‘Carbon Copy' is a wonderful allusion to the all-analogue signal path of this retro-style delay pedal from MXR
. This is an old-school delay pedal featuring ‘bucket brigade technology' - a phrase which refers to an analogue delay line that was developed in the late 1960s by Philips Research Labs. It uses capacitance to store the analogue signal, which is then moved along a line of capacitors one step at each clock pulse, much like a line of people passing buckets of water to extinguish a fire.
Just about every classic delay, chorus and flanger employed Bucket Brigade Devices (BBDs), and many enthusiasts maintain that the digital signal processors that superseded BBDs can't achieve the same warm tone. Mind you, they can't achieve the same crystal clarity either, so it's horses for courses. In this case BBDs are an appropriate choice.
Maximum delay time is quoted at 20ms to 600ms, which is pretty impressive for an analogue delay. It's the same size as a Phase 90, but MXR
has managed to squeeze on three knobs: Regen (number of repeats), Mix, and Delay (time), as well as a Mod switch. Mod modulates the pitch of the delay signal to mimic the small fluctuations in speed that are typical of tape echo devices. The speed and width of the modulation can be adjusted internally using a small screwdriver. The footswitch is true bypass and you can run the Carbon Copy
from a battery or a negative centre 9v power supply.Sound
Tape echo enthusiasts prize WEM Copicats, Echoplexes and Space Echos because of the way that they colour and distort a guitar. Despite being a mere stompbox the Carbon Copy does the same; it has a thick, slightly scuzzy quality, distinctly analogue and with a convincing hint of overdrive. It's a perfect formula for slapback echo, so if you're into rock'n'roll and rockabilly sounds then it's ideal - and slapback's short, bathroomy reverb effect doesn't obscure or swamp what you're playing, unlike excessively long reverbs.
The Carbon Copy
is equally adept at generating psychedelic atmospheres and Pink Floyd-style soundscapes. The great thing is the way that the repeats sound completely different to the dry signal, with a significant amount of treble roll-off and with further degradation taking place as they regenerate. The stuff you're actually playing retains its form and definition, while the repeats almost sound like a different guitar. The Carbon Copy also has a discernable three-dimensional, surround-sound quality.
Turning up Regen quickly provokes the Carbon Copy
into feedback. This is particularly true at shorter delay settings, so a little more range on the Regen control might have been useful.
However, the Mod feature is particularly effective. On the factory settings it combines with shorter Delay times to create a pseudo-chorus effect, which the internal controls could make even more pronounced. On the other hand, widening and slowing the modulation brings the Carbon Copy
much closer to a wow and flutter effect, thickening chords and adding extra movement under the dry signal.
With the Carbon Copy, MXR has managed to add versatility and minimise noise without sacrificing the ever-popular tonal qualities of BBDs. As with the vintage echo devices it seeks to emulate, your opinion of it will depend on whether you like the way it colours your sound.