Hi folks, just wondering how to properly use a scope to setup the turntable parameters. Anyone here do this? I have the Analog test disc with the 1khz some wave, anti-skating tests, resonance frequency test, channel separation...
Cheers
Cheers
Some things you can do.
- Cartridge azimuth; set it visually initially and check crosstalk with scope/test record. Fine adjust if nessecary, but don't alter more than within a degree or so.
- High frequency response, adjust loading for MM cartridges for more linear response.
- Compliance: use test grooves to determine the resonance frequency and the compliance of the cartridge.
- Tracking force: you should start to set it in the middle of the recommended range. If the compliance is the same as the specification says, keep it in the middle. If compliance is higher, you can lower VTF a bit, and if it is lower, you can increase VTF a bit. it varies between different cartridges. Finally, fine adjust depending if you hear mistracking.
- Antiskate: Using high level modulated test tones for antiskate usually sets antiskate too high. You can however use it to set the highest antiskate setting and then use the blank vinyl test to set the lowest setting, and then finally end up with a setting that is between those two endpoint settings. Final check can be done looking at the cantilever with a loupe when it is set down into a music groove. It should not move to the left or right with respect to cartridge body, but be steady in its original "resting position".
I did this check this morning and found no deflection in my cantilever when putting the stylus down on the record.
An ungrooved record is not useful for setting antiskating. A different part of the stylus (the bottom)
touches the ungrooved record, than when it is in a groove (the sides).
touches the ungrooved record, than when it is in a groove (the sides).
Well I did use the actual playing surface for this test as well as the deadwax. So I think I have correct as I saw no deflection when lowering to the playing surface.
Clearly not the case as a 'scope shows infrasonic and ultrasonic signals your ears cannot sense.
You just need groove-free vinyl and eyes to watch the arm for this one. Its best that the test disc is black vinyl as coefficient of friction between the disk and the stylus is responsible for the skating force and varies from material to material.
Some 12 inch singles/LPs have spare room after the lead-out groove, some have very spaced out lead-out grooves so you can just about check this (you've nearly 2 seconds at 33rpm before the groove captures the stylus again) My best test disc for this is a Dead Kennedies 12 inch single that's about 50 seconds long IIRC!
Mark Tillotson My best test disc for this is a Dead Kennedies 12 inch single that's about 50 seconds long IIRC
That "dead wax" idea for determining antiskate is old worn-out mis-information already.
Because laying the stylus "tip" on the smooth vinyl is a single contact point with substantially less friction than "in a modulated 45 degree groove" with the "sides" of the stylus bearing down on two inner sides of the groove.
Because laying the stylus "tip" on the smooth vinyl is a single contact point with substantially less friction than "in a modulated 45 degree groove" with the "sides" of the stylus bearing down on two inner sides of the groove.