Eminent Technology ET-2 Tonearm Owners

Philcoffino, a couple of things to check.

- Make sure the ARM is level, not just the platter. I will bet you an I-beam that your arm (spindle/housing) is not level, and is slightly higher in the rear. Even if a bubble level tells you that it is, try raising it slightly at the front.

- Check the dressing of the tonearm wires to make sure they are not pulling on the arm when it reaches the end of the record.

- If you are using a clamp on your tt, check to see that it's diameter is not so wide that cartridge body actually hits it at the end of the record. Had that happen with a certain carbon fiber clamp.

Frogman, I couldn't agree more. I just assumed that his arm was perfectly parallel with his platter's surface!

Philcoffino,
If it's not, make that adjustment first, then level your suspension with the oracle gauge to make sure that your aluminum plinth is parallel to the acrylic plinth. After that's perfect, use the arm as a level and level it by adjusting the spikes under your Oracle.

Again, issues of ultimate technical performance aside (tracking), in my system with certain cartridges one spring is obviously preferable to the others, otherwise the sound can be either too lean (lower compliance spring), or too full, even bloated and diffuse (higher compliance spring). Having said that, I seldom use the single spring anymore since the improved detail retrieval and refinement that I generally hear with the double and triple springs are difficult to give up; and when the system starts to move in the direction of too lean a sound as a result of the lower compliance, I find that I can make adjustments elsewhere (VTA, slightly higher VTF, a different tube, etc.) and retain the benefits.

Frogman – What a profound post. Your experience with this ET2 tonearm, different cartridges and different I Beams just oozing out. Well maybe oozing is not the right word.

As a guideline then and remembering all our systems/rooms are different so we need to experiment and the reason we cannot call it a "silver bullet".

Summarizing this makes it clearer for me.

2 or more leaf springs - heads more toward a leaner sound due to lower compliance – more detail and refinement.

One leaf spring – best tracking - but sound can become too full, even bloated and diffuse due to the higher compliance of just one spring.

What I am hearing going from the single to double spring supports this.

Cheers

Rebounding arm fix!

I thank the forum contributors for their suggestions.
Careful leveling has mitigated but not solved the problem. Rebound is now observed only with some records, perhaps those with runout grooves more steeply pitched.

I assume that energy is stored in the I beam spring upon inward acceleration of the arm as it encounters the more steeply pitched runout groove, then suddenly decelerates when the groove becomes circular nearest the record center, and the Ibeam with associated mass gives up its energy, pitching the arm back toward the periphery.

Bruce Thigpen offered to send me an I beam with a less compliant spring, which may solve the residual problem.

Arm setup was impaired by my inability to find my stylus pressure gauge. It is useful to know that a US dime weighs ~2.2 grams. That made it possible to jury rig a balance so that my Benz Micro Ref could be set to that pressure.

Hi Philcoffino – welcome to the thread. Interesting point about the smaller circle and built up energy ? I need to give that some thought. The smaller circle is what caused the most problems for me when I tried to convert a belt drive designed TT to thread drive. Pitch stability suffered when longer thread was used.

I will say “again” any one with an ET-2 on a suspended TT needs to pay extra attention to detail. Here are 3 additional leveling tips based on taking down and remounting the ET 2.0 / 2.5 over 20 times in the last year. 4 different tables plinths / no plinths and also 4 armpods.

These 3 techniques saved me a lot time and frustration.

I went to one of those neat hardware stores and bought a level that is as close to the same length/size as the ET2 Straightline Jig.

1) Place it on the platter in the EXACT line that your ET-2 straight line alignment jig would go – levelling this way ENSURES your platter is level in the path the arm will take.

2) The tonearm air bearing spindle is not IMO in the same exact level plane as the tonearm armpost it attaches to. It a physical connection with bolts – DON’T TRUST IT. Some of these arms are old now. Many people level the arm post. IMO - this is a mistake.

Use Blue Tac (Fun Tac) a little heavier than the cartridge on the counterweights to raise the Arm Tube and Cartridge and have the Bearing Spindle float with gravity. Adjust armpost vertical screws until it does not move either way.

3) While arm is floating (in 2) move wires around with pencil or your finger – Fix/dress the wires so they don’t affect the arm. Do this with the arm raised at the START and END of the record.

If the above three points are done the stylus "run-in" and "run-out" should be the same.

Thoughts?