POSITIVE FEEDBACK ONLINE - ISSUE 33
as reviewed by Roger Gordon
Tonearms come in many different designs such as unipivot, gimbaled, linear tracking, etc. The armwands themselves come in different shapes such as J, S or straight with and without offset. Such a diversity of tonearm and armwand design can lead to much discussion as to the merits and demerits of particular designs. When vinyl lovers get together the topic of favored tonearm(s) and its related subject of tonearm design has a fair probability of arising. The probability of the design portion of the discussion and the heat of that discussion usually increases in direct proportion to the amount of alcohol ingested. One wise sage said that ‘all tonearms are a compromise between many variables. Thus, there can be no perfect tonearm’. In my experience, this is true. I have heard a lot of highly acclaimed tonearms over the years at the various audio shows and I have never heard one tonearm, regardless of cost, that consistently did everything better than any other tonearm. For most of us, the best we can hope for in our own systems is to have a tonearm that meets as many of our personal preferences as possible at a price we can afford.
In my own system I have two turntables, a Nakamichi TX-1000 direct drive with two arm boards and a Garrard 401 idler-wheel with three arm pods. Having space for five tonearms I, obviously, need five tonearms. Nature abhors a vacuum after all. Actually, though, all I really need is three tonearms. One tonearm for my mono cartridge so that I can play mono LPs whenever I want. A second for my stereo MC cartridges for playing my classical, vocal, and small ensemble LPs. And a third tonearm for my stereo MM cartridges for playing rock and soundtracks where dynamics and bass slam are more important than soundstaging and pin-point imaging.
The three tonearms that I own are a VPI 12.5, a Schröder Reference, and a Mørch DP-6. The VPI 12.5 is a 12" unipivot. It came with a used VPI TNT-V HR turntable that I had purchased. When I sold the turntable I kept the arm. The 12.5 is a good arm. There are thousands upon thousands of 12.5 arms being used so it is a convenient reference to use when comparing different tonearms. The 12.5 is also the ideal tonearm for doing cartridge reviews. The 12.5 armwand has the adjustments for vertical tracking force (VTF) and azimuth built into the removable armwand. Thus, if you have two armwands, each mounted with a different cartridge and each properly set up for VTF and azimuth, you can swap armwands and be ready to play a different cartridge in ten seconds. If you need to adjust VTA the 12.5 has a very simple to use VTA tower that can be used to rapidly dial in a specific height. So swapping cartridges is a 10-20 second affair even with VTA adjustments. Very nice. The only drawback to the 12.5 is that the armwands only have one effective weight—11.8 grams per an e-mail exchange with Mike at VPI. Thus, the 12.5 can only be used with low to medium compliance cartridges.
The Schröder tonearm is very different in design. The armwand is suspended by a single thread. On the bottom of the armwand opposite the thread is a powerful magnet which is attracted to another magnet set into the tonearm base just below the armwand magnet. By varying the gap between the two magnets you can control the damping of the arm. My Schröder Reference has a 9" jacoba armwand that has an effective mass of 12 grams which can be increased by using the heavier brass headshell rather than the standard, lighter aluminum headshell. The Schröder Reference is a easiest tonearm to set up that I have ever seen. The effective length is fixed—there are no slots in the headshell for moving the cartridge back and forth. You align the cartridge by rotating the body of the tonearm itself. You are changing the spindle to pivot distance rather than the overhang. Setting VTF, azimuth and anti-skating is equally as easy. While armwands for the Schröder tonearms come in different lengths and effective masses, you have to return the tonearm to the factory in order to switch armwands.
The Mørch DP-6 is a Dual Pivot tonearm, hence the DP in the model number. In the case of the DP-6 this means that there is an assembly of ball bearings that control the horizontal movement and two pivoted sapphire bearings that control the vertical movement. The sapphire bearings are right on top of the horizontal bearing assembly so that the vertical and horizontal pivot points are essentially the same. This pivot point is located at the same height as the playing surface of the LP. Locating the pivot point at this level effectively eliminates warp wow from slightly to moderately warped LPs.
Unlike the VPI and Schröder tonearms which have adjustable VTA on the fly, the Mørch tonearms do not. The Mørch tonearms are mounted via a central column like Rega/Origin Live tonearms. VTA is changed by loosening a grub screw and manually moving the column up or down and then retightening the grub screw. This is neither quick nor is it possible to accurately repeat a VTA setting at a later date.
What the DP-6 does have, that the VPI and Schröder don’t have, is interchangeable armwands in four effective masses (4gm, 6gm, 8gm and 14gm) and in two lengths (9" and 12")—eight arms in total. Unlike the VPI 12.5 armwand, the Mørch armwands are nothing more than an armwand. Setting VTF and azimuth is done using the tonearm base. There is nothing to adjust on the armwand except overhang. This lack of adjustment is good because it does keep the cost of the armwands down ($400 for 9" and $550 for 12" Mørch armwands versus $1300 for a VPI 12.5 armwand).(1) The downside is that when you switch armwands you have to reset VTF and azimuth. Thus, switching the Mørch armwands takes minutes not seconds.
The effective mass of the armwand you buy is dictated by the weight and compliance of the cartridge(s) that you plan to mount on the armwand.(2) Whether you buy a 9" or a 12" arm may be dictated by the size of your turntable. Many turntables do not have the room required to mount a 12" tonearm. However, if you can mount either a 9" or a 12" arm which should you choose? There are a number of advantages to a 12" arm over a shorter arm with two primary advantages. The first primary advantage of the longer armwand is that the arc that the stylus makes as it plays across the LP is flatter. A linear tracking arm has no tracking distortion because the stylus is always tangential to the grooves of the LP. A linear tracking arm is essentially a pivoted arm with infinite length. As the length of the pivoted arm shortens, tracking distortion appears since the stylus is no longer tangential to the LP grooves except at zero, one, or two null points depending on the alignment geometry chosen. The commonly used Baerwald and Lofgren alignments do generate two null points—points where the stylus is tangential to the LP groove and tracking distortion is zero. A12" arm does have less tracking distortion than a 9" arm by virtue of its additional length. The second advantage of a longer armwand is that it is less affected by record warps. An armwand that is only 1" in length going over a 1/4" vertical warp moves through a much larger arc than a 12" armwand going over the same warp.(3) While there are advantages to longer tonearms, there are also disadvantages. Longer armwands, if they are to have the same effective mass, must have thinner walls which makes them less strong and thus, more prone to vibrate. Frank Schröder, of Schröder Tonearms, discourages his customers from buying armwands longer than 10" because he says the advantages of less tracking distortion and less susceptibility to LP warps of the longer armwand is more than negated by the extra vibrations and resonances caused by the extra length. There is no such thing as a free lunch. On the other hand, the word on some of the vinyl forums is that certain 12" arms do sound better than their shorter brothers. The word on the Mørch arms is that the 12" armwands do sound better than the 9" armwands all other things being equal. However, I have seen nothing written by someone that has done A-B comparisons between 9" and 12" Mørch armwands of the same effective mass. Caveat Emptor. I had not read the buzz about 12" Mørch armwands sounding better than the 9" arms when I bought my DP-6. I bought the DP-6 with a 12" 14gr armwand because a longer armwand was a better fit for the plinth of my Garrard 401 and 14gr was a good match for my low compliance MC cartridges. Later, when I decided I wanted to experiment with high compliance MM cartridges I bought a 12" 6gr armwand.
So how does the Mørch DP-6 with 12" armwand stack up against the VPI 12.5 and the Schröder Reference? In order to find out I mounted Audio-Technica OC9/II MC cartridges on each of my three tonearms. I had envisioned doing tonearm reviews when I designed the plinth for my Garrard 401 and had purchased three OC9/II cartridges from the same lot.(4) With the help of two friends I broke-in these three cartridges and had them on-hand for this review. Thus, the only variables in the comparisons were the tonearms themselves, the armpods the tonearms were mounted on, and the phono cables used. The VPI and Schröder arms are surface mounted. They were both mounted on top of identical 8.2kg brass columns. Because the Mørch is mounted via a central column I had purchased a surplus armboard from Teres Audio and had them install one of their VTA Adapters (http://www.teresaudio.com/vta.html) in the arm board (see photo below). The Teres armboard, which is made of purpleheart wood, was mounted on top of a shorter brass column weighing 6.4kg.
Because of design differences different phono cables also had to be used. The VPI 12.5 has a terminal block at the base of the tonearm that has two female RCA plugs. The Schröder has a captive phono cable, cryoed Nordost Valhalla, terminated in male Eichmann RCA Bullet Plugs. The Mørch has a 5 pin female DIN connector located inside the central mounting column. The Mørch came supplied with a TCI Viper phono cable with a 5 pin DIN connector at one end and male RCAs and a ground wire at the other end. The VPI 12.5 was connected to the phonestage via a .5 meter phono cable from Bent Audio which has a junction box in the middle with a pair of binding posts for the loading resistors. The Schröder and Mørch tonearms could have been plugged directly into the phonostage. However, to provide proper loading a 1 meter DIY cable made with silver wire with a junction box in the middle with binding posts for the loading resistors was placed between the Schröder and Viper cables and the phonostage.
Once everything was set up (5) I listened first to the VPI 12.5 versus the Mørch and then to the Mørch versus the Schröder. The LPs that I listened to were:
VPI 12.5 versus Mørch
Bird on the Wire - With the Mørch the initial transients were sharper while the VPI’s were slightly rounded-off in comparison. The bass that sings in the background came out more clearly and slightly louder with the Mørch. Normally this difference can be caused by VTA not being properly set. However, this is the track that I used previously for setting VTA on all three tonearms. VTA had been set for the best balance between the openess and naturalness of Jennifer Warnes voice and the loudness without bloating of the bass singer’s voice.
About a Girl - With the Mørch the sound seem to be a little bit clearer, there was a little bit more texture to Kurt Cobain’s voice. Also, with the Mørch, the bass guitar came across with more authority. The VPI sounded slightly darker in comparison to the Mørch with regards to overall tone.
Three Cornered Hat - The Mørch sounded slightly clearer with a little more detail coming through. Also, with the Mørch the soprano’s voice was fuller and the strings had a slightly warmer, richer tone to them.
Pinball Wizard - With the Mørch the initial transients were more clearly delineated and there was slightly more detail; i.e. there was more of the subtle sounds of Townshend’s fingers on the strings of his acoustic guitar. The VPI again sounded slightly darker in comparison to the overall tone of the Mørch.
St. James Infirmary - Again the Mørch was slightly clearer with the words of the vocal coming through a little more distinctly. The sound of the Mørch just seemed to be richer, fuller, more natural. With the Mørch, the musicians weren’t in the room with me, but they were much closer than with the VPI 12.5.
Mørch versus Schröder
Bird on the Wire - With the Schröder there was a lot more subtle detail. You could now hear the skin of the drum when it was hit, there was more bass. The whole presentation was smoother and more effortless.
About a Girl - The Mørch was not as good as the Schröder at digging out the subtle details of fingers on guitar strings or or textures of voice. With the Mørch, the sound was also a little bit thinner, not as rich and lush as with the Schröder. However, on this type of music, being a little raw is actually good.
Three Cornered Hat - The Schröder clearly had more hall sound. The handclaps with the Schröder were more explosive. The string tone was smoother and richer. In fact, all of the instruments just sounded more like the real thing.
Pinball Wizard - With the Schröder there was significantly more of the subtle sounds of Townshend’s fingers on the strings of his guitar. The initial transients were sharper. Townshend’s voice and his guitar sounded more natural, more relaxed, more effortless.
St. James Infirmary - On this recording, which is a superb recording sound and performance-wise, the Schröder really showed why it is a world class tonearm. There was a naturalness, an effortlessness to the music that made it sound so real. I played the clarinet for a number of years. The clarinet coming out of the left speaker sounded just like what I remember a real clarinet to sound like. I don’t hear that realness from many systems. I did not get that same feeling of naturalness or realness from the Mørch. The sound was very nice, but Louie and the boys were not playing in the same room with me with the Mørch—they were with the Schröder.
In comparison to the VPI 12.5 the Mørch was a clear winner. With the Mørch leading transients were sharper, with more impact. The Mørch provided more inner detail and allowed you to see deeper into the performance. There was also more low frequency energy with the Mørch. In overall presentation the VPI 12.5 sounded a little bit darker than the Mørch. Both tonearms were musical, but the Mørch brought you closer to the music.
Against the Schröder, the Mørch was not as good at pulling out the inner detail. It did not show the refinement, the smoothness of the Schröder. Music flowed effortlessly from the Schröder, less so from the Mørch. The Mørch was musical, but it did not have the same level of realism as the Schröder.
Based on this comparison and my living with the DP-6 for over a year I can say conclusively that the Mørch DP-6 is a very fine tonearm. It is clearly better in this test setting than the VPI 12.5 which is a tonearm that is highly thought of. The current version of the 12.5, the VPI 12.7, sells for $3,000. At a price of $2,100 with a chrome plated 9" and $2,250 with a chrome plated 12" armwand, you are getting quite a lot of value for the money with the DP-6. As fine a tonearm as the DP-6 is, it does fall short of the Schröder Reference. That is as it should be as the Schröder sells for over 2.5 times what the DP-6 12" sells for. Also, there is a 12-18 month wait for a Schröder while you can buy a DP-6 immediately. The fact that you can buy, fairly inexpensively, armwands with different effective masses is a real plus for those of us that have cartridges of different weights and compliances. If you are in the market for a tonearm in the $3000 range I would definitely put the DP-6 at the top of your audition list. Roger Gordon
(1) The prices for Mørch tonearms and armwands are based on the listed prices of the USA Moerch distributor which sells direct and not through dealers. See www.sorasound.com. The price for the VPI 12.5 armwand and VPI 12.7 tonearm comes from the VPI Industries website. See www.vpiindustries.com.
(2) There are a number of spreadsheets available on the web to help you calculate the resonant frequency of a cartridge/tonearm combination. Or you can use the following formula:
Resonant Frequency = 1/((2*3.14159) X (Square root of ( C X (A+M))))
where C = compliance of the cartridge. A compliance of 15 is entered as .000015. A compliance of 9 is entered as .000009.
where A is the effective mass of the tonearm in grams
where M is the mass of the cartridge plus mounting hardware in grams.
The resonant frequency should be between 8 and 12Hz.
(3) There is another advantage of longer armwands that may comes into play with certain types of tonearms. Tonearms that have their center of gravity below the pivot point change VTF as VTA (or the height of the pivot point above the LP surface) changes. The VPI 12.5 is one such arm. As an experiment I placed the stylus of my cartridge mounted on my VPI 12.5 on my electronic cartridge scale (accurate to 3 decimal places) and then turned the VTA tower knob. As I turned the knob the reading on the scale changed. Each complete revolution of the VTA knob changed VTF by .03 grams. This may not seem like much, but my Van den Hul cartridges have a recommended tracking force of 1.35 - 1.5 grams. Five turns of the tower knob moves the VTF completely out of the recommended range. The thread pitch in the VTA tower is very fine. Thus 5 revolutions is not that much—about 3/16ths of an inch. The weight change per revolution of the VTA knob increases as the length of the armwand decreases. Thus, the VTF of the VPI 10" tonearm changes even more with the same change in height and the VTF of the 9" VPI tonearm changes even more than the 10" arm.
(4) I did switch cartridges between the tonearms to see if that changed my impressions of the sonic differences between the tonearms. It did not. The cartridges sound virtually identical.
(5) Before the listening sessions began I experimented with VTA and VTF to arrive at what sounded to me to be the best settings. The AT OC9/II has a recommended tracking weight of 1.25 - 1.75gm. The VPI 12.5 sounded best at 1.80gm. The Schröder sounded best tracking at 1.60gm and the Mørch sounded best at 1.55grm