Andromeda - Nobels ODR-1 Natural Overdrive Guitar Pedal PCB



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Project description

Nobels ODR-1 Clone PCB - Aion AndromedaThe Andromeda Overdrive project is a clone of the Nobels ODR-1, a really interesting overdrive that’s a favorite among Nashville session players but remains fairly obscure otherwise. It’s a complex circuit with a great deal of precise filtering and tuning.

The overwhelming criticism of the ODR-1 is that it has too much bass. It’s true—the corner frequency in the op-amp clipping stage is very low and the stock circuit has no way to dial it out. It pairs up very well with a Telecaster bridge pickup, but not much else.

So, for this project I borrowed the Bass control from the Timmy, which makes the corner frequency variable. With the knob all the way up, it’s the stock ODR-1, but now you can turn it down to more reasonable levels. With this modification, the ODR-1 is easily in my top 3 overdrives—and I’ve played a lot of them.

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Nobels ODR-1 circuit history

Nobels is a German company that’s not very well-known in the United States. The ODR-1 Natural Overdrive was first released in in 1992[1]. In 2002[2], a silver “tenth anniversary” reissue was released, which was the standard for a long time until circa 2011 when the green version was rereleased.

The circuit has never changed and all versions are identical, except for some of the silver versions—the initial run of these had the Drive and Volume pots mistakenly switched during production, so Drive was 50k and Volume was 250k. This severely limited the pedal’s maximum gain. Later productions had this corrected, but many owners had to take out the soldering iron and switch the pots around to correct the factory error.

Their circuits are very original and well-designed, but their build quality and durability leaves something to be desired, not unlike Behringer. The high marks for the pedal’s sound quality were balanced by skepticism about its roadworthiness. This created a pretty decent market for clones. The Visual Sound Open Road was the most accurate and certainly the most affordable, but is no longer in production (though the left side of the newer Truetone VS-XO is apparently based on the Open Road). The Rockett Chicken Soup was another one, now out of production as well, although they tweaked the circuit from the original and the general consensus is that it’s not an improvement.

Nobels sold a variant called the ODR-1 Plus that included a boost switch. This switch adds an additional 3rd filter from the op-amp feedback stage to ground which extends the range of the gain knob and changes the EQ slightly.

The ODR-1 also has a cousin called the Overdrive Special ODR-S, which features a three-band tonestack in place of the ODR-1’s Spectrum control. The circuits share a lot in common, but the tonestack is completely different, and most people still prefer the ODR-1 despite the added flexibility of the ODR-S. There’s something unique about the Spectrum control that the 3-band tonestack doesn’t capture.

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Notes & references

  1. Nobels History. There is some discrepancy on this page: at the top, it says the ODR-1 was engineered in 1985, but later on in the timeline, it says that 1985 is when the company itself was founded but that the ODR-1 didn’t come around until 1992. The earliest units I’ve seen are from 1992-1993, so unless one turns up that is dated to the 1980s, I think the 1992 date is sensible.
  2. I’m assuming it was 2002 since it’s the tenth anniversary edition, but I don’t have a source for this.