altering motor speed for 78 to 45

[jessefreelance]

is this at all possible

[Steve E.]

Hmmm! I'm sure anything's possible. Perhaps you could mess with the motor or electricity in some way if you were that sort of whiz (which I am not...I would fry myself if I tried, and I bet you would, too). BUT...most record players seem to control speed mechanically....that is, by changing the way gears or belts meet the turntable, instead of doing it electrically. (Analogous to changing gears on a bicycle.) I think it might be hard to alter the mechanical design of your lathe cutter to that extent.

The simplest thing will be to speed up the recording as you feed it into the lathe, and just keep cutting at 78. If you play a recording at 1.7333333 times its normal speed when recording into a lathe cutting at 78, it should play correctly at 45.

This will involve the recording taking about 57.6923% of its normal running time. (That's 1/1.733333.) If you are playing a test signal, I believe you would be retuning it/speeding it up so that it plays about a major 6th higher than normal. It's pretty easy to do this in the digital realm using the pitch shift/ time compression features of most sound editing programs. Just make sure you simultaneously time compress and up the pitch. (Sometimes this feature is simply called "pitch bend.")

You will probably enounter other problems: namely, you probably won't get much high end on playback and you may get a warbly tone. And 78's have a wider groove than 45's. But....try it and let me know what you find out!

[jessefreelance]

thanks it seemed to work somewhat
i still cant get much of a clear sound

-proper functioning tubes
-new cutting needles
-new blank acetate


am i cutting to deep not deep enough

what is a good cutting depth
do you know any websites on home lathes for beginners.
thanks for all yr help

[Steve E.]

am i cutting to deep not deep enough

Probably not deep enough. Do you know how to alter the depth on your machine? Look for a manual online. That would help.

Try going extremely shallow and extremely deep, and see what happens on each extreme. "Too Deep" would mean that the grooves would actually overlap. If you hold the record up to the light you should see more groove than space between the grooves (or "land").

do you know any websites on home lathes for beginners.

As far as I know, this is IT! That's why I started this site. But check the links section.

It could also be a problem with the cutting head, I suppose. (different issue than the stylus.) But if you are getting SOME sound, that's a promising sign.

Have you tried boosting the volume of the incoming signal? Your meters could be off, too. Try piping in a "too loud" signal and see what happens.

One thing to keep in mind is that the frequency response that this thing can cut is going to be much lower that you are used to. (In other words, it will inevitably sound muffled because of the limitations of the medium.) "Busy" sounding mixes will sound poor. You may want to try EQ'ing out high frequency info that could be confusing your meters.

I found a good test mix, weirdly enough, to be Madonna's "Get Into The Groove". The thing was mixed for vinyl, and it works on my acetates! Compressed mixes are better, too, because the medium doesn't have much dynamic range.

I'm grappling with these same problems, by the way!!

(and I'm not really much of a Madonna fan, by the way, either....)

[ameisevinyl]

you shouldnt try to cut 45s at 78
you shoudl even go for a 33 motor and cut 45 at 33,

you see the problem is: all the old not so professional cutterheads,
dont have a good frequency range...

so if you pitch up your recordings to 78 that is 78/45 times the original
all the frequencies of the original master will go up and you will have
more problems to record them without distortion at a useable volume...

you should try to find out what your motor is like:

is it an DC-motor --> you could try to reduce voltage to the motor to
slow it down (but it might no be powerful enough to drive the turntable then...)


or is it an AC-Motor? than you shoudl get an industrial AC-frequency converter --> i am german so we use Siemens stuff for that...
we get them from siemens

on my presto there are two motors one for 33 and one for 45
they are attached through a belt drive to the turntable...

if you change the dimensions of the beltdrive-wheels (oh my god
my technical english is crap)
you might be able to get the right speed...

there are stroboscope-disks out there (e.g. from lenco in europe or westrex or fairchild in the US)
you can measure if your turntable is spinning with the right speed
easily with them.·..

you can also print out such a thing...but that was not your question

peace
mart

[ameisevinyl]

shoudl = should

[motorino]

or you can use (yes, my english its too really bad) a dc motor with tachometer and dc regulator with feedback!! i believe its the best solution for one recording lathe, you can attach directly the turntable chaft, without belts

you have a lot in ebay, dc regulators and tacho-motors at good price

[Dub Studio]

It's pretty easy to do this in the digital realm using the pitch shift/ time compression features of most sound editing programs. Just make sure you simultaneously time compress and up the pitch. (Sometimes this feature is simply called "pitch bend.")

I think if you time stretch or pitch bend more than about 10% the sound starts to become very ropey, but I am fairly sure there is a way to use the sample rate of a digital file to play it faster or slower, which should theoretically be lossless? For example, if you have a file with a sample rate of 44100, you could record it at 45rpm using a sample rate of 44100 / 45 x 78 (76440). Theoretically the exact same number of samples would be recorded, just faster, so there would be no actual difference in the sample rate when you slow it down to 45rpm during playback. Anyone tried this?

[blight]

You seem to forget about the RIAA encoding/decoding which happens before/after the vinyl disk.

If you stretch your sound then the RIAA encoding will not work correct, when you play it back at a different speed you will be listening to an EQd signal.