terry, im basing this on results of other ideas i checked out... it seems the key is making the laser beam as small as the tip of a stylus through a lense, parts to do this seem to be readily available and i can probably use the same type of lasers i used for my pickup... theyre cheap little things and come in a variety of colors, im not sure color will make much of a difference.. but it would be curious to try a couple laser colors and see if it does since they operate at different wavelengths
stylus isnt really the major issue.. i guess making a stylus to read the music is the easy part.. making a laser stylus that actually tracks the groove is different... as the record turns the stylus rides in the groove until the record is done... but without physical contact how will the laser move to stay with the groove? do all records have the same groove spacing? if not it would be very, very difficult to make this work.. but if they do you could simply use a gear ratio with the main motor to move the laser across the surface of the record at a rate according to the speed of the rotation, which for my project would be 33 1/3
another way i guess would be to have another laser or photodiode programmed to read the location of a groove, and somehow follow it... i dunno, this is definitely the hard part
stylus isnt really the major issue.. i guess making a stylus to read the music is the easy part.. making a laser stylus that actually tracks the groove is different... as the record turns the stylus rides in the groove until the record is done... but without physical contact how will the laser move to stay with the groove? do all records have the same groove spacing? if not it would be very, very difficult to make this work.. but if they do you could simply use a gear ratio with the main motor to move the laser across the surface of the record at a rate according to the speed of the rotation, which for my project would be 33 1/3
another way i guess would be to have another laser or photodiode programmed to read the location of a groove, and somehow follow it... i dunno, this is definitely the hard part
seems the least light touching the record besides that of the laser, the less noise you will receive as there would only be light from the laser reaching the photo-diode... so i wonder if you could remove noise by getting a matching laser and diode that worked in a very, very uncommon spectrum of light... or possibly one that bounces a radio wave off of the surface of the record which wouldnt have any feedback from light.. though cell phones would probably screw it up
Following the groove "is" the hard part.
To answer the question about groove spacing: They aren't evenly spaced as the cartridge traces side to side movement to create the sound. Really loud passages have wider swings than quiet passages and the spacing is adjusted accordingly.
Best Regards,
TerryO
You really need to educate yourself in the science of record making, so you have a understanding of just whats involed in making a record. To put it bluntly, it might actually be easier to make a DIY CD or DVD player than make a laser turntable. A company many years ago tried to do this and after many years and 20 million dollars spent was finally able to bring a product to market. You can buy one for the tidy sum of 10000 dollars.
Laser turntable - Wikipedia, the free encyclopedia
I should ad to my post that if your looking to minimize record wear there are readily available techniques to do this. Get a cartridge with a fineline stylus, align the cartridge on the tonearm properly, set the tone arm to the proper tracking weight, properly adjust the vertical tracking angle, clean the stylus, and most importantly keep your records clean. Record wear comes from playing dirty records with a worn, improperly aligned stylus. If you eliminate the dirt and keep a good stylus your records will last decades, and take 100's of play with almost no wear. That's why you really need to take the time to go on site like Vinyl Engine or others and read. You will find you don't need fancy lasers, just good proper execution of the available conventional record technology's and techniques to get the most enjoyment out of your records.
is there any way to back up a record into a computer without losing the quality of the sound?... i know records are analog with a perfectly smooth soundwave, where digital audio is stepped, but are digital to analog converters good enough to perhaps take a 96,000hz 24 bit stereo lossless audio file and convert it back into an analog signal worthy of perhaps cutting a new record in the future should mine ever wear and be hard to find?
anyway.. back to the origional question... i have a few different ways i know to make the tonearm.. is my best bet to buy a complete cartridge? if so.. whats a good cartridge for playing new records?... and about what sort of power will i need in a motor for spinning the table, and what sort of electronics am i looking at needing for the table?..
is it better to have a motor that can automatically turn at 33 1/3, 45, and 78 RPMs?.. or maybe a variable dial i can use to fine tune the RPMs like a potentiometer with a strobe light to aid in fine tuning the speed?
is it better to have a motor that can automatically turn at 33 1/3, 45, and 78 RPMs?.. or maybe a variable dial i can use to fine tune the RPMs like a potentiometer with a strobe light to aid in fine tuning the speed?
apparently i dont need any fancy strobe device.. just a strobe disc in which case i can burn the proper marks into the sides of a wooden platter, or just buy a platter somewhere that has them... or print the disc out on paper
what i think ill do is have a single motor hooked up to the platter via a belt, of course, and then very simply wire that motor into a 3 way switch, and each setting on the switch will be wired to a potentiometer to control the motor... so if the switch is set to position 1, the power is routed through potentiometer one which will be set to 33 1/3 RPM... pot 2 would be used for 45, and pot 3 for 78s... or i can just use each individual pot to pre-set the speeds i want
maybe ill just have a small perfboard set up for all of that.. and have screw driver adjusted pots under a panel on top i can pop off and use a screwdriver to fine tune each one to the three speeds, then replace the cover because if they were knobs on top it would just be too likely for me to accidently bump one and mess up the timing... then i could wire up a small 60hz LED strobe circuit board i could permanently mount inside the turntable with an on/off switch
that all solves the motor and timing... im really liking the idea of making the tonearm out of a piece of carbon fiber tubing i can get really inexpensive
found a circuitry "kit" for a phono pre-amp to use on turntables, thatll give me the amplification ill need
ill make a platter out of red oak which i can route a bit of a recess into to set a cork mat.. under the cork mat however, im going to print off the strobe sheet for 60hz 33 1/3, 45, and 78 RPMs onto a transfer sheet... transfer the ink onto the platter below, and then clear coat the wooden platter before laying the cork mat on... then i can just lift up the mat for the strobe markers
that being said.. i think i pretty much figured out what i want to do for the diy turntable... did i miss anything?
what i think ill do is have a single motor hooked up to the platter via a belt, of course, and then very simply wire that motor into a 3 way switch, and each setting on the switch will be wired to a potentiometer to control the motor... so if the switch is set to position 1, the power is routed through potentiometer one which will be set to 33 1/3 RPM... pot 2 would be used for 45, and pot 3 for 78s... or i can just use each individual pot to pre-set the speeds i want
maybe ill just have a small perfboard set up for all of that.. and have screw driver adjusted pots under a panel on top i can pop off and use a screwdriver to fine tune each one to the three speeds, then replace the cover because if they were knobs on top it would just be too likely for me to accidently bump one and mess up the timing... then i could wire up a small 60hz LED strobe circuit board i could permanently mount inside the turntable with an on/off switch
that all solves the motor and timing... im really liking the idea of making the tonearm out of a piece of carbon fiber tubing i can get really inexpensive
found a circuitry "kit" for a phono pre-amp to use on turntables, thatll give me the amplification ill need
ill make a platter out of red oak which i can route a bit of a recess into to set a cork mat.. under the cork mat however, im going to print off the strobe sheet for 60hz 33 1/3, 45, and 78 RPMs onto a transfer sheet... transfer the ink onto the platter below, and then clear coat the wooden platter before laying the cork mat on... then i can just lift up the mat for the strobe markers
that being said.. i think i pretty much figured out what i want to do for the diy turntable... did i miss anything?
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The quality of the best digital gear is getting pretty close, if our Club's A/B comparisons a few months back is any indication. I'm not convinced it's better, but it is getting pretty hard to distinquish between an analog LP and the same LP that has been thru a ADC/DAC process. If kept in the digital domain like a music server, you're probably going to do well. However, burn it onto a CD and it won't be nearly as good.
We're not quite there yet, but it's coming!
Best Regards,
TerryO
i have another question about the turntable... lets say i use silicone rubber/glue stuff to glue an abec-7 bearing inside of bottom of the wooden platter, and the center of the bearing just gets screwed into the base of the turntable, this will allow my platter to move freely...
but how would i spin this?.. one idea i had was to mount a roller-skate wheel to a motor, and the rubber edge of the wheel would ride along the edge of the turntable... would this work? or am i better off using pulleys and a belt?.. i could glue rubber edging to the edge of the turntable, i dont think the wheel on rubber would have any slipping at all
but how would i spin this?.. one idea i had was to mount a roller-skate wheel to a motor, and the rubber edge of the wheel would ride along the edge of the turntable... would this work? or am i better off using pulleys and a belt?.. i could glue rubber edging to the edge of the turntable, i dont think the wheel on rubber would have any slipping at all
well... ive decided im going to do like what many other players have done and actually cut a groove into the edge of the platter and wrap a belt directly around that... that seems to be the absolute most simplest way to do this, with the power supply feeding into a 3 way switch feeding into a potentiometer per switch which all in turn feed into the motor so i can fine tune 3 different speeds for the selector switch
then, ill print the strobe disc on a transfer sheet to transfer to the surface of the platter which will then be sealed in
then, ill print the strobe disc on a transfer sheet to transfer to the surface of the platter which will then be sealed in
question... has anyone built a turntable using a "lazy suzan" flat ball bearing swivel as the base for the turntable?... ive found one for $5 thats 12" in diameter and rides entirely on ball bearings.. cant hold tons of weight so it should be incredibly sturdy... and just above 1/3 of an inch thick and its really as simple as bolting this to the table and your platter, then looping a belt around a groove in the edge of the platter and voila, a turntable
Ball bearings are noisy, and low quality ones such as found underneath a lazy susan are likely to be extremely noisy.. I can't imagine the rumble levels you could achieve but I expect it would be terrible. Interesting idea just not one likely to work as is.. Perhaps as the basis for a platter with a conventional spindle and bearing..
hmm...could always put a ring of magnetcs under the turntable, and some on the turntable so the forces would repel eachother allowing the turntable to "hover"... how does that sound?... seems to me it would be easy to make that thing wobble though... any recommendations as to what i should use to allow the table to spin freely?... it has to have something
for the tonearm im thinking of having a linear tonearm by having a bar go across the back side of the player with a 4-way coupling sliding over it so it can move left and right and tilt up and down, with the tonearm coming out of the front and an extension for holding weights out the back... ill draw up a 3D image of that idea later
but if the ball bearing swivel isnt such a good idea, what SHOULD i use?
for the tonearm im thinking of having a linear tonearm by having a bar go across the back side of the player with a 4-way coupling sliding over it so it can move left and right and tilt up and down, with the tonearm coming out of the front and an extension for holding weights out the back... ill draw up a 3D image of that idea later
but if the ball bearing swivel isnt such a good idea, what SHOULD i use?
I mentioned earlier that you do a search of this site for DIY turntables. I'm getting the feeling that you haven't bothered, as these ideas and many others have already been discussed at some length. If you are actually serious about this and really want to do something besides just talk, I suggest that you make an effort to come up to speed by doing some research. Otherwise you're just wasting everyone's time, including your own.
Best Regards,
TerryO
I would steer clear of carbon fiber for a tonearm. I hand laid a tonearm with carbon fiber and found that it, being conductive, must be well grounded, otherwise an omnipresent hum will be your reward.
I really like uni pivot tonearms, but anti skating is harder to implement. I simply didn't...
I am going to try a paper arm tube, hardened with lacquer, and packed with granular aerogel. Here's the source for the aerogel: Aerogel : United Nuclear , Scientific Equipment & Supplies
I really like uni pivot tonearms, but anti skating is harder to implement. I simply didn't...
I am going to try a paper arm tube, hardened with lacquer, and packed with granular aerogel. Here's the source for the aerogel: Aerogel : United Nuclear , Scientific Equipment & Supplies
the $200-$400 "platter bearings" are in fact nothing but an elongated ball bearing.... hmm... i could just stack a few of these abec 7 bearings into the base of a hardwood "hub" and screw the main platter to that and it should do just fine
ill probably make the platter with a layer of boards horizontally, with another layer glued on vertically with a shelf routed on the edges to give a belt something to ride on and just wrap the belt directly around the platter
i like the paper and lacquer idea, but you could really use any kind of fabric with a laquer i bet... maybe a strip of canvas wrapped around a lubricated tube... dip it in laquer, hang it to drip away the excess and dry and there you go
one question.. what is packing it with aerogel supposed to do?
ill probably make the platter with a layer of boards horizontally, with another layer glued on vertically with a shelf routed on the edges to give a belt something to ride on and just wrap the belt directly around the platter
i like the paper and lacquer idea, but you could really use any kind of fabric with a laquer i bet... maybe a strip of canvas wrapped around a lubricated tube... dip it in laquer, hang it to drip away the excess and dry and there you go
one question.. what is packing it with aerogel supposed to do?
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