Well, finally here it is, my first diy scrapyard turntable.
As I was very happy having a few thorens parts doing nothing in my scrapyard I started building an new turntable using these. So the turntable can also be regarded as an extreme make over or a drastic tweak
.
Attached an overview image.
More in the next post.
MArco
As I was very happy having a few thorens parts doing nothing in my scrapyard I started building an new turntable using these. So the turntable can also be regarded as an extreme make over or a drastic tweak
.Attached an overview image.
More in the next post.
MArco
Attachments
Arm detail
HEre a photograph of the arm part of the turntable (yes, I know, I'm a lousy photographer).
The arm I regard as having build myself (otherwise it should be considered as a major tweak of a badminton racket). It's a full carbon arm with an aluminium head shell and a brass counterweight. Of course I used an unipivot. The VTA is adjustable in a wide margin (about 5 cm).
Marco
HEre a photograph of the arm part of the turntable (yes, I know, I'm a lousy photographer).
The arm I regard as having build myself (otherwise it should be considered as a major tweak of a badminton racket). It's a full carbon arm with an aluminium head shell and a brass counterweight. Of course I used an unipivot. The VTA is adjustable in a wide margin (about 5 cm).
Marco
Attachments
Details and a question
A little on the details of this turntable.
The plinth is solid concrete in which a part of the sub chassis of a Thorens TD160 is embedded. This basically gave me a standard Thorens bearing in a concrete plinth. The sub chassis gave me a means of having it exactly vertical (as I assumed that the bearing is mounted axactly right in the sub chassis metal).
In this bearing a standard Thorens sub platter. I actually used a fibre one. I didn't need the mass of a metal one, and I believe the damping of the fibre one is better. On this I stacked two Thorens outer platters. I made the spindle longer.
I plan to fill the top platter with either concrete or Acryllic resin. I get worried a bit about the weight. How much platter weight can a Thorens bearing support before wear gets excessive? And when it does would a small Teflon plate on the bottom of the bearing help?
The motor is again a standard Thorens TD160 (synchronous AC) motor, but driven by my own power supply (wien bridge oscillator, power op-amp, step up transformer).
greatings, MArco
A little on the details of this turntable.
The plinth is solid concrete in which a part of the sub chassis of a Thorens TD160 is embedded. This basically gave me a standard Thorens bearing in a concrete plinth. The sub chassis gave me a means of having it exactly vertical (as I assumed that the bearing is mounted axactly right in the sub chassis metal).
In this bearing a standard Thorens sub platter. I actually used a fibre one. I didn't need the mass of a metal one, and I believe the damping of the fibre one is better. On this I stacked two Thorens outer platters. I made the spindle longer.
I plan to fill the top platter with either concrete or Acryllic resin. I get worried a bit about the weight. How much platter weight can a Thorens bearing support before wear gets excessive? And when it does would a small Teflon plate on the bottom of the bearing help?
The motor is again a standard Thorens TD160 (synchronous AC) motor, but driven by my own power supply (wien bridge oscillator, power op-amp, step up transformer).
greatings, MArco
Arm details
The arm I've made from a badminton racket. Actually these are well suited for the job (at least the one I used). The shaft is hollow and made from carbon. But the part where the counterweight is mounted is solid (that's the part here the racket handle was mounted on).
I left a small part of the blade on the shaft, so I could fix a flat piece of aluminium as a head shell (see image). The nice thing is that there is a little bit of metal at the end of the shaft so I could use a little bolt to fix the aluminium to the arm.
I created enough degrees of freedom in the cartridge/ arm/ head shell mounting that I can have the cartridge properly aligned AND the needle exactly under the middle line of the arm (actually the line around which the mass evenly distributed in that plane). I think that's vital to keep an unipivot arm from wobbling in around it's length axis. In this way I could avoid dampening this movement.
The counterweight is made of brass strip and is clamped on the arm. Heat shrink tubing is in between. The counterweight has a few screws for azimuth adjustment and tracking force adjustment. The thread for the anti skating is also attached here.
The point of the unipivot is a dart, which I've mounted in a piece of water pipe by means of molten lead and tin. I've inserted a little tube as well trough which the arm cable runs (made from a dead mouse).
The water pipe is mounted with a standard clamping water pipe support. (excuses for my horrible English here). I hope you understand.
The arm lift is again made from a Thorens part. A bicycle brake pad supports the arm. A bicycle seat post handle is the lever for operating the lift.
Well, that's about it.
As the whole concoction operates flawlessly it's time to mount a decent cartridge. First I have to make a phonoclone for that.
greetz, MArco
The arm I've made from a badminton racket. Actually these are well suited for the job (at least the one I used). The shaft is hollow and made from carbon. But the part where the counterweight is mounted is solid (that's the part here the racket handle was mounted on).
I left a small part of the blade on the shaft, so I could fix a flat piece of aluminium as a head shell (see image). The nice thing is that there is a little bit of metal at the end of the shaft so I could use a little bolt to fix the aluminium to the arm.
I created enough degrees of freedom in the cartridge/ arm/ head shell mounting that I can have the cartridge properly aligned AND the needle exactly under the middle line of the arm (actually the line around which the mass evenly distributed in that plane). I think that's vital to keep an unipivot arm from wobbling in around it's length axis. In this way I could avoid dampening this movement.
The counterweight is made of brass strip and is clamped on the arm. Heat shrink tubing is in between. The counterweight has a few screws for azimuth adjustment and tracking force adjustment. The thread for the anti skating is also attached here.
The point of the unipivot is a dart, which I've mounted in a piece of water pipe by means of molten lead and tin. I've inserted a little tube as well trough which the arm cable runs (made from a dead mouse).
The water pipe is mounted with a standard clamping water pipe support. (excuses for my horrible English here). I hope you understand.
The arm lift is again made from a Thorens part. A bicycle brake pad supports the arm. A bicycle seat post handle is the lever for operating the lift.
Well, that's about it.
As the whole concoction operates flawlessly it's time to mount a decent cartridge. First I have to make a phonoclone for that.
greetz, MArco
Attachments
power supply
For details on the power supply see this: http://www.diyaudio.com/forums/showthread.php?s=&threadid=33479
succes, MArco
For details on the power supply see this: http://www.diyaudio.com/forums/showthread.php?s=&threadid=33479
succes, MArco
Dave,...
just get SCD or Chris to turn you a new pulley for the motor. Then you could make whatever changes to the Linn supply and still allow for future upgrades
Speaking of SCD, I finally drilled out the centre of the record clamp he gave me, not sure of the effect of the record clamp, although it definitely doesn't ring like my stock Oracle one.
If you want to regen a power supply, try playing around with oscillating crystals...and then amplifying the output. Or go DC and use a battery
just get SCD or Chris to turn you a new pulley for the motor
. Then you could make whatever changes to the Linn supply and still allow for future upgradesSpeaking of SCD, I finally drilled out the centre of the record clamp he gave me, not sure of the effect of the record clamp, although it definitely doesn't ring like my stock Oracle one.
If you want to regen a power supply, try playing around with oscillating crystals...and then amplifying the output. Or go DC and use a battery
Re: Dave,...
No Linn supply. Just an inner platter & bearing on the metal subchassis, and a motor with pulley. I figure keeping that will allow me to use a regular Linn belt.
dave
Nanook said:just get SCD or Chris to turn you a new pulley for the motor
No Linn supply. Just an inner platter & bearing on the metal subchassis, and a motor with pulley. I figure keeping that will allow me to use a regular Linn belt.
dave
and especially the badminton racket, I'll keep that one in mind
Hi miniwatt,
thank you for the nice words. At least someone seams to like it. I think most people are put of by the distinct low-fi looks. Although it is designed to LOOK very low-fi, at the same time it was designed to sound very hi-fi.
Well, I'm not quite convinced that a builder of a piece of audio equipment should comment on the sound (especially of the person designed it as well).
So I'll refrain from any hilarious comments especially while the budget test-cartridge (Ortofon OM-20) is still playing.
Nevertheless, I can conclude that it sounds better than both a standard Thorens TD 160 MK II and a modified one.
The sound is much more relaxed and firm. For example the record of Paul Simon's "Graceland" always sounded much more "bouncy" and not at all relaxed than the CD. With the new turntable it sounds much better.
Also wow and flutter is less, easily audible on Erik Saties solo piano work.
By the way, I think a badminton racket is an excellent source for arm material. The weight distribution is quite good as I obtained an arm-cartridge resonance frequency of about 12 Hz without any tuning or tweaking.
Greetz, MArco
thank you for the nice words. At least someone seams to like it. I think most people are put of by the distinct low-fi looks. Although it is designed to LOOK very low-fi, at the same time it was designed to sound very hi-fi.
Well, I'm not quite convinced that a builder of a piece of audio equipment should comment on the sound (especially of the person designed it as well).
So I'll refrain from any hilarious comments especially while the budget test-cartridge (Ortofon OM-20) is still playing.
Nevertheless, I can conclude that it sounds better than both a standard Thorens TD 160 MK II and a modified one.
The sound is much more relaxed and firm. For example the record of Paul Simon's "Graceland" always sounded much more "bouncy" and not at all relaxed than the CD. With the new turntable it sounds much better.
Also wow and flutter is less, easily audible on Erik Saties solo piano work.
By the way, I think a badminton racket is an excellent source for arm material. The weight distribution is quite good as I obtained an arm-cartridge resonance frequency of about 12 Hz without any tuning or tweaking.
Greetz, MArco
Some of the carbon-fibre kit used by model aircraft builders might be of interest as well. Hollow tapered carbon-fibre thin-wall tubes are available. In the UK you could check out this site.
http://www.freeflightsupplies.co.uk/hitech.htm
I've not used any of this stuff, but it looks of interest in making homemade arms.
http://www.freeflightsupplies.co.uk/hitech.htm
I've not used any of this stuff, but it looks of interest in making homemade arms.
Thank you for the kind words. I DID use the kitchen sink though (at least, sort of). The turntable actually started out as a test case for making my kitchen sink out of concrete.
As I do believe that tests should always be for real somehow, I decided to make a turntable as a test. I learned a lot of that, especially that I won't use this particular type of concrete for a kitchen sink.
greetz, MArco
Fantastic work.
I understand that the Thorens type bearing cannot take much more than 1 or 2 kg without excess friction and wear.
One possible solution to this is to lift some of the weight of the platter with magnets, while using the bearing to locate it. There is a thread on here about someone using magnets to totally levitate a Linn platter, but in there I posted about relieving the bearing of some of the weight of the platter.
I also want to do something fairly similar, using a concrete plinth, and possibly platter too. I was planning to use a Thorens (or possibly rega) bearing with magnets, too.
After casting the plinth, did you have to clean it up- remove material from it, or is it just 'as cast'? What concrete did you use, and why will you not use it again?
James
I understand that the Thorens type bearing cannot take much more than 1 or 2 kg without excess friction and wear.
One possible solution to this is to lift some of the weight of the platter with magnets, while using the bearing to locate it. There is a thread on here about someone using magnets to totally levitate a Linn platter, but in there I posted about relieving the bearing of some of the weight of the platter.
I also want to do something fairly similar, using a concrete plinth, and possibly platter too. I was planning to use a Thorens (or possibly rega) bearing with magnets, too.
After casting the plinth, did you have to clean it up- remove material from it, or is it just 'as cast'? What concrete did you use, and why will you not use it again?
James
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