Project: racktx [custom rack mount ATX case] - [UPDATE: new photos + done first mods]

'Proper' in the rack mount world, is... weighing about 6 tonnes each, made of cast iron, and about 3 foot deep...

Thanks for the feedback... i have planned it a lot.. but i need some help with this VU meter circuit... tis a bit.... um.. complicated to say the least the band filters i'm struggling on.. so if anyone would like to give me a hand designing the filters.. i'd love you in the face! >_<

 

calling all electronics buffs ... i REALLY do need some help (in the form of schematics) for these frequency filters.... i need to split this single input into three outputs.. each output containing a different range of frequencies, google searches arent really helping, nor is my electronics tutor at college.. so... i'm getting a bit desperate now

could someone help.. i'm sure there are quite a few of you who have done similar things, or know how to... just need a little guidance, or something to copy the schematics of... y'know.. just to get this thing working...

 

ok, first drawback encountered....

stuff arrived at my mums house today... and.. to my surprise.. 4U cases are now 2U cases.. :O... or so maplin think... yes.. they sent the wrong one... idiots... :|

Invoice says:
4U 19in Rack Case N37AN £39.98

Product Code is totally different on the product.. and its half the size.. how they managed that i have nfi

/me cries

problem is.. these cases weigh a tonne... 2mm thick steel all round, apart from the front which is ~4mm thick aluminium.. so.. i dont know how we're gonna get it back to them.. surely, because its their cock up.. they'll have to pay for postage back to them.. right ?...

anyway.. rest of stuff is here, on time, all accounted for... from the supplier i expected to get it wrong too... OcUK ... perhaps my judgements of them are wrong

 

nice sketchup skills. it seems you have everything planned well.hope it turnes out the way you want it.happy modding!!

 

mmm, plans are falling apart already though it seems stupid maplin pickers.

also the VU meter is being redesigned... but is now doable.. cheaper than before too

will be drawing up the schematic either tonight or tomorrow

 

what you need for you VU meter my friend, is a crossover system to split the frequencies.

http://www.quasarelectronics.com might have some kits for you, but if you want the full DIY route and some more background on filters/crossovers try http://www.passivecrossovers.com/index.htm

 

there is a problem with using crossovers, you need to know the resistance of the load circuit... which i really dont know how to figure out for my A to D converter
its not a simple circuit.. i'll upload it in here, and ask in the electronics section
other than that, crossovers are out of the question

EDIT: the circuit... can anyone calculate what the resistance across the INPUT terminals is [top is +, bottom is -]

 

If you're having troubles with max load you should try using an opto-coupler so you don't load the original signal that much ...

but the project looks awesome so far are you going to put a neon in the desk ? (would be pretty cool )

 

You really have some good SketchUp skills mate I love the desk, and the case should be looking pretty fancy when finished as well.
Besides that, go for the three channel version of the VU metre. Good luck!

 

for the vumeters, instead of custructing a huge circut, why not just use a couple of lm3915's or lm3914's?

case should look nice none the less

 

Would it not be better to have an auto leveling input signal, i saw the circuit that somebody used as a previous as level electronics project, dont know what its called but it removes the 10k pot and levels the output on the vu meter its self

 

i will be, my software doesnt have them in though... right now i need to concentrate on the design of the bass, mid, and treble filters... which i'm getting help with from the lovely acrim.

i think i have figured out the bass filter though.. the opamp circuit i've designed seems to reject anything after 150Hz.. which is a good sign... although its Db/s falloff isnt very quick.. i'd like to make it faster.. but it'll do if that's not possible

 

ok.. Filter network sorted , this network has a VERY quick falloff, it uses second order filtering (filters twice).. gotta love accuracy ;P i will be using this exact same schematic in my A2 electronics project at college... so.. killed two birds with one stone.. as they say...

i'll need a total of 10 op-amps for the VU meter now.. so.. 2 quads and a double... ... ah well..

the schematic below has a gain of 1, so.. same voltage goes in as comes out.. only thing undecided at the moment is if i want to make this VU meter go on the negative scale... because music normally alternates around 0v.. there are some negative portions.. atm, i'm simply ignoring the fact that they exist.. and half wave rectifying it... (hence the +12 and 0v supplies to the opamps)

 

Something came to me while looking so I did a 5 min sketchup:



Maybe a tighter spiral... but you get the idea

 

2c: i prefer the lines straight up and down to the spiral, but its whatever floats YOUR boat

 

i agree...

both look good.. but the straight one keeps in with the clean straight edges of the case.. if the case were more rounded, i might consider the spiral.. thanks anyway.. nice idea

 

i vote spiral, purely because it will look cool with every beat of teh music, the lighs sort of rotating a bit then goin back.. if you get me!

Nice case though!

 

personally, i think the spiral would be nice, but to balance the image on both sides, i'd suggest you have some design on the otherside, like to give it a cutting or something ^^ that'd be nice, cause the spiral is too damn tight

 

ok, i've made some modifications to my design, and i agree, it looks MUCH better with the spiral .. i think i might stick to that only thing not final on this now is the location of the DVD drive... i was thinking at the top, in the center, very discrete, but there...


Click for big version.

 

Nice work so far. Looks like this will be a one-of-a-kind project. *Subscribed*