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markiemrboo

Oh noes! Not another amp...

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[color="#FF8C00"][size=3][b]Building the case[/b][/size][/color]

A pea-sized tiny-small update is here. It is not much, but I have finally got around to nagging about the case again. I will use my nan visiting for the week as a semi-excuse for it not happening a bit sooner :P

It is not much, but the case itself should be roughly the same height as my current case, and only slightly bigger than the piece of paper in the following picture. The case that the paper is laying on is my current case.

[url="http://allyoucanupload.webshots.com/v/2002090535658814268"][img]http://aycu10.webshots.com/image/18969/2002090535658814268_rs.jpg[/img][/url]

The cases front panel will be similar to the current 2U case, with the slight over hang at the sides. I also think the top and / or bottom of the case may well be metal too. It is not going to be anything particularly fancy with the joins. Just simple 90 degree's stuff, as, well, it's simple. I figured that it doesn't matter too much, as you shouldn't be able to see the joins from the front anyway. It would just be between the back and sides.



Here's a picture of the scrap pieces of wood that is going to be used at least for the sides, back and front of the case. It is real wood. Oak. Salvaged from some old furniture!

[url="http://allyoucanupload.webshots.com/v/2003097577570379463"][img]http://aycu37.webshots.com/image/19476/2003097577570379463_rs.jpg[/img][/url]

As you can see, not looking in the greatest shape at the moment!



I was also having a few thoughts about the power switch the other day. With a potentially nice case, it seems a bit silly to have a [relatively] ugly power switch on the front. I really liked the idea of having a switch looking something like one of these:

[img]http://news.thomasnet.com/images/large/486/486552.jpg[/img]

[img]http://www.epreston.co.uk/epblog/wp-content/uploads/2006/03/Vandal%20Blue.jpg[/img]

Nice, round, metal. Inbuilt power light in the form of a nice ring. The only problem is that they are momentary and seem to be mostly for low voltage, where as I want mine 'latching' and rated for mains voltage.

Thankfully I found this over at diyaudio, which will allow a low voltage switch to be used and 'converts' a momentary switch in to a toggle type switch which I am after. Looks simple enough!

[url="http://allyoucanupload.webshots.com/v/2004109162706569715"][img]http://aycu30.webshots.com/image/18549/2004109162706569715_rs.jpg[/img][/url]

[url="http://www.imagineeringezine.com/PDF-FILES/4013oneshots.PDF"]http://www.imagineeringezine.com/PDF-FILES/4013oneshots.PDF[/url]



More to follow..... err..... soon, with any luck! Edited by markiemrboo

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Dude... this is going to be frickin' awesome when it's done! Can't wait to see the finished product :)

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Me three :)

I'm really eager to get it finished and use it now. Then I can update the preamp :rolleyes: Get that put in an identical sized and same style box, with one of those nicer looking power buttons I reckon. Could be quite yum!

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Yet another small update. I will merge everything together on to the front page once it is complete and just post the updates as they come I thinks.

I have drawn the PCB artwork for the push button switch latching circuit posted previously. I haven't produced the PCB as I will have to run off to staples and get it photocopied. I think I may also need some new ferric chloride too! Doh.

[url="http://allyoucanupload.webshots.com/v/2005350505648892237"][img]http://aycu10.webshots.com/image/19249/2005350505648892237_rs.jpg[/img][/url]


As far as the case goes, I have updated the rough drawing to be somewhat more accurate, now that I know the thickness of the wood. I think the top and bottom will be a metal of some description -- probably 4/5mm thick aluminium. Not that I have thought about it :rolleyes: Both the top and bottom plates will screw in to the wood / heatsink I think. There will also be a gap present on the bottom over the heatsink so there is some sort of opportunity for air flow!

[url="http://allyoucanupload.webshots.com/v/2005336347192166247"][img]http://aycu14.webshots.com/image/18013/2005336347192166247_rs.jpg[/img][/url]


Sketch with the top off. This should be the rough layout of things inside, minus the wiring, with any luck. I am still not sure I am 100% happy with it, but I can't seem to do it any better than that really. I am mainly concerned about the position of the new push button circuit. The transformer for it is right under one of the amps power supply wires. I'm sure it'll be fine though really!

[url="http://allyoucanupload.webshots.com/v/2005301850856464723"][img]http://aycu23.webshots.com/image/16182/2005301850856464723_rs.jpg[/img][/url]


I very almost forgot these poor creatures! I've been meaning to do it for ages. The output inductor / resistor. I do not seem to have any problems without it on the amp I am running right now. I might use them as an extra bit of security. It should apparently help stability and possibly any RF from entering via the speaker cables. They are just placed in series with the +ve output :)

[url="http://allyoucanupload.webshots.com/v/2006147642169875814"][img]http://aycu31.webshots.com/image/16550/2006147642169875814_rs.jpg[/img][/url] Edited by markiemrboo

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That is going to look awesome with the salvaged wood... ;)

I actually forgot about this thread, It's good to see your still working on it though...

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[quote name='Andrewr05' post='694588' date='Jun 6 2007, 11:38 PM']That is going to look awesome with the salvaged wood... ;)

I actually forgot about this thread, It's good to see your still working on it though...[/quote]

The wood will obviously be finished nicely too :)

I have photocopied the artwork today with some minor alterations. The photocopy looks really good this time too. Nice and sharp, very black... not patchy like last time. I like to think this is because I realigned the print head on the printer and used the 'fine' print setting instead of 'normal' :rolleyes: I also printed off some artwork for a refined preamp, but that's for another thread and at a later date ;)

I think should I later get in to micro controller stuff, like digital volume control and IR remote controls, this push button circuit should allow it to be 'turned off' with a remote control really quite easily too. I guess it would be more like 'stand by' though. The push button circuit will always be on, but the power consumption should be hardly anything at all, I think, especially when the relay is inactive.

I do think I am probably going to get some new ferric chloride before I continue though. My current stuff must be well used up by now! Here's a quite uninteresting picture of the photocopy, for now :D

[url="http://allyoucanupload.webshots.com/v/2000203953718031399"][img]http://aycu13.webshots.com/image/16852/2000203953718031399_rs.jpg[/img][/url]

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[quote name='suchuwato' post='696269' date='Jun 12 2007, 08:46 PM']Looks good :) I was in that rain too :([/quote]

:lol: unlucky! I swear that it seemed to start raining harder each time I went to try and step outside!

Well I have built it and the problems have started to appear ;) I have followed the circuit, and I understand completely how it works. It's quite simple and quite clever. 'D' and 'Q' are linked, so when Q = 1, D will also = 1. Qbar is the inverse of Q, so when D = Q = 1, Qbar will = 0. Now, since Qbar is connected to D, when Q = 1, Qbar = 0. Qbar will then feed D = 0, which will make Q = 0 (since Q follows D), and Qbar changes to 1. The trick is, that the state of Q can only change on a pulse at CLK, which happens at the push of the button. The RC network at RST insures that upon receiving power D/Q are 0.

The problem is that the CLK input of my CD4013 (STmicro) is very sensitive to rise time. With a 15v supply it expects a maximum of 1uS rise or fall time for the clock input. The push button switch can't make this happen, so it's misbehaving. Sometimes it will switch on and off fine, other times it might switch on and off very rapidly, sometimes it might not switch at all etc. The solution is apparently something called a 'Schmitt trigger'. Some 4013's have this built in, otherwise you have to do it yourself. I seem to have been very lucky in that I think I *may* have found some 4013's, manufactured by Toshiba, that have this built in, so I don't have to make it any more complex and built another board *phew* I will let you know how I get on with that one in a couple of days time!

[url="http://allyoucanupload.webshots.com/v/2003905356749378305"][img]http://aycu13.webshots.com/image/19332/2003905356749378305_rs.jpg[/img][/url]

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Looks interesting :)

Can anyone remeber before the OCC HDD failed (name was ginger3131 i think) , when I posted about my dad building that 1000w amp ?

Anyway, he just finnished it, took him over a year (or two, i cant remember) :)

Not much free time atm, so he hasnt bought it home yet :P I think hes going for two 15" woofers!

anyway, gj :D

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