Newbie project idea (high-pass/low-pass)

[jimkeaney]

Hi guys,
I'm a newbie to DIY electronics. I've successfully built some CAPI stuff (not always pretty, but functional) and a couple 51X 500series racks and dual power supply. I'm simply following the instructions and (thankfully) other builders "photo threads" as points of reference. I'd love to start learning what these components I'm soldering together are actually doing but I'm not sure where to begin. I feel like buying books is probably the way to go, but I'm also wondering if maybe tackling some really basic projects may help me grasp more, since it'd be a bit more hands-on?

One project idea (which seems 'easy' in my head) I had was to build a passive guitar box that is a steep high-pass & low-pass filter. Input/output. 2 knobs to control the frequency roll-off points and a bypass switch.  Would anyone here care to help talk me through this idea? Does it make sense to be passive? What sort of components and where I might find them. Any general advice. I'm all ears

Thanks
-Jim

 

[abechap024]

Welcome!
Harrison Ford Filters.

They aren't guitar impedance but are line level so maybe fx loop?


If you wanted to have totally passive switchable HP/LP filters you would have to calculate the various inductors and capacitors, and what impedance you are going to interface with everything

 

[pyjaman]

Hi, you might want to look at this :
http://home.online.no/~jaeioluf/sound/eqpassiv.htm
After you read it, you may be able to start experimenting, and get the limitations of a totally passive design.
Laurent.

 

[jimkeaney]

Thanks for the info, guys. I actually tracked down a Harrison Ford Filter board, but as far as actually understanding this stuff, I think I need to start even smaller.

 

[horvitz]

Jim,

Picked up any books yet?  Certainly Doug Self's Small Signal Audio Design book is a great reference.  Also, maybe have a look at some of the projects at sound.westhost.com.  Lots of good well explained and easy to build stuff there.

  Brian

 

[chrispbass]

This may help Jim

http://www.amazon.com/Preamplifier-Filter-Circuits-BP309-Penfold/dp/0859342549

I've got a few of these books published by Babani and although not a complete reference by any means, they introduce and explain in a reasonably friendly manner and generally don't presume any prior knowledge.

Chris

 

[jimkeaney]

Hey thanks guys for all the great info and links. I just ordered that Pre/Filter book, Chris.  Brian, the book you linked looks great too, but at $60+ for a used paperback, I'm gonna start with the $5 book Cant believe they only offer the Kindle version for week-long "rentals". That project site is awesome too.

Would you guys care to recommend me some places to order general components needed for these kind of projects (resistors, caps, etc)? I'm familiar with mouser. Any others?

thanks again!

 

[Rochey]

Doug Self's book is on the expensive side, but worth every penny, and will be something you return to againand again.

I keep it on my ipad for longhaul flights.  There's always something new to learn in its pages.

/Dafydd

 

[jimkeaney]

Rochey, how'd you get it onto your ipad? I couldn't find an option to purchase it that way (only "rent"). I'd prefer to own it digitally.

 

[dmp]

Would you guys care to recommend me some places to order general components needed for these kind of projects (resistors, caps, etc)? I'm familiar with mouser. Any others?

The general supply places in the US are mouser, digikey, allied elec, and newark. I usually order from mouser because they are generally cheapest for small quantities.

 

[websoul]

Thanks to this thread, I now have Douglas Self's Small Signal Audio Design book.  It's very informative and have picked up lots from it.  Thanks for sharing here