothing too paranoid, but you don't want to be holding that iron against some part for a very long time since it is entirely possible to overheat it. I took some pictures during my assembly process which will give you some idea about general order. See http://picasaweb.google.com/schro20/FinalBuildOfRevCFromKit# (note how I did not mount the chip before I put on the big caps and promptly had a hard time with the mounting screw for the chip on the heatsink...) Important when mounting the chip on the heatsink is to ensure that you have perfect insulation (with the help of the nylon bushing) between chip and heatsink. Test this with an ohm meter to make sure. Very very important.
One thing to watch out for is the polarity on the diodes and the electrolytic caps. It's all marked but you need to pay attention.
peter
Dear Marc,marc brown said:
there really is very little magic. The basic idea in stuffing the boards is to do it so that smaller lower lying things get done before bigger things that overshadow them for purely matters of convenience. So: all the little resistors first, then all the small caps. One suggestion that's been made is that putting in the very caps after you mount the amp chip because you might have a hard time otherwise to get the screw driver in there. For the soldering, if you don't have much experience, you might practice on something else first. Basic rule is to go in quick. Nothing too paranoid, but you don't want to be holding that iron against some part for a very long time since it is entirely possible to overheat it. I took some pictures during my assembly process which will give you some idea about general order. See http://picasaweb.google.com/schro20/FinalBuildOfRevCFromKit# (note how I did not mount the chip before I put on the big caps and promptly had a hard time with the mounting screw for the chip on the heatsink...) Important when mounting the chip on the heatsink is to ensure that you have perfect insulation (with the help of the nylon bushing) between chip and heatsink. Test this with an ohm meter to make sure. Very very important.
One thing to watch out for is the polarity on the diodes and the electrolytic caps. It's all marked but you need to pay attention.
peter
Re: color coded BOM and assembly instructions
Thanks Peter. I've gotten all the small resistors and caps installed. I read up on capacitor markings so I'd get the polarity right. I've got a nice soldering station so I'm pretty confident that I didn't overheat any components. Four of the caps confused me for a bit. In most everyone's in-progress pics they look like dark red jelly beans but mine were little yellow boxes. I finally realized I had to carefully bend one of the pins to fit those guys on the pcb.
I'm thinking about installing one of the big caps on the back of the board so that it makes it easier to get to the 3886's mounting screw. Once I'm finished I'm nervous about powering it up for the first time. I'm sure things are in the right place but it's like starting up a rebuilt motor . . . . .
I'm looking forward to checking out some waveforms on my o-scope to see what sort of job the amp is doing. I'm also going to use the o-scope to help me mod an old Magnavox cd player.
schro20 said:
Thanks Peter. I've gotten all the small resistors and caps installed. I read up on capacitor markings so I'd get the polarity right. I've got a nice soldering station so I'm pretty confident that I didn't overheat any components. Four of the caps confused me for a bit. In most everyone's in-progress pics they look like dark red jelly beans but mine were little yellow boxes. I finally realized I had to carefully bend one of the pins to fit those guys on the pcb.
I'm thinking about installing one of the big caps on the back of the board so that it makes it easier to get to the 3886's mounting screw. Once I'm finished I'm nervous about powering it up for the first time. I'm sure things are in the right place but it's like starting up a rebuilt motor . . . . .
I'm looking forward to checking out some waveforms on my o-scope to see what sort of job the amp is doing. I'm also going to use the o-scope to help me mod an old Magnavox cd player.
Re: Re: color coded BOM and assembly instructions
You can post a picture and we can double check the placement of the parts..
I have a close up photo here:
http://picasaweb.google.com/troystg/Rev_C#
Click on the picture and then when it opens on the right hand side of it is a magnifying glass to "zoom in" on the PCB's.
marc brown said:
You can post a picture and we can double check the placement of the parts..
I have a close up photo here:
http://picasaweb.google.com/troystg/Rev_C#
Click on the picture and then when it opens on the right hand side of it is a magnifying glass to "zoom in" on the PCB's.
Attachments
Re: Re: Re: color coded BOM and assembly instructions
There are a few other small differences (some of the power resistors, some relays; nothing major).
peter
Troy has the red jelly beans for C4/C5. Most people have small yellow boxes. This is because we got some parts from Brian.troystg said:
There are a few other small differences (some of the power resistors, some relays; nothing major).
peter
Re: Re: Re: Re: Re: Re: color coded BOM and assembly instructions
Marc-
Yes, if Peter and Uriah say that is the correct value for those caps (C4 & C5) then your installation should work fine.
As mentioned, my first kit was a "trial" test fit and apparently had different caps but I am sure Peter and Uriah double / triple checked the parts before ordering / mailing and yours should work.
marc brown said:
Marc-
Yes, if Peter and Uriah say that is the correct value for those caps (C4 & C5) then your installation should work fine.
As mentioned, my first kit was a "trial" test fit and apparently had different caps but I am sure Peter and Uriah double / triple checked the parts before ordering / mailing and yours should work.
Re: Re: Re: Re: Re: Re: Re: color coded BOM and assembly instructions
Peter
Basically, if you followed the white paper labels on the caps everything should be fine. See the picture of the caps bag contents http://www.diyaudio.com/forums/attachment.php?s=&postid=1717114&stamp=1232334559schro20 said:
Peter
Do your parts match? (They should!)
Brian Donegan donated leftover parts from the TP kits to this group buy. Most of those were resistors and we bought the exact same kind. So you won't see any difference. Some of those were capacitors (and we bought the exact same kind) and in some cases the newly bought types were the same values but different packaging. C4/5 comes to mind. There are also different versions of C3/8 because we just couldn't get enough of one kind (recall the horror stories of vendors flaking out on us). But in each case I made sure that a given pair has exactly the same components. (I packed them in pairs, so I am quite certain that I got that part right; you should check however if this is a major concern for your application). Across pairs I can't say for sure though I certainly tried to be mindful of that.
Please check now. Basically Uriah and I want to draw the big fat line underneath all of this and close out this GB. It'll be much harder to deal with issues after that point.
Thanks much to everyone!
peter
All pairs are matched. For those who ordered multiple pairs they *ought* to be matched across the pairs as well. Anybody who is concerned about this, PLEASE check now.troystg said:
Brian Donegan donated leftover parts from the TP kits to this group buy. Most of those were resistors and we bought the exact same kind. So you won't see any difference. Some of those were capacitors (and we bought the exact same kind) and in some cases the newly bought types were the same values but different packaging. C4/5 comes to mind. There are also different versions of C3/8 because we just couldn't get enough of one kind (recall the horror stories of vendors flaking out on us). But in each case I made sure that a given pair has exactly the same components. (I packed them in pairs, so I am quite certain that I got that part right; you should check however if this is a major concern for your application). Across pairs I can't say for sure though I certainly tried to be mindful of that.
Please check now. Basically Uriah and I want to draw the big fat line underneath all of this and close out this GB. It'll be much harder to deal with issues after that point.
Thanks much to everyone!
peter
Re: Re: Re: Re: Re: Re: Re: Re: Re: color coded BOM and assembly instructions
Remember, these things were put together by a meat computer with meat servos, not one of those new fangled all metal robot devices.
Peter
Absolutely! These are good things to check up on and be certain. Better check twice than be disappointed later!marc brown said:
Remember, these things were put together by a meat computer with meat servos, not one of those new fangled all metal robot devices.
Peter
madisonears said:
I second that!!
I had NO problems with the channels I built nor do I expect ANY from the 2 channels yet to be built.
The only concern was that there might be different components in the 2 kits thus not making them 4 identical channels.
I can find out if there are any differences and order matching components if there are.
I still think the GB was 100% a success and appreciate all the work you two did!
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