I don't have a 2amp fuse in that size only a 6 amp one, so I've put that in & connected it back to the Linn proper (no stalling probs their) checked the fuses etc its not doing anything at all now. I think the input resistor R1 ? is ok, cant tell about the rectifier, possibly something as you say may have gotten bridged, Ive had a good look & cant see anything.
6 amps is too much ( on PCB ) . Even 1 amp is really . The point is the Valhalla is never off as fitted to LP12 , 6 amps is a minor fire risk . . I would replace the rectifier ( WO8 or W10 > 800 V PIV ) . I think it is 1AT on the fuse marking on the PCB . Make sure you are connected to live and 240 V only . Put an ohm meter on the 220 V capacitors ( Maplin cheap one will do fine ) . They should only read zero for a while .
Newcastle - Grainger Street : Maplin Electronics
Newcastle - Grainger Street : Maplin Electronics
Many interesting comments...
Nigel, I'm interested in your ideas on LP-12 sub-chassis set up. And offset of the Valhalla board. I refurbished my (circa 1985) LP-12 this summer, and spent a fair bit of time fiddling with the spring tension, to try to get the right "bounce," as described in the set-up instructions. (And other sources--I looked at several, including a youtube video on it). I settled for less than perfect. Sad to say, it went south on me within a few weeks. I've cued up another turntable for now, until I have time to work on my Linn. Any thoughts ?
Nigel, I'm interested in your ideas on LP-12 sub-chassis set up. And offset of the Valhalla board. I refurbished my (circa 1985) LP-12 this summer, and spent a fair bit of time fiddling with the spring tension, to try to get the right "bounce," as described in the set-up instructions. (And other sources--I looked at several, including a youtube video on it). I settled for less than perfect. Sad to say, it went south on me within a few weeks. I've cued up another turntable for now, until I have time to work on my Linn. Any thoughts ?
http://www.diyaudio.com/forums/analogue-source/88246-linn-lp12-files-archives.html
http://www.diyaudio.com/forums/analogue-source/135148-lp-12-mark-kellys-board-2.html
http://www.diyaudio.com/forums/analogue-source/30363-linn-lp12-first-mod.html
You'll probably find most useful information on pinkfishmedia, vinyengine and the linn-forum.
http://www.diyaudio.com/forums/analogue-source/135148-lp-12-mark-kellys-board-2.html
http://www.diyaudio.com/forums/analogue-source/30363-linn-lp12-first-mod.html
You'll probably find most useful information on pinkfishmedia, vinyengine and the linn-forum.
Paul . All I know it the most off centre spring should go near the motor ( rotate about a fixed point , view the wobble of the spring , +/- 1/10 inch is common ) . Ideally this spring should be longer . If you have a dead spring that will not seem to work it should be placed front right where the arm-board says Linn Sondek . The arm cable tension can be used to stop gyration of the bounce . Don't use it to the extent it shorts out the suspension bounce . The dealer had a box of springs .to help him . None the less it should be possible to find a good bounce with any set of springs . If not the chassis is bent ( 90% I guess were to the extent it matters , 10/1000 " at a guess ) . A simple Vernier depth gauge and the sub platter will say if it is ( set the depth and see it touches evenly the chassis at all points ) . Simply make a tool to reset it . You will be surprised how easily the bearing outer moves . The tool fitted the top bearing section ( platter side ) and looked like gas pipe . Approximately 10 inches long .
All the Linn's problems come from the centre of mass being between the arm pillar and the bearing rather than at the platter centre . This was copied from the Thorens TD 150 . The Thorens TD 160 attempted a cure by placing the front spring in about 1 inch . In my opinion it made it worse although easier to manufacture . If someone placed a mass the opposite side I dare say it would help . Myself , I see the bad ways of the Linn ensure correct set up . A deck I tried where this was solved seemed not to have the rock solid sound of a Linn . I suspect it is the very difficult set up of an LP12 that ensures it works well . It is almost binary . It is possible to set up an LP12 to have the loosest bounce rather than a vertical bounce . It will sound more detailed . It will sound wrong to my ears if you do . Also a bounce that stops quickly is unlikely to sound good . Minute adjustment of arm cable is important . If taking the cable off changes the deck position it is wrong . The arm-board can be adjusted for best looks ( 3 screws ) . We used to put superglue in the screw threads to give them strength ( let it set before putting screws in , use a cocktail stick to ration the smallest amount of glue ) . The screws are very thin and strip treads in the wood easily . The setting is not just for looks . It says if the deck has gone off tune . If the arm board is slightly off centre in the hole try again to reset it . Often this was the No1 compromise . It shouldn't be drastically out . The belt needs to be on to test bounce . If the platter is up side down the belt can be checked in rotation . It should run central . This usually requires the motor to be tilted backwards slightly . The adjustment should be 1/4 turn at a time . Do one screw up and unwind the other . Getting this wrong bends the motor . I sometimes had to straighten motors on LP12's , they didn't leave the factory that way . The tilting does involve a slight bend .
The 5 mm black bolts ( zinc plate originally ) that position and hold the springs need to be vertical . The Linn tool looked wonderful and wasn't . All you need is a tight fitting tube of about 10 inches again and a spirit level with a V groove that helps set the vertical . Check it all around as what might look vertical could be 1/8 inch out . The deck has to be level if checking this . Use the plinth wood as a reference point . Not the stainless steel plate as that has a deliberate curve , A Linn jig was very useful for this . It clamped the deck and had level adjust . 90% of LP12's needed this adjusting . The flimsy fixing of the stainless steel is deliberate . Like the tyres of a car it contributes to the suspension . Don't over-tighten the bolts . If someone has , fit a new mudguard washer and re-tighten to less than 5 lbs torque ( guess ) . The wood screw Linn us at the top is to help locate the plate and needs to be sensibly tight . Matches + wood glue restore stripped threads in the wood if they have been over tightened . The hardboard bottom is OK , the risk is emphasizing the boom the LP12 has if using something high tech . Hardboard might be a better choice than armchair engineers might think . It has minimal mass and losses energy quickly . Cardboard might be better . It is fitted to offer some electrical protection .
Finally , support the spring as you rotate it top and bottom . Move it a small amount at a time. If not the setting is lost over the next day as it unwinds . Linn suggested spit as a lubricant rather than talc . Now for a drastic solution . If the deck will not bounce I have been known to stretch the motor side spring by about 1/10 inch . This would be when miles from home and asked to set up an LP12 . It always works . The thing to say is if it went wrong I took the deck with me . You will not have a box of springs as I did .
All the Linn's problems come from the centre of mass being between the arm pillar and the bearing rather than at the platter centre . This was copied from the Thorens TD 150 . The Thorens TD 160 attempted a cure by placing the front spring in about 1 inch . In my opinion it made it worse although easier to manufacture . If someone placed a mass the opposite side I dare say it would help . Myself , I see the bad ways of the Linn ensure correct set up . A deck I tried where this was solved seemed not to have the rock solid sound of a Linn . I suspect it is the very difficult set up of an LP12 that ensures it works well . It is almost binary . It is possible to set up an LP12 to have the loosest bounce rather than a vertical bounce . It will sound more detailed . It will sound wrong to my ears if you do . Also a bounce that stops quickly is unlikely to sound good . Minute adjustment of arm cable is important . If taking the cable off changes the deck position it is wrong . The arm-board can be adjusted for best looks ( 3 screws ) . We used to put superglue in the screw threads to give them strength ( let it set before putting screws in , use a cocktail stick to ration the smallest amount of glue ) . The screws are very thin and strip treads in the wood easily . The setting is not just for looks . It says if the deck has gone off tune . If the arm board is slightly off centre in the hole try again to reset it . Often this was the No1 compromise . It shouldn't be drastically out . The belt needs to be on to test bounce . If the platter is up side down the belt can be checked in rotation . It should run central . This usually requires the motor to be tilted backwards slightly . The adjustment should be 1/4 turn at a time . Do one screw up and unwind the other . Getting this wrong bends the motor . I sometimes had to straighten motors on LP12's , they didn't leave the factory that way . The tilting does involve a slight bend .
The 5 mm black bolts ( zinc plate originally ) that position and hold the springs need to be vertical . The Linn tool looked wonderful and wasn't . All you need is a tight fitting tube of about 10 inches again and a spirit level with a V groove that helps set the vertical . Check it all around as what might look vertical could be 1/8 inch out . The deck has to be level if checking this . Use the plinth wood as a reference point . Not the stainless steel plate as that has a deliberate curve , A Linn jig was very useful for this . It clamped the deck and had level adjust . 90% of LP12's needed this adjusting . The flimsy fixing of the stainless steel is deliberate . Like the tyres of a car it contributes to the suspension . Don't over-tighten the bolts . If someone has , fit a new mudguard washer and re-tighten to less than 5 lbs torque ( guess ) . The wood screw Linn us at the top is to help locate the plate and needs to be sensibly tight . Matches + wood glue restore stripped threads in the wood if they have been over tightened . The hardboard bottom is OK , the risk is emphasizing the boom the LP12 has if using something high tech . Hardboard might be a better choice than armchair engineers might think . It has minimal mass and losses energy quickly . Cardboard might be better . It is fitted to offer some electrical protection .
Finally , support the spring as you rotate it top and bottom . Move it a small amount at a time. If not the setting is lost over the next day as it unwinds . Linn suggested spit as a lubricant rather than talc . Now for a drastic solution . If the deck will not bounce I have been known to stretch the motor side spring by about 1/10 inch . This would be when miles from home and asked to set up an LP12 . It always works . The thing to say is if it went wrong I took the deck with me . You will not have a box of springs as I did .
Thanks to you both for your suggestions !
I'll check the chassis the next time I have it accessible!
Good to know. I'll try this.
I put an acrylic baseboard on -- had a shop cut it to fit for about $15. Haven't been able to tell what difference it makes, but will do more listening tests when I get the chance.
So compress the spring, pulling it away from where it makes contact top and bottom, and rotate it slightly, let it loose, then recheck the bounce? I was alternately compressing one end, then the other, and assuming the spring would land in the right position -- one that was "stable." Didn't prove to work very well.
Actually, I have 3 sets of springs -- each set is slightly different. The set I removed was zinc in appearance, wound CCW if I remember correctly. The set I put in was the darkest, anodized, CW, and looked newest. Problem is, I bought this set so long ago (off e*bay) I can't remember if they were posted as new or not. For the time I've put into it, I think I'll pony up for a new set of springs the next chance I get !
Ultimately, if I can't get it both good and stable, I'm lucky to have an audio store nearby that has techs who still remember how to work on Linn tables !!
I'll check the chassis the next time I have it accessible!
Good to know. I'll try this.
I put an acrylic baseboard on -- had a shop cut it to fit for about $15. Haven't been able to tell what difference it makes, but will do more listening tests when I get the chance.
So compress the spring, pulling it away from where it makes contact top and bottom, and rotate it slightly, let it loose, then recheck the bounce? I was alternately compressing one end, then the other, and assuming the spring would land in the right position -- one that was "stable." Didn't prove to work very well.
Actually, I have 3 sets of springs -- each set is slightly different. The set I removed was zinc in appearance, wound CCW if I remember correctly. The set I put in was the darkest, anodized, CW, and looked newest. Problem is, I bought this set so long ago (off e*bay) I can't remember if they were posted as new or not. For the time I've put into it, I think I'll pony up for a new set of springs the next chance I get !
Ultimately, if I can't get it both good and stable, I'm lucky to have an audio store nearby that has techs who still remember how to work on Linn tables !!
Hi Paul . Zinc springs are very old , black were the improved version . New is unimportant . Some defective ones turned up from time to time . Usually too short or too long . Also too centered (place front right if so ) , ironically they need a slight offset . Again with a box of springs it was easier to spot them . We are talking 1/16 inch in any direction ( < 2 mm ) . Even so none were absolute rejects . It was just about being careful not to have the whole set like it .
Remove each spring and rubber in turn . Spit on the larger rubber where it meets the chassis . When each spring is in place go around the deck doing small rotations of the spring .Test the bounce each time . Do not compress the spring . Done this way it presents no problems . To do a deck as I describe takes 4 hours ( 1 1/2 if perfect as some were ) . If you do it will only need tweaking and might stay good for 20 years after the critical set up . If the chassis is slightly bent , no chance . I used to have one on the bench and return to it over an 8 hour day . The finishing touches the next morning .
The nuts on the spring supports need to be flat . If the spring wobbles when the nut rotates they are a problem . Somehow get the proper ones . Linn used a nut with splits in the sides , a lock nut without plastic insert .
I fancy making a new chassis for my LP12 . I suspect an aluminum + plywood composite might work . Keep the mass as low as possible , no greater than the original I hope . Use a suitable epoxy to bond it ( weighted down to a flat surface whilst bonding , glass can be OK ) . 1/8 inch plate and 3 ply . The idea is to have the greatest rigidity whilst having moderate self damping , moderate being a quality rather than a compromise . The epoxy being part of the recipe rather than just a glue . Perhaps a small ring below the bearing as a brace ( 3 bolt fixing , 1 inch ring thickness x 1/4 inch , Aluminum is usually sold in imperial sizes , 1/8 1/4 1/2 machine to 3 , 6 , 12 mm nicely . Best is 2 inch to 50 mm . 3/8 is almost 9.5 mm . 9/32 is the turntable spindle . Often made 7 to 7.1 mm to allow for LP shrinkage ) . I would use the original LP12 arm-board . I have a hunch this would equal or better the Linn upgrade . The composite is so as to have no prominent resonant frequency and damp at higher frequencies . Wood is underrated as an engineering material . It's strength to mass ratio is excellent and has a relaxed structure . Paper being an excellent example when a speaker cone . Traffolyte is made from reject wallpaper ( was in the original version ) and is the typical 1930's material used for signs on doors . I suspect it would make a good chassis . It would look beautiful and not cost too much .
Cheapest Traffolyte Material | UK Engraving Services
Remove each spring and rubber in turn . Spit on the larger rubber where it meets the chassis . When each spring is in place go around the deck doing small rotations of the spring .Test the bounce each time . Do not compress the spring . Done this way it presents no problems . To do a deck as I describe takes 4 hours ( 1 1/2 if perfect as some were ) . If you do it will only need tweaking and might stay good for 20 years after the critical set up . If the chassis is slightly bent , no chance . I used to have one on the bench and return to it over an 8 hour day . The finishing touches the next morning .
The nuts on the spring supports need to be flat . If the spring wobbles when the nut rotates they are a problem . Somehow get the proper ones . Linn used a nut with splits in the sides , a lock nut without plastic insert .
I fancy making a new chassis for my LP12 . I suspect an aluminum + plywood composite might work . Keep the mass as low as possible , no greater than the original I hope . Use a suitable epoxy to bond it ( weighted down to a flat surface whilst bonding , glass can be OK ) . 1/8 inch plate and 3 ply . The idea is to have the greatest rigidity whilst having moderate self damping , moderate being a quality rather than a compromise . The epoxy being part of the recipe rather than just a glue . Perhaps a small ring below the bearing as a brace ( 3 bolt fixing , 1 inch ring thickness x 1/4 inch , Aluminum is usually sold in imperial sizes , 1/8 1/4 1/2 machine to 3 , 6 , 12 mm nicely . Best is 2 inch to 50 mm . 3/8 is almost 9.5 mm . 9/32 is the turntable spindle . Often made 7 to 7.1 mm to allow for LP shrinkage ) . I would use the original LP12 arm-board . I have a hunch this would equal or better the Linn upgrade . The composite is so as to have no prominent resonant frequency and damp at higher frequencies . Wood is underrated as an engineering material . It's strength to mass ratio is excellent and has a relaxed structure . Paper being an excellent example when a speaker cone . Traffolyte is made from reject wallpaper ( was in the original version ) and is the typical 1930's material used for signs on doors . I suspect it would make a good chassis . It would look beautiful and not cost too much .
Cheapest Traffolyte Material | UK Engraving Services
External PCB box or replace metal brace?
Nigel, you spoke earlier about putting the PSU in an external box or replacing the metal brace the PSU is mounted to ... or putting distance in between with standoffs.
Do you think any of these are needed if the input voltage is 60 Hz, as in the U.S. ?
Nigel, you spoke earlier about putting the PSU in an external box or replacing the metal brace the PSU is mounted to ... or putting distance in between with standoffs.
Do you think any of these are needed if the input voltage is 60 Hz, as in the U.S. ?
The 60 Hz makes it slightly worse . Paxolin would be excellent as it has self damping . The 1920's solution is still the best . Plywood also as it has great rigidity . No standoffs required if those materials . The space saved might be useful . Some Nylon / fibre washers to allow for solder and wires stubs .
Be very careful when updating the Valhalla . The output voltages seem to be specific to each one . The reason being is that the voltage is set by a zener diode which will have a wide tolerance range . The 45 RPM mod seems to bring problems . I had beginners luck with the 4 or 5 I did . The recent one I tried seems to be very unhappy . Just upgrading the caps and the Paxolin would be fine and only take minutes. Don't bother using the two old caps ( retain the one output cap at 90 degrees to the others ) . 2 x 220 uF 250V is what the Valhalla needs .
Be very careful when updating the Valhalla . The output voltages seem to be specific to each one . The reason being is that the voltage is set by a zener diode which will have a wide tolerance range . The 45 RPM mod seems to bring problems . I had beginners luck with the 4 or 5 I did . The recent one I tried seems to be very unhappy . Just upgrading the caps and the Paxolin would be fine and only take minutes. Don't bother using the two old caps ( retain the one output cap at 90 degrees to the others ) . 2 x 220 uF 250V is what the Valhalla needs .
Valhalla mod
Nige,
Any joy yet with the Valhalla mod, perhaps it might be best to just revert it back to 33, Id'e be happy with that at the moment.
I have affected a Cartridge Cantilever repair, How to link:
http://www.lencoheaven.net/forum/index.php?topic=14507.msg213333#msg213333Jay
With a steady hand most will be able to fix a busted Cartridge
Jay
Nige,
Any joy yet with the Valhalla mod, perhaps it might be best to just revert it back to 33, Id'e be happy with that at the moment.
I have affected a Cartridge Cantilever repair, How to link:
http://www.lencoheaven.net/forum/index.php?topic=14507.msg213333#msg213333Jay
With a steady hand most will be able to fix a busted Cartridge
Jay
James . I did a bit of work on it and it is still misbehaving .
Would a simple original Linn circuit do ? I think the latter LP12 uses that ? If so I will test and build one . I will be in Cornwall this weekend . I could test it before then with luck post it before then .
The cartridge repair is excellent . It will be inferior to the original . However far better than a Shure .
Nige
Would a simple original Linn circuit do ? I think the latter LP12 uses that ? If so I will test and build one . I will be in Cornwall this weekend . I could test it before then with luck post it before then .
The cartridge repair is excellent . It will be inferior to the original . However far better than a Shure .
Nige
Thanks Nigel,
That would be great, just to have it running at all would be a huge improvement on a stationary platter!
And far better than no sound at all !
It was intended to show that a repair could be made to even a very small & fragile thing such as a cartridge.
When I get the Linn running again I can see & hear just how a repaired OC5 stacks up against an OC9.
Though I think if it proves to be a fair repair, sound wise, it might be worth looking for an AT stylus that comes close to the OC9 in terms of profile etc & see what happens.
Jay
That would be great, just to have it running at all would be a huge improvement on a stationary platter!
And far better than no sound at all !
It was intended to show that a repair could be made to even a very small & fragile thing such as a cartridge.
When I get the Linn running again I can see & hear just how a repaired OC5 stacks up against an OC9.
Though I think if it proves to be a fair repair, sound wise, it might be worth looking for an AT stylus that comes close to the OC9 in terms of profile etc & see what happens.
Jay
I will have a clear run at it tomorrow . The UK grid is very stable so speed should be excellent . If you haven't seen this it is exactly what is seen in the power station . All house through the UK are the same as it is a National grid . 50 Hz = 33 1/3 RPM . Humans can hear at best 49.95 to 50.05 Hz
Dynamic Demand
Dynamic Demand
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