Unicorn
"Legendary transparent boutique boost/overdrive"
The Unicorn overdrive rack effect module could also be classified as a boost. It compares to Bill Finnegan's Klon Centaur buffered transparent boost/overdrive pedal. While it will likely always be a legend, it is no longer as unique as it once was. Browse the other GT overdrive and boost modules and you'll find other boost/overdrive modules that may also meet your "give me more of what I've got" needs. Best with a tube amp.
Description
When it comes to hype, Bill Finnegan's Klon Centaur pedal leads the pack. Love it or hate it, some facts are indisputable. It was one of the first boutique pedals, and at the time its transparent boost and mild overdrive were unique on the market. Another fact is that some players like it so much that they are willing to pay thousands of dollars for an original vintage unit.
We won't dive into all the hype, claims, counter-claims, opinions, and hearsay. There are some important things to keep in mind, though. One is that there is no "magic mojo" in the circuit's buffer. The buffer is made of common parts, and the design has been public since before the Klon Centaur was first made. There is some "magic" in the fact that a buffer is used. That can have an impact on the sound, and the specific buffer used is a good one. There are discussions about other "magic mojo" components, most famously the clipping diodes. The exact parts used are a bit difficult to find. But other diodes work equally well, producing results few, if any, could distinguish from the originals. The latest version of the pedal is a mass-produced, surface-mount circuit that does not use the same diodes as the older models. We haven't seen any marketing releases that say "yeah, the new ones kinda suck because they don't have the same diodes", as the original diodes used aren't particularly special.
The original circuit does color the tone slightly, but it is mostly transparent. It can most definitely be used to achieve some wonderful tones. What seems to be key to getting those tones is how the pedal is used. If you try to use it as an overdrive, you may or may not be wowed by the results. But if you use it more like a clean boost to push a driven tube amp, then you may find what causes some of the hype. Using a clean boost to push a tube amp into "the zone" is a pretty standard trick these days. It wasn't that common when the Klon Centaur came out. How it was used was as important as the actual circuit design in some sense. It wasn't long ago that pushing a tube amp like that required a fair amount of volume, perhaps more volume than would be suitable in many situations. But with lower-wattage tube amps being widely available today at great prices, it is something anyone can consider for a wide range of venues. Our Unicorn compares to the Klon Centaur, but other modules such as the GT-820, Color Bomb, Teledrive, Edge Boost, Trail Boss, and Sonic Boom may also provide options for abusing tube amps in a similar way, with varying amounts of cleanliness.
Configurations
- Unicorn - compares to Klon Centaur
Buffers
There is an input buffer that can be switched with the effect, or always on whether the effect is engaged or not.
Options
- Always On Buffer - By default we setup the buffer so that it is switched with the effect. If you want it to always be on even when the effect is bypassed, choose this option.
- Switched Buffer - This option adds a toggle switch. In one position the buffer is always on, and in the other position the buffer is toggled with the effect.
- Custom Clipping - By default we use Russian D9E, which some think was used in the original circuit. Others say standard 1N34A diodes were used. You can specify something else if you prefer. They should have a low Vf value, though if you want to stick close to the original tone.
- Clipping Switch - This option adds a switch to change between two clipping configurations of your choice, with an optional third switch position for no clipping.
- Custom Op Amp - We use the TL072 by default, like the original. You can choose any pin-compatible op amp.
- Tone Shift Mod - This is a popular mod that keeps the tone from thinning out as you increase the treble.
- Tone Shift Switch - Same as the Tone Shift Mod, but switched.
- Bass - This option changes several components to make it more bass-friendly.
- Crank - This option allow more treble to pass through the gain stage. In addition to allowing more treble through, it adds a bit of gain, with attitude and some presence. Can be subtle with some control settings.
- Custom Components - We use metal film resistors and a selection of capacitors that provide good tone and low noise.
Front Panel
- Gain
- Tone
- Level
- (optional) Buffer switch
- (optional) Clipping switch
- (optional) Tone Shift switch
Rear Panel
- Audio In
- Audio Out
- On/Off Footswitch
- On/Off Override
- DC Power
- DC Power LED
Module Width
- 1.5"
- 2" with options
- 2" left wing and 1.5" right wing available for 3-4 control configurations
Power Consumption (aprox)
60 - 85mA
Base Configurations
Part # | Description | List Price |
MOD-UNICORN | Unicorn module | $209 |
Options
Part # | Description | List Price |
MOPT-UNICORN-AOBUF | Always On Buffer | $39 |
MOPT-UNICORN-SWBUF | Switched Buffer | $69 |
MOPT-UNICORN-CLIP | Custom Clipping | $0 - TBD |
MOPT-UNICORN-SWCLIP | Clipping Switch | $19 - TBD |
MOPT-UNICORN-OPAMP | Custom Op Amp | $0 - TBD |
MOPT-UNICORN-TONE | Tone Shift Mod | $0 |
MOPT-UNICORN-SWTONE | Tone Shift Switch | $19 |
MOPT-UNICORN-BASS | Bass Mod | $0 |
MOPT-UNICORN-CC | Component Changes | TBD |
Parts
Part # | Description | List Price |
MPT-UNICORN-CA | Replacement pot, switch, jack, LED cable assembly | $19 |
MPT-UNICORN-KNB | Replacement control knob | $2 |
MPT-UNICORN-PB | Replacement power board | $29 |
MPT-UNICORN-SB | Replacement switching board | $29 |