This is where record cutters raise questions about cutting, and trade wisdom and experiment results. We love Scully, Neumann, Presto, & Rek-O-Kut lathes and Wilcox-Gay Recordios (among others). We are excited by the various modern pro and semi-pro systems, too, in production and development. We use strange, extinct disc-based dictation machines. And other stuff, too.
i'm having trouble cutting a groove on my VR everything worked perfectly a few months ago, until i took everything apart and changed my setup. i've calibrated everything i can think of but when i try to cut an unmodulated groove, the playback needle won't even stay in it, it hops out and slides across the record. i'm using a brand new stylus, weight is set properly, disks are heated to 40C using an infrared lamp, cutterhead and stylus are properly aligned, etc. i even thought it might be my playback needle, so i got a new one. my blanks have been sitting in a hot garage, is it possible that they have gone bad? the only other variable that has changed is my lamp, since i switched from a white bulb to an infrared reptile bulb from the pet store. could the infrared light possibly be damaging the surface of the disk? i know it's a stretch but i'm out of ideas, please help!
it's hard to describe, but i see little white spots, which i fear might be bubbles or something in the vinyl. the grooves themselves look normal i guess, just straight lines since they are unmodulated.
OK, well if you're absolutely sure that everything else is set correctly (e.g. weight, angle, stylus) then the next thing to do is buy a few more new blanks and try again. I think that's the only way to rule out the blank as the problem.
just wondering if there's anything else i can rule out before the blank, or if it's even realistic to wonder if the blank is the issue. i just noticed my platter is not very front-to-back level, maybe that's the problem.
the platter was about a centimeter off from being level but i balanced it out. the grooves look good under the microscope. i can play commercially pressed records without any problem, so i assume my playback turntable is fine. really at a loss as to why i still can't cut a playable groove
when i try to cut an unmodulated groove, the playback needle won't even stay in it, it hops out and slides across the record
If you watch the playback stylus closely, does it actually jump out of the groove as though it has hit something, or is it more like it slides but never loses contact with the record? The latter would suggest a groove depth issue which you should be able to see through the scope I would have thought.
does the chip pickup ok? if it does, I would think your depth and stylus are somewhat in a good range. If you have dropped chip you may be losing contact with the disc (not enough depth) or the stylus is in bad shape, misaligned, or something else
making lathe cuts on a Presto 6N, HIFI stereo cuts on vinylrecorder at Audio Geography Studios, Tallahassee, FL USA http://www.audiogeography.com
the playback stylus just slides across. the grooves look fine, not broken or anything. no way of measuring how deep they are but weight and heat are at known good settings. i guess i could increase my weight for deeper grooves but that doesn't seem right. i set my cutterhead weight to 45g/~16g as suggested for a new stylus. blanks are heated to 40C and treated with souri spray. cutterhead is parallel and platter is level. stylus is straight and firmly inserted. what am i missing?
chip suction is fine. i have followed the vr tutorial on myshank's page (thanks for that, steven! invaluable!) and upgraded to a real vacuum pump. everything seems like it should be working really well.....
Sorry for the possibly silly questions but is your lathe level? Not the platter, but the base of the lathe itself. Have you checked that the dashpot is not 'bottoming out'? Also, when did you last strip and re-grease your TT bearing? That last one can catch you out, with the Technics 12xx TT's at least... An unhappy bearing can cause subsonic resonances which in turn can activate tonearm resonance.
yes, the lathe is level. i put a spirit level on top to check. regarding the bearing though - before i moved the lathe out of my garage, it got REALLY dirty. i was having my foundation repaired so there were workers in and out of the garage excavating dirt. they did their best to cover the lathe up with a tarp (i honestly wasn't expecting the amount of dust they created), but by the time i poked my head in to see how things were going, EVERYTHING was covered in a fine layer of dust. after they left, i cleaned everything off and hooked it back up, but it hasn't worked since then. i was very pleased with the records i was cutting immediately before the whole thing, so my system has worked before. is it possible that dust could have gotten inside something like the turntable bearing? i bought my tt used but professionally refurbished and recalibrated about a year ago.