Eminent Technology ET-2 Tonearm Owners



Where are you? What mods have you done ?

I have been using these ET2's for over 9 years now.
I am still figuring them out and learning from them. They can be modified in so many ways. Bruce Thigpen laid down the GENIUS behind this tonearm over 20 years ago. Some of you have owned them for over 20 years !

Tell us your secrets.

New owners – what questions do you have ?

We may even be able to coax Bruce to post here. :^)

There are so many modifications that can be done.

Dressing of the wire with this arm is critical to get optimum sonics along with proper counterweight setup.

Let me start it off.

Please tell us what you have found to be the best wire for the ET-2 tonearm ? One that is pliable/doesn’t crink or curl. Whats the best way of dressing it so it doesn’t impact the arm. Through the spindle - Over the manifold - Below manifold ? What have you come up with ?
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This is how I test my vinyl setup for Structure Feedback and my ET2 (2.5) Pump for Noise and Vibrations.

I am interested to know what techniques others use. I’d like to learn different ways of doing this.

TEST FOR STRUCTURE FEEDBACK

Some people think that direct sound waves affect our cartridge. Some people put plastic shields around their turntable. If you think that direct air waves really affect your cartridge “trying yelling at your cartridge and see what happens” infamous quote from Audiogon user Halcro.

Can you hear yourself through your speakers when you do this?

Henry – if you see this I hope you don’t mind me quoting you.

My test for structure feedback is to set up the TT on mute and lower the stylus onto the lead in groove. Record not spinning. Unmute the phono and turn to a level that is considered high for your room.

Start jumping up and down right beside your TT. Pretend you are dancing with your spouse. Actually invite her/him in and jump together with no music. Just be prepared she may ask you to boogie to real music later as she gets warmed up. If your setup survives this test you should be good to go.

TESTING THE PUMP for NOISE and VIBRATIONS.

This test should actually be good for any air bearing linear tracker that uses a captured bearing like the ET2 and ET 2.5.

No jumping this time just listening.

Same as the above in regards to muting your phono with a still record and unmuting but with a BIG difference.

1st – DO NOT turn on your pump and lower your stylus onto the lead in groove. Unmute and turn the volume up. Listen to how quiet it is. When finished mute system and raise the ET2. I say raise the ET2 because I don’t know how good your pump and setup is. More on this later.

Now have a friend turn on your pump and repeat the above procedure and lower the stylus again. Is there any noise in the background now that has been transmitted down the airline into your system that was not there before?

Is it the same level of quietness, or is there now a little more background noise with the pump on. If you are using a regular aquarium type pump and no surge tank you will hear differences. For those with good pumps and a properly setup ET2, ET 2.5 there is no need to raise the stylus or unmute after listening with no pump. Have the friend turn your pump on and off while you have your ear on one of the speakers.

If you are introducing noise with your pump down the airline you are not hearing what the ET2 can do. The sound is being glazed over by air noise vibrations from the pump.

I came across this years ago – maybe 8? by accident. I had an actual small ground hum type noise and could not for the life of me figure out how to solve it. I tried for two days. I could just hear the pump at the time in the other room running faintly. It was a Medo AC110.

Finally after a couple of days of trying to fix the problem, I unplugged the pump and I tried the above test. No more noise. Damn! I substituted my backup Medo pump at the time and all was quiet again. The bad pump was still delivering PSI but had a piston problem sending noise and vibrations down. I also found back then that a long run of air tube coiled up also helps to minimize the vibrations.

I didn’t discover the above problem until I had swapped in cartridge, wires, amps, preamps, speakers first ! That set me on my pump journey the next few years and I ended up with the pump I use now.

So how do you guys test for structure feedback and airline noise/vibrations with an air bearing?

Cheers.
With regard to the high horizontal mass the standard ET2 has a very high horizontal effective mass as standard ( 25g plus the weight of the cartridge ) compared to a pivoted arm.
However the FR64 of course, has Eff Mass of 30-35gms (or more).
Richardkrebs has advocated adding 60+g of horizontal mass by adding lead to the bearing spindle and removing the decoupling mechanism of the counterweight. With the ET2 the decoupling of the counterweight is part of the strategy to keep horizontal mass not too high.
I'm not sure if there is any (groove tracking) disadvantage in having Eff Mass too high, ie. Res Freq too low.

Sure, there may be issue with particular TT suspension or TT support resonances, but arguably not detrimental to good record tracking?
Richardkrebs has advocated adding 60+g of horizontal mass by adding lead to the bearing spindle and removing the decoupling mechanism of the counterweight. With the ET2 the decoupling of the counterweight is part of the strategy to keep horizontal mass not too high.
I'm not sure if there is any (groove tracking) disadvantage in having Eff Mass too high, ie. Res Freq too low.

Sure, there may be issue with particular TT suspension or TT support resonances, but arguably not detrimental to good record tracking?