Messages

hmm...

Nothing looks wrong with your voltages. And you've triple checked the value of your pots?

Jacob

After C3? No, there should be no sound there. That's VB.

Jacob

If either R3 or C3 were an incorrect value or not properly soldered into place, that would be an instant and obvious issue. Other than that, We'd need some pictures and/or voltages to tell you. Mostly of the IC itself.

Jacob

Part of your problem is that the LM386 is not a dual op amp. Its a power amplifier. Totally different kind of chip.

Jacob

I would suspect your values on some parts. I don't know specifically what parts, but it may also be that you have a solder joint as well. Those would be my suspicions.

Jacob

cool beans.

Jacob

The quick answer is probably not. The definitive answer is found in the datasheet.

Jacob

I'd actually like to go a step further and design my own PCBs for these kinds of projects, but the hard part is finding good schematics to work from, and the right parts for my Eagle Library.

I find that most of the expense in these DIY mic pre's are the inflation of the kits and the costs of the PCBs. It's the same with the stuff from BYOC. We all know we can do our own PCBs and source our own parts and build the exact same kit the way we want to for much less than the cost of the kit from BYOC, but for someone beginning who has no idea how to do all that a BYOC kit is money in the bank! I always recommend nervous beginners to try that out before learning to source their own parts. It's way easier that way. But, when you get into doing this, I can build stuff that they charge 100 bucks for, for a mere 25 or 30 bucks before my labour - and most of that is hardware, not the PCB or electronics.

Jacob

With a small circuit like a sprout, you can easily breadboard the circuit before building it and installing the transistor permanently. That way you don't need to worry about a socket.

A second suggestion is to use sockets, but when you've found the transistor you want to use, you can solder just one leg into one of the sockets. That way, if you ever need to pull it it's fairly easy to 'break' that solder connection, or even to heat up that leg, pull out the transistor, then use a pump or some braid to clean up that socket.

Jacob

No mojo. Just electronics.

Jacob

Voltages look just about normal to me.

I would suspect your wiring to be the problem. Dime the volume knobs and then take voltages again.

Jacob

Have the 3rd switch bypass both of the others...

Jacob

well... they're not new. I know that guys got super excited about them at DIY Stompboxes a while back.

Since I don't etch I don't really see them being useful for me at all. I use a breadboard, then do a layout, then get someone to etch it or do a prototype through Dorkbot. The pens don't fit in with what's working for me.

But super cool idea. I saw a video at least a year ago where a guy did a circuit drawing on a piece of white paper. He used masking tape to apply some resistors and stuff to the paper, then had an LED that was flashing in time after hooking up a battery pack. Neat experiment.

Jacob

Impressive that she was able to crochet a pair of children who look much more like little statues than crocheted things. How did she get the fine detail in the girls hair? And that sax in the little boys hands! Wow! She's very skilled at crocheting...

Jacob

The finish and graphic on this one came out really well! Nice work. Also, those Red knobs really pop.

Jacob