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主旨寄件者更新日期
回覆 (604): What is this??
Not 1PK ? @[email protected]  
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no. it is likely that we will have more than one that is PK.^-^
drwkng
10-11-30
13:55:30
回覆 (603): What is this??
ha! i'm sure we can design one called PR1 .  
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Not 1PK ? @[email protected]
daiwok
10-11-30
13:42:38
回覆 (602): What is this??
Agreed, it looks like a beef up and better looking version of the Airtech MG1, and both are low pressure design. I have no doubt daiwok can modify the MG1 with a short wand for similar performance ;-)  
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ha! i'm sure we can design one called PR1 .  
 
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Yes, Midas PR-1 has a nice ring to it...
jaspert
10-11-30
13:13:47
回覆 (601): What is this??
Agreed, it looks like a beef up and better looking version of the Airtech MG1, and both are low pressure design. I have no doubt daiwok can modify the MG1 with a short wand for similar performance ;-)  
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ha! i'm sure we can design one called PR1 .
drwkng
10-11-30
12:44:52
回覆 (600): What is this??
>Got some more info. I think it's made in Taiwan and will cost quite a bit more than a Phantom II.. Lust level just dropped to zero. <  
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Agreed, it looks like a beef up and better looking version of the Airtech MG1, and both are low pressure design. I have no doubt daiwok can modify the MG1 with a short wand for similar performance ;-)  
 
thekong
10-11-30
11:36:00
回覆 (599): What is this??
Got some more info. I think it's made in Taiwan and will cost quite a bit more than a Phantom II.. Lust level just dropped to zero.  
 
Trans-Fi T3 Pro any day...  
 
jaspert
10-11-30
11:21:51
回覆 (500): 四盤八臂十六頭
What a sight!  
You can't have too many tonearms..can you..:)
jaspert
10-11-30
11:19:41
回覆 (500): 四盤八臂十六頭
You make me itchy to get my Ortofon SPU Reference up and running @[email protected] I am still having fun with the various MIDAS on hands ^_*.
icefox
10-11-30
11:13:20
回覆 (500): 四盤八臂十六頭
Midas! Midas! Midas!
Vash
10-11-30
11:06:05
回覆 (499): 四盤八臂十六頭
icefox,  
 
this is for you !!  
 
I still have more artillery to come ^__^  
 
Photobucket  
 
Photobucket  
 
Photobucket  
 
Photobucket
daiwok
10-11-30
10:51:56
回覆 (599): What is this??
回覆 (598): What is this??  
Dear Jaspert, anymore info. for this beautiful tonearm setup ?  
 
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Vash,  
 
I have no other info at the moment. Got the pics from an email.  
On second look, i think the wiring could be better.
jaspert
10-11-30
08:59:09
回覆 (598): What is this??
Dear Jaspert, anymore info. for this beautiful tonearm setup ?  
 
Vash
10-11-30
04:24:55
回覆 (597): What is this??
Lust...  
 
 
Photobucket Pictures, Images and Photos  
 
Photobucket Pictures, Images and Photos  
 
Photobucket Pictures, Images and Photos
jaspert
10-11-29
22:47:31
回覆 (596): Moerh DP8
That's the point, I don't think the spring mass system can be a generalization of the pivot tonearm system.  
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this has nothing to do with any generalisation. it is just sloppines of those who use that terms.
drwkng
10-11-29
19:41:04
回覆 (595): Moerh DP8
There is even an Excel spreadsheet that you can play around with.
http://www.luckydog.demon.co.uk/images/EMC.xls
icefox
10-11-29
18:49:20
回覆 (594): Moerh DP8
but the effective mass is referring to the mass of the spring. not the mass of the whole structure. so i can't see how you can change the effective mass of the spring.  
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That's the point, I don't think the spring mass system can be a generalization of the pivot tonearm system.  
 
In fact, I run into this thread, http://www.vinylengine.com/phpBB2/viewtopic.php?t=24136&postdays=0&postorder=asc&start=195  
 
The talk about another model that is a balance about a pivot which seems to be a better generalization model. However, I can't really finish all 14 pages...... too bored. ^__*  
 
I guess in the end we will conclude, throw away all those rules, it's AGAIN an Asshole hitting Stick Saga........ there no guarantee. Use your common sense and have some luck!  
 
Good luck to all vinyl freaks!  
http://www.vinylengine.com/phpBB2/viewtopic.php?t=24136&postdays=0&postorder=asc&start=195
icefox
10-11-29
18:37:53
回覆 (594): Moerh DP8
so it does matter what you do to the counterweight, it would not change the effective mass of the spring.  
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should be  
 
so it does not matter what you do to the counterweight, it would not change the effective mass of the spring.
drwkng
10-11-29
18:09:09
回覆 (593): Moerh DP8
I think we are really dealing with a spring system in a tonearm/cartridge system, as the damper/suspension in the cartridge is actually some sort of a spring!  
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but the effective mass is referring to the mass of the spring. not the mass of the whole structure. so i can't see how you can change the effective mass of the spring. in the tone arm situation, i would have thought only the coupling between the stylus and shell bodY(if that is the right term) forms a flexible spring structure. the arm is not part of the spring structure. so it does matter what you do to the counterweight, it would not change the effective mass of the spring.
drwkng
10-11-29
18:05:54
回覆 (592): Moerh DP8
>But that Effective Mass on Wiki is for a Spring System<  
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I think we are really dealing with a spring system in a tonearm/cartridge system, as the damper/suspension in the cartridge is actually some sort of a spring!  
 
 
 
>effective mass of the tonearm, when combined to compliance of the cartridge  
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It looks like we are going down a really slippery slope and a big can of worms is opened. ^__^ fun part of discussion. <  
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The effective mass of the tonearm, by itself, is not really useful in this context. It is the combined effect (resonance frequency) of the tonearm's effective mass and the cartridge's complinace that we are after. That's why tonearm with high effective mass should mate with cartridge with low compliance, and vise versa.  
 
thekong
10-11-29
12:27:55
回覆 (591): Moerh DP8
effective mass of the tonearm, when combined to compliance of the cartridge  
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It looks like we are going down a really slippery slope and a big can of worms is opened. ^__^ fun part of discussion.  
 
Compliance is another concept that I am still figuring. Looking at the units to describe compliance cm/dyne (as print in the Denon 103 manual) is that a measurement of distance per unit of force (is dyne a smaller unit of Newton)?
icefox
10-11-29
11:55:54
回覆 (590): Moerh DP8
Well, take a look at the Wikipedia :-)  
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But that Effective Mass on Wiki is for a Spring System. I am not sure if we can use that to describe the pivot arm "system". Want some enlightenment too!!!  
 
On this document, http://www.moerch.dk/files/Cartridge%20Armtube%20Combination%20List.pdf , there is a formula to calculate Resonant Frequency, is this universal or just specific for the Moerch pivot arm system?  
 
 
 
icefox
10-11-29
11:50:06
回覆 (590): Moerh DP8
>what the hell does effective mass mean in this context?<  
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Dr. King,  
 
All I know is that the effective mass of the tonearm, when combined to compliance of the cartridge, would result in a resonance frequency. Ideally, this resonance frequency should be kept in the 8-12Hz range!  
 
I was told the effective mass, at least when we are talking about the tonearm, has to do with the weight of the total moving mass (armtubes, headshell, cartridge, and counterweight etc), and the distance between its center of gravity and the pivot!  
 
That probably doesn’t help much, but it is all I know :-(  
 
thekong
10-11-29
11:45:33
回覆 (589): Moerh DP8
Can I have the formula or mathematical expression for the vertical and horizontal effective mass. I want to get an appreciation of what are the parameters that affect this.  
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what the hell does effective mass mean in this context? can someone be so kind to enlight me?
drwkng
10-11-29
11:16:50
回覆 (589): Moerh DP8
>Can I have the formula or mathematical expression for the vertical and horizontal effective mass.<  
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Well, take a look at the Wikipedia :-)  
 
I have absolutely no idea on this, so you need to get confirmation from engineers like CP, Dr, King, and diawok :-)  
 
 
http://en.wikipedia.org/wiki/Effective_mass_(spring-mass_system)
thekong
10-11-29
11:10:45
回覆 (588): Moerh DP8
While most tonearm designers aimed for a relatively even horizontal and vertical effective mass in their designs (relatively easy for pivotal arms), there are a few exceptions, like the Dynavector DV507, which intentionally designed to have a much higher horizontal effective mass.  
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Can I have the formula or mathematical expression for the vertical and horizontal effective mass. I want to get an appreciation of what are the parameters that affect this.  
 
icefox
10-11-29
11:01:45
回覆 (588): Moerh DP8
>Sounds like the Moerch guy does not know his shit then.  
 
Take a look at this PDF, http://www.moerch.dk/files/Special%20about%2012%20inch%20armtubes.pdf .  
 
The last statement, "The sound image most likely will be best, if counterweights are adjusted with the center of gravity ABOVE the counterweight rod.  
 
I think you mean having the CG of the counterweight BELOW the rod would be better. <  
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I think we are talking about 2 different concepts here. What diawok has achieved using a smaller counter weight further away from the pivot is to increase the EFFECTIVE MASS of the arm.  
 
While by saying “if counterweights are adjusted with the center of gravity ABOVE the counterweight rod”, Moerch is talking about the CENTER OF GRAVITY. In my experience, many gimble bearing arms do benefit from using a counterweight with lower center of gravity. A lot of the aftermarket upgrade counterweights for the Rega 300 series arms have lower center of gravity. I have also used a custom drop weight for the FR64s with excellent result.  
 
However, the Moerch is a bit different, while most arms have their counterweight rods at the same level as the armtubes, the Moerch’s counterweight rod is already way lower than the armtube, so it already has low center of gravity built in. So, could it be that Moerch thinks the center of gravity could be “too low” if the counterweight is adjusted to have the center of gravity below the counterweight rod? I suppose, like many other things in audio, you just need to try it out to find the best combination!  
 
Interestingly, as I understand it, Graham (unipivot arms) has been using a low center of gravity system for their pervious arms, but switch to a neutral balance designed for their latest Phantom, where the center of gravity is at the same level of the pivot point,  
 
thekong
10-11-29
09:45:48
回覆 (587): Moerh DP8
>“Anisotropic because the effective mass for the horizontal mode of motion is many times larger than the effective mass for the vertical mode of motion - no matter the effective mass of the armtube used. This provides tremendous improvements in bass response and a lot more dynamics.”  
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That means all linear tracking arms must have no bass and no dynamics! <  
 
 
_____________________________________________________________  
 
Wait, shouldn't it be the other way around? If that statement is true, then all linear trackers should have excellent bass response and a lot of dynamics, as all of them have a much higher horizontal effective mass than vertical effective mass.  
 
While most tonearm designers aimed for a relatively even horizontal and vertical effective mass in their designs (relatively easy for pivotal arms), there are a few exceptions, like the Dynavector DV507, which intentionally designed to have a much higher horizontal effective mass.  
 
 
thekong
10-11-29
09:07:18
回覆 (586): Moerh DP8
Sounds like the Moerch guy does not know his shit then.  
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I would not go so far to say that ! but like most equipment including arms and carts, the manuals are written for 80 or even 90% of those Joe Bloggs the remaining itchy assholes like to tinker and experiment and apply some arm chair engineering to the thinking. You see the counter weights are designed to cater to a range of cartridges and not specifically for one particular cartridge - hence your performance is never truly optimised. To me an optimised arm is when the counter weight is right at the end of the tonearm to give it maximum inertia. Of course you could add weight to the the arm such as headshells or even a MIDAS TOUCH ^__* this will allow you to move the counter weight further back.  
 
The Artemis counterweight is in 2 halfs, separated by an o-ring and by turning the bottom half of the counter weight, one can tune the sound of the arm ! - very smart ^__^  
 
now if you apply the 80 / 20 theory to everything you have in hand you will find 80% percent of hi fi systems are setup to cater for the normal guy, by understanding the fundamentals you may end up optimising and maximising performance by focusing on the 20% and the return far exceeds the investment involved in upgrading in most cases. Try this theory with cartridge setup - what is written in the manual is a general rule not the bible ^__*
daiwok
10-11-28
22:55:05
回覆 (585): Moerh DP8
Sounds like the Moerch guy does not know his shit then.  
 
Take a look at this PDF, http://www.moerch.dk/files/Special%20about%2012%20inch%20armtubes.pdf .  
 
The last statement, "The sound image most likely will be best, if counterweights are adjusted with the center of gravity ABOVE the counterweight rod.  
 
I think you mean having the CG of the counterweight BELOW the rod would be better.  
icefox
10-11-28
21:14:19
回覆 (584): Moerh DP8
Sir CP makes a valid statement  
 
>That means all linear tracking arms must have no bass and no dynamics!<  
 
What simply the DP8 has achieved is increase the inertia on the arm - notice the drop of he counter weights on the side much lower that the wand.  
 
Like what I have demonstrated on the Moerch in the past, you can increase inertia by using only the smallest possible counter weight as far back as possible the increase in inertia on the arm which in return helps in dynamics in the arm.  
 
A recent observation which I made was listening to the Artemis arm by Frank Schroeder which also employs the same principle on the counter weights.  
 
daiwok
10-11-28
20:45:16
回覆 (583): Moerh DP8
 
 
“Anisotropic because the effective mass for the horizontal mode of motion is many times larger than the effective mass for the vertical mode of motion - no matter the effective mass of the armtube used. This provides tremendous improvements in bass response and a lot more dynamics.”  
________________________________________________________________________________________________  
 
That means all linear tracking arms must have no bass and no dynamics!  
 
 
 
cpsjj
10-11-28
19:48:28
回覆 (582): Moerh DP8
“Anisotropic because the effective mass for the horizontal mode of motion is many times larger than the effective mass for the vertical mode of motion - no matter the effective mass of the armtube used. This provides tremendous improvements in bass response and a lot more dynamics.”  
 
What does that mean? Is that marketing crap? daiwok, you seems to offer some setup tricks to achieve that "tremendous improvements in bass response and a lot more dynamics."  
 
icefox
10-11-28
18:30:34
回覆 (581): Moerh DP8
There is an official page now.
http://www.moerch.dk/DP8.htm
icefox
10-11-28
17:56:13
回覆 (580): Idler Wheel Turntables
group order for the newest PTP for "so many" coming up lenco fans?  
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Sure ! ^__^ the latest PTP is PTP4, I will post some images and photos later on what this is
daiwok
10-11-26
11:30:54
回覆 (579): Idler Wheel Turntables
>>>our friend abc2007 also has a Lenco now .....  
 
Dear daiwok, would u consider to arrange a group order for the newest PTP for "so many" coming up lenco fans?  
 
Vash
10-11-26
10:57:49
回覆 (578): Idler Wheel Turntables
 
Absolutely, Hans looks like a very sweet man! Reminds me a great deal of a 300 lbs biker buddy I know in Oakland (Dirk) that can easily mistaken as Hans' twin brother. During early 80s, we used to ride the "Harley Davidson Annual Toy Run" every year in different parts of the country along with few hundreds other Harley nuts to deliver toys for the less privilege children living in the suburbs (kinda like you bringing Lencos back to the kids in HK). Dirk always wore his Santa-Clause outfit (with leather chaps of course) and rode an open baffles Pan-head which made sound similar to a rattling jet engine, you could hear him coming miles away, the kids just went wild, one of their highlights every Christmas!  
 
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Kris,  
 
Cool pic and a nice deed you guys did.  
 
You must love this movie then.... ;)  
 
 
 
jaspert
10-11-25
19:28:43
回覆 (577): Idler Wheel Turntables
our friend abc2007 also has a Lenco now ^__*  
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daiwok, you are the man......... 又一個入邪教 ^__* ,善哉!
icefox
10-11-25
10:22:17
回覆 (577): Idler Wheel Turntables
 
 
 
 
 
 
you and Hans will get on superbly...........  
 
_____________________________________________________________________________________________________  
 
daiwok, welcome home!  
 
Absolutely, Hans looks like a very sweet man! Reminds me a great deal of a 300 lbs biker buddy I know in Oakland (Dirk) that can easily mistaken as Hans' twin brother. During early 80s, we used to ride the "Harley Davidson Annual Toy Run" every year in different parts of the country along with few hundreds other Harley nuts to deliver toys for the less privilege children living in the suburbs (kinda like you bringing Lancos back to the kids in HK). Dirk always wore his Santa-Clause outfit (with leather chaps of course) and rode an open baffles Pan-head which made sound similar to a rattling jet engine, you could hear him coming miles away, the kids just went wild, one of their highlights every Christmas!  
 
ps: Btw, I'm waiting anxiously for my X'mas treat from UK:-)  
 
Photobucket  
 
Photobucket  
kris
10-11-25
10:21:24
回覆 (576): Idler Wheel Turntables
diawok,  
 
Welcome back !  
 
Other than the Lencos, how many arms have you brought back? :-)  
 
thekong
10-11-25
09:44:06
回覆 (575): Idler Wheel Turntables
After living in exile for 2 weeks I am back !!!  
 
first thing I ate was Wonton Noodles ! its good be back to civilisation ..... I have more artillery now ^__^  
 
kong, icefox and Good Doctor - I have you Lencos ^__* my luggage weighed in at 102KG @[email protected]  
 
Master Kong, I also have your essential book ......"The Closest Approach"  
 
BTW - our friend abc2007 also has a Lenco now ^__*
daiwok
10-11-25
01:51:28