Lo-Fi/Bandpass pedal?

[theviper21]

Hello all! I am looking for a DIY pedal that has low cut and high cut, similar to the Ibanez LF7 here: http://www.youtube.com/watch?v=a-eLTP3Zdtc

I am guessing all I would really need is some kind of EQ pedal that can make steep cuts, but I haven't really found a good project out there for it. Seems like this would be a pretty simple circuit to make, but I'm very much a newb so far.

[mgwhit]

Here's a good starting point for learning about lo-pass and hi-pass filters: http://www.muzique.com/schem/filter.htm

Since both high-pass and low-pass filters are subtractive, you're probably going to want a gain make-up stage in there somewhere.

[Strategy]

There is also a Tim Escobedo project called "LoFoMoFo" which does this. Google that and you shall find. There are PCB, vero, and perfo-board layouts for this on sites such as General Guitar Gadgets and diystompboxes.com forum.

Strategy

[Chi_Boy]

The telephone noise pedal by R.G. Keen sounds like it may be what you are after.

http://www.geofex.com/FX_images/lofi.gif


There are some posts on DIYSB about it too.  Mark Hammer made some suggestions to make it more flexible by adding dual gang pots to the filters.  You could easily build it without the noise part too. 

Be aware that there is an error in the schematic.  The center lug of the wiper has to go to VB, not GND as shown.

[Matt Gnarly]

The telephone noise pedal by R.G. Keen sounds like it may be what you are after.

http://www.geofex.com/FX_images/lofi.gif


There are some posts on DIYSB about it too.  Mark Hammer made some suggestions to make it more flexible by adding dual gang pots to the filters.  You could easily build it without the noise part too. 

Be aware that there is an error in the schematic.  The center lug of the wiper has to go to VB, not GND as shown.

This sounds interesting, have you seen/heard clips of this anywhere?

[theviper21]

I think I'm gonna go with the LoFoMoFo, looks pretty easy to lay out on perfboard. Thanks for pointing me in the right direction!

[Chi_Boy]

This sounds interesting, have you seen/heard clips of this anywhere?

Yes, built it, but never boxed it.  I thought the filter part was great.  With the Hammer mods it is possible to get a nice AM radio sound.  Much different than the LoFoMoFo.  I think it might actually be pretty close to the LF7. 

The thing I didn't like was the panner part and the way it worked.  I thought a constant signal for the guitar with the option to mix in the noise as desired would be better.   

I changed the design and made a board but never finished it.  I've been looking at it on my desk for weeks, but just haven't found the time.

[Strategy]

If you do get a layout going, please share! I'd be really into trying out this circuit. Maybe even put LoFoMoFo and the RG design in the same box for some double lo-fi effects!

Strategy

[Matt Gnarly]

If you do get a layout going, please share! I'd be really into trying out this circuit. Maybe even put LoFoMoFo and the RG design in the same box for some double lo-fi effects!

Strategy

Seconded! That'd be a very interesting build.

[Chi_Boy]

You guys have inspired me to finish this build.  I moved the populated boards to the front of the desk.

[Strategy]

thanks much that will be a fun project! looking forward now to an eventual "Lowest Fi" pedal!

Strategy

[Chi_Boy]

Not much of a demo, but it should give you an idea.

The sound is a little hissy and crappy by design.  I built it with lofi 1458 op-amps and ceramic caps for everything.  It is lofi after all.

http://soundcloud.com/georgep-2/lofi-sound-sample

[Chi_Boy]

SoundCloud changed the sound of the file a bit.  This might be a little more true to the sound:

http://home.comcast.net/~gprause/LOFI_Sound.mp3

and yes there is a volume drop as the controls are maxed.  I haven't experimented with how to get the level back, but I think it's just a mater of replacing R16 with a pot.

http://home.comcast.net/~gprause/LOFO_MOD.gif

Any feedback on the R16 is appreciated too, BTW.

[Matt Gnarly]

Just saw this on Sabrotone.com (I hope it's okay to post this)