Thigpens' recommendations are that with records with an eccentricity of 1/8" a low mass pivoted arm will be superior. Dover this has been mentioned many times here and is documented in the ET2 manual. What I am curious about however is that at the time of printing of the original ET2 manual MM’s were in their heyday. MC’s became more popular later and BT adjusted with the 2.5. I am wondering if he was printing an update to his manual, if a heavier mass pivot over a lower mass one would be recommended for MC specifically. Any opinion ? Fwiw From my record collection there are idk maybe 150 -200 put aside – they can be seen on the ground in the pic of my listening room. These I listen to on a regular basis. From this group there is only one record I am aware of that falls in that range of 1/8 inch. This record happens to be one of my wife’s favorites and I use it to ....entice her into the room :^) My solution to this oddball record was to drill out the hole and spend 30 seconds centering it with my DIY center weight seen here. http://cgim.audiogon.com/i/vs/i/f/1366423048.jpgThe pressure points are on the outside and there is a washer underneath. Actually various size washers can be used as needed. Mostly however my records are in good shape warp and off center hole wise (meaning not visually noticeable). Cheers |
ct0517 wrote: " Does the wiring on the Terminator play a role in damping (stabilizing) the stylus?"
It may do so, but not by design. If not carefully dressed between the gantry and the wand, the tonearm wires have the greater potential to do harm by fouling the wand's free movement. The torque effect is exacerbated with a five-wire balanced harness. To minimize torqueing, one of these days soon I'm going to try making a harness with very light-gauge AN silver wire. |
Chris
Am I up and running?
Yes and no. I have a loaner compressor, so I have music but it is very noisy and does not pass your stylus on a stationary record test.
I will do the compliant CW arm and spring test once the proper compressor arrives.
I have been thinking about making a longer fixed counterweight rod. The current one is around the same length as original. The issue is making it stiff enough, not easy with conventional materials. |
Dgarretson - If not carefully dressed between the gantry and the wand, the tonearm wires have the greater potential to do harm by fouling the wand's free movement. DG - I will make sure the petition of names to the cartridge makers for a wireless cartridge makes it to your house too :^) Thanks for the info |
RK - but it is very noisy and does not pass your stylus on a stationary record test. ...the old dreaded stylus on a stationary record test with the system volume knob cranked to hear turbulence and hum test..... Air Bearing linear trackers everywhere that depend on clean consistent air delivery cringe at the thought of owners subjecting them to this test. Its bad enough if they have not been set up to operate in a straight line evenly. But being subjected to a partner pump that is not so great is un-imaginable. Some of the worst arm/pump relationships I have heard of don't even relate to the quality of the pump itself but its placement. There are some owners in the southern US where winter does not exist. These owners place compressors in their garage (not climate controlled) with a long line going to where their stereo is in a nice climate controlled room kept at 72 degrees F. The garage where the compressors starts air delivery can be anywhere from 30-40 F in the winter at night to well over 150 degrees inside the closed barn on a hot summer day with wildly differing humidity. Imagine the changes to the air as it travels down 100 feet of tubing. RK - I will do the compliant CW arm and spring test once the proper compressor arrives. I look forward to your impressions Richard. |
I recently purchased a ET2 and now need to get it mounted on my VPI classic. A friend gave me the actual jig used by ET, unfortunately it is missing the bushing to drill the mounting hole. I'll take my time and get this right the first time. I hope.
Tim |
Hi Tim
Congrats on the ET2.
Please let us know how you make out.
A number of folks here with many years experience with the ET2 & ET2.5 to help out if any questions.
There are also measurements on page 63 of the online manual on Bruce' website. from looking at the online diagram for the mounting hole.
1) From the middle of the spindle go out 8.258 inches (209.753) millimeters anywhere on the plinth that works for you and mark the spot.
2) Draw a straight line from the middle of spindle to this marked spot.
3) Go up 90 degrees from this line .885 inches (22.479 millimeters)
Mark the spot - that's where the mounting hole goes.
Welcome to the thread.
Cheers Chris |
Thanks Chris,
I talked with Bruce today and put in an order for the missing bushing,magnesium arm,and high pressure manifold.
I will keep posting my progress.
Tim |
Random Included Record Angles When they Make Records You play a couple of records from your collection that are the same thickness. They sound different for some reason ? One might be brighter, the other a little warmer and full ? This was not something I took much notice of many years ago with a very basic TT and tonearm. But as the TT and tonearm got better it became more noticeable. We hear about how engineers in creating the master disc put their spin on how the records will sound. But how about the physics part of it. In addition to the final engineering differences record masters are cut with random included angles by the cutter. The angle of the cut when the record master is made. http://www.aardvarkmastering.com/riaa.htmfrom the site Recording Groove Contour
a. Included angle 90 degrees + 5
b. Bottom radius 0.00025" max.
c. Width--Monophonic .0022"--.0032"
d. Width--Stereophonic, Instantaneous .001" min.
Minimum Inside Diameter of Recording 4 1/4"
Runout of Recording Grooves Relative to Center Hole .050" max. Notice the record included cut angle standard that was set can be 90 degrees give or take 5 degrees....:^( So there is no standard. This is also captured in the ET2 manual and has been mentioned before. Bruce realized the importance of this and the reason he built into his arm VTA on the Fly that does not change parameters when used. Vertical Tracking Angle Adjustment (VTA) - Page 51 ET2 Pt. 2 manual "Several articles have appeared which address the area of cartridge performance. Vertical Tracking Angle (VTA) and Stylus Rake Angle (SRA). We have designed the Model 2 tonearm to optimize the vertical tracking angle of the cartridge.
The angle that the cutterhead is placed at when a record is cut results in an included angle in the final disc. This included angle must be duplicated with the reproducing stylus or distortion will result. The problem today lies in standardization of the angle by record manufacturers and corresponding standardization by cartridge manufacturers. Presently most records are cut with resulting vertical angles between 16 and 20 degrees. The average vertical angles of cartridges manufactured today is slightly higher than 22 degrees. The result of this mismatch is less than optimum performance for many cartridges." Maybe those that use scopes should be pointing the camera - down - to the groove to try to figure out what angle has been used ? Some ET2 owners I have talked to have locked down (tightened the screws controlling the VTA feature) to make it more rigid? fwiw - I have sent an email to a couple record pressing plants as I am curious what determines what angle they cut at. Is it based on temperature, record thickness, condition of stylus cutter ? Will post back what they say ...if they respond. How important is the VTA adjustment to you ? |
Great topic! VTA adjustment on the fly is, for me, THE most important feature of the ET2. I find it invaluable and use it all the time. The benefits for me have to do with fine tuning tonality, timbre, and the integration of the uppermost frequencies with the lower highs (sibilance, among other things) and the transition-range between the midrange and upper bass. I have not found (maybe simply don't care as much) dramatic changes in soundstaging due to different VTA settings as some have reported. Azimuth adjustment (also relatively easy with the ET) does make significant changes to soundstaging in my set-up.
Re the locking down of the screws that tighten the VTA feature: I feel that too much torque at ANY of the ET2's screws is a bad thing. I think the arm simply sounds better with moderate and similar torque at all the screws. I adjust the VTA adjustment screws so that the adjustment can still be made without loosening the screws; but with some effort. So, to make sure I am not stripping anything, I simply loosen the screws about a 1/4 (or less) turn, adjust, and re-tighten; just a couple of extra seconds for the procedure. |
09-16-13: Ct0517
Random Included Record Angles When they Make Records
...record masters are cut with random included angles by the cutter. The angle of the cut when the record master is made.
Recording Groove Contour
a. Included angle 90 degrees + 5
b. Bottom radius 0.00025" max.
c. Width--Monophonic .0022"--.0032"
d. Width--Stereophonic, Instantaneous .001" min.
Minimum Inside Diameter of Recording 4 1/4"
Runout of Recording Grooves Relative to Center Hole .050" max.
Notice the record included cut angle standard that was set can be 90 degrees give or take 5 degrees....:^(
So there is no standard.
The angle that the cutterhead is placed at when a record is cut results in an included angle in the final disc. This included angle must be duplicated with the reproducing stylus or distortion will result.
The problem today lies in standardization of the angle by record manufacturers and corresponding standardization by cartridge manufacturers. Presently most records are cut with resulting vertical angles between 16 and 20 degrees. The average vertical angles of cartridges manufactured today is slightly higher than 22 degrees. The result of this mismatch is less than optimum performance for many cartridges."
How important is the VTA adjustment to you ? 1. The "included angle" has nothing to do with VTA. The included angle of 90 degrees is the angle between the 2 45 degree walls of the groove. ( 45+45=90 ). In theory if the cutterhead is set up with an error of say 5 degree in the "included angle" then you would possibly need to adjust azimuth. 2. One of the fundamental problems is that the cutter moves in a fixed plane, whereas the stylus moves in an arc about the cantilever pivot, and therefore all cartridges with a conventional cantilever produce distortion. The notable exceptions are the Decca London Cartridges and the original Ikeda cartridges both of which do not have cantilevers and therefore these are the only cartridges that do not have this distortion built in. I own the Ikeda and have personally set up around 20 Decca's over the years. The speed, lower distortion and lack of phase and time smear with these cartridges is superior to anything else for the reasons outlined in the 1st sentence of this paragraph. 3. Cutterhead angles are a minefield as they varied historically over the years and different cutting lathes were set up with different cutting angles. There was a standardisation of sorts in the 60's but bear in mind the US settled on 15 degrees +-5 degrees and the Europeans settled on 20 degrees +-5 degrees. The actual cutting angle used would also depend on how the engineer sets the equipment up and that is unpredictable. Springback is a common problem when cutting and this will alter depending on the composition and quality of the lacquers used ( they are soft ). Temperature is a big factor and if the lacquers have been stored at room temperature, as opposed to the recommended cool room temperatures, then often engineers would alter the cutting angle to get a clean cut due to the changing properties of the lacquers at different temperatures. A few points to note : Increasing the room temperature by 5 degrees F or approx 3 degrees C will lower the tracking angle by approx 1 degree. Increasing the tracking weight by 0.1g will result in a lowering of the tracking angle by approx 1.5 degree A spherical stylus profile will help to reduce these distortions in points 2 & 3 above. If you add lead mass to the ET2 and remove the decoupled counterweight, as suggested earlier in this thread, then VTA doesn't matter as the increased distortion from a tracking angle error of +-5 degrees is almost certainly significantly less than the distortions introduced by the addition of lead mass and removal of the decoupled counterweight. For ET2 aficionados, with a conventional cartridge that uses a cantilever, the combination of tangential tracking and a spherical stylus would minimise distortions due to VTA issues. I have run the Denon 103 which although not the ultimate in transparency, produced very good timing and coherence. The EMT TSD15 with spherical tip option would be an interesting cartridge to try. |
Frogman - I think the arm simply sounds better with moderate and similar torque at all the screws. I adjust the VTA adjustment screws so that the adjustment can still be made without loosening the screws; but with some effort Based on the years with mine I think this is really good advice Frogman. Frogman - VTA adjustment on the fly is, for me, THE most important feature of the ET2. I find it invaluable and use it all the time. I agree plus the fact it tracks in a straightline. In the early days I was trying to figure the arm out and did not even notice how Bruce designed the VTA system in the ET2. I was ignorant to it. How many ET2 owners are not aware (or take it for granted, not notice) that the VTA system is on a gearing system? The ET2 VTA cylinder mechanism (for lack of a better word) pulls the armtube in as you raise VTA and back out when you lower VTA. So it maintains the VTF and alignment. I just tried this again with my Dynavector tonearm the other day. Lowering VTA increases VTF. Raising VTA lowers VTF. Some are really anal about how they set VTF on their tonearms. Just be aware you are affecting your VTF. |
Dover The "included angle" has nothing to do with VTA Cutterhead angles are a minefield as they varied historically over the years and different cutting lathes were set up with different cutting angles. There was a standardisation of sorts in the 60's but bear in mind the US settled on 15 degrees +-5 degrees and the Europeans settled on 20 degrees +-5 degrees.
The actual cutting angle used would also depend on how the engineer sets the equipment up and that is unpredictable. Springback is a common problem when cutting and this will alter depending on the composition and quality of the lacquers used ( they are soft ).
Temperature is a big factor and if the lacquers have been stored at room temperature, as opposed to the recommended cool room temperatures, then often engineers would alter the cutting angle to get a clean cut due to the changing properties of the lacquers at different temperatures. first statement is true on its own. but in the data that you provided especially the last sentence - "engineers would alter the cutting angle to get a clean cut due to the changing properties of the lacquers at different temperatures" With the ET2 VTA system angle changes can be corrected without affecting VTF and alignment - see previous post. this is also documented in the manual. This is what I was referring to. Dover when you say Increasing the room temperature by 5 degrees F or approx 3 degrees C will lower the tracking angle by approx 1 degree. Lets say we have a situation where the room is left alone to go up in temperature. So the sound will become more warm and full bodied - less treble brightness - as you have lowered the tracking angle ? Is this because of warmer plastic (record) ? Can this explain why the music can sweeter (warmer) toward the end of a session? |
Ct0517..
Increasing the room temperature by 5 degrees F ( 3 C ) is enough to soften the rubber suspension in the cartridge and drop the VTA by 1 degree.
I would assume by the time you have finished a session you will have softened up the suspension and this may explain some of what you hear.
Where you live it is quite easy to experiment - start with a cold room and warm it up, or put a lamp over the cartridge so the heat is localised. You will hear quite a difference - as the cartridge reaches optimum temperature the sound opens up and becomes more natural, as you overheat the cartridge the sound will literally go gluggy. What I have experienced is some cartridges mistrack on a seasonal basis (winter vs summer) here in NZ even though the temperature swings are not large, eg the Shelters. The Benz's generally spec out the optimum temperature and humidity ranges in their cartridge packaging. |
Dover - in the winter the OTL's are enough to keep my room at the temp it started at - heating vents closed. The last couple summer months with the door/windows closed in my basement room the temp will go up 1 degree every hour. The OTL's are like two 50 inch plasma tv's as far as heat out put goes. With the door or window open this drops by half - 1 degree every two hours. |
The last couple summer months with the door/windows closed in my basement room the temp will go up 1 degree every hour. forgot to mention this is with the AC turned off. with it on having your room in the basement pays off. cold air sinks down from rest of the house. |
Just got mine up and running! This is a very big change from the stock Classic arm. Took some time to find a compressor and build a surge tank, but well worth it.
Tim |
Hi Tim This is a very big change A comment with a certain amount of suspense attached to it. :^) Please do share impressions with us once you have had enough listening time. Cheers |
Just getting started. Much better on the soundstage. More balanced and smoother on the highs.
Tim |
Hi Tim - thanks for the impressions. I look forward to learning from your experiences. Are you familiar with our celebrity Acutex 420 str cartridge? http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1325551242&openflup&316&4#316It has been waiting in the wings with me for some time now. I had thought the next recipient would on the other side of the world - downunder - but I have not heard back yet ? I am aware of four separate ET2, ET2.5 projects right now. All in North America. Three in the US and one in Canada. If I had to put money on it - it appears the cartridge will be crossing the border again. Once you are established in your setup let us know if you would like to listen to this cartridge and provide a short review for us here. The only requirement is you ship it back within 3 months so it can go to the next person. This offer is open to any ET2 user. Cheers |
Thanks for the offer. I will work on the arm for a while and let you know. I still have only 2 or 3 hours on it! Home life has been a bit buzy.
Tim |
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Yeah, I picked it up. Didn't realize the carbon arm, but I really wanted the jig. This is my third. |
Manitunc.
Hi, if you are interested in on selling the arm without the jig, I would be interested.
please let me know.
thanks
Richard. |
Hi Richardkrebs,
I was anticipating the presentation to the forum of your new arm which you were intending to build. Are you having second thoughts ? |
You can get new arms from ET. I just bought one from Bruce a couple weeks ago.
Tim |
Second thoughts....nope. I only want the mag wand and the sleeve/spindle. All other parts would be discarded. |
Nah, I like them too much |
Manitunc.
Thanks for that. I thought that you would want to keep it, but it was worth a shot.
Cheers. |
Hi Richardkrebs 10-03-13: Richardkrebs
Second thoughts....nope. I only want the mag wand and the sleeve/spindle. All other parts would be discarded. I imagine it might be a bit challenging producing these parts for a DIY enthusiast. Given you have access to CNC machines and a fully qualified engineer at your workplace who could design something for you, it surprises me given your criticisms of the ET design in this thread. There are companies that can design and fabricate these components for you. Here is a link to a company that could do the engineering design and fabrication... http://www.dovermotion.comCheers |
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Yeah, I have 3. Or will have when it gets here, one for the lenco ptp, sp10 and then maybe the empire 208.
Cool air supply though. |
It looks like the arm is the magnesium version. Isnt that what came with the 2.5? Is there any other way to tell? |
You can put a Mag wand on an ET2 or a ET2.5. The gooseneck - the joint part that connects the wand to the spindle is the same design for both allowing for this to happen. One of the dark secrets - imo - for ET2, ET2.5 owners is why Bruce never bothered to put a ET 2.5 label on the ET 2.5 manifolds. They all say 2.0. It makes it very confusing because when looking at pictures themselves, the part you see - the spindle - it is impossible to tell. Its like an illusion. But when comparing the ET 2.0 and ET 2.5 in person it is very obvious. The ET 2.5 is bigger in diameter. The actual diameter measurements are published here "somewhere" . 5/8 inch rings a bell but not sure. or does the spindle look like this ? http://cgim.audiogon.com/i/vs/i/f/1366417696.jpgManitunc - Please compare with your others and let us know. You may have an ET 2.5 on your hands. Cheers |
As Chris says, it's difficult to tell the 2 spindle from the 2.5; but not impossible. I can usually tell when it's a 2.5. Look at the diameter of the spindle in relation to the diameter of the arm wand. In photos, the 2 spindle usually looks to be about the same or slightly larger in diameter as the original aluminum arm wand or smaller than the magnesium. The 2.5 spindle clearly looks wider than the original wand and about the same or slightly larger than the mag. Based on the pic in the ebay link, I believe Manitunc has a 2.
BTW, there seem to be two different magnesium wands. Mine (I bought it years ago right after Bruce started making them) does not have the "step" in it's diameter toward the rear of the arm. |
Yeah, its the step that suggests to me its a magnesium arm, but it should arrive today, so I will check. That being said, is there any other difference between a 2 and a 2.5 than the spindle or manifold size? |
I have no direct experience with the 2.5, but my understanding is that the larger diameter spindle also has a tighter gap between it and the manifold's interior creating a stiffer bearing. Chris can give you a much better description. |
to my knowledge other than the different larger 2.5 spindle
all other changes are "under the hood" in support of it.
The I beam/leaf spring and lead weights;
and the different armwands are interchangeable between 2.0 and 2.5 |
I think I've got the 2.0 with the magnesium arm. All my spindles are the same size |
"All my spindles are the same size" maybe they are all 2.5's manitunc? :^) my ET 2.0 spindle appears to be about 5/8 inch. The 2.5 is about 3/4 inch. Here is a picture of the inside that ketchup was nice enough to post earlier on. http://i272.photobucket.com/albums/jj177/picswamp/20121124_150329s_zps44708d12.jpgIf you push yours out you can see the condition of it and determine if it needs cleaning. Bruce used to put the initials HP on 2.0 and 2.5 manifolds to indicate high pressure versions. |
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You now have ET2 triplets Manitunc - impressive. |
Yeah, I am now looking into creating an air supply system to run all 3 off a single supply. I intend to include separate filters for each arm and central water collection off the surge tank. I have a medical grade air pump, but I could just use my Wisas, either alone or parallel into the surge tank. I need to get a better guage and regulator to try playing with different air pressures. right now I only have one running, on the PTP Lenco L75 along with a Helius Aurora 10". I need to go back through this thread one evening to remind myself of the various tweaks others have found helpful. |
Manitunc.
Sounds like you are going to build a shop air supply. Cool.
Don't forget to earth the air lines close to the arm. Don't know if you would need 3 earth lines or just 1. Suspect 1 would be best.
What pressure do the Wisas run into the arms?
thanks |
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yeah, saw the ad. My system has enough going on without adding a step down transformer. |
Manitunc - did a damping trough come with any of your three ET2's ? |
What effect does the damping trough have on the arm?
Does Bruce still sell them?
Tim |
Was told that "troughs" are no longer available.
Sent my ET-2 in for upgrades which should be ready in few weeks.
Wonder if we get enough people together to make a group purchase that Bruce may make them available once again.
Anyone interested ?
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