The Secret Society of Lathe Trolls

Hey Guys, I found the original installation instructions and info on the x-26 astatic cutter head that uses salt crystal piezo. PDF files attached. I also found an old, unmanaged website that details how to replace the salt crystal with a modern piezo element. I've never done it but the site claims ...

Loaded some PDF schematics I found. I used them when I built my cutter using an astatic cartridge recently. Useful information.

Jason

Hi there, I've been experimenting for a while and have been cutting vinyl records. I use an astatic head and I cut into vinyl with a heated diamond stylus. I basically cobbled my machine together from a bunch of others and 3D printed parts. If you want to be able to play a vinyl cut record with a he...

Behold, the beast. It was originally an A92 Wilcox Gay Recordio from about 1938 (attached schematics). Screenshot_20180325-120513.jpg I'm not sure 'restoration' really applies here. I basically replaced 90% with non-standard parts. HOWEVER! First I tried to restore the original tube amplifier but co...

Hi, Jason, Yeah, I'm in Brea, just a hop-skip-jump away. If you're cutting at 78 into a bona fide lacquer recording blank, and the stylus is fairly new, you should have virtually no noise. Back when I was a kid doing much the same thing with a General Industries recording deck, I'd get noiseless 78...

Hi, Jason, a couple of questions. 1) are you cutting with a traditional stylus, or are you embossing with a spherical tip? 2) what speed(s) are you recording at? Typically with a Recordio or other vintage-consumer-targeted machine, a hot stylus doesn't work all that well. I am assuming that your cu...

Hi, I had good luck just wrapping a few turns of nichrome wire on the mental shank. I used Duco cement (made out of nitrocellulose, just like a lacquer blank) to bond the turns. If the Duco starts to smoke, the heating level is a bit too high. Give it a try and see if it works for you. Using D Batt...

Hey guys! So I FINALLY have my Recordio 72A fully restored. Idler wheels rebuilt, all new tubes, and West Tech rebuilt crystal cutter head. (hear it on instagram at HardlyHumanFX) I have played around a bit with trying to heat records but they always warp so I decided to heat my stylus instead. I fi...

Hi, So it looks like I'm in the right ballpark for the cutter head impedance. That should help you get in the ballpark if you elect to use a power transformer. Transformers are usually rated in VA. In this case VA and watts are essentially the same, assuming the voltage and current are in phase (re...

Hi, Probably not. That would be great for a moving iron 500 ohm head. You need to go with a larger step up ratio to drive the crystal head. You need something on the order of 100-180 Vrms to drive the head. At 10 watts, that implies an impedance of about 3K ohms R = V Squared / Watts So R = 180 Vol...

Hi, Probably not. That would be great for a moving iron 500 ohm head. You need to go with a larger step up ratio to drive the crystal head. You need something on the order of 100-180 Vrms to drive the head. At 10 watts, that implies an impedance of about 3K ohms R = V Squared / Watts So R = 180 Vol...

Hi, If you go with the solid state power amplifier, then you can use an off the shelf 70.7 V PA style transformer in reverse to match the head to the power amp. There are several posts here about how that is done. Because the crystal head is a constant amplitude device as opposed to a constant velo...

Hi, If you go with the solid state power amplifier, then you can use an off the shelf 70.7 V PA style transformer in reverse to match the head to the power amp. There are several posts here about how that is done. Because the crystal head is a constant amplitude device as opposed to a constant velo...

Hi, If you don't care about being original, then why not junk all of the electronics and drive the head with a modern solid state power amp? Since the head is a high impedance crystal type, you will need to add a step up matching transformer from the amp to the cutter head. Or you can use a modern ...

Hello Trolls I have two machines. A Recordio 6B10 and a Recordio 9J9 (A70). I have only restored the 6B10. The 9J9 chassis needs a ton of work to get working right again. Anyway, I have noticed a key difference in the hardware: --The 9J9 (large console unit) recording arm is heavier, has a non-flexi...

Hi, So it seems like you are in good shape. Its probably a grounding/shielding issue. What did you replace the old jack with? How is it tied to the chassis ground? If I understand correctly, if you plug in a line level source into the mic input you have no hum issues. Is this correct? Mark Hi Mark!...

Hi, You are probably jumping the gun ordering up a replacement tube and grounded power cord. What are you using for a mic? If its the one that comes with the cutter, it is probably a crystal mic and could very well be bad. How are the selector switches set ? After you plug in the mic, does the leve...

Hi, You are probably jumping the gun ordering up a replacement tube and grounded power cord. What are you using for a mic? If its the one that comes with the cutter, it is probably a crystal mic and could very well be bad. How are the selector switches set ? After you plug in the mic, does the leve...

Hello Trolls! My name is Jason. I'm new here. I just acquired a couple Recordios and set about restoring Model 6B10 circa 1939. I found the schematics and components lists and soldered in new capacitors. I'm certain that was done correctly. HOWEVER! When I plug in any input into the microphone jack ...

Cutter head service notes attached