Over the past month I had gotten back into refining the air regulation arena, partly inspired by Don @redcars and Terry. The additions of gauge and surge tanks have provided some numerical data points. I am able to make the following observations:
1. The starter kit:
The supplied Sera 220 pump and a 1 gallon surge tank should be considered the most basic kit that will allow the proper operation of the Terminator. The Sera 220 has a max pressure output of less than 1 psi and a 4 liter / min flow. The actual air pressure at the manifold is probably as low a 0.1 psi - 0.3 psi.
The addition of surge tanks and air filters is I think fundamental in improving the performance of any air-bearing linear tracking tonearm. The terminator sounds very good with the starter kit, but it will only improve will better air filtration, modulation, and damping. The purpose is to minimize as much as possible the air pulsation produce by the compressor. The glider that carries the wand with the attached cartridge should operate in as close to a 'friction-less' bed of air cushion as possible.
2. The signature Kit
Taking the cue from Terry, I began last year to introduce more filtration in the form of additional plastic surge tanks. With the initial addition of a 20 liter tank, the improvement to sound quality was immediate. More detail, more stable sound-stage, ..etc. And then came an additional 20 liter tank as well as a 4" pipe capped at both ends acting as a air filter. The sound quality improved further. With the last addition I had come to the limit of what the Sera 200 can pump out.
The 'signature' kit consists of a compressor that can put out at least 3-5 psi. The usual suspect is a Hiblow hp 40, max 5 psi with 44 liter / min flow. I am using a Hiblow clone, Alita, with the same specification. I have a total volume of 80 liter worth of surge tanks. And the pressure out of the compressor is at 1.25 psi. Both Terry and Don have pressure levels at 0.3 - 0.7 psi. The reason for my high pressure level has to with the type of tubing and the total volume of surge tanks.
It is possible to add more air filtration ( which I intend to do ), the limit being the output of the compressor. How much sound improvement with the increase yield ? When is the point of diminishing return ? These question I do not have answers to. However, given that the Terminator operates in a low-pressure environment, I think it is possible to extract a bit more. If on the other hand we use a Air-Tangent of Kuzma Airline where the operating pressure is around 35 psi, then the use of even more powerful compressors may be prohibitive for domestic use. I believe this is one of the main advantage of a low pressure air bearing LT arm. It is more accommodating to air modulation. And in LT arm, increased air filtration is really one of the important factors in maximizing its sound quality.
In the most recent Analog Corner segment in Stereophile, there is a reprint of Framer's 2019 review of a linear tracking pivot arm, Klaudio's KD-ARM-AG12. He commented with respect to this arm that "the tangential possession is misguided". I am of the opinion that there is not necessary a clear advantage of linear tracking vs pivot arm. And the Terminator is always thought of by me as a highly musical, utterly under-valued and under-appreciated arm that happens to be tangential tracking. Given what it is, then maximizing its air filtration potential should really be on every Terminator users' to-do list.
1. The starter kit:
The supplied Sera 220 pump and a 1 gallon surge tank should be considered the most basic kit that will allow the proper operation of the Terminator. The Sera 220 has a max pressure output of less than 1 psi and a 4 liter / min flow. The actual air pressure at the manifold is probably as low a 0.1 psi - 0.3 psi.
The addition of surge tanks and air filters is I think fundamental in improving the performance of any air-bearing linear tracking tonearm. The terminator sounds very good with the starter kit, but it will only improve will better air filtration, modulation, and damping. The purpose is to minimize as much as possible the air pulsation produce by the compressor. The glider that carries the wand with the attached cartridge should operate in as close to a 'friction-less' bed of air cushion as possible.
2. The signature Kit
Taking the cue from Terry, I began last year to introduce more filtration in the form of additional plastic surge tanks. With the initial addition of a 20 liter tank, the improvement to sound quality was immediate. More detail, more stable sound-stage, ..etc. And then came an additional 20 liter tank as well as a 4" pipe capped at both ends acting as a air filter. The sound quality improved further. With the last addition I had come to the limit of what the Sera 200 can pump out.
The 'signature' kit consists of a compressor that can put out at least 3-5 psi. The usual suspect is a Hiblow hp 40, max 5 psi with 44 liter / min flow. I am using a Hiblow clone, Alita, with the same specification. I have a total volume of 80 liter worth of surge tanks. And the pressure out of the compressor is at 1.25 psi. Both Terry and Don have pressure levels at 0.3 - 0.7 psi. The reason for my high pressure level has to with the type of tubing and the total volume of surge tanks.
It is possible to add more air filtration ( which I intend to do ), the limit being the output of the compressor. How much sound improvement with the increase yield ? When is the point of diminishing return ? These question I do not have answers to. However, given that the Terminator operates in a low-pressure environment, I think it is possible to extract a bit more. If on the other hand we use a Air-Tangent of Kuzma Airline where the operating pressure is around 35 psi, then the use of even more powerful compressors may be prohibitive for domestic use. I believe this is one of the main advantage of a low pressure air bearing LT arm. It is more accommodating to air modulation. And in LT arm, increased air filtration is really one of the important factors in maximizing its sound quality.
In the most recent Analog Corner segment in Stereophile, there is a reprint of Framer's 2019 review of a linear tracking pivot arm, Klaudio's KD-ARM-AG12. He commented with respect to this arm that "the tangential possession is misguided". I am of the opinion that there is not necessary a clear advantage of linear tracking vs pivot arm. And the Terminator is always thought of by me as a highly musical, utterly under-valued and under-appreciated arm that happens to be tangential tracking. Given what it is, then maximizing its air filtration potential should really be on every Terminator users' to-do list.