Dlcockrum
Yes I agree that damping may be required in some cases, and that running the paddle at the surface would be best. That is how I set the paddle with the Townsend TT.
However, the application of damping should be a last resort. In my experience many folk have applied damping to cure a "resonance" that has resulted from poor set up eg VTA, tracking force, etc and could have been removed by careful set up and in the case of the ET tuning..
I have used electromagnetic damping on my ET2 as discussed earlier in this thread. The damping is created by eddy currents which are only generated when the arm moves relative to the magnet.
I have run the ET2 for 25 years and found that the higher compliance cartirdges such as my Shure V15vmr benefitted most from electromagnetic damping.
With lower compliance cartridges such as Madrigal Carnegie, Koetsu, Denon 103 and Benz Micro fluid damping slugs the sound in my experience. Bear in mind that I run a decoupled counterweight assembly rather than a sprung counterweight - this has the advantage of keeping the ET2 horizontal mass as low as possible. As your friend Frogman has found, running the counterweight decoupled has produced quicker, more transparent bottom end in his system.The set up procedure he described above is the same as I have used.
A little history here -
If you read Bruces manual and patents he starts with a low mass arm, and then brings the effective horizontal mass up very gently by providing variable spring rates on the decoupled counterweight. This is formulated to keep the differential resonances between horizontal and vertical in sync with the compliance of the cartridge and the Q of the system. The Q is related to the dampening of the oscillation - the use of magnetic dampening will shift this slightly. Very small adjustments can give quite dramatic changes to the sound, especially in speed, transparency and articulation.
Krebs approach has been to load up his ET2 with 30+ grams of lead. He has also removed the decoupling spring from the I beam. Effectively he has added some 60g to the horizontal mass of the ET2. It is no wonder that he has changed his mind after 20 years and is now using fluid damping. Mass increases inertia and has no dampening properties. The high horizontal mass he is running has increased the side forces on the cantilever by over 300% when the arm moves back and forth increasing cantilever flex and distortion.
Quote from Thigpen
I note that DGarretson has been experimenting with his Terminator tonearm. The Terminator in standard form has a much higher horizontal effective mass than the ET. DGarretson has reduced the horizontal mass quite substantially by reproducing some of the parts and yielded significant improvements.
Yes I agree that damping may be required in some cases, and that running the paddle at the surface would be best. That is how I set the paddle with the Townsend TT.
However, the application of damping should be a last resort. In my experience many folk have applied damping to cure a "resonance" that has resulted from poor set up eg VTA, tracking force, etc and could have been removed by careful set up and in the case of the ET tuning..
I have used electromagnetic damping on my ET2 as discussed earlier in this thread. The damping is created by eddy currents which are only generated when the arm moves relative to the magnet.
I have run the ET2 for 25 years and found that the higher compliance cartirdges such as my Shure V15vmr benefitted most from electromagnetic damping.
With lower compliance cartridges such as Madrigal Carnegie, Koetsu, Denon 103 and Benz Micro fluid damping slugs the sound in my experience. Bear in mind that I run a decoupled counterweight assembly rather than a sprung counterweight - this has the advantage of keeping the ET2 horizontal mass as low as possible. As your friend Frogman has found, running the counterweight decoupled has produced quicker, more transparent bottom end in his system.The set up procedure he described above is the same as I have used.
A little history here -
If you read Bruces manual and patents he starts with a low mass arm, and then brings the effective horizontal mass up very gently by providing variable spring rates on the decoupled counterweight. This is formulated to keep the differential resonances between horizontal and vertical in sync with the compliance of the cartridge and the Q of the system. The Q is related to the dampening of the oscillation - the use of magnetic dampening will shift this slightly. Very small adjustments can give quite dramatic changes to the sound, especially in speed, transparency and articulation.
Krebs approach has been to load up his ET2 with 30+ grams of lead. He has also removed the decoupling spring from the I beam. Effectively he has added some 60g to the horizontal mass of the ET2. It is no wonder that he has changed his mind after 20 years and is now using fluid damping. Mass increases inertia and has no dampening properties. The high horizontal mass he is running has increased the side forces on the cantilever by over 300% when the arm moves back and forth increasing cantilever flex and distortion.
Quote from Thigpen
If the weight is coupled the system resonant frequency would be extremely low, a resonant frequency at 3Hz with a significant rise in response (6-12dB) results, which would affect tracking slightly because of the asymmetric position of the cantilever, we opt for splitting the horizontal resonance frequency into two points and lowering the "Q" which improves tracking.
More important than tracking, the intent was to reduce the modulation effects of low frequency energy (FM and AM) that increase distortion in the cartridge
I note that DGarretson has been experimenting with his Terminator tonearm. The Terminator in standard form has a much higher horizontal effective mass than the ET. DGarretson has reduced the horizontal mass quite substantially by reproducing some of the parts and yielded significant improvements.