Paul White checks out a new emulation of vintage tape echo based on both valve circuitry and DSP.
The Hughes & Kettner Replex is a delay unit that combines digital processing and valve analogue circuitry in order to emulate the sound of a vintage echo unit, without having to change tapes or clean heads. It offers a choice of three basic effect types: reverb, single‑tap delay and dual‑tap delay. Powered by an external mains adaptor, the Replex is a very solidly built pedal with a metal case, traditional‑style recessed rotary controls and four momentary‑action footswitches. The leftmost switch acts as a Bypass, while the other three switches engage the three different effect modes — only one process can be used at a time. Audio connections to the unit are simple, given that this isa mono unit, with Input and Output jacks, the former having a high impedance for use with electric guitar.
In addition to the main Output level control, there are knobs for Reverb Volume, Delay Volume and Second Head Volume, which allow the user to tweak the exact mix between dry, delayed and reverberant sounds reaching the output. Two controls set the delay times for the two heads: Single Head Time sets the delay time for the single‑head tape‑echo effect and Dual Head Time sets the time for the dual‑head effect, though the relative spacing between the two 'virtual' tape heads is preset in this mode at a proportion of the overall delay time. The maximum delay time seems to be around three quarters of a second, which should suit most conventional applications. The number of repeats is set using the Delay Feedback knob. The Drive control can be used to add a little valve overdrive at the input, if you want to dirty things up a little.
A final control in the Delay section is called 'Vintage', and affects the signal that's fed back to create regenerating echoes. Turning it clockwise introduces subtle modulations, distortions and high‑frequency filtering effects, to simulate the non‑linearities of a tape‑based system. On the whole, it does this rather well — although I think there's still a way to go before modelled delay boxes sound exactly like their tape‑loop counterparts, the Replex gets pretty close, with individual repeats getting successively more distant and more grungy, making it easy to approximate those old '60s guitar sounds. As for the reverb, that sounds very much like the spring from a typical guitar combo, but without the 'sproing' when you knock it, of course...
In many ways, the Replex is no more complicated than the vintage boxes is seeks to emulate — given that so many vintage effects units had three or even four replay heads, I'm a little surprised that Hughes & Kettner didn't provide this option too. It's also disappointing that you can't use both reverb and delay at once. However, the overall sound quality is good and generally convincing, though the small knobs are rather too coarse for making precise settings — a tap tempo switch would have been useful for setting delay times because of this.
Ultimately, the Replex is a bit of a one‑trick box, but it does that trick better than most — both the reverb and delay are creditably close to their vintage forebears. In addition, it's more reliable, more affordable, and built to last.
- Convincing emulation of vintage tape‑delay and reverb effects.
- Sturdily built.
- You can't use delay and reverb simultaneously.
- A tap tempo button would have been very useful, given the comparatively coarse control provided by the small knobs.
A well‑built unit which can provide convincing vintage‑style effects both live and in the studio.