paralooper pcb wiring questions

[bigandtall]

Hi,
I'm new to building and this is my first ground up build after putting together a noisy cricket amp.

I've been doing a lot of searching around for the answers, so hopefully I haven't missed them somewhere.

Anyway, I'm planning on building a bass paralooper based on mooseapotamus's design. I'm having John Lyons make me a PCB and while I'm waiting for it, I'm trying to understand exactly how to wire it. I have a few questions, but my first is how you wire the low pass switch to the PCB. It's not entirely clear to me from the schematic and PCB guide.

I'm also not sure on the PCB what YR2-1, YR2-2, YR2-3, and YR3-3 are. I'm assuming that they are the blend and volume pots but I'm not sure which is which and why one is only wired to the 3 (I have checked out the offboard wiring diagram linked to the site and realize that not all posts on the pot are wired to the board).

Thanks in advance. Source material below:

General info:
http://www.moosapotamus.net/THINGS/paraloop.htm

PCB layout:
http://www.moosapotamus.net/THINGS/paraloop/paralooperLYT.gif

Schematic:
http://www.moosapotamus.net/THINGS/paraloop/paralooperSCH.gif

[captntasty]

I'm also not sure on the PCB what YR2-1, YR2-2, YR2-3, and YR3-3 are.

Yes, they are the pots - it's actually VR-1 and VR-2 (for variable resistor).  The second number (VR1-1 in this case 1) is the lug number on the pot.  If you look at a pot from the rear the lugs will be numbered 3 2 1 from left to right - from the front 1 2 3 from left to right.

how you wire the low pass switch to the PCB.

The low pass is just a capacitor (C5) to ground.  It can be removed completely for full range if you want.  You could also tack two capacitors, say the .047 and a .01, onto a DPDT switch for two tones.  You could insert a SPST switch either before C5 or after to switch C5 in or out.  Lots of options...

edit:  ps, this is a great circuit... I have built three of them for various applications - very handy.  One thing I would add - get some non-polarized 1uf film capacitors as a substitute for the 1uf electrolytic input cap, otherwise, it will pop loudly when the switch is engaged

[bigandtall]

Thanks for responding! That all pretty much makes sense-- of course, it will make more sense when I'm actually putting things together.

I'm sure that I'll have more questions as I get on with my build.

Okay, a few more questions:

on the PCB layout (http://www.moosapotamus.net/THINGS/paraloop/paralooperLYT.gif), there are two things I don't understand:

1) on the bottom left there is a component called 1M. What is that?

2) on the top, right above R6, there is an unnamed component. What is that?

[bigandtall]

I'm gonna bump this... please help if you can... and if you are a paralooper master and are open to a few newb questions, please shoot me an email or PM.

[captntasty]

1) on the bottom left there is a component called 1M. What is that?

That is a resistor - a 1 megohm.  It is called a pulldown resistor.  Do a search on that and you will learn about it.... makin' you work for it   !

2) on the top, right above R6, there is an unnamed component. What is that?

That is a diode - probably a 1n4001 - I believe it is reverse polarity protection... yep, look that one up too!

There's so much to learn - and I'm sure you know about teaching how to fish rather than giving them away.... the search function and Google are your friends...  datasheets also!

Good luck and always ask a lot of questions... and welcome.

edit:  I almost forgot to point out the Links link at the top and the others - check em out...

[bigandtall]

Thanks again. Yes, sometimes I just need to be pointed in the right direction. The goal here is to learn by doing. I don't think I'll get a full understanding on the first go round, but I'll get closer every time.