hardwiring a pcb mount mono switched jack

[bournemouthmusician]

hi all, looking forward to being part of the group i have a lot of experience repairing guitars, wiring mods etc but have a conundrum ! i am building a Cajon and have taken the guts out of a little Nevada G10 ss amp to put in it, which will be linked to a condenser mic inside so that its self amplified.

The G10 has a mono jack input, volume, treble, bass and headphone out. So i have mounted the pdb inside the cajon and drilled so all the controls are usable from the outside except the input jack as this will be internally wired.

I have removed the plastic surround on thew input socket just leaving the 4 poles sticking out of the pcb.

To test and get the right connections before soldering up the mic lead to it, i have used a guitar lead connected to a guitar to make sure i solder to the right poles etc - my problem is i cannot work out how to do this as every configuration i try either is silent or you can hear the guitar but with a huge amount of earth buzz.

I have checked the back of the circuit board and seen that one pole goes into the circuit and all the others appear to go to ground I had just presumed it would be tip wire from the guitar lead going to circuit and ground to one of the others - but not the case clearly.

As i say i have tried all configs of connecting the poles, putting a jumper on from pole to poles etc but no joy . I have scoured the net for any info on how to do this but came up with nothing - any help or ideas would be totally appreciated. many thanks

PS - The mic i am using inside the cajon is an audio technica condenser mic that is powered by a single AA battery and has a balanced output. The actual mic has been stripped down so that only the capsule and battery bay will be inside the cajon.


Craig ps this is the type of mono jack i have stripped to the poles.

[J M Fahey]

Welcome

With due respect, rewrite your post separating ideas each in its own paragraph (one or two lines usually) separated by blank lines, use Capitals where needed, etc.

As is, your post is unreadable and/or one idea or concept mixed with the next , making it very hard to properly answer in a useful way .

Thanks.

PS: please state what is the microphone you are using, also:

* does it need Phantom powering?

* Is it a balanced out only output?

* based on what I understood, you might not even need to convert a handheld mic but simply mount and feed (very easy) an electret capsule , which will end up being a better solution ... not forgetting cheaper too

[bournemouthmusician]

re thread

Hi Juan, many thanks for the reply and i have edited the post so is clearer. It is a balanced output and phantom powered by a single AA battery. I want to use this mic capsule as oppose to the electret capsule as it has great sound quality. Any thoughts much appreciated, cheers Craig.

[Enzo]

Hi, welcome. All you have to do is register and start posting, and you are a member. Of course you won't be fully accepted until you have sent me a $50 retainer...

I don't know what a Cajon is though. Google tells me it is a wooden drum box, is that the thing?

So you have just the bare metal thingies with the plastic pulled from around them? I would then unsolder those thingies, pull them out and just solder my wires to the board where the thingies used to be soldered.

Look at your picture. There are two pins in the front - the end near the nut. and two in the rear. The rear ones involve the tip of your guitar cord and are the "hot" side of the signal. The front ones are ground - the sleeve and shield of your cord.

Now look at the jack from the front- as if you were the guitar cord plug. There are two pins on the left - the near side in the photo. And two on the right - the far side in the photo. If you look close, or just plug into the jack as you look at it, you will see the two thingies on the right extend over the top across the plug - these are the contacts that touch the plug when it is inserted. Note that the plug lifts those contacts a little when it is inserted. By lifting them, it makes a space between them and the near side short thingies. In the photo you can just see the tips of those upper contacts above the lower near ones.

To hard wire, first we won't need the two near side ones. remove them. Now the front farside one is the ground, connected to the shield an shaft of your guitar plug. And the rear farside one is the hot, or tip of your plug. That should work.

Did you test the mic capsule with the amp before you tore it apart? That would have been a good idea. The hot lead goes to the right rear connection on the board, and the ground/shield goes to the front right. However, most condenser mic capsules I know need a voltage source to work. IS that the case here too?

[bournemouthmusician]

Hi Enzo, thanks for the reply bud. yes its powered by a single AA battery and yep tested both the mic and amp before taking apart and all works fine. I am sure i already tried the config you suggested and whilst worked, there was an almighty amount of noise - just so i am sure i know what you mean - if you were looking at the jack from the front, with all 4 poles sticking up, so not connected in any way - ground goes to the right front pole and hot to the right rear pole ? if thats so then yes thats the connection that works but very noisy. i am presuming removing the the poles from the board and hardwiring to the slots left wouldnt change the amount of earth noise ? cheers craig

[Enzo]

And to be sure, it is real hum, and not the mic feeding back? Is the lead to the mic assembly shielded wires? The wires inside a mic body are often not shielded since the mic metal body does the shielding.

[bournemouthmusician]

re

hi Enzo, i havent used the mic wires yet as was testing with a

shielded guitar cable first to make sure i had the right poles before soldering the mic leads so yep was shielded properly and not feedback. cheers Craig