I know a few things about the Linn ...
I've been gathering info on the Linn TT for a few months; my power control board went down this Spring, and I just installed a replacement Valhalla board (also newer than the one I had, so had a few updates).
The first thing to know is that because the Linn TT uses a "synchronous" AC motor, the speed of rotation is dependent on the line frequency, not voltage. So the motor spindle (also called the pulley) will have a different diameter for a 50Hz motor vs. a 60 Hz motor. If I understand correctly, Linn sold all their LP-12 'tables for use with 50 Hz output, whether in Great Britain or the U.S. The less expensive Basic TT would be different, and would come outfitted with a 60Hz motor. So if you upgrade a Basic to use the Valhalla or Lingo power supplies, you have to replace the motor and spindle as well.
A variation on the Valhalla PSU is manufactured and marketed by a third-party -- this is the Hercules power supply, and its variants. This can be obtained as an "outboard" PSU, or tucked in under the TT sub-chassis. Many speak highly of the Hercules, and many feel that separating the PSU from the TT makes an audible improvement as well. The Hercules comes in both 50-Hz and 60-Hz versions, though I think the 60-Hz may be harder to find.
Probably the second thing to know about these power supplies is that they are transformerless, so can be vastly more dangerous for the diy'er than other projects. I didn't even take any meter readings from my replacement board until I hooked up a proper isolation transformer. (That is, I modified a commercial isolation transformer to remove the ground reference, to create a "tech bench isolation transformer" for this use).
Schematics of the Valhalla board can be found online. Are you thinking of designing your own PSU, or modifying an existing one? What other info are you looking for?
I've been gathering info on the Linn TT for a few months; my power control board went down this Spring, and I just installed a replacement Valhalla board (also newer than the one I had, so had a few updates).
The first thing to know is that because the Linn TT uses a "synchronous" AC motor, the speed of rotation is dependent on the line frequency, not voltage. So the motor spindle (also called the pulley) will have a different diameter for a 50Hz motor vs. a 60 Hz motor. If I understand correctly, Linn sold all their LP-12 'tables for use with 50 Hz output, whether in Great Britain or the U.S. The less expensive Basic TT would be different, and would come outfitted with a 60Hz motor. So if you upgrade a Basic to use the Valhalla or Lingo power supplies, you have to replace the motor and spindle as well.
A variation on the Valhalla PSU is manufactured and marketed by a third-party -- this is the Hercules power supply, and its variants. This can be obtained as an "outboard" PSU, or tucked in under the TT sub-chassis. Many speak highly of the Hercules, and many feel that separating the PSU from the TT makes an audible improvement as well. The Hercules comes in both 50-Hz and 60-Hz versions, though I think the 60-Hz may be harder to find.
Probably the second thing to know about these power supplies is that they are transformerless, so can be vastly more dangerous for the diy'er than other projects. I didn't even take any meter readings from my replacement board until I hooked up a proper isolation transformer. (That is, I modified a commercial isolation transformer to remove the ground reference, to create a "tech bench isolation transformer" for this use).
Schematics of the Valhalla board can be found online. Are you thinking of designing your own PSU, or modifying an existing one? What other info are you looking for?
No, I was thinking of importing EU table to US and a possibility of voltage conversion.
I have early Linn , nirvana (I think it's correct name for one speed controller) which has 60hz pulley so yes, there are 60hz versions of nirvana/ valhalla out there. I think I'll try DIY Geddon supply for this one. Thank You for a nice post!
I have early Linn , nirvana (I think it's correct name for one speed controller) which has 60hz pulley so yes, there are 60hz versions of nirvana/ valhalla out there. I think I'll try DIY Geddon supply for this one. Thank You for a nice post!
Converting an EU table
If you end up importing a Linn table from the EU, I would expect it to be easy to switch over to US mains voltage and frequency -- I'm assuming Linn designers have been consistently great in this regard. I only know in detail about the Valhalla board -- for the Valhalla, the changeover would involve opening the unit and moving the location of one fuse and one power cord wire. A simple ten minute project, if that.
If you end up importing a Linn table from the EU, I would expect it to be easy to switch over to US mains voltage and frequency -- I'm assuming Linn designers have been consistently great in this regard. I only know in detail about the Valhalla board -- for the Valhalla, the changeover would involve opening the unit and moving the location of one fuse and one power cord wire. A simple ten minute project, if that.
I'm using an externally mounted Hercules II. It's definitely a sonic upgrade over a later Valhalla, plus you get 45 RPM.
jeff
Guess I'll butt right in...
The simplest and quickest way to do a speed conversion (non-electronically) is buy the correct motor pulley from the maker of the turntable, or get a new pulley machined if one is not available. As trupaul points out the frequency of the mains determines the speed of synchronous motors. Those of us in North America have 115VAC@60Hz, and Europe usually has 220VAC@50 Hz. The motors themselves are the same motors, just the voltage being fed to the circuitry prior to the motor and the frequency vary.
If one were to create a 50Hz PS, with the appropriate voltage, then you could run a European table here without any other changes. If creating a 60Hz PS, then a smaller diameter pulley would need to be had or as stated above, a 60Hz pulley from the table manufacturer. The math is just a simple equality:
D₁*S₁=D₂*S₂
where the subsrcipt indicates a specific motor and pulley, D is pulley diameter, S is in RPM. To solve for a new Diameter pulley:
D₂= D₁*S₁/S₂
We know that common synchronous motors used in turntables spin at 300RPM in North America, and 250RPM in the UK (for example). We can measure D₁ and know S₁ and S₂. Just plug n' chug.If an Ariston (or Linn or whatever) uses a 38mm pulley in the UK, we then know that it requires a 31.66mm pulley to operate at the correct speed in North America, or we must generate a 50Hz signal and step up the voltage to the point that there is around 80VAC to 90VAC (the common Airpax/Thomson motors as used in many turntables are quietest around 72 VAC, but that could be just for a specific motor example not all motors of that part number).
Don't hate me: I bought a Roksan Xerxes for $150 (in CAD) that required a minor tweaking to the power supply. Once completed it was speed stable. YMMV. I think the final output was 78 VAC@50Hz.
The simplest and quickest way to do a speed conversion (non-electronically) is buy the correct motor pulley from the maker of the turntable, or get a new pulley machined if one is not available. As trupaul points out the frequency of the mains determines the speed of synchronous motors. Those of us in North America have 115VAC@60Hz, and Europe usually has 220VAC@50 Hz. The motors themselves are the same motors, just the voltage being fed to the circuitry prior to the motor and the frequency vary.
If one were to create a 50Hz PS, with the appropriate voltage, then you could run a European table here without any other changes. If creating a 60Hz PS, then a smaller diameter pulley would need to be had or as stated above, a 60Hz pulley from the table manufacturer. The math is just a simple equality:
D₁*S₁=D₂*S₂
where the subsrcipt indicates a specific motor and pulley, D is pulley diameter, S is in RPM. To solve for a new Diameter pulley:
D₂= D₁*S₁/S₂
We know that common synchronous motors used in turntables spin at 300RPM in North America, and 250RPM in the UK (for example). We can measure D₁ and know S₁ and S₂. Just plug n' chug.If an Ariston (or Linn or whatever) uses a 38mm pulley in the UK, we then know that it requires a 31.66mm pulley to operate at the correct speed in North America, or we must generate a 50Hz signal and step up the voltage to the point that there is around 80VAC to 90VAC (the common Airpax/Thomson motors as used in many turntables are quietest around 72 VAC, but that could be just for a specific motor example not all motors of that part number).
Don't hate me: I bought a Roksan Xerxes for $150 (in CAD) that required a minor tweaking to the power supply. Once completed it was speed stable. YMMV. I think the final output was 78 VAC@50Hz.
17mm 60Hz pulley?
limono: I did the math, and it should be 17.50 mm. Regardless, the replacement of the motor pulley with a factory one should be suitable enough. Any pulley that is the same size as one made for that table for the North American market should be suffice. Minor tweaking can be easily done.
About the Xerxes: Somehow I ended up gifting it to a friend (not my original intent, I wish I had tried it in my system first). We rewired an RB250, put a tecno-weight on it, and a VTA adjuster nut from JAMichelle. The "sagging plinth" had to be addressed, and was done easily with some threaded rod and couple of nuts. The suspect "blobs" (Roxan's nomenclature not mine) were replaced with squash balls to good effect. A Denon DL103r now sits on it feeding a modified Jolida JD9A phonostage.
limono: I did the math, and it should be 17.50 mm. Regardless, the replacement of the motor pulley with a factory one should be suitable enough. Any pulley that is the same size as one made for that table for the North American market should be suffice. Minor tweaking can be easily done.
About the Xerxes: Somehow I ended up gifting it to a friend (not my original intent, I wish I had tried it in my system first). We rewired an RB250, put a tecno-weight on it, and a VTA adjuster nut from JAMichelle. The "sagging plinth" had to be addressed, and was done easily with some threaded rod and couple of nuts. The suspect "blobs" (Roxan's nomenclature not mine) were replaced with squash balls to good effect. A Denon DL103r now sits on it feeding a modified Jolida JD9A phonostage.
The stock pulleys are slightly barrel shaped, and are pressed on to the motor shaft, not easy to remove unless you have a small arbor press. The barrel shape gives the user a small speed adjustment.
jeff
Advice on Hercules PSU for Roksan Xerxes
I've just come into ownership of a Roksan Xerxes and am in need of a power supply. A fellow on ebay is selling a Mose/Hercules PSU (Simplified Mose Hercules II for Turntables Similiar to Linn LP12 Upgrade | eBay) which he noted would work for the Roksan.
Anyone ever used/bought one of these? Do you have a sense of how involved the work would be to get it working with the turntable?
Thank you.
I've just come into ownership of a Roksan Xerxes and am in need of a power supply. A fellow on ebay is selling a Mose/Hercules PSU (Simplified Mose Hercules II for Turntables Similiar to Linn LP12 Upgrade | eBay) which he noted would work for the Roksan.
Anyone ever used/bought one of these? Do you have a sense of how involved the work would be to get it working with the turntable?
Thank you.
I came a crossed this design, TTPSU, which was designed by Jonny Norre (c 2006 DuNo Electronics I/S) for any 2 phase AC motor. Has anyone built one of these? I would like to try it, if I could get a circuit board. The article I found had a Eagle Layout file with the pcb. No sure if a pcb could be made from it? Anyone know where I can get a pcb made?
I attached the document.
I attached the document.
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