The advent of electrical amplification in the mid twentieth century brought with it a desire to augment its dry, sometimes harsh amplified sounds with reverberation. This was mainly achieved through the use of reverberation chambers, metal plates, and spring reverbs for portability. These technologies provide shimmering, hall-type echoes, but cannot produce sharp early reflections or clear echo repeats.
Magnetic tape, which became widely available in the sixties, made it possible to emulate clear, well-defined echoes, that could be repeated numerous times, by using a combination of read and write heads to physically delay the signal along a tape. For years, tape and other magnetic supports were the only available technology widely available to achieve this. Thousands of tape delay machines were built throughout the sixties, seventies and early eighties. Such devices could be seen on stage and in studios all over the world.
During the eighties, most of these heavy, bulky and sometimes unreliable units were replaced by smaller, tougher machines requiring less maintenance: analog bucket brigade (BBD) delays, followed later on by digital delays. Nevertheless, due to the sheer amount of units manufactured, the market is still full of vintage tape delays, which many people prefer to other echo devices. In fact, new tape delays are still manufactured even today, albeit in much smaller quantities than forty years ago. The imperfections and unpredictability of tape delays is what makes them so interesting and so difficult to emulate digitally.
Most units presented on this site were designed and built in Japan, where ESTECHO is based. A good amount of them were also sold in Europe and North America, licensed to various companies and marketed under different names, a common practice at the time. (In most cases, only the front panel is different.) Often, not much is known about the companies that built these units, except for those that still exist to this day, such as Roland and Korg.
Magnetic Support Types
Although tape is by far the most common support used in magnetic-based delays over the years, various other technologies and supports have also been developed, more or less successfully. Furthermore, tape delay transports come in different styles, with pros and cons for each. Below is a short description of various magnetic support types found in delay units.
Endless loop tape cartridge
These come in various formats, from the common 8-track tape to more obscure cassette and cartridge formats such as the Sony RE-4/RE-5 spherical cartridges used in early Roland Space Echos. Custom cartridges also exist, for example in Echoplex units. More information on these cartridge formats can be found on this page.
8-tracks and cassettes are usually part of small, low-budget units. They provide limited features, mostly due to their short delay time and single repeat head. Cartridges such as the Sony RE type can be fitted on more complex transports, making full featured, multi-head units possible.
Tension tape loop
This technology uses a short loop of tape kept under tension by a spring-tensioned roller. This is one of the most common tape transport types for delay units, and can be found on countless machines around the world, especially in earlier units from the sixties and early seventies. Perhaps the most famous devices in this category are the Watkins Copycats.
Although units based on this design can provide high-quality, stable echo repeats, they also have major drawbacks, the biggest of which are short tape length (leading to rapid degradation of the delay signal unless replaced frequently) and high sensitivity to the amount of tension applied on the tape loop (creating wow and flutter when out of spec).
Considered the most “sophisticated” tape transport system, it can hold a longer length of tape for increased fidelity, is more reliable than cassettes or cartridges, and less susceptible to wow and flutter caused by tape tension issues. Perhaps the most famous tape delay, the Roland RE-201, uses such a system. The tape is encased in a closed space, out of which it comes out, goes past the tape heads, and then back in; inside this space, the tape is free to move as it pleases, which reduces friction considerably, increases tape life and makes tape replacement much easier.
This magnetic support was developed for one unit, the Melos Disk-Echo EM-200 (known as the Univox Echo-Tech in North America, and under other names as well). Whether this was considered for other units as well is unknown, but despite a few advantages, the design didn’t catch on.
The tape heads are riding on top of a magnetic disc similar to an old style computer floppy disc. This provides very steady delays and minimal wow and flutter. Drawbacks are rapid wear of the magnetic surface, and replacement discs that have become extremely rare over the years. More information can be found on the Melos page.
A technology used in Binson units only. The tape heads are positioned around a rotating metal disc whose circumference is magnetic. Binson claims that this magnetic drum has a ‘permanent guarantee’. Although the magnetic support is very durable, playback and write heads positioned around the drum need to be positioned very precisely, which can sometimes lead to problems such as noisy operation, or low delay signal. Furthermore, these heads are very difficult to adjust properly. More info on Binson units here.
Another rare and obsolete magnetic support consists of a special, electrically conductive oil spinning in a can-type container, with read and write heads swishing around in the liquid. This is said to produce very wobbly, organic sounding delays. Unfortunately, these are very difficult to maintain in working condition, and nowadays the specific type of oil needed for their operation is very hard, if not impossible, to source.