LM386 AMP MANHATTAN STYLE

[Digger1770]

Here is my first attempt at a Manhattan style circuit. Hopefully it wont pick up too much RF with all the un shielded signal path



I roughed it out in pencil then stuck down the tabs and worked off a schematic, great fun and happy with the result so far.
Cheers, Dave

[FUZZZZzzzz]

looks pretty sexy!

[GibsonGM]

Nice work, looks good!  That ground plane is big, will probably help with shielding altho it's directional.  If you enclose it, you could use foil on the other 3 sides, grounded, to quiet it down - if it's even needed...

[anotherjim]

Would it have done any good to mount the 386 chip upside down? So it's in contact with all that copper for some heat sinking?

I used to know someone who made his project boxes out of double side glass fibre copper clad board.

[duck_arse]

I've always found the best way to prevent RF pickup is to sand the edges of the fibreglass board smooth.

but it does look good.

[R.G.]

You might want to go read http://www.geofex.com/Article_Folders/protostyles/proto_styles.htm and especially read the section on dots and dashes.

The dots approach lets you do much of what you have there, but also lets you make the interconnects much sturdier, as all or most connections are fixed to the substrate, not just the ground connections.

Nice, neat work, by the way.

[Digger1770]

Thanks for the comments. All tested and its nice and no RF ( As pointed out I think

That ground plane is big, will probably help with shielding

) . The old ROLA speaker sound good

Would it have done any good to mount the 386 chip upside down? So it's in contact with all that copper for some heat sinking?

Great idea I struggled a bit with how to mount the chip, and it was hard to pre mount all the wires to the vero in the correct place before taping it down. This way I can change the chip easy though.
Thanks R.G. I had read that article and many others before having a go at this. I like the idea of cutting the copper with a small hole saw that tilers use (diamond) to form the Dots, but I think that having the the wire instead of the Dashes adds more levels to the "Manhattan style" circuit IMO. Plus as an Electrician I have heaps of scrap copper cables
Thanks again now to build a cab.
Cheers Dave

[bluesman69]

being a noob to all things electronic and having only build the tiny giant amp by Taylor (excellent amp and a pleasure to build) and constantly looking for my next project, I'm curious to know if this project is an amplifier (as I suspect) or for a pedal?  If it's an amp, how many watts does it put out?  And how do you like the tone?

[Digger1770]

Hey Bluesman69, The circuit is a Noisy Cricket 0.5 watt Amp, its a great easy project, I have also done one on vero. There are several similar amps using the 386 ic like the Ruby amp. They sound good for what they are, the tone control is a bit lacking as pointed out by the designer but I don't mind it, the dirt switch is good too. They are cheap and quick to build. Makes a good gift for the nephew or friends, using an old speaker/box works well.


Here is a link to the Beavis page,  with info and links to other relevant pages. This is a great site and I for one am thankful that they keep hosting this site even though it seems no longer active.
http://www.beavisaudio.com/projects/NoisyCricket/
Cheers Dave

[stm]

A bit off-topic, but I'm curious to know if the "Manhattan style" name comes from the Manhattan Project, the similitude to the Manhatan skyscrapers, or other.  Real question, no kidding :-)

P.D.  Your build looks great, by the way.

[amptramp]

This may be an older construction style than you think.  The front piece is polished black bakelite (phenolic plastic):



and the obligatory gut shot (which is flipped over as well as upside down):



Old (1920's) battery radios often used a style similar to what you are using, but without the same level of shielding.

There also used to be a construction technique that used a tool that was a hand-turned drill surrounded by a holesaw of about 0.125 inch diameter.  The tool I used was a Vector P138D pad cutter that looked like this:

http://www.vectorelect.com/Catpdf/New%20Page%2076.pdf

You would put holes where you needed them and there would be insulation provided by the holesaw and you applied eyelet-style rivets that looked like the metal eyelets used for shoelaces.  These eyelets were brass and you could solder to them and fit a number of components into a hole.  The eyelets were insulated from the board by the ring cut out by the holesaw.  I used this type of construction for an RF filter and it seemed to work well.