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setting azimuth on VPI turntables

I purchased a VPI Scoutmaster a few weeks ago, being unenthusiatic over the sound, I was considering selling up until last night.

I had been over cartridge setup for this table a number of times, getting overhang, alignment, azimuth, VTF, and VTA just right. Still, things were not sounding all that good.

I had previously purchased the Fremer DVD so I did know about setting up this table optimally. I surmised the rod method of setting azimuth, as instructed in the VPI manual, was not optimal and part of the culprit in non-involving sound.

I finally got around to purchasing a DMM with a low enough AC voltage scale the other day. After much trial and error I finally got a crosstalk differential of less than 1%, a miracle with this setup. Setting azimuth on this table is a real PITA, everytime I got azimuth within specs, VTF went out of balance.

Eventually I got it right, the payoff in sound was way big time! Center image is now 'locked in', way more solid and dimensional. Images are also now floating free of the physical speaker, spaciousness, air in spades, a much more organic sound.

Having heard some complain about this table's uninvolving nature and lack of musicality prompted me to post this thread. I suspect many have not had their table set up correctly, because I certainly heard what they were talking about prior to getting azimuth 'locked in'. VPI owners, it is absolutely necessary to set azimuth electronically, the rod method in not nearly good enough! Get a proper DMM or get someone knowledgable to set up your table, you just might be in for a big surprise!

Vinyl setup:
VPI Scoutmaster, non-signature, Valhalla wired arm wand in near future
Dynavector 20XL
Cayin Phono One
DIY wall shelf using 3" thick maple
Bright Star Big Rock, going to try Gingko 11 in near future
SDS and ring clamp coming soon
sns
sns OP
3,561 posts
 
Almost forgot, another thing that may result in azimuth error is how tight each screw is. At one point in the midst of doing my measurements I had gotten crosstalk deviation within specs, I decided to retighten the cartridge screws just to be sure, this changed crosstalk deviation beyond specs.

To reiterate, my experience teaches me no physical measurements protocol will result in proper azimuth settings. One may get lucky and find the mark, but for proper azimuth it is absolutely necessary for an electronic measurement.

With practice this method is actually quite easily accomplished, not rocket science here. Purchase or borrow the Fremer video, the PDF files alone are worth the price. Actually, now that I think of it, it may be necessary to buy that video as it has the Wally azimuth voltage to decibel conversion chart that is absolutely necessary. It may also be available elsewhere on the web for free, I haven't checked. You also need a record with 1kz test signal for both left and right channels, I used the Cardas record.
sns OP
3,561 posts
 
While we are on the topic of cartridge allignment, it may be interesting to note that the vacuum state website (in their white papers) has another take on cartridge allignment. I have not read it in detail, but it may be worth further exploration.
jamnperry
123 posts
 
Is there any other test records besides the Cardas with the 1khz tracks? I used the rod method but would like to check it electronically.
kotemaori
1 posts
 
As a total novice when it comes to measuring with DMM, my first thought on your method of measuring at speaker posts is that you are also measuring the differences in the power amps, would it be more useful to measure at the output of the t/table (i'm using TNT HR)
sns OP
3,561 posts
 
Jamnperry, there is the Analogue Productions test record, this even may be better as the 1kz tracks are longer.

Kotemaori, I would think they have you measure at the speaker outs in order to get the readings closest to what they would be coming out of your speakers. Therefore, taking into account the IC's between phono pre and preamp and preamp to amp, preamp, amp. It would be interesting to test at both output of the table and amp outputs and see what differences there are.

I also mis-wrote the acceptable tolerance in one of my posts as 5-10%, wrong, the acceptable tolerance is 1-5%.

I've also thought about a possible means to test electronically without the wally conversion table. You may be able to get azimuth to proper specs just by reading small reading (the actual crosstalk) in each channel.

Procedure: Play a 1kz stereo test tone and set volume to output 3ac volts (DMM at 2acVolt setting, it will read as .300 or close) at amp outs, test both channels, adjust and balance volume accordingly. Now play the left channel only and right channel only 1kz tracks. When playing the left channel tracks insert the DMM probes into the right amp speaker posts (in phase), write down the reading, you should get something between .010 and .023 or so (DMM at 2vAC scale). Play right channel, place probes in left channel, write down reading. If you have a reading that deviates more than .002 between the two you can be sure to be out of tolerance. The best I was able to achieve was a difference of .001. To reiterate: You want a differential reading of .000 to .002, no other reading will be within tolerance.

I cannot guarantee this method is best, but my own readings on big and small voltages show this should work.
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