Beta 22 amplifier build

I got a fair amount of work done on my next project the last couple days. This one is a high power, three-channel, active ground amplifier and matching power supply. These also come from AMB labs.

Here’s the power supply board in progress:
sigma 22

And here it is complete:
sigma 22

Here are the three amplifier boards in progress:
beta 22beta 22

More to come… there’s still a lot to do!

Edit: The boards are done… now comes the difficult task of connecting them all up together and running tests to make sure everything works as it should.
three channels of beta 22 boardsclose up of beta board

In the meantime, here’s the obligatory Ashley and Amanda pic:
IMG_9991

Edit 3/8/2009:
Just about done with the amp. I still have to wire in the headphone jacks when I get them, but it works with the speaker jacks already.
Here’s the full amp in all it’s cookie tin goodness:
IMG_0200
The front panel:
IMG_0202
The back right:
IMG_0205
The guts:
IMG_0207

Edit 3/17/2009:
I was getting some transformer hum problems despite my best efforts to keep the signal wires on the opposite end of the enclosure, so I ended up moving the toroid into it’s own enclosure while keeping all the wiring, IEC, and on/off switch in the original tin.

As luck would have it, I had a round cookie tin lying around so I put it to good use! As such, I present to you the cookie tin/beta 22 hybrid:



I just need to trim and mount everything to that board (scrap piece of shelf from IKEA) and then it should be completely finished.

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6 Responses to Beta 22 amplifier build

  1. Ed says:

    what a great idea, thanks for the writeup – the baby pics were the icing on the cake. I’m also looking for an easy b22 enclosure – do you have any links or advice? (I can’t consult headwize because their forums are down). Thanks again!

  2. jason says:

    Ed – If you like the cookie tin idea, it’s mostly a matter of finding one that fits that you like the looks of. If you happen to live near any asian markets, they seem to have lots of cookie tins available for you to choose from. I would say cookie tins are easier than a “real” enclosure because you can make cuts and holes with just a dremel vs. a drill press. But I would recommend you have a wood base or 1/4″ piece of aluminum or steel to kill any flex the tin might have otherwise. There are two caveats to this. First, if you think you really won’t ever move the tin much then it’s fine as is. Also, if you have the top on all the time with a few smallish vent holes to allow air flow, then the tin is much much stiffer than without the lid on. In that case, you might be able to get away with not having a base.

    Otherwise, the tins work just fine and offer a unique and cheap solution to the dreaded case work. The one thing you might want to upgrade is to screw a piece of plastic (maybe 1/8″ thick or so) into the side with all the connections so you more evenly distribute the forces applied when you connect and disconnect your headphones, RCA plugs, etc.

    Hope that helps. Let me know if you have any other questions.

  3. Michael Ting says:

    HI Jason, I think your using the cookie tin case for the b22 is the coolest case i’ve seen for the b22.. I really going to implement your idea onto my b22!!!

    Thanks for the inspiration, dude!

  4. jason says:

    Good for you! Let me know how it turns out.

  5. Pingback: IC: My B22/Cmoy hybrid - Head-Fi: Covering Headphones, Earphones and Portable Audio

  6. Bill Kilpatrick says:

    You’re a genius! Instead of making your B22 larger than life, you’ve reminded us all that what matters is what’s on the INSIDE. It’s all about the parts and how they function together. It’s all zen, baby. It’s all about harmony and love and inspiration.

    You rock!

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