Users of Alpha DPDTs (and millenium bypass users!)

[amckinley100]

Hey all - given the sudden interest in using alpha switches (thanks to Small Bear's stocking of the same item) I thought I'd share this with y'all.  I've been using the alpha switch for all of my effects, as it is the only one which is available easily in the UK.
I got inspiration from a link in a previous post (can't remember exactly) whereby the switches were mounted directly to the PCB - this coupled with the fact that when I had to de-solder and replace a switch, I had a near miss when some hot solder flicked up from the wire and landed at the base of my eyelashes!!! :shock:

Anyway, coupled with the apparent FUD over alpha switches, I thought that people may want an easy way to mount their alpha switches for easy replacement...and here it is - a circuit board with holes for your switch lugs! (while I was at it, i thought I'd include a circuit for the Millenium Bypass 2 as well).



Can people check the layout and make sure it's ok (haven't actually used it yet, but I think the circuit is ok) and once i've been given the go-ahead, I'll post the normal template with scale and everything

Cheers guys

[Jered]

Isn't a 1N4001 a low leakage diode?
  Jered

[ExpAnonColin]

Thanks, I was wondering when someone would PCB layout this.

-Colin

[amckinley100]

*bump*

[Alpha579]

Cool idea. Looks right...

[javacody]

If you ask me, this should go in the iSi forum (hint, hint Peter!)

[kdawg]

Will R2's location clear the switch once it's soldered? Other than that, I think it looks OK. Is the 100k a fix for some pedals? I didn't need it on my TS-9 clones. If you put up a normal version, I might be able to etch one this weekend and try it out, since I was going to make some millenium bypass boards anyways and I've already got Alpha switches.

-kdawg

[amckinley100]

Good point kdawg - i just did a cardboard mockup, and the fitting is a wee bit tight around the switch - possible, but a wee bit tight!.  I've redone the transfer pattern to allow for this - not much extra, as I'm trying to keep the board as small as possible.  Anyway, here's the transfer for those that are interested...



Have fun guys....let me know your results!

Oh, the 100k pulldown resistor is there by RGs recommendation - when I made a MB2 before, i forgot this resistor, and the LED slowly came back on when the effect was still switched off.  Other people on this forum have had the same problem since then, so I thought it would be prudent to include the resistor.  Besides, if it's not needed, you can always leave it off!   :wink:

Cheers

[kdawg]

Ok guys... I've redrawn a *different* version on this little board, but I haven't checked it at all yet to make sure everything still fits. I will etch a board tomorrow once I get some feedback and hopefully this thing works!

Now I wasn't sure if this will fit both solder and PC alpha switches, but looking at the spec sheets, they look very similar sizing-wise.

Millenium Alpha Rev 1: http://www.jnd.com/kdawg/millenium_alpha_rev1.pdf

-kdawg

[kdawg]

I did another rev with slightly smaller layout. Rev 1.1: http://www.jnd.com/kdawg/millenium_alpha_rev1_1.pdf

-kdawg

[R.G.]

If you're going all the way to putting a small PCB on the bypass switch, you're in the territory of something I messed with a while back.

You might want to use an even cheaper momentary switch, a CD4049 hex inverter and a small latching relay. There are latching relays in the NEC line that would fit nicely. The GEO latching relay circuit would fit on a 1" by 2" circuit board, including a 1/2" hole in the center for the switch bushing. You print the PCB with all the copper and components on the top side, leaving the back side bare. The board goes against the box, the switch goes through the board and the box and holds the board in place, and wires go from there to the circuit.

I have the pcb layout somewhere here if there's much interest.

I suspect that if properly motivated, Small Bear would get a batch of NEC's latching relays in the 9V variety. I keep wondering why he hasn't already.

[kdawg]

I finally got around to making one of these. I like your idea R.G., but I think I'm done with this for now . Here's a photo:



I like it... clean, simple, you could even drill a hole right next to the Alpha switch and bend the LED over to it instead of running wires.

The PDF was OK except I had the transistor footprint reversed. Here's a new rev with the change:
http://www.jnd.com/kdawg/millenium_alpha_rev1_2.pdf

Enjoy!
-kdawg