Daily Blog – John E. Johnson, Jr. – July 30, 2008: AN ADDITIONAL REFERENCE TURNTABLE IN OUR LAB.

The VPI HR-X turntable arrived, and I installed it in our lab over the weekend. Here is a photo.

This turntable is very large and is extremely heavy (the platter alone is about 25 pounds), so I have ordered a 2″ thick platform to place on top of the welded steel rack which will give me a few more inches of depth. THe HR-X is hand-made, with each component lathed to fit that individual turntable. Although using a 12″ tonearm does not usually require an anti-skate mechanism, I had one installed on the turntable so I could experiment with it and measure the results on our Audio Precision test instrument. At $13,600 this fully tricked out HR-X should give me a lifetime of listening fun.

The McIntosh MT10 turntable will be used to compare various cartridges that we review (our Manley Steelhead phono preamp has three inputs, so I can simply switch back and forth between cartridges as both turntables are playing). The cartridge in the MT10 is also MC, and it will be the reference because of its fantastic sound quality, and I will put review cartridges in the HR-X. A second reason the MT10 will be the reference is that the turntable, tonearm, and cartridge were designed as a unit by Clearaudio. This means that everything was matched in the design stage to work together, whereas with most turntables, you just choose a cartridge to go with it, or, if a cartridge is supplied, it is not necessarily one that the turntable was specifically designed for. (I have already found some interesting things comparing the Blackbird to the MT10 cartridge, and will discuss them in our Vinyl vs. CD series.)

The tonearm rests on a very sharp pivot point rather than moving on a gimbal joint, so there is virtually no friction as the arm moves up or down or side to side. Thus, when I installed the Sumiko Blackbird cartridge (MC, $799, compliance 12, mass 9.6 grams, tracking force 2 grams), the arm tended to tilt to the left as shown below (look at the rear of the tonearm).

To correct this, I adjusted the “lateral tracking angle” by rotating the tonearm counterweight, pointed out by the arrow in the photo below. The counterweight is oval shaped so that when you rotate it, additional weight is placed on one side or the other, depending on which way it is rotated. I then had to recheck the tracking force, just to make sure it remained at 2 grams.

This eliminated the tilt, such that the cartridge was now horizontally level with respect to the surface of the platter, as shown in the photo below (the cartridge is mounted with an angle to the left so that it is tangential to the grooves, which is the “azimuth” adjustment).

I am using the HR-X turntable for the discussion of three phono preamps in the next installment of our Vinyl vs. CD article series tro be pubished shortly.

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