Knock out box

[Tubetec]

Ive used a few knock out boxes for projects over the years , plastic and metal
There avaialable from any electrical retail outlet and blank front panels come in a variety of metal finishes .
As either a chassis for a small preamp project or maybe to help screen a toroid on a larger chassis there perfect .

They come in a variety of sizes and the knock outs are more or less ready for mounting up tube sockets and XLR's in what ever orientation suits your build ,
You can hard wire up an idea in no time at all on tag strips , theres plenty of pre drilled holes , you also get a riveted brass grounding terminal .

Ok its never going to win any beauty contests but you can prototype an idea very quickly and cheaply and have good screening
If its just a preamp module that sits in a rack it doesnt need to look the pigs knickers , utillitarian will do just fine .

 

[Rob Flinn]

I have used this type of Patress Box before, You can get smooth blanking panels with rounded edges for them. They don't look quite as crude as the ones on your pics. I have found them good for small stage boxes amongst other things.
Fished box with plate looks like this
They even do bigger versions


However the bigger front plates only come pre punched for grid switch modules.//


One thing to be careful of with this type is getting the patress box & front plate from the same manufacturer, because they can be quite a snug fit and an MK lid might not fit a British General box for example.

 

[Tubetec]

Ah yes MK , always high quality stuff , worth the extra money if its in use by the public ,

For nesting transformers I was thinking a combination of the oval and square kind , it would be easy to add extra MU material layers if required .
A small toroid would fit in very neat and tidy .

 

[scott2000]

I had to find a quick and dirty solution for replacing a center tapped wall wart transformer and threw a flathead in one of these with a few cuts with cutoff wheel.... The holes for the mounting actually lined up perfect too which was nice.

 

[Tubetec]

Its a great when intelligent design coincides in the bits you have to hand and an idea realises itself ,

I'd have to tried maintain the metal screening around the transformer , but maybe you needed room for a PCB below or height was restricted . In any case its away from sensitive circuitry so it wont matter much . For safety Id put a transformer bell end over the top , your only a mm of paper away from a high voltage rock and roll misadventure , then again if its just for your own private usage in a specific task it may not matter at all.

These exact Flathead transformers are great , they have low magnetic field and well balanced incidental capacitance on the windings
combined with a screening when used near other iron cored components it should give the excellent performance .


The partitioned 2 and 3 gang enclosure looks like a handy platform for old style hardwired tube preamps ,

Ive always liked the munition box mic/preamp idea , like the Dave Royer mics ,
Plenty of room to house a PSU ,line level output stages ,control panel , safe storage for mics and cables and its all sealed in a bomb proof enclosure .
Battery back up so comms dont go down along with the grid if you want .

They have the 50 cal boxes brand new at the army surplus place down the road , on offer , its big enough to build a small tube mixer into ,
Thats around 20 Euros including a few masonry boxes from the hardware store,
a drill and a file ,
no special tools required ,

Law Enfarcement/Security will get a twinge in its ring when you rock to up to the joint and start pulling that shit out of the trunk of your car ,




.

 

[scott2000]

your only a mm of paper away from a high voltage rock and roll misadventure

A real knock out box eh?
Really could just make things easy and put a danger sign on the door to cover all the other things too. Parents never let me have cool stuff like that so maybe it's time... but, then again, the door isn't usually closed and the dogs can't read anyway. Maybe you're right. oh...danger sign above the door...oh yeah, the dogs....

 

[Tubetec]

An end-bell from an old transformer would do the trick ,



With the standard 50cal box it looks like 8 x 35mm slots of two gang boxes will just about fit with space for air flow above and below , the knock outs along the top and end of the box can be punched through as required so the air can rise ,the tubes towards the top drawing cool air in from below over the components ,

Best head down to see my buddy at the surplus ......
I'll report back later .

 

[scott2000]

An end-bell from an old transformer would do the trick ,

That looks great. Was already hunting around the big box site for something...like an in use cover or something but not the right plan....think I have some old hammond transformers from an organ I can try the bells from although thinking they are too small.... really wanted to try to test them for their place in audio anyway....

edit....just got back from the orange box store...grabbed stuff for this contraption.... seems like it'll work...clears everything more than enough....probably just predrill/self tap scews on the perimeter

 

[Tubetec]

It looks like a job well done Scott .
I have a couple of Boss 9v supplies I'd like to box up like this , maybe rail mounted ,

I picked up a new medium sized ammo box , 16.50 euros , they have the large for 22 ,
'OMAN MUNITION PRODUCTION COMPANY' and the usual military nomenclature stenciled on.
The lid seal means these boxes are impervious to environmental conditions in transit , its rated from -40 to +70C
the lid is removable also.

The two gang box proportions up extremely well with the medium sized can , it fits long ways ,with plenty of room for dials and switches on the front ,
It fits vertically , and four in a rectangular config fills the front panel space to perfection , it allows lots of flexibility .

Agreed Rob,
I picked up a few cheap galvanised boxes, they have nasty burr's and metal dog ears to hold it together , a quick rub with a file and a spot of weld would do the job , but by the time you'd prime and top coat the galvanised its better just to buy the proper painted wall mounting boxes which have better seams, are spot welded and also made of much heavier gauge steel .

 

[Tubetec]

One more thing about mounting bolts in transformers that pass through the core , they are usually insulated by slipping a short lenght of silicone/glass fibre high temp wire slieveing over ,then a fibre washer at either end .

 

[k brown]

I was immediately reminded of this old Tape Op article:

http://recordinghacks.com/articles/how-to-build-a-microphone/

 

[Tubetec]

Good ole Screw-fix have the MK metal clad boxes on special here at the moment ,
single gang , 1.95 euros
double 3.65 euros
four gang 7.50 euros

I brought the galvanised in-wall boxes back , took my cash and got the MK's instead ,
All up the metal work for my new project stands at just over 30 euros , fully painted/finished with no risk of corrosion or moisture rotting out bare metal , everything inside sealed from the elements , hard to beat for that kind of money .

Security will need to change their manpons after I show up at the gig

 

[Tubetec]

I found a UK company that do dimmer panels , single ,dual gang , in beautifully plated brass , without electronic controls included
also a full range of really nice looking toggles and associated panels ,
My gears gonna look like the control panel from an Abrams tank , 100 f@#!ing % idiot proof , has to be for Christ's sake


https://www.click4electrics.co.uk/click-toggle-switch-modules-c-328_712

 

[ruffrecords]

Maybe I am missing something (a working brain?) but your link goes to the toggle switches themselves rather than the box. I cannot find the box anywhere on that site.

Cheers

ian

 

[scott2000]

I didn't look into it too much but, there's an accessories section

https://www.click4electrics.co.uk/wiring-accessories-c-328/

 

[nsalis]

I was on a holiday in the UK a few months ago and actually had toggle switches like this on the wall in two of the hotels in the rooms. How beneficial this simple and logical operation was. Instead of having to struggle through touch panels with incomprehensible menus and sub-menus, simply having to activate a toggle switch that is clearly assigned to a lighting group.

We (Switzerland) no longer have such simple switch plates. If one had to use such, they would have to be safety tested according to EU standards (we are not a member, but we are subject to the EU standards). This is probably not considered worthwhile because there are too few interested architects and electrical planners.

Nick

 

[Tubetec]

https://www.click4electrics.co.uk/a...cat=0&search_in_description=0&sort=20a&page=2
Theres the empty plates for toggles , the back boxes come in a variety of sorts , either in wall or the painted kind that was shown earlier .
They also do dimmer blank panels which would be perfect for mounting up pots .

 

[Tubetec]

Old fashioned simplicity is hard to find these days , everythings over complicated .

 

[Newmarket]

I was on a holiday in the UK a few months ago and actually had toggle switches like this on the wall in two of the hotels in the rooms. How beneficial this simple and logical operation was. Instead of having to struggle through touch panels with incomprehensible menus and sub-menus, simply having to activate a toggle switch that is clearly assigned to a lighting group.

We (Switzerland) no longer have such simple switch plates. If one had to use such, they would have to be safety tested according to EU standards (we are not a member, but we are subject to the EU standards). This is probably not considered worthwhile because there are too few interested architects and electrical planners.

Nick

Those switches should already be qualified to conform to EU standards.

 

[nsalis]

"Those switches should already be qualified to conform to EU standards."

You're right, I found relevant information on the data sheets.


Here is the manufacturer's website. They also have socalled "Media Modules" (HDMI etc.):

https://www.scolmore.com/products/gridpro-aux/

Combined Media and 230VAC plates (pg 41):

https://www.scolmore.com/products/gridpro-aux/

The said toggle switches are here:

https://www.scolmore.com/technical_specification_bim/_brochures/Deco/Deco - Toggle Switches.pdf

Nick