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Warren Jones

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About Warren Jones

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    Warren

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  1. This is measured from the bearing, but it shows how much energy the stylus imparts into the LP. https://korfaudio.com/blog44
  2. Drop the stylus on an LP with the volume control down and place a stethoscope on the plinth. Another good test if you have 2 arms is to place 1 stylus in the runout groove and listen to it while the other arm plays music, you will be surprised how much of the music is picked up by the stylus in the runout groove.
  3. Weights/clamps couple the LP to the platter so if they deaden the sound then what is happening is they are highlighting other deficiencies in the chain. Any form of damping (other than viscous) that has a negative impact on SQ is highlighting other issues, narrow vs broad band damping. Lets look at the Physics of the stylus LP interface. The LP is exerting a force on the stylus (the groove modulation) classical physics tells us the stylus will push back on the LP with equal and opposing force. So the stylus is vibrating the LP, this vibration energy must be dealt with or the result w
  4. This is a difficult question to answer, it would certainly effect the suspension, which would need to be adjusted depending on the weight of the ring/clamp It may be better to use a reflex clamp like the Mitchel. The issue with adding clamps peripheral rings and other addons is what part of the reproduction does it effect. To give an example if the a ring and center weight are added and in conjunction with the platter/mat it only damps HF vibration and has no effect on LF vibration the sound will become muddy. BUT if the damping is wide band and damps all vibration equa
  5. Wow a Deckstand I have one of those packed away in the workshop. Nice setup too
  6. Not the same, the foam inside the spring cage is to damp spring resonance. The measurements are down this page.
  7. I use similar springs under my TT, after doing some testing with a spectrum analyzer with the stylus on a stationary LP running a sweep from REW I found adding a very small foam damper that JUST touches each spring improved the performance significantly.
  8. Ok here is my experience. I started with a center weight but found it kicked up the outer edge of the LP sometimes. When I used the linear arm the carriage would touch a warped LP so I made a reflex clamp similar to the Mitchel which worked well to flatten all but the very worst warps. I now use a center weight and peripheral ring which is by far the best for SQ and flattening almost any warped LP.
  9. My LP's moved from Sydney to Perth and back to Sydney in cardboard boxes with no ill effect apart from losing 2 boxes.
  10. Hi Andy, IMD is primarily caused by non-linearity in the amplification device/s. No active device is perfectly linear and good designers choose devices with good linearity across the audio band. Then they need to ensure that the devices operate within these parameters. This is why IMD and THD increase with output level, and specs should include output level for the % distortion. To give you simple example. Say an amplifier has good linearity at 1kHz and poor linearity at 100Hz these signals will mix causing one signal to modulate the other.
  11. Further information: I have 4x SP10mk2's and have decided to sell this one after building my highly modified SP10, note this one is stock. This was my daily TT and is the same SP10 I have posted about in the SP10 thread, the one that had the linear tracking arm in the photo (not include in this sale). The TT came from a NSW radio station. I am a retired qualified electronics technician and have fully serviced this unit including. * Re-capped and voltages adjusted. * Reference oscillator and period adjusted and the unit has been tested. In fact I used it
  12. To put this in perspective Sydney median house price in 1972 was about $64k so it's a tad more than 1% of the median house price.
  13. After lockdown ends I have a couple of spare carts you are welcome to try out. I live about 1.5hrs west of Geelong. You would also be welcome to come and listen to a Stanton 881s. IME vintage cartridges are as good or better than a lot of carts made today and this will at least give you another reference.
  14. When I rebuilt one motor I removed the spindle from the rotor. The spindle from the factory is glued into the rotor. To rectify this I made a brass insert, both the insert and spindle are now a press fit. Damping was also added in the form of Blu Tack to both the rotor and motor housing. Next mod is a new 10mm spindle and PTFE bush in place of the bronze. The main reason for this mod is to delete the C clip which reduces spindle diameter and will allow the spindle to flex just above the bearing sleeve.
  15. Another platter made from POM for a friend. The POM sits directly on the motor and there is a gunmetal insert in the bottom to lower COM. Decoupled spindle so the motor spindle has no contact with the LP. This one is so good I'm now making another for myself.
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