Yes and makes people think it is of higher quality. The mass Thorens, Linn and Garrard used seems almost the best you can do ( about 6 lbs and flywheel mass to the other rim ). A friend insisted on using a Garrard 401 platter on his Technics 1210, it sounds very good. It was a small bit of work on the lathe to get it to fit. The plinth is solid wood.
LP12 springs work very well in the TD160 so should in the TD125. They are a bit stiffer which could help. The TD125 has the very best motor drive until this very day. It has a Wien oscillator and the motor is a low voltage synchronous motor to run from boosted op amps. From memory the Wien is a propper quadrature type giving sine and cosine outputs unlike Linn Valhalla. It uses a small light bulb to make it gain stable. WD40 being a repair sometimes to the switch contacts. Transitors not unlike BC327/337 ( 2 of each ). Linn missed a trick with the Valhalla. The Airpax motor would be a simple rewind for 2 x 7 Vrms. That motor is a doddle to open and will solder back together if zink plating removed. I have fixed many of the motors this way when a coil went open circuit. Just solder to the old clamping points. Standard solder and a very hot iron.
A good Valhalla upgrade is an isolation transformer giving either 115 or 230 V with fuse moved to corect position. It seems to work by allowing the Valhalla to float. Centre grounding is worse although better than standard! A nearly equal upgrade is 2 x 220 uF 250 V for the main caps. The one that goes to the motor is optional. This is worth about 9 db better beat frequency measured for the two mods ( beat between cap ripple and fixed 50 Hz ). The caps being the cheaper option. 220 uF does not cause the rectifier any problems. The 47 R carbon comp resistor and rectifier often fail without any other damage, comp is a good choice for inrush. The latter Valhalla seem to have an inrush thermistor. The big resistors often unsolder themselves and can fail.
Thanks Chris.
LP12 springs work very well in the TD160 so should in the TD125. They are a bit stiffer which could help. The TD125 has the very best motor drive until this very day. It has a Wien oscillator and the motor is a low voltage synchronous motor to run from boosted op amps. From memory the Wien is a propper quadrature type giving sine and cosine outputs unlike Linn Valhalla. It uses a small light bulb to make it gain stable. WD40 being a repair sometimes to the switch contacts. Transitors not unlike BC327/337 ( 2 of each ). Linn missed a trick with the Valhalla. The Airpax motor would be a simple rewind for 2 x 7 Vrms. That motor is a doddle to open and will solder back together if zink plating removed. I have fixed many of the motors this way when a coil went open circuit. Just solder to the old clamping points. Standard solder and a very hot iron.
A good Valhalla upgrade is an isolation transformer giving either 115 or 230 V with fuse moved to corect position. It seems to work by allowing the Valhalla to float. Centre grounding is worse although better than standard! A nearly equal upgrade is 2 x 220 uF 250 V for the main caps. The one that goes to the motor is optional. This is worth about 9 db better beat frequency measured for the two mods ( beat between cap ripple and fixed 50 Hz ). The caps being the cheaper option. 220 uF does not cause the rectifier any problems. The 47 R carbon comp resistor and rectifier often fail without any other damage, comp is a good choice for inrush. The latter Valhalla seem to have an inrush thermistor. The big resistors often unsolder themselves and can fail.
Thanks Chris.
That is exactly what I have in mind to try. We have an old Garrard 201 circa 1938 direct drive. Also a 1952 version with 33/45. The idea was to get the best possible distance between motor and stylus ( hum ) . Also for use on a 301 for interest. Bakerlite is very good. I suspect in India it is possible to have things made from it ? Bearing noise is usually less of a problem than people think. Motor noise a greater problem. All the same it is exactly right to say this, noise is noise. Cracked glass is very good. The car window type sometimes sold as bullet proof glass. Some crack a middle layer of three.
Hi Nigel,
Thank you!
Now I will need to find a source for those and have the table set up.
Have you seen the suspension made from small wire cable bent in a circle with mounting "blocks" at each end? I have a sample from somewhere. It has very high internal loss and is reasonably stiff. The amount and thickness of the loops determine what load it can support and what the natural resonant point would be. This is what I want to try with the TD-125. This would be for the subchassis. These act very much like a damped shock from what I can determine.
Those old glass air dampers might also be the ticket as well. I used to see them on multi-track tape machines (Tascam 8516) to damp the arm movement. They would beat the normal suspension and also provide a way of tuning the suspension (some have variable air leaks). From what I can see, they will last longer than the motor might. Just throwing out some ideas for you. I can't remember the manufacturer at the moment. I'll post it as soon as I find their catalog.
-Chris
Thank you!
Now I will need to find a source for those and have the table set up.
Have you seen the suspension made from small wire cable bent in a circle with mounting "blocks" at each end? I have a sample from somewhere. It has very high internal loss and is reasonably stiff. The amount and thickness of the loops determine what load it can support and what the natural resonant point would be. This is what I want to try with the TD-125. This would be for the subchassis. These act very much like a damped shock from what I can determine.
Those old glass air dampers might also be the ticket as well. I used to see them on multi-track tape machines (Tascam 8516) to damp the arm movement. They would beat the normal suspension and also provide a way of tuning the suspension (some have variable air leaks). From what I can see, they will last longer than the motor might. Just throwing out some ideas for you. I can't remember the manufacturer at the moment. I'll post it as soon as I find their catalog.
-Chris
Air dampers Customizable Pneumatic Actuators, Dashpot & Snubber Experts - Airpot Corporation still very alive and well. Great toys and with adjustable damping for many hours of tweakdom fun.
I never knew the Valhalla drive was single phase. Kinda cheap and nasty under the circumstances. I designed the first gen drive for the Rockport as a two phase drive which is really not hard to do. Just use a state variable oscillator. I also set it up to reduce the drive after about 10 seconds to the minimum necessary and made the two phases separately adjustable to minimize vibration. Ultimately you are limited by the balance etc. of the motor.
I have the drawings for the circuit somewhere and can share them if anyone is interested.
I never knew the Valhalla drive was single phase. Kinda cheap and nasty under the circumstances. I designed the first gen drive for the Rockport as a two phase drive which is really not hard to do. Just use a state variable oscillator. I also set it up to reduce the drive after about 10 seconds to the minimum necessary and made the two phases separately adjustable to minimize vibration. Ultimately you are limited by the balance etc. of the motor.
I have the drawings for the circuit somewhere and can share them if anyone is interested.
Hi Demian,
Sure, it would be interesting. Don't go nuts looking for the drawings. I know what finding old paperwork can be like.
Linn service and parts are both grossly overpriced in these parts. From what I've seen, the Linn "upgrades" ought to be warranty fixes. For the money they charge, what you get is inexcusable. I was expecting quadrature drive electronics like the Thorens. Nope.
I did my first upgrade for someone in 1/2 hour coming in completely cold and not knowing what to expect. The local Linn guy was charging $300 plus parts for the same work.
-Chris
Sure, it would be interesting. Don't go nuts looking for the drawings. I know what finding old paperwork can be like.
Linn service and parts are both grossly overpriced in these parts. From what I've seen, the Linn "upgrades" ought to be warranty fixes. For the money they charge, what you get is inexcusable. I was expecting quadrature drive electronics like the Thorens. Nope.
I did my first upgrade for someone in 1/2 hour coming in completely cold and not knowing what to expect. The local Linn guy was charging $300 plus parts for the same work.
-Chris
Here is a poor scan of the oscillator circuit.
There are two oscillators, one for 33 and one for 45. The trimmers in the oscillators are for frequency. There are also level trimmers for both phases and I used CMOS to select the speed. Its doesn't show the LME 3886's used to drive the output transformers.
I have another more elaborate variation that allows continuous adjustment from below 30 to 90 RPM and used with a 2 speed motor allows for 1/2 speed transfers. This was used in a system for Columbia/Sony to transfer old lacquers and disks from the vault to digital. That used a constant current drive to the motor so the internal flux was pretty constant as the speed changed. It worked quite well. It may have produced less torque ripple etc. as well but that's only speculation.
Needless to say these were not $500 add ons to build, but in volume they do not need to be expensive.
There are two oscillators, one for 33 and one for 45. The trimmers in the oscillators are for frequency. There are also level trimmers for both phases and I used CMOS to select the speed. Its doesn't show the LME 3886's used to drive the output transformers.
I have another more elaborate variation that allows continuous adjustment from below 30 to 90 RPM and used with a 2 speed motor allows for 1/2 speed transfers. This was used in a system for Columbia/Sony to transfer old lacquers and disks from the vault to digital. That used a constant current drive to the motor so the internal flux was pretty constant as the speed changed. It worked quite well. It may have produced less torque ripple etc. as well but that's only speculation.
Needless to say these were not $500 add ons to build, but in volume they do not need to be expensive.
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Hi Chris. This would be a very good thread and I would not be an expert ( a bit time limited right now also ). I am using a 1989 LP12 again whilst my old company is building me a Garrard 401 ( my own ) and a plinth. For that I will use squash balls as they seem to work surprisngly well. You are right about tuning. Put simply just like a motorcar the suspension needs to be very loose and very tight. The AR/TD150/RD11/LP12 set up is not bad and has subtle ways of working that often seemed wrong to someone who guessed at the importance of decoupling. Linn copied the TD150 compromise that allows the deck to resist what became called dynamic wow. If the deck is too loose in the rotational sense the deck can resonate. To my ears the LP12 is as good as it can be whilst having useful decoupling. What a lot of people will not know is the LP12 is mostly decoupling it's motor. Squashballs tend to prove this on a Garrard as room effects are neither better nor worse. Use a 60 dB scale and RIAA correction if wanting to look at that. Never forget the rotational problems even if you can get a better feedback decoupling . The effect of that is performers who seem slightly drunk. The belt itself is half of it ( put simply and not as a ratio ).
One thing you can try with a LP12 and similar turntables. If you set up the motor to have massive vibration ( wrong capacitor ) it will sound mostly the same. If you reduce the motor voltage ( with ideal capacitor found by selection ) it will sound very different. The range is 60 to 120 Vrms. This to me says the LP12 belt is a device for low cost motors, the Airpax is one regardless of it's now price. It is a very good belt in terms of quality control. TD150 belts last about 6 months, my LP12 belt is the 1989 one and is as new. It is possible a LP12 belt could be made to work on a TD150/160/145/125.
Dejan. I am backwards engineering a Rega P2 ( Colleen has one ). I am going to ask an engineer I know in Yorkshire if he can sell me his top grade albeit simple bearing as an over the top upgrade. I have a very limited budge but might just afford this. Compared with LP12 or SME30 this bearing is much harder , I won't quote the exact number as I guess no one would believe it. This wont make a big deal difference, but will make it best of type. The motor is sorted ( I hope ). The arm will be RB250 or whatever it is called now and I suspect the Rega Carbon ( AT91 ). If the budget allows an arm wire improvement. In the ideal world I would use Bakerlite for the platter. There is one twist I will get killed for saying so must keep quiet.
I have used a SVFO for years. The one at ESP Audio looks similar. The text book Quadrature type says R1 needs to be smaller to have oscillation. It seldom works as well as said. The Valhalla is fine if the capacitor is carefully chosen ( 220 nF ). For 45 RPM I keep it the same as 33 1/3 as it seems to start better. There is a crystal that is about 0.2% out , someone said a colour burst type, no idea if right, The pot after the Valhalla CD4060 needs shorting with a resistor to get 110 V ideally when 45 RPM, the filter is too steep to give the best voltage when 67.5 Hz.
I hadn't realised Pluto was to be visited. I always doubted I would see that in my lifetime. My mum started to be before it's discovery and my dad slightly after. To see something that small that long ago is hard to believe. Should be about now it happens.
Yes sir Bakelite sheets are available. Polychem.
Little more than one hour from my place. Don't know if bakelite is safe health wise. I have seen very old (Probably 70 years) bakelite/brass electrical switches at my grandparents home like this. Nice tactile feel and still working, so can be considered durable. Glass Epoxy sheets are available too. Can they be used for plinth ? sandwiched between metal plates ?
Fortunately Nige, my worries are oh so much simpler. I will remain loyal to my Dual 604 direct drive TT and it's by now standard Ortofon LM20 pickup. AS I said before, I have not heard any cartridge play as well as that one on this TT, and I have never heard the Ortofon cartridge play better on any other TT. A limited comment, of course, I haven't exactly been trying by testing all that many cartridges.
I first have to freshen up the servo circuit, based on the NE555 timer by chnaging all of five (5) capac itors present on its motherboard. Then i have to clean the bearings and its gimbal suspension and to oil what's in need of oil (and that's not much). All that is no problem.
But I should buy a replacement Ortofon LM20 tip, which costs €170, which I find to be a rather steep price. It will be ordered by a friend in Germany, so I evade shipping costs, customs duties and local VAT. That should save me some € 52. With all the wild expenses I have been subjected to this year, that sum has a good meaning.
Oh yes, I am looking forward to the summer holidays, scheduled to begin on August 4. In Greece, where else? One of four apartments in a private villa, with its own decent size swimming pool. Just what I need, what with my challenged walking capabilities. Goddamn diabetes ate up my nerve ends. While my sugar counting never went over 7, I have akways had 6.8-7 all my life.
I first have to freshen up the servo circuit, based on the NE555 timer by chnaging all of five (5) capac itors present on its motherboard. Then i have to clean the bearings and its gimbal suspension and to oil what's in need of oil (and that's not much). All that is no problem.
But I should buy a replacement Ortofon LM20 tip, which costs €170, which I find to be a rather steep price. It will be ordered by a friend in Germany, so I evade shipping costs, customs duties and local VAT. That should save me some € 52. With all the wild expenses I have been subjected to this year, that sum has a good meaning.
Oh yes, I am looking forward to the summer holidays, scheduled to begin on August 4. In Greece, where else? One of four apartments in a private villa, with its own decent size swimming pool. Just what I need, what with my challenged walking capabilities. Goddamn diabetes ate up my nerve ends. While my sugar counting never went over 7, I have akways had 6.8-7 all my life.
Bakelite possibly isn't safe, but is wise. A friend in Germany makes a material called RDC. We always upset him by calling it his Bakelite. RDC was from post 1945 German submarines adapted to audio energy levels. RDC is super safe. The 1950's RDC offered a way of subs being quieter. As vibration isn't always a simple question RDC is a broadband vibration solution. The link with the subs is only in that he approached it's inventor to be sure no patent issues existed. The originator was delighted it had been adapted, he was a very old man and possibly not alive now.
A friend of mine was astonished I was making a turntable. For perhaps 30 years we have talked about them. My day job isn't making them. So I said this. Mr Westerby our local heart specialist most likely could do any hospital work within reason that involves a knife. He is known for artificial hearts. I must have worked on 3000 to 4500 turntables so know a little. 1500 were of my own design albeit an improved version of a Percy Wilson design. It is just possible it is 5000, I never kept an exact account.
Good on you Dejan. I should go to Corfu again and show solidarity. Have the very best holiday possible. My dad has the CS510, wish it was the DD as I would measure it. I had a CS704 briefly and liked it very much. Piano music was rock solid and it had a broadcast quality about it. If being critical broadcast via a good FM radio and not as in the studio. That's not a big critism really. The LP12 as much as I knock it, now is my better source. It is sad to get like I have and treat it like a cast off girlfriend.
I hit 7 the other day on my blood count, I won't say been there done that as this is only the last 5 years of my life. I lived to see Pluto so must be happy. I was tested for Parkinsons which it seems is not exactly what I have. Very honestly Dr Hu ( sounds like Who ) said they don't know it all and 5 years ago knew very little. Seeing as the Oxford hospital is a teaching hospital it will be as good as the best. That honesty was so refreshing. I don't always see it in hi fi people. At least I am not pumped with Parkinsons drugs for no good reason as I would have been. The scan was done with a radioactive source and was the best scanner in the hospital. As Oxford is where scanners started that is likely to be world class.
I have built gradient coils for scanners and tested them in X Y Z and worked a bit with the electronics. The gradient and a very strong magnet work together to show what we call a scan ( that saves pages of writting ). The tests of the coils being a set of magnetic fields looking quite like a sine wave tested with a calibrated magnetometer ( Bartington, interesting how they work ). The qustion being the X Y Z should come to a focus where designed for. That isn't always at the exact centre. We used a big Amcron amplifier using 3 phase power to do the tests. The gradient also has an active shield which is verified by inductance tests. The inductance of the two coil sets connected being lower than the main coil when correct ( about 10% less if I remember ). Magnets can be as low as 1.5 Tesla and rarely above 8 Tesla. We had a supposed 23 Tesla magnet for undisclosed use. I worked for the inventor(s) of scanners. I never met him. The stability needed is about 10 power 8 to have any chance of working. That is power 3 better than active magnets with electonics could do. I did propose how that could be solved. My boss said I think if I remember " And kill the goose that lays the golden eggs Nigel "? He was also a Pearson which didn't help.
Hi Demian,
Many thanks sir! Nicely done circuit. I can get the jest through the unclear copy. That was enough though, don't worry about getting anything more clear.
Handling the oscillator change was inspired thinking. Why not? It clearly works in addition to "looking right". Too bad Linn didn't simply use your designs. It would have saved a lot of people a great deal of money and grief. Give something a cute name and call it an upgrade is a warranty dance they pulled off.
-Chris
Many thanks sir! Nicely done circuit. I can get the jest through the unclear copy. That was enough though, don't worry about getting anything more clear.
Handling the oscillator change was inspired thinking. Why not? It clearly works in addition to "looking right". Too bad Linn didn't simply use your designs. It would have saved a lot of people a great deal of money and grief. Give something a cute name and call it an upgrade is a warranty dance they pulled off.
-Chris
Hi nigel,
Someone else will have to dive into that thread. I'm too busy right now to give it any attention also. I would say that the TD-160 dimensioned belt seemed to have a long life. My father had a TD-160 and the family still has it. This is where the name Thorens first came into my life. Several tables later of all kinds, and the TD-125 really stands apart.
Do you recall a product called a "Platter Matter"? It is a cleanable plastic mat that bonds to the record. You have to (lightly) peel the two apart after play. The material is also very dead to vibration. That thing put my table over the top as the small amount of noise in the background vanished completely. It also cleaned up the music so you could clearly hear pre-echo between cuts. The mat was about 3/8" to 1/4 thick. It may have been called something else in England. If you haven't tried one, try one for sure.
-Chris
Someone else will have to dive into that thread. I'm too busy right now to give it any attention also. I would say that the TD-160 dimensioned belt seemed to have a long life. My father had a TD-160 and the family still has it. This is where the name Thorens first came into my life. Several tables later of all kinds, and the TD-125 really stands apart.
Do you recall a product called a "Platter Matter"? It is a cleanable plastic mat that bonds to the record. You have to (lightly) peel the two apart after play. The material is also very dead to vibration. That thing put my table over the top as the small amount of noise in the background vanished completely. It also cleaned up the music so you could clearly hear pre-echo between cuts. The mat was about 3/8" to 1/4 thick. It may have been called something else in England. If you haven't tried one, try one for sure.
-Chris
Turns out its cheaper than switches for caps. (TL074 is less that $1 in small quantity.) And you can optimize each oscillator. They are always on so a 10 second stabilization is not an issue.
Nige, I harbour no false hope that my modest CS 604 Dual TT is more than just that, a modest model, distinguished only by its unusually good compatibility with low mass cartridges, such as Ortofon's LM series. All that means is that with LM cartridges, it manages to sound a bit better than one would expect of its price class. Its resonance peaks at just +2 dB and that in the optimal range 8...10 Hz. This was achieved with their double mechanical antiresonance filters. And it a DD, so no hassels with belts, stretching, slipping and clutches. Hassle free.
I keep it because I am emotionally attached to it and for the sake of my 400+ LP collection which I also intend to keep. But my primary music source today is the CD player, the NAD C 565BEE, which I feel is a surprise machine and performs quite a bit better than you'd expect from its price class and of NAD in general.
That's good enought for me. I don't want to be too ambitious.
I keep it because I am emotionally attached to it and for the sake of my 400+ LP collection which I also intend to keep. But my primary music source today is the CD player, the NAD C 565BEE, which I feel is a surprise machine and performs quite a bit better than you'd expect from its price class and of NAD in general.
That's good enought for me. I don't want to be too ambitious.
Dejan. I have a total interest in turntables so nothing is uninteresting. Dual in details of engineering is better than any I know. It is clock engineering at it's best. The PE turntables are very interesting. A Dual familly member who wanted to do better. Some say he never listened to them as they sound relentless ( too ridged ?) . Engineered by logic rather than by ear perhaps? That says they might be excellent with a little work.
Today if I have a moment I will try to build what I would call a 1920's solution. It is so simple it should be easy to follow and even easier to make. It asumes you already have a sine wave oscillator. I will add a circuit if not. Here is a list of worthy turntables.
Kenwood Trio KD 1033 - Pioneer PL12D
Dual CS 505 ( and nearly all other Dual )
Rega 2
Ariston RD 80 ( must be cheap )
TD150 / 160 ( AR ) 145 / 125
Technics 1210
Systemdek
Lenco 75
TD124 (I prefer Lenco based on price )
LP12 ( some are cheap enough ).
Garrard 301/401
These are ones you might find on eBay. Plenty more like ERA mk 6 if ever seen. Even at the silly prices seen now Lenco is the interesting one. One day I will get some real hands on with a Technics 1210. Until then it isn't quite a winner for me. My friend Bobs one is so it can be done.
Today if I have a moment I will try to build what I would call a 1920's solution. It is so simple it should be easy to follow and even easier to make. It asumes you already have a sine wave oscillator. I will add a circuit if not. Here is a list of worthy turntables.
Kenwood Trio KD 1033 - Pioneer PL12D
Dual CS 505 ( and nearly all other Dual )
Rega 2
Ariston RD 80 ( must be cheap )
TD150 / 160 ( AR ) 145 / 125
Technics 1210
Systemdek
Lenco 75
TD124 (I prefer Lenco based on price )
LP12 ( some are cheap enough ).
Garrard 301/401
These are ones you might find on eBay. Plenty more like ERA mk 6 if ever seen. Even at the silly prices seen now Lenco is the interesting one. One day I will get some real hands on with a Technics 1210. Until then it isn't quite a winner for me. My friend Bobs one is so it can be done.
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