Hello,
Been reading for about a year but this is my first post. It is a real testament to the ET arm and Bruce that this thread has lasted over 5 years for a tonearm over 30 years old. The real purpose of my post is to thank you all for the knowledge and expertise you have shared. While I have owned my ET II arm for nearly 30 years, I have only recently started tweaking it. My tweaks are a direct result of the knowledge shared by all of you.
I have the original ET II arm with few upgrades except the trough which I abandoned years ago. I found The silicon migrated out of the trough and created a real mess. I was still using the original pump that came with the arm but had added a home made surge tank.
After reading posts here I bought a Wisa pump from eBay. Got stung. The pump was extremely noisy and had obviously been used with a salt water fish tank. I took it apart and got it quieted down but it only lasted about two weeks and broke down. I replaced it with a Medo pump and in the process discovered my surge tank was leaking at the connectors. Built a new PVC surge tank with brass connectors and bought a pressure gauge which showed I was running @ 8 1/2 PSI. The improvement in sound quality was jaw dropping. And remember, this an original arm without the high pressure manifold.
However, the Medo pump was a little noisy and since it is rated for only 60 minutes, it ran quite hot. So.......I built a soundproof (well almost soundproof) box, installed a fan on one end and vent on the other to enclose the pump. Voila, not audible from more than a few feet away and now runs just barely warm.
Well, with this success I had to have more and read a bunch more posts here which got me intrigued with the debate over less weight further out the beam or more weight closer in. I am using a Lyra Delos cartridge which Bruce considers light weight. I was using 4 weights at about the 3 1/2 position on the beam. I removed one weight which moved me out to about 4 on the beam. This lowered base response but was muddy and sacrificed high frequency response. I considered adding weight back and moving them in, but thought, what the heck, let's take more weight off and move further out. I am now using only two weights and they are at the end of the beam at the 6 position. Wow! Base got even deeper, tightened up and the resolution returned in spades. Add me to the fewer weights, further out crowd.
I am not sure which of the tweaks had a larger effect, the higher pressure pump or the weight redistribution. I do know they were not the psychoacoustic improvements that disappear in a day or two. These tweaks were the equal of a major cartridge upgrade.
Thank you all for sharing your knowledge and experience.
