Within the creative use of tape recorders, disabling the erase head to build dense tape loops is a common practice. Throughout the history of both musique concrète and pop music, sonic worlds are built by stacking layers of material upon each other, saturating and thickening in density as the loop kept running and new material kept filling up the tape. This requires adjustments to the electric circuit of the tape recorder, as every recorder is automatically equipped with an erase head. Disabling the erase head is quite simple and very absolute: your tape recorder either has an erase head, or not. When the erase head is disabled, you create the possibility to have an ongoing musical dialogue with your material without it becoming static: the layers stacking upon each other will blend in such a way that they will morph into something new.
In detail, each time a piece of a tape loop passes the recording head again, a little bit of the initial material will be pushed back by both the new input and the regular magnetization that occurs when the tape passes the erase- record- and playback head. If the erase head is bypassed completely while new input is being sent to the tape, a dense cloud of sound will form and soon fill up the sound to something unrecognisable - interesting, but absolute. But if we could control the functioning of the erase head, we would be able to control the amount of magnetisation of the new material onto the old, therefore creating space (literally) in which layers of material can correspond with each other. Drop-outs will occur, while at the same time initial material can be fed back into the same loop, creating audible spaces where prominent frequencies are even more articulated. In a very organic manner, one bit of musical material starts to evolve into new configurations. Objectively speaking the quality of the recording deteriorates, but seen from a creative perspective new material emerges, which could only have derived from this particular input and process. It is unrepeatable, a direct form of recorded studio improvisation and a method through which the agency of the tape recorder becomes more prominent.
Together with artist, instrument builder and engineer Paul van Twist, we have researched and tested different versions of intermediate erase heads on the Revox B77 tape recorder. Is it possible to create gradual positions on an erase head and create sound-on-sound alterations? How would this affect the operation of the tape recorder? Would it be possible to record and partially erase simultaneously? How does the modified operation of a tape recorder influence its creative use? As a result of these questions we have created an additional circuitry in the tape recorder to control intermediate functioning of the erase head.
The intermediate erase head on a Revox B77 was developed around the working process of the interdisciplinary performance Minaminotori, directed by Daniel Cross in collaboration with NKK NXT.
The development process expectedly came with lots of technical disputes. One of them being very brutal at first sight: the first prototype of the altered Revox B77 could only be used as a mono recording device – while originally being a stereo phase tape recorder. The Revox B77 could still playback two tracks, but the sound-on-sound functionality could only be used on one track. This had to do with the fact that each track functions as an autonomous electronic circuit, thus every track also needed an additional circuit for this modification. In our research phase we decided to focus on getting one of the two tracks to work as sound-on-sound track. Thus we started using the machine as a mono sound-on-sound device in conjunction with stereo material played live: all sound-on-sound material is sent out in mono, but we could control the signal to the loop on the B77 and play additional material in stereo simultaneously. This can be clearly heard at 06:59-07:10, where the material you hear is less detailed, in the back is the mono representation of earlier played stereo no-input feedbacks. The louder pulses at 07:02 clearly have a movement within the stereo image of the recording, these are played live. All signals (both from the Revox B77 and the live played electronic feedbacks) were mixed on a Soundcraft K1 mixer.
The result of this ‘limitation’ was that the tape recorder became more of a conversation partner than a purely functional device to create controlled sound-on-sound material on. The loop on the Revox B77 was used as a means of “storing” passages that arose in a live situation. This material could then be used as material to play over, or by erasing it to a greater or lesser extent, recording over it or physically playing it by grabbing the tape, slowing it down or fast-forwarding it. In this way, the limitation of the mono machine forced it to be used as one of the voices in a larger ensemble of instruments and sounds.
Another dispute concerned an internal bounce option, a functionality which is already present on the non-adapted Revox B77. This function became important as a creative tool during the process of working with the customised Revox B77. The internal bounce option provided the option to bounce materials that you would want to keep, before erasing the track and/or stacking material upon the existing sound-on-sound track. So initially the internal bounce option was used as a method of ‘storage’ and as a way to fill up the complete bandwidth of the 1/4” tape, but when working with this method we started to notice that you can create internal feedbacks within the tape recorder when pushing the levels of the recording amplifiers. Due to the fact that the two tracks are literally next to each other and not strictly divided, both on the tape itself as on the tape head, an internal feedback occurs on the tape loop. This can be heard at 06:50. The internal feedback became a musical element, for instance listen to 07:40. Also note that the initial very clear washes (at 07:40) of internal feedback start to vanish more and more behind the new material (up until 11:38), which is being put on the loop. Here, the organic effect of the sound-on-sound function (that of decay over time) can be clearly heard in combination with the musically used limitation of the internal feedback (which acquires its musical function through the specific operation of this machine).
We are still in the process of developing the method of erase head control. And even though it is still full of flaws, the idea has proven itself to be creatively interesting and valuable. The option to deliberately work with intermediate positions of the erase head allows for musical movement in a way that exceeds linearity. Recording new material onto a loop is no longer an all-or-nothing decision, we can now blend in sonic material into existing material, playing with the strength of the magnetic field by gradually controlling how far the erase head is removed from the tape. The audio track exemplifies this at 00:06-00:48, where live material from the no-input mixer is continuously present in an increasing textural form up until 03:40, where the material vanishes completely between 03:40 and 03:44. By activating the fader which controls the erase head, material which is present on the tape loop can be erased partially or completely, depending on how far the fader is open. The Revox B77 intermediate erase head allows us to metaphorically sketch in sound – pressing our charcoal deeper into the paper to create articulated forms and stroking it lightly as to fill in shadows or highlights.
At the time of writing, we are still working on the further development of this functionality. For example, we are working on a stereo sound-on-sound machine and experimenting with increasing the range of the faders the control of the erase head, effectively giving you a larger area over which you can exercise control.
It is also worth noting that, in addition to these adjustments, we have also conducted many experiments with adjustments that could be described as more drastic: hard interventions in the wiring that run to the erase and record head. Additional information about this will be published shortly, including sound samples. Although the idea is similar (fader control over the functioning of the erase head) the sonic results are different.
The most important aspect of this research and experiment has been the unforeseen outcomes. The by-products that caused the relationship between musician and instrument to shift. Seen in this light, this process is above all an encouragement to dare to adjust the parameters of your own instrument in order to gain a better understanding of your wishes and needs as a creator.
Within the creative use of tape recorders, disabling the erase head to build dense tape loops is a common practice. Throughout the history of both musique concrète and pop music, sonic worlds are built by stacking layers of material upon each other, saturating and thickening in density as the loop kept running and new material kept filling up the tape. This requires adjustments to the electric circuit of the tape recorder, as every recorder is automatically equipped with an erase head. Disabling the erase head is quite simple and very absolute: your tape recorder either has an erase head, or not. When the erase head is disabled, you create the possibility to have an ongoing musical dialogue with your material without it becoming static: the layers stacking upon each other will blend in such a way that they will morph into something new.
In detail, each time a piece of a tape loop passes the recording head again, a little bit of the initial material will be pushed back by both the new input and the regular magnetization that occurs when the tape passes the erase- record- and playback head. If the erase head is bypassed completely while new input is being sent to the tape, a dense cloud of sound will form and soon fill up the sound to something unrecognisable - interesting, but absolute. But if we could control the functioning of the erase head, we would be able to control the amount of magnetisation of the new material onto the old, therefore creating space (literally) in which layers of material can correspond with each other. Drop-outs will occur, while at the same time initial material can be fed back into the same loop, creating audible spaces where prominent frequencies are even more articulated. In a very organic manner, one bit of musical material starts to evolve into new configurations. Objectively speaking the quality of the recording deteriorates, but seen from a creative perspective new material emerges, which could only have derived from this particular input and process. It is unrepeatable, a direct form of recorded studio improvisation and a method through which the agency of the tape recorder becomes more prominent.
Together with artist, instrument builder and engineer Paul van Twist, we have researched and tested different versions of intermediate erase heads on the Revox B77 tape recorder. Is it possible to create gradual positions on an erase head and create sound-on-sound alterations? How would this affect the operation of the tape recorder? Would it be possible to record and partially erase simultaneously? How does the modified operation of a tape recorder influence its creative use? As a result of these questions we have created an additional circuitry in the tape recorder to control intermediate functioning of the erase head.
This text provides a brief overview of the creative and technological steps that were taken, the problems that arose, the solutions that were developed and the unforeseen results which occurred. It is important to emphasize that this was not a linear process. Some problems turned out to generate interesting artistic results, and some artistic ideas were abandoned because they proved too technically complex (for now) or simply did not yield enough results. Nor does this article provide a ready-made answer to the question of how best to convert a tape recorder. It merely outlines an artistic process that went hand in hand with technical modifications to a specific type of tape recorder. The different schematics which have been developed in the process of researching this functionality can be downloaded here and here.
The intermediate erase head on a Revox B77 was developed around the working process of the interdisciplinary performance Minaminotori, directed by Daniel Cross in collaboration with NKK NXT.
The development process expectedly came with lots of technical disputes. One of them being very brutal at first sight: the first prototype of the altered Revox B77 could only be used as a mono recording device – while originally being a stereo phase tape recorder. The Revox B77 could still playback two tracks, but the sound-on-sound functionality could only be used on one track. This had to do with the fact that each track functions as an autonomous electronic circuit, thus every track also needed an additional circuit for this modification. In our research phase we decided to focus on getting one of the two tracks to work as sound-on-sound track. Thus we started using the machine as a mono sound-on-sound device in conjunction with stereo material played live: all sound-on-sound material is sent out in mono, but we could control the signal to the loop on the B77 and play additional material in stereo simultaneously. This can be clearly heard at 06:59-07:10, where the material you hear is less detailed, in the back is the mono representation of earlier played stereo no-input feedbacks. The louder pulses at 07:02 clearly have a movement within the stereo image of the recording, these are played live. All signals (both from the Revox B77 and the live played electronic feedbacks) were mixed on a Soundcraft K1 mixer.
The result of this ‘limitation’ was that the tape recorder became more of a conversation partner than a purely functional device to create controlled sound-on-sound material on. The loop on the Revox B77 was used as a means of “storing” passages that arose in a live situation. This material could then be used as material to play over, or by erasing it to a greater or lesser extent, recording over it or physically playing it by grabbing the tape, slowing it down or fast-forwarding it. In this way, the limitation of the mono machine forced it to be used as one of the voices in a larger ensemble of instruments and sounds.
Another dispute concerned an internal bounce option, a functionality which is already present on the non-adapted Revox B77. This function became important as a creative tool during the process of working with the customised Revox B77. The internal bounce option provided the option to bounce materials that you would want to keep, before erasing the track and/or stacking material upon the existing sound-on-sound track. So initially the internal bounce option was used as a method of ‘storage’ and as a way to fill up the complete bandwidth of the 1/4” tape, but when working with this method we started to notice that you can create internal feedbacks within the tape recorder when pushing the levels of the recording amplifiers. Due to the fact that the two tracks are literally next to each other and not strictly divided, both on the tape itself as on the tape head, an internal feedback occurs on the tape loop. This can be heard at 06:50. The internal feedback became a musical element, for instance listen to 07:40. Also note that the initial very clear washes (at 07:40) of internal feedback start to vanish more and more behind the new material (up until 11:38), which is being put on the loop. Here, the organic effect of the sound-on-sound function (that of decay over time) can be clearly heard in combination with the musically used limitation of the internal feedback (which acquires its musical function through the specific operation of this machine).
We are still in the process of developing the method of erase head control. And even though it is still full of flaws, the idea has proven itself to be creatively interesting and valuable. The option to deliberately work with intermediate positions of the erase head allows for musical movement in a way that exceeds linearity. Recording new material onto a loop is no longer an all-or-nothing decision, we can now blend in sonic material into existing material, playing with the strength of the magnetic field by gradually controlling how far the erase head is removed from the tape. The audio track exemplifies this at 00:06-00:48, where live material from the no-input mixer is continuously present in an increasing textural form up until 03:40, where the material vanishes completely between 03:40 and 03:44. By activating the fader which controls the erase head, material which is present on the tape loop can be erased partially or completely, depending on how far the fader is open. The Revox B77 intermediate erase head allows us to metaphorically sketch in sound – pressing our charcoal deeper into the paper to create articulated forms and stroking it lightly as to fill in shadows or highlights.
At the time of writing, we are still working on the further development of this functionality. For example, we are working on a stereo sound-on-sound machine and experimenting with increasing the range of the faders the control of the erase head, effectively giving you a larger area over which you can exercise control. It is also worth noting that, in addition to these adjustments, we have also conducted many experiments with adjustments that could be described as more drastic: hard interventions in the wiring that run to the erase and record head. Additional information about this will be published shortly, including sound samples. Although the idea is similar (fader control over the functioning of the erase head) the sonic results are different.
The most important aspect of this research and experiment has been the unforeseen outcomes. The by-products that caused the relationship between musician and instrument to shift. Seen in this light, this process is above all an encouragement to dare to adjust the parameters of your own instrument in order to gain a better understanding of your wishes and needs as a creator.
The development of the intermediate erase head on the Revox B77 was part of the working process around the interdisciplinary performance Minami-no-tori, directed by Daniel Cross in collaboration with NKK NXT.
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