sharing my electret condensor mic

Here is a mic whose schematic will be familiar to most. It is a Scheops circuit without the DC-DC convertor. I adapted it to use a Transound 14mm capsule and designed a compact PCB for use as a pencil condenser mic. I also have a Mouser project saved for this. If any body wants the gerber files just shoot me a PM.

here's the PCB

a different view of the PCB

Which capsule and what type of mic body works best?  This looks interesting 8)

Sorry, that wasn't clear, which of the 14mm capsules, and is there a cheap donor body you had in mind?

Wouldn't that be the standard MXL 603S, CAD GXL 1200 style that is commonly used for mods? What do the mics sound like?

I designed this mod for some real cheap CAD electret mics I have. I think I paid 60 bucks for a pair @ Guitar Center. The capsules I have for it are Transound TSB-1460A http://jlielectronics.com/transsound/electrets/tsb-1460a.htm

I haven't built this yet. If anyone is interested in being an alpha tester and wants to take on this project I'll send them capsule to get started

Are they the CAD C9's or the ICM417? Both are back-electrets, but with different capsules. Any reason why you chose the back-electret over a externally polarized capsule? You can't really beat the price, though. If I didn't already have ten mics to build, I would take you up your offer.

CAD CM217 are the ones I have. I never got around to even getting PCBs made. It wasn't high on my priorities list. The reason for using electret capsules was that they are cheap and I wanted to see if I could improve and the stock 6mm capsule.

Seems like a very nice design and very clear.
I'd love to give it a try, do you have PCBS printed?

Manu

manulaudic said:

Seems like a very nice design and very clear.
I'd love to give it a try, do you have PCBS printed?

Manu

Click to expand...

sorry, I never did get around to getting PCBs made for this. I did get an estimate from Futurlec for about $70 for 10. btw, if anyone gets these made I highly recommend that the PCBs be 1/32 inch (.8mm) thick. they should fit into some of the smaller donor mic bodies easier. I've got the gerber files for this if somebody wants them.

How would this design performs with a large Capsule, say CK12 type?

Manu

I would assume that, since the original design calls for a back-electret capsule, the LDC would be fairly incompatible without a serious circuit redesign.

-James-

Thank you Hellfirestudios !
It might have been a silly question, though good to have a straight answer

M

There's no such thing as a silly question.Don't ever be afraid to ask questions around here. Just google search it first... Saves people from repeating themselves to the point of insanity.

-James-

manulaudic said:

How would this design performs with a large Capsule, say CK12 type?

Manu

Click to expand...

This circuit, as an amplifier, works just fine fine with a LDC. Most of the Chinese mics use a variation of this. What is missing is a DC-DC converter to provide a polarizing voltage to the capsule. I did design a DC-DC converter board that goes with this. I had plans to adapt this circuit to my various needs. This daughter board attaches to the underside of the main board at two points and provides around 60VDC for polarizing a LDC. If you look at the schematic you will see pin J4 which is the power take off for the DC-DC converter and pin J5 which ties the converter daughter board ground to the main board ground. This daughter board is all SMD.

That is cool. Only a few small changes to the circuit to make it work with LDC's. Maybe people would want a modular sytem they could DIY with both SDC and LDC "heads." Sounds versatile. DIY Colette anyone?

here's a little more

and another

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