Hi All, due to an accident with my very durable Medo AC0110 air pump, I am now looking for a new more quiet air pump for my ET-2 tonearm.
I have found a direct replacement but I want a more quiet pump around 15psi for my ET-2. I will be using an exiting Air Pressure regulator and just a low noise pump now.
any info on where I may find one will be greatly appreciated.
I have found a direct replacement but I want a more quiet pump around 15psi for my ET-2. I will be using an exiting Air Pressure regulator and just a low noise pump now.
any info on where I may find one will be greatly appreciated.
The ET-2 manual states that the air pressure requirement is 3 psi. Why do you need higher pressure, 15 psi for your ET-2? Usually, the higher the working air pressure, the noisier the pump will be.
Yes, I agree. These arms don't need much pressure. You might give Bruce a call and ask for suggestions. I'm using an Alita AL-15 which is quiet, but I also put it into a sound deadening compartment in a small cabinet since it is 3' off the floor and right inline with ears when in use.
Because I use a regulator and set my PSI at 5psi, but I use a surge tank as well so that's why I want a around a 15psi pump. Running the pump from the next room with a long run of air line and air filter in-line before and after the regulator. It works and sound better at 5psi, @ less than 5psi the arm sometimes gets stuck. I have the manual and have been using the ET-2 for over 18 years now.
I had mine on a shelf (bottom) in the next room about 4-5" off the floor with the Medo pump and worked well but still looking for something a little more quiet.
I looked on another forum and someone answered my question there as well, linking me to what Bruce recommends. That is the pump that was linked.
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If the arm sticks at 5 psi then most likely you need to take it apart and clean everything including the small air passage screws around the perimeter outer supply cylinder.
You will notice the each stainless steel screw has rounded down thread pitch profiles so the air follows this path down and around the threads to supply a turbulent air pressure to the movable tonearm section.
These thread holes should be cleaned with a small pipe brush of some
kind to get down deep into the thread pitch sections or air path area
The arm can start sticking when you get below 3 psi so 5 psi is good margin
You will notice the each stainless steel screw has rounded down thread pitch profiles so the air follows this path down and around the threads to supply a turbulent air pressure to the movable tonearm section.
These thread holes should be cleaned with a small pipe brush of some
kind to get down deep into the thread pitch sections or air path area
The arm can start sticking when you get below 3 psi so 5 psi is good margin
Well, I am not surprised the arm performs better under high air pressure. If you can put the air compressor in a different room, I would recommend a Super Silent 20-A air compressor. Its noise level is only 30 dbs. However, you may need to add more oil filters. For ET-2, clean air may be as critical as New Way air bearings because New Air bearing uses porous material.
I like the idea of a tank to contain reserve pressure. If I understand correctly, then perhaps the tank might supply enough by itself as to not run the pump? I have had a curiosity about these for years.
I considered a compressed-air tank, but the moisture content is too high, even with a dryer. The surge tank only serves to dampen pressure oscillations due to the action of the air pump. I made one of those with a rubber membrane near the top to further dampen pulses, but it takes too much room, and the soft Tygon tubing I use is long and soft enough to do a suitable job of dampening the air pump pulses.
Way back, in my past life, I worked for the Bell System. Outside we had air pressure in the lead covered cables that hung off the telephone poles. So, yes, since moisture was a problem nitrogen was used instead of air, for the same reason. At a welding supply, nitrogen can be bought in small tanks. just thinking out of the box. Of course, this would be something to research first.
@AVWERK: My ET-2 doesn't seem to have any of the screws you mention in the manifold housing. Can you elaborate? Here's the parts diagram.
The owner's manual is available from ET's website and provides details on cleaning the manifold housing, bearing spindle, and manifold.
@Ixnay: One might be spending a lot of time and money on nitrogen. The air pressure is low, but if a listening session is several hours, I think the capacity of a small tank would be the limitation.
Still think Bruce Thigpen engineered it thoughtfully and has kept up with best solutions to providing air, though I agree, thinking outside the box can be entertaining and fruitful.
The owner's manual is available from ET's website and provides details on cleaning the manifold housing, bearing spindle, and manifold.
@Ixnay: One might be spending a lot of time and money on nitrogen. The air pressure is low, but if a listening session is several hours, I think the capacity of a small tank would be the limitation.
Still think Bruce Thigpen engineered it thoughtfully and has kept up with best solutions to providing air, though I agree, thinking outside the box can be entertaining and fruitful.
Correction:
For ET-2, clean air may NOT be as critical as New Way air bearings because New Way air bearing uses porous material.
One other tidbit: ET offers a high pressure manifold. Here is an excerpt:
- 3.6 PSI - 0riginal Takatsuki and ET-2 or 2.5
5.0- 7 PSI - WISA 300 air pump and ET-2 or 2.5 with high pressure manifolds
Note, if the pressure readings are higher than those listed above, the manifold could be clogged, if the pressure readings are lower, this suggest that the pump may not be performing correctly.
The break down doesn’t show the manifold seperated from it’s housing
You have to remove the sliding air bearing first, then the manifold has
2 ‘O’ rings for the pressure seal which means you have to put some pressure
to get it to slide out of its manifold housing.
You will then see the small allen set screws placed around the bearing manifolds
perimeter
Some pics I just found
This is the latest large diameter version (more surface area) for the et-2 and shows
the internal makeup in question
You have to remove the sliding air bearing first, then the manifold has
2 ‘O’ rings for the pressure seal which means you have to put some pressure
to get it to slide out of its manifold housing.
You will then see the small allen set screws placed around the bearing manifolds
perimeter
Some pics I just found
This is the latest large diameter version (more surface area) for the et-2 and shows
the internal makeup in question
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Arm stick once in a while @ 4psi or lower. 5-7psi works great with my ET-2, nothing wrong on the arm end. I checked the pump and it is the pump that is not performing as before.
Just an update on the pump issue. I decide to just stick with what I had in the Medo AC0110. I found some like new and bought two for under $60, so this should out last me.
Arm is back up and funning fine. I set the air pressure to 5psi and sounds wonderfully!
Thank Everyone for their replies and info.
Arm is back up and funning fine. I set the air pressure to 5psi and sounds wonderfully!
Thank Everyone for their replies and info.
I run my Maplenoll arm bearing at ca. 35 psi. At 5 or so psi the balance is on a knife edge: it will tend to fall asleep off to one end or the other. At the beginning and end of travel there is a substantial cantilever effect and the "bearing" was sagging just a bit towards one side or the other.
I had to remove the manifold and tighten the set screws to get the air flow down. As Bob Dilger explained it to me, the gap is way too big for any pressure to build and the air is coming out of the set screw holes like water from a fire hydrant. There are 4 tiny high pressure "points" at each end. By raising the pressure the points get stronger.
He said that he and Bruce Thigpin experimented with a tighter gap between the manifold and the moving spindle but it became impossible to keep clean before it began to sound any better.
I have a crazy system that starts with a California Air Tools compressor in a different building, two surge tanks -- the first one is 20 gallons and is at 95psi, the second 5 gallon tank in the listening room is at 50psi. I got a 100' spool of 3/16 hose and left most of it on the spool for the final measure of air pulse filtering.
Pete
I had to remove the manifold and tighten the set screws to get the air flow down. As Bob Dilger explained it to me, the gap is way too big for any pressure to build and the air is coming out of the set screw holes like water from a fire hydrant. There are 4 tiny high pressure "points" at each end. By raising the pressure the points get stronger.
He said that he and Bruce Thigpin experimented with a tighter gap between the manifold and the moving spindle but it became impossible to keep clean before it began to sound any better.
I have a crazy system that starts with a California Air Tools compressor in a different building, two surge tanks -- the first one is 20 gallons and is at 95psi, the second 5 gallon tank in the listening room is at 50psi. I got a 100' spool of 3/16 hose and left most of it on the spool for the final measure of air pulse filtering.
Pete
Pete, Thank You for the info, that is what I was noticing at 4psi but at 5psi its a lot better with no issue that I can detect. I will increase to 6psi and see how that works. As of right now, the arm is not having edge issues like you mentioned, but will try to slightly increase and see what the performance is after.
Pete, I just increased the air pressure to 6 psi and it does sound slightly better than at 5 psi. Thanks again.