How to build and Use a Basic Testing Rig

[bigmufffuzzwizz]

We're talking about 9 volts which is pretty safe. It's not like a tube amp having 500-600 volts on the plate of a power tubes.

[tenwatt]

What voltage cap did you use for the probe.  I'm needing to, atleast, make a test probe.

[jkokura]

I just used a topmay box cap. 10-100nf, 100v works just fine.

Jacob

[drbob1]

I have a breadboard/box thing I used for this purpose this time out. The only problem I had was that I couldn't tell if the static I was hearing was from the unprotected board and pots sitting on the desk or from a problem with the build. I guess the mounting strip for the pots and the insulation provided by the plywood version might work the best?

[jimmybjj]

here is a pic of mine. Its from a failed drilling layout but it still served a purpose  Use it just about every day.

[keysandguitars]

I'm building a test rig today. I went to harbor freight yesterday and picked up some cheap storage containers for stocking components and hardware. I thought I'd post a link to some cheap test leads for others who might want to build a testing rig. Harbor Freight sells tons of cheap stuff handy to a DIY'er.

http://www.harborfreight.com/18-inch-low-voltage-multi-colored-test-leads-66717.html

[bgalvao]

About using the testing rig with an audio probe I came up with something that might be helpful (probably some of you already do it/thought of it) instead of strumming my guitar I plugged my Ipod to the input so I don't need to move around and strum every 30 secs...probing became real easy and quicker...

Bruno

[jkokura]

Great idea! A looper pedal or a oscillation generator works well too,

Jacob

[shawnee]

I just finished mine and I don't know how I lived without it. I looks similar yo JimmyBJJ's. I ended up with about 20 1/4" jacks when I took them off of everything I had laying around!

Just for grins I wanted to boost a distortion project with a Klone and I noticed that even when the Klone was off that most of the hum and squeal of my laid out distortion build went away. When building hi-gain pedals, you may want to run a buffer of some sort to tame some of the kaos. Of course it's good to have the kaos when you are done experimenting and get ready to box so you can identify noise and shield or route properly.

[Loztboy]

I built a testrig/probe like jkokura described.
Is it supposed to be noisy?
Is there any point in making the probe/out switchable?

[andrapgm03]

I built a testrig/probe like jkokura described.
Is it supposed to be noisy?
Is there any point in making the probe/out switchable?

mine also, some sort noisy, but I try to shield the ground and the Input jack (all tip), reduce a little bit but still have a noisy sound

I used acrylic boxing (I made one for testing).

also try to put the ground alligator jack to the DC 9VDC Ground, it will reduce a lil bit the noisy sound too..

[Guybrush]

Has anyone got a wiring diagram for this (ideally including the audio probe) that they would like to share?  I'm still pretty unconfident when it comes to wiring up so a diagram would really help.  Also is there any way of including a 3pdt so you can test if the circuit will work in bypass.  I guess an LED would be useful too to see when the test rig is 'on'.

Thanks.

[night-B]

You can build a pedal using the standard wiring diagram :
http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf
In place of the PCB replace the IN OUT 9v and GND of the board by a connector or a crocodile clip.
When you finish a project, connect the wires to the connectors and plug the jacks on your test box and then you can test your circuit and use the bypass.
For building an audio probe : in your test box, you can solder a wire on the tip of the output jack. At the end of the wire you just soldered, add a small non polarized cap (this is a filter to remove eventual DC).
Move the lug of the cap along your pcb to hear what's in.

Hope that helps 

[Guybrush]

Thanks Night-B that's simplified things for me!  I'll get building in the morning.

In terms of the audio probe, I'm guessing (as in jkokura's original post) I can attach a multi meter probe (or just a piece of wire) to the cap to make it a bit easier to use?

Thanks again!

[Guybrush]

I finally got round to making my test rig and it works like a charm.  I pinched a bit of an extendable aerial from an old radio I have and attached a croc clip to hold whatever board I'm testing.  Works really well! Here it is:




Thanks to everyone who helped me out with this.