[odoe]

I have a proto board, the last version before the final as far as I know. Is there anything I should take into consideration when building it that's different from the final, aside from the lack of fuse

?

 

[vixr]

I built both a proto and a production from TomBs BOM without any problems...

 

[tomb]

Quote:

Originally Posted by odoe /img/forum/go_quote.gif I have a proto board, the last version before the final as far as I know. Is there anything I should take into consideration when building it that's different from the final, aside from the lack of fuse ?

Differences between the final prototype board and the Group Buy production board:
1. The fuse position was added.
2. The power input was changed to a 3-position terminal block so that the fuse position could be bypassed if desired.
3. The optional input pads on the outside of the volume pot were enlarged to a full-size terminal block position.
4. A terminal block position was added to the outside of the headphone jack pads.
5. Two duplicate test points were added for Gnd for convenience.

Except for the fuse, none of these changes have any impact on the operation of the circuit. As I've repeated many times, my recommendation is that you bypass the fuse and not get caught up in trying to protect something that was supposed to protect either the walwart or the rest of the circuit, but can't really do either because of its location.

 

[adfinni]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Looks like you're trying for a balanced approach already.

Don't confuse me further, im still learning about the basics of the millett and how and why certain parts are chosen. Anyhow, 20 vit Q's in total heading to RuZZ.il and myself, plus im ordering the rest of the parts today for mine.....

COsts are really mounting up, but i know it's going to sound amazing !

 

[c0nsumer]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Test etch on the photo mask for the experimental MAX went well. Picture not so good.

Something in the rectifier isn't right. If you note, that entire row of top holes are connected. They aren't that way in the actual MAX. The way you have it will take the two AC lines and tie them directly together.

This error is in the image you posted earlier.

I haven't looked at the rest of the layout to look for other errors.

 

[tomb]

Quote:

Originally Posted by c0nsumer /img/forum/go_quote.gif Something in the rectifier isn't right. If you note, that entire row of top holes are connected. They aren't that way in the actual MAX. The way you have it will take the two AC lines and tie them directly together. I haven't looked at the rest of the layout to look for other errors.

Yes, you are correct. The reason there are two traces feeding those pads for the rectifiers is that one trace connects to the first 4 pads and the other trace connects to the last 4 pads.

I'm still astounded that Amphead is trying this, though.

 

[c0nsumer]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yes, you are correct. The reason there are two traces feeding those pads for the rectifiers is that one trace connects to the first 4 pads and the other trace connects to the last 4 pads. I'm still astounded that Amphead is trying this, though.

Scans of the boards and Illustrator's raster to vector converter should make it trivial.

That said, if someone were to just ask cetoole to run the CAM processor on his boards again, dumping each layer as postscript (also: don't fill pads), it'd be trivial to make PDF masks. (This is how I make masks whenever I'm etching boards...)

 

[adfinni]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Vixr is correct, but the small counter sink on the endpanels works just fine as it is. Socket head cap screws are tough enough to buckle the endplate if you tighten down on it from the reverse side. There would be nothing backing the cap head up if you reversed it. I wouldn't do that. A 6-32 x 3/4" will go far enough to cover the length of the threads that a typical 6-32 tap will make. A 1" is too long and will be cutting on untapped metal. 1/2" will not make use of all the threads that are possible. I settled on 3/4" as the best fit. This is probably a good thing to do because the slots only provide a partial thread surface, anyway. The 3/4" length might change if you use a different endplate or forego the end bezel.

Im looking at using the socket head cap screws, but am having a little trouble converting the imperial to metric that we use here in the UK. Was a lot easier at uni as we had the tables on the workshop walls.

From my browsing around an M3.5 socket head cap screw is equivalent to a 6-32 version. Also, from the MAX site im having trouble understanding if the holes in the hammond have to be tapped again, or the correct length socket head cap screws can be screwed straight in ?

 

[tomb]

Quote:

Originally Posted by adfinni /img/forum/go_quote.gif Im looking at using the socket head cap screws, but am having a little trouble converting the imperial to metric that we use here in the UK. Was a lot easier at uni as we had the tables on the workshop walls. From my browsing around an M3.5 socket head cap screw is equivalent to a 6-32 version. Also, from the MAX site im having trouble understanding if the holes in the hammond have to be tapped again, or the correct length socket head cap screws can be screwed straight in ?

The Hammond case is NOT tapped. They come with cheap little self-tapping sheet-metal screws that are worthless and shouldn't be used, IMHO. The slot/hole has enough meat to work for a 6-32 tap without drilling - but probably not if you use one of the screws that come with it, first. Although, you can probably cut threads beyond whatever those little screws tear up. I've found 3/4" long 6-32 socket head cap screws to work best.

I don't know how all that relates to metric, however. You'd have to also use a metric tap, too, if that's the way you're going.

 

[bperboy]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif The Hammond case is NOT tapped. They come with cheap little self-tapping sheet-metal screws that are worthless and shouldn't be used, IMHO. The slot/hole has enough meat to work for a 6-32 tap without drilling - but probably not if you use one of the screws that come with it, first. Although, you can probably cut threads beyond whatever those little screws tear up. I've found 3/4" long 6-32 socket head cap screws to work best. I don't know how all that relates to metric, however. You'd have to also use a metric tap, too, if that's the way you're going.

I don't know if I got a freak, but my Hammond was already tapped. This wasn't the case on my hammond for the mini3, but my Millett Max hammond that I ordered from mouser already had threads. A nice little surprise, but I wouldn't count on it in the future.

 

[tomb]

Quote:

Originally Posted by bperboy /img/forum/go_quote.gif I don't know if I got a freak, but my Hammond was already tapped. This wasn't the case on my hammond for the mini3, but my Millett Max hammond that I ordered from mouser already had threads. A nice little surprise, but I wouldn't count on it in the future.

Maybe somebody tapped it but returned it.

 

[adfinni]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif The Hammond case is NOT tapped. They come with cheap little self-tapping sheet-metal screws that are worthless and shouldn't be used, IMHO. The slot/hole has enough meat to work for a 6-32 tap without drilling - but probably not if you use one of the screws that come with it, first. Although, you can probably cut threads beyond whatever those little screws tear up. I've found 3/4" long 6-32 socket head cap screws to work best. I don't know how all that relates to metric, however. You'd have to also use a metric tap, too, if that's the way you're going.

Ah right......... I assumed it would be tapped, but now there is no way im using some cheapy self tapping screws that will probably end up stripping the thread they bore.

Well found a model shop online here that do metric and imperial taps.... But itl be $20 for all 3 taps, so i think im only going to buy the Taper tap and just use that to make a hole deep enough.

 

[amphead]

Quote:

c0nsumer: that entire row of top holes are connected. They aren't that way in the actual MAX. The way you have it will take the two AC lines and tie them directly together.

Yes, you and Tom are correct, just don't give me more than 20 lashes for my infraction.
Thats what I need, more eyes to get this board right.
As far as getting Colin to supply us with his mask, that may not be possible. IMHO, he deserves to get paid whatever can happen from selling boards from the group buys for his hard work. The boards that we can build outside of his original effort is up to us. Thoughts?
Corrections on the way!

 

[c0nsumer]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Yes, you and Tom are correct, just don't give me more than 20 lashes for my infraction. Thats what I need, more eyes to get this board right. As far as getting Colin to supply us with his mask, that may not be possible. IMHO, he deserves to get paid whatever can happen from selling boards from the group buys for his hard work. The boards that we can build outside of his original effort is up to us. Thoughts? Corrections on the way!

I think if you just ask him for PS outputs of each layer you'll have what you want and everyone will be happy. If he doesn't want to give them out, then keep going...

Masks as images (even vector images) aren't particularly useful to anyone mass producing boards. They'd only be good for those who are etching their own boards. Anyone having boards mass produced illicitly would do better off redrawing it. It wouldn't be too difficult.

All he'd have to do is give out the PS files and state that they are for personal, non-commercial use only, and for any clarification of this, people should contact him.

 

[amphead]

Well, you may have a point. He is busy with his studies at the university right now. So this may not work, but here goes.
Colin may we have your MAX mask images for non-commercial reproduction please?