jimbo's chipamps

[jimbo1968]

I've got 3 kits on the way (lm3875, lm3886, lm4780) to be used eventually as the amps for 3-way active front speakers (once i've worked out the system configuration).

To start I will build them as straightforward stereo amps, with attenuation, to allow comparison, trial of different attenuators etc.

Here are some pictures of my layout scheme for comment.

I've bought a sheet of 10mm aluminium, and have access to a milling machine and a sheet bending machine and plenty of thin stainless sheet.

3 amps:

 

[jimbo1968]

inside side view

 

[jimbo1968]

Top view, and inside view with lid/base removed

 

[jimbo1968]

The idea is to have separate power and amp compartments.

Lid and base will be removable to allow assembly/modifiaction of the 2 section.

The lid/base will be sheet metal bent into a simple C shape, the chassis will be held together by M4 socket screws in counterbored holes. The dividing middle 'floor' will be fixed from the inside.

The front/rear panel will be milled down where necessary for fixing of sockets.

10mm Al sides for heat sinking, and a width of 140mm were the design drivers.

 

[steenoe]

Looks promising, indeed. Very nice drawings you made there🙂

Steen😎

 

[jimbo1968]

Thanks. If I had autocad I'd do some proper drawings, but for now Powerpoint is my design tool🙄

 

[Nuuk]

for 3-way active front speakers (once i've worked out the system configuration).

Jimbo, you may find this gives you some ideas! 😉

 

[daatkins]

Nice work Jimbo!

I'm after some sheet aluminium for an 8-channel LM3886 gainclone. Where did you buy yours?

 

[jimbo1968]

http://www.metalfast.co.uk/ would have cost about 60quid for 1200mm x300mm x10 inc vat and 15quid delivery. I got mine via my brothers company for the same price.

Once again I was tempted to buy in bulk 'just in case' because of the delivery charges, so I nearly bought sheets of 8mm and 6mm as well.