Eminent Technology ET-2 Tonearm Owners

Chris.

I also thank you for your insightful testing of the ET2.5.
It confirms that adding too much mass, by way of locking the counterweight is not a good idea, if it takes the arm out of the appropriate resonant frequency range. I did say earlier that in my testing of the ET2, I added too much weight and had to backtrack. The key point being where does the arm in standard form sit relative to the optimum.

Adding additional weight to an ET2.5 would be inadvisable since it is already in the Goldilocks zone I mentioned. Namely its horizontal resonant frequency is in the range of 2-3hz, when using a decoupled counterweight and a low to med compliance cart.
Now bringing the ET2 down to this optimal range, that would be interesting. Are you able to fit 3 leaf springs to an ET2 carrying a low to med compliance cartridge?
Another question please. How stiff is the beam with the 3 leaf springs? As I mentioned earlier, the arm is very sensitive to any resonance at this point. I would urge caution if the resultant assembly rings in the audio band.

Richardkrebs

Readers of this thread will now see that you are contradicting yourself.

Adding additional weight to an ET2.5 would be inadvisable since it is already in the Goldilocks zone I mentioned. Namely its horizontal resonant frequency is in the range of 2-3hz, when using a decoupled counterweight and a low to med compliance cart.

Richardkrebs - this comment is unbelievable. This completely contradicts your earlier posts.

You encouraged Thekong to add horizontal mass to his ET2.5 and I quote;

03-12-13: Richardkrebs
Thekong
I don't know how long patents last, but would suggest the reason that Lloyd does not decouple the counterweight is simple.

It sounds better.

03-12-13: Richardkrebs
Thekong

We look forward to reading your comments.

03-13-13: Richardkrebs
Thekong.

Thanks for posting the photo of the counterweight arm. One suggestion is that you need to be very carefull with the stiffness of this. Any shake rattle and roll here is bad since it is no longer free to pivot about the leaf spring. I experimneted with the rod carrying the weight and finished up with an aluminium rod with a M10 thread for adjustment. Smaller diameters were quite flexable.

I repeat, you have now opined that it is inadvisable to add mass to an ET2.5, whilst you have been encouraging Thekong to add mass to his ET2.5 by coupling his counterweight and furthermore, stiffening the counterweight assembly with an M10 bolt no less.

Your advice on adding mass and coupling the counterweight has been wrong.

Earlier I advised readers to be aware of the pitfalls and possible deleterious consequences. In a response you hysterically claimed that I was scaring people off from trying your suggested modifications and accused me of being a scaremonger.
Richardkrebs - readers of this thread are quite capable of evaluating the arguments put forward for and against. I have a higher respect for the intelligence of the readers of this thread.

Your refusal to acknowledge the recommendations outlined in the ET manual, your continual refusal to acknowledge the laws of physics, and now a complete reversal on the advice given Thekong on his ET2.5 suggest that readers should disregard your advice completely.

Dover.

Mea culpa. Although it is blindingly obvious that Thekong will be using a ET2.5, since he states same several times, I completely overlooked that fact, thinking that he was working on a ET2. My mistake.

It would still be informative if Thekong is interested since the rigidity of the counterweight arm is critical in non decoupled applications. While I would expect similar results to Chris, there would likley be some material differences which would be well shared with the rest of us.

ALL of my comments re weight and the ET2 stand. Its resonant frequency tells us that it is a completely different animal.

Hi Ct,

I am using the Apogee Fullrange, so should be able to tell the bass difference between the different setup. However, I will need to order the extra left springs from Bruce.

As I got my original ET2 secondhand, I am missing the lead counter weight. I remember asking Bruce a couple of years back but the price was really high, due to some special reasons (high cost to machine lead as it is hazardous to health ?).

So, I would like to check with other users whether using other substitutes would cause a big difference?

After a week in Australia for F1 racing, I checked this thread.

Surprised I was, that it continues: high horizontal/lateral mass wrecks cartridges (words to that effect), or at least Richardkrebs arm setup does (words to that effect).

It catalysed me, finally, to read Michael Fremer’s review of the Kuzma Air Line Tonearm.

I figured as Franc Kuzma uses significantly MORE horizontal mass than Richardkrebs with his low compliance cartridge, Mr Dover would implicitly conclude Kuzma doesn’t know what he’s about, selling a defective design.

Well, revelation: Michael Fremer says (after initial academic objections to the design)

“Ultra-black backgrounds; enormous, airy, startlingly stable soundstages; palpable images perfectly placed and sized; ear-popping harmonic, dynamic, and transient complexity—I could blather on about the Air Line's convincingly natural performance and brilliant overall balance.
I'd rather just get to the point: In every playback parameter I was able to delineate, the Kuzma Air Line's presentation was staggeringly better than that of any other arm I've auditioned—with the exception of the one included with the $70,000 Rockport System III Sirius.”

“With the addition of a damping trough, the Air Line could very well be the finest tonearm ever built.”

Mr Kuzma replies to MF

"A question of damping..."
A system will resonate only when disturbing forces appear at the resonance frequency. If there are no disturbing forces, then there are no problems. However, if a system is overdamped, then instead of one resonance, two smaller resonances occur, one below and one above the previous resonance, which can create further problems. There is, in fact, a level of effective damping on the Air Line tonearm. The cantilever suspension, and the air supply tube add damping. Our choice was for either too little or adequate damping; we chose the latter.

"Eccentric LPs and any deviation from absolute horizontality will create...problems..."
Horizontal disturbances of an eccentrically spinning record occur only at 0.55Hz or 0.75Hz (33rpm or 45rpm). This is well out of the Air Line tonearm's resonance in the horizontal plane, which is between 2 and 5Hz and does not cause problems tracking virtually all LPs. Plus, if one has a defective disc so poorly pressed or off-center that it might cause such problems, it is perhaps most prudent to simply not play it.”
(Sorry guys if these comments are already part of the thread).

After such a classy weekend I cann’t energise myself to provide a series of theoretically derived, professorial quotes.

It is self evident Franc Kuzma is the real deal, producing superlative product with inherent sonic performance at the far end of world class designs.

Suffice to say Franc Kuzma can be trusted to confidently illuminate the subject.

The same cannot be said of Mr Dover’s bombastic contentions.