Slaw - That pump doesn’t have enough output for a high pressure manifold, does it? The surge tank, at this point would not be safe run at higher psi, as they weaken over time.
Steve
The surge tank and original 3 psi pump in the picture provides clues into the history of ownership. I am making an assumption that another pump was used with that setup. Not available now, so the original pump is included. The original pump showing may also indicate that the tonearm started life as a 2.0 and might have been beefed up to a 2.5 by Bruce later....when he used to do these modifications.
As we know, Bruce designed the ET tonearm in a way that the tonearm PSI can be built to customer specs. 3 PSI to higher up to 19 psi.
I would recommend the person buying "that" tonearm to just pickup an aftermarket pump on the wholesale market and bypass the original pump seen in the photo. The pump as we have discussed here is an audiophile journey on its own, for the person that wants to explore that rabbit hole.
We have discussed here as well, how to determine what the PSI has been set for at the factory, for anyone buying a used ET 2 version tonearm with PSI unknown.
We can rehash if anybody wants. I do enjoy talking tech. Takes my mind of these markets - lol
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Pegasus
- Surge tank: My Airtech tanks end caps broke during a long time of being stored away. My replacement was a standard HDPE gasoline tank, 10l (ca. 2 gallons) with two 5mm holes drilled in the screw cap, with silicone tubing entering each hole, one with a short piece entering the tank, one with a long piece touching the "floor". The tank is filled with polyacryl wool for damping. The seam of screw cap / tubing then is "glued" with hot glue. This stays air tight since 10-15 years, and i’s cost were almost nothing.
- My original ET pump with ET 2 arm gave ca. 0.25 to 0.3 Bar. With the improved
Pegasus - I am sure your surge tank is built to Swiss Specs 8^0 and very good ....however
I am of the personal opinion that technical talk of surge tanks, scares new potential owners away. I think the air bearing tonearm talk itself may intimidate people enough, without getting into details on the tonearm peripherals. JMO
With that, I believe a better solution is to use a pump whose surge tank, and water removal functions are part of the pump's integral design - plug and play, no maintenance needed. How does that sound ?
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@the nature boy
re: your question about the ET1.
I believe your question was for the most part answered in the previous posts ?
Visually looking at both versions one can see many differences. The ET1 is probably as rare to be seen for sale, as the 2.5 for different reasons.
Now if one is of the belief that the vinyl hobby is a vibration resonance adventure; well Bruce has done "extensive" analysis on materials, resonances; just look at his sub woofer product Low Frequency testing, that he took to Africa to test Elephant responses. Anyway
Look at the materials used in the ET1 compared to the ET 2.0 and 2.5. The 2.0 - 2.5 have VTA on the Fly, exchangeable armwands, and an I beam design that allows for matching up to different carts.
Now with that, I am sure there are ET1 owners out there loving them, and they work great with their systems. It’s all about tweaking and tuning - isn’t it ?
Myself - I think a better question is what is the difference between the ET 2.0 and 2.5 ? It is not obvious to the general onlooker ?
Cheers