Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #104404  by wolftigerrosebud
 Mon Oct 17, 2011 1:26 pm
Best OD pedal ever, and I love the mossy green. Also, I've noticed a bit of buzzing going on with the pedal activated that I either hadn't previously noticed or that wasn't previously there. Any thoughts, Brad?
 #104453  by SarnoMusicSolutions
 Wed Oct 19, 2011 6:05 am
Not sure about the buzzing. That's not normal to the pedal. First check your DC power daisy chain. Try unplugging the DC power and see if it goes away. Possibly the daisy chain is not in an ideal sequence.

 #104466  by rugger
 Wed Oct 19, 2011 10:55 am
Ran across this a little while ago and meant to post then, but this thread seems appropriate.

A little Earth Drive love from Kit Rae. If you're into or appreciate Gilmour's playing and gear, this site is a must along with

For those that don't know, Gilmour achieved his searing solo tones by stacking overdrives with Big Muffs/Fuzzes. Kit talks about using the Earth Drive in this application. ... ngBigMuffs

Still digging my Earth Drive btw, Brad.


John in San Diego
 #104475  by SarnoMusicSolutions
 Wed Oct 19, 2011 1:29 pm
I realized after posting that link that I think you need to be a forum member there to view the page. This guy Kit Rae is basically the "Waldo" of the David Gilmour gear world. He ran his Earth Drive thru all kinds of tests and made a ton of audio samples. The thing he was after was not only a mild overdrive, but also a post-Big Muff driver/warmer like the way Gilmour uses a Tube Driver as a clean-ish Muff driver pedal. His reviews gave the Earth Drive very high praises as a Gilmour type tool. Now if only David could get his hands on one...

 #110102  by mgbills
 Sun Feb 26, 2012 4:23 pm
By the way...

If you don't have an Earth should. Just got tired of futzing with my "Vintage" MXR. Maybe it needs to go to the doctor....

Love it. Love it (the Earth Drive that is). Love it. I'm playing low low low today. Wife is 1 room away. SMS>GCX>MC250>K120. Swirly on the middle Super2. Dimed the tone knob 'cause I likes me some trebles. Set the Volume to match the rig volume. There is a beautiful line in the Drive pot that swings beautifully between Loud Jerry, to the TR breakup of the '72 period. Loved it. Then...I brought the other coil on and my mind...I was Neil Young just busting into "Like a Hurricane." might've been a flashback, or maybe lack of's pretty dang sweet.

I'm going to give it a shot between the guitar & the preamp next. Just have to come up with a 9v power supply that's not in my road case.

Peace to all.

 #110147  by waldo041
 Mon Feb 27, 2012 6:56 pm
claytushaywood wrote:what circuit is the earth drive based on?
The earth drive. :smile:

 #110148  by SarnoMusicSolutions
 Mon Feb 27, 2012 7:48 pm
Nice answer Waldo!!

To be fair, it belongs to a huge family of overdrive topologies that relate back to the ubiquitous Ibanez Tube Screamer. But that shouldn't be considered a fair association. There are essentially, generally, 3 types or distortion/overdrive pedal topologies. Fuzz types are related to the old Fuzz Face and Tone Bender where two transistors are used, one slamming the next one creating that distinctive sound we all know. Then there's the "Distortion" pedal topology based on clipping a pair of reversed diodes that live between the signal and ground. This would be the MXR Distortion+, the Rat, the Boss DS-1 for the most well known examples. Then there's the family of "Overdrive" types. This is what most boutique overdrive pedals are built around. The idea here is that there are reversed diodes that generate the clipping, but the diodes live in the feedback loop of an opamp. This creates a milder, more compressed, more amp-like kind of clipping and a slightly more rounded "squarewave" when they clip. But there are so many thousands of ways you can set up this type of circuit, how you voice it, how you color it with diode symmetry/asymmetry and types, whether it's inverting or non-inverting, buffered, pre-EQ'd, post-EQ'd, etc. It's a very basic template for a gazillion ways to carve out a unique sounding overdrive circuit. So Waldo's right. It's pretty much its own design, but it does belong to this particular family of overdrive pedal circuit types with clipping in the feedback loop. But beyond that major generality, it's its own animal.

It was first inspired by my wife Auset. She plays a '62 Strat into a sweet '68 Fender Deluxe Reverb. A lot of our gigs are very quiet and there's no way for her to push the amp into that zone where it does its thing with 6V6's singing. So she wanted a way to get something like that at any volume. We lined up more than 10 boutique or classic pedals in our collection like the Zendrive, AC Booster, Nobels ODR-1, Tubescreamer, OCD, Timmy, Turbo OD, Rat, MXR+, Barber LTD, and more. They all did something cool, but not one of them was exactly right. She wanted one with a very natural EQ that didn't really change the guitar, something that would tame the ice-picky top end without over-dulling it, something that retained some fullness in the low mids, and something that generated a symmetrical clipping kind of like a push-pull Fender amp like a Deluxe, Pro, Super, Twin, Princeton, etc. that had that clean-ish-ness even when pretty dirty. So that sent me on a mission, and a few prototypes later we settled on this circuit.