I have a beat to hell portable Motorola record player that I'm modifying to a smaller, more portable version. I had the idea to maybe add a headphone jack running straight from the needle, but it looks like no one has done this before. Would a record player stylus produce sufficient voltage to produce sound through headphones?
Pic related, painted turntable
Previous color after cutting the corners.
>>955462
>portable record player
>but it looks like no one has done this before
Gee I fuckin wonder why
>>955477
Are you telling me that people haven't been making portable record players for the past 80 years? Anyways, that's not the question hotshot. Try again.
>>955462
what type of cartridge will you be using?
Magnetic?
crystal?
ceramic?
astatic?
>>955490
No. Record players dont make enough to drive headphones unless you want it to sound like shit through the shittiest crystal radio ear piece.
You need a phono preamp or phono headphone amp.
>>955709
Not Sure what the cartridge is because Motorola is shady about their stuff apparently.
What I plan on doing is using the old circuit and running speakers inside the case, I'll send some case pictures later. I still need to sand it.
For power I plan on using a 12v battery and a power inverter. Would it be more efficient to switch to a 12 car amp? Either way I would still need power to the AC motor for the turntable. The player is 35 watts which means it draws 3.3 amps.
>>955735
no they are not. What model record player is that?
>>955740
Yeah....
That may not work, without a pure sign wave that motor may not even turn or may run too slow. If you want that to be portable you would need to replace the motor with one that runs on DC.
really what you are doing is reinventing the wheel and trying to do it with a tank tread.
>>955717
it also has to have RIAA equalization.
https://en.wikipedia.org/wiki/RIAA_equalization
>>955740
actually it runs off of about .29 to .30 amps depending on the mains voltage
>>955740
120vac x 3.3amps=396 watts
120vac x .29amps=34.8 watts
>>956027
Model pp218dn
most likely it uses an induction spindle motor. these have a steady speed based on the line frequency. if you use an inverter, that frequency is not guaranteed to be precise, so you may get speed distortions. if you replaced it with a DC motor, you'd need to add speed sensors/adjusters.
you can find phono preamps, for use on stereos that dont have a phono input. it's possible that one might be loud enough to drive headphones, but i expect it would be pretty low volume.
>>956030
Yeah, I forgot about the complicated relationship between induction motors and AC frequency.
Any way to find the RPM and torque on an induction motor? Where to buy or find a DC motor to fit those specs?
>>956097
You think this might work?
http://www.goldmine-elec-products.com/prodinfo.asp?number=G14957
I think I have one of these lying around somewhere.
>>956092
ok so your record player uses an Astatic phonograph cartridge part number 59c60868b01 it puts out .35 volts so you are gonna need a lot of pre-amplification.
I can get you the sams for the record player but will need the model number for the turntable itself.
>>955462
If what you want out of it is the cleanest sound possible into headphones, then get a Class-A stereo headphone amp, preferably vacuum tube, and some studio monitor-quality headphones. It probably won't sound right though, phono preamps have equalization that's required to reproduce the sound properly.
>>956092
>>956616
>>956109
You would need a motor that you can mount the stepped shaft to and it would need to be strong enough to turn the idler wheel and the turn table about .04 horsepower at the proper rpm.
>>956585
> the cleanest sound possible into headphones, then get a Class-A stereo headphone amp, preferably vacuum tube
right, and oxygen-free cable with gold-plated connectors, and bags magic crystals taped to them.
portable, and vacuum tube-powered, is not a good combination.
and, if the dude wanted '' the cleanest sound possible'' he wouldnt be using a turntable, he'd use a CD player which has 30dB lower noise levels. you can get a used battery-operated Sony or Samsung for about $4. but they're not hipster enough, of course.
>>956616
Nice job on the Photofacts.
