Maddog's Lamington Jr Amplifier build diary

[wazkelly]

Would be nice if they came with an attenuator as 2w is OK fully driven, but 15w and higher would be very, very loud indeed.

Yes, I have been looking long and hard at these for months now and always weighing up cost of a completed combo with 8" speaker that is anywhere from $229 for Joyo up to $429 for Bugera or Vox AC4 or BWM for $375 versus building a kit where 2w = $195 or 15w = $295 plus you need a speaker on top of that too. Tend to think 15w with a decent speaker would end up costing more than a ready made and have less features. Just my 2c worth.

Also not so confident playing around with all that current and would have therefore gravitated towards this 2w one. Still pondering and will watch how this turns out with interest.

[Simon Barden]

Rather than buy a kit, I might try and see if I can source all the parts myself and build my Lamington Amp on a diecast Aluminium box from Jaycar Electronics.

If I was making one, I'd be tempted to do something similar. Far easier to then put it in a proper protective enclosure.

[Maddogm]

So I'm about 10/15 steps in on the wiring up the power supply section which looks like:


Doc the amps are designed with being able to source parts easily within Australia in mind so you shouldn't have any trouble with that.

Waz, I was also unsure about playing around with the current which is why I got this one as well as a bigger one (buying 2 at once doesn't save on shipping FYI)

[DrNomis_44]

Just need to work out which Lamington Amp I'm going to try building, all the models on offer look really interesting.

[Maddogm]

One issue I have come across with the instructions is with the order it gets you to solder things to and around the star ground means you layer stuff above it before you've finished soldering wires to it.

The green and black wire in that picture were soldered in after the diodes and and the resistor.
The star ground being the tab behind the lower diodes
I may have cheated with the black wire

Power supply done:

[DrNomis_44]

One issue I have come across with the instructions is with the order it gets you to solder things to and around the star ground means you layer stuff above it before you've finished soldering wires to it.

The green and black wire in that picture were soldered in after the diodes and and the resistor.
The star ground being the tab behind the lower diodes
I may have cheated with the black wire

Power supply done:

You could try adding more solder eyelets to the Star-Ground.

[Maddogm]

You could try adding more solder eyelets to the Star-Ground.

It's more getting the soldering iron etc in there
I think if I was doing it again (like the other lamington amp I have), I'd cut the wires going in there to length and solder that end on before adding the diodes over the top

made some more progress

Oops:


I'm onto the output stage now:

[Simon Barden]

I was wondering how good a ground connection you get with all the Teflon coating on the tray. Have you done any resistance measurements to the other bolts that go through the tray?

[Maddogm]

I was wondering how good a ground connection you get with all the Teflon coating on the tray. Have you done any resistance measurements to the other bolts that go through the tray?

There was a lot scratching away with the swiss army knife to remove the coating under the ground

[Simon Barden]

But you'll also need to do it for the other grounded items as well, such as the transformer fixings. As I said, check the continuity with a multimeter, you may be fine.