The Alice mic - profect , firts time i do this

manuelmateus

New member
I'm trying to make the DIY Alice mic its a simple scematics , already I bought the parts and have , this was the first time i try some eletronic circuit, fell free to laugh
microfonejpg.jpg

its not working, XD any ideas why? , I test the capsule and its working , it is possible so damage the eletronic components with the heat welding involves?
thanks
 
It's possible that you have damaged some components. However, more importantly, you need to develop your soldering skills, because there is solder all over the place, and it is likely you have short-circuits by the bucketful.

I'd suggest:

1 Have a look on the web(or somewhere) for what good soldering looks like and how to achieve it;
2 Check to make sure you have the right soldering iron for the job; and
3 Throw this out and start afresh.
 
+1 to the above.
Get a multimeter that'll let you check for continuity, if you haven't already.
Check between neighbouring solder points to make sure they aren't shorted.
As said, no doubt some of them will be.

I'd put it down to experience and start the board again from scratch, but if you want to salvage it the above should help. :)

None of the components there are extremely delicate, but if you really cooked them you could have done damage ok.
Your solder doesn't look like it was easy work. Is it particularly thick solder? Was your iron hot enough?
It kinda looks like it was half melted...?
 
I'd say take another look at that picture and take a guess why it's now working. That soldering deserves a WOW!

Get a new board for it and practice your solder skills on the old one in the meantime.
 
The bigger the blob, the better the job.

Desolder everything.
Clean the components.
Get a new breadboard.
Wire everything up and get it working before soldering them together.

It's very cool you're trying to do these mic mods. Keep us updated.
 
Solder joints should be shiny. Yours seem pretty dull in the photo.

Use a good iron. Get the right solder. Tin your tip, prepare the joint, heat the joint, apply solder to the joint (not to the iron).
 
The bigger the blob, the better the job.

Desolder everything.
Clean the components.
Get a new breadboard.
Wire everything up and get it working before soldering them together.

It's very cool you're trying to do these mic mods. Keep us updated.

Hey Chili, if you're interested in mic mods, I just recently did one on my Studio Projects C1 that came out great. I posted sound clips in the mic forum (you may have seen it already, but just thought I'd mention in case you hadn't).

Please excuse the hijack.
 
Hey Chili, if you're interested in mic mods, I just recently did one on my Studio Projects C1 that came out great. I posted sound clips in the mic forum (you may have seen it already, but just thought I'd mention in case you hadn't).

Please excuse the hijack.


Yeah, I saw your thread. I am almost interested, but not quite ready to start mic mods. I'm building a bass right now and then probably have a ton of other things to do after that. (recording songs with the kids has become a priority. They're into the notion!! :) )

I have the C1 and it definitely could stand to lose some high end sensitivity.
 
+1 to all the comments about the soldering but I believe there is a bigger, more serious issue.

The gate bias resistor is ONE Gig Ohm! These usually come in glass sleeves and must not be touched with a finger or the resistance drops dramatically. The source capacitance of the mic cell is minute, about 5puff and so any load, even a meg or two will short it out!

The capsule/gate/bias R connection is usually "vestigial" i.e not mounted on conventional PCB. I would not think standard resin bonded board had a highe enough resistance. FR4 fibreglass would be better but I would fabricate that part of the circuit on PTFE sheet AFTER cleaning it carefully with surgical alcohol!

However, the whole circuit is just a high Z preamp so you can test it first by replacing the mic with a jack socket and plugging in a guitar!
Also...BASIC to any diagnosis is a voltage table!

Dave.
 
Not going to laugh at anyone who gives it a try. However...

Others have said it but lets make sure it is getting across:

1) What type of solder are you using? You must use solder designed for electronic use. Use 60/40 Tin/lead rosin core solder of a small diameter. Stay away from lead free solder, its rubbish.

2) What type of soldering iron are you using? It should be a "pencil" type, low wattage, temperature controlled with a small pencil point tip.

3) practice soldering on another piece of proto-board. That board has tarnished copper and would be difficult to solder beautifully to. Start by cleaning the copper on the bare board until shiny. Steel wool or scotch bright. Be sure to clean and dry after this.

Soldering: KEEP THE TIP CLEAN! a small sponge dampened with water is a good way. When you are ready to solder, wipe the tip, apply a small amount of solder to the tip. put the wetted tip in contact with one of the copper squares. wait a small amount of time, then apply solder at the junction of the tip and the copper. It will flow beautifully when you get it right. once cool, it is a must to clean off the extra rosin around the solder. use a small stiff brush and alcohol. Once you are getting nice squares of solder with the hole still in the middle and they are as shiny as chrome you are ready to move on. Which would be soldering a wire into one of the holes. Now the soldering iron tip needs to contact the copper and the wire, wait briefly and add a touch of solder. keep the iron in contact until it flows to the wire smoothly.

Some other suggestions. The wire you are using to hook things up is just too damn big. Everything in a mic can be handled with #26, #24 and at the largest #22. Are you using solid core wire? DON'T, stranded only.

Cut yourself a new perf board. This time make the cuts square, not at angles.

If it is worth doing it is worth doing right.

Good Luck!
 
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