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VanArn

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About VanArn

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    australia

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  1. VanArn

    FS: ORTOFON SPU 15T CARTRIDGE AND STYLUS

    The transfer at the front of the cartridge says " Elliptical".
  2. VanArn

    Help finding power supply caps

    There are Rubycon , 10000 mFd ,100 volt capacitors available on eBay via the USA.; that meet your requirements. just do a Google search.
  3. VanArn

    FS: ORTOFON SPU 15T CARTRIDGE AND STYLUS

    The Ortofon MC cartridge shown is the S15-T circa 1966, which superceded the earlier SPU. This S15 was introduced at the time 'Trackability' became an important issue in reducing record and stylus wear and being able to track recordings at reduced stylus pressures was a feature of this model. The stylus is not user replaceable and the cartridge had to be returned to the Melbourne importers for the fitting of a changeover assembly.
  4. Gary Cawsey is now at 41 Edward Street, Brunswick.
  5. Yardbird, you went to the wrong place for speaker repairs. The common failure with this model Spendor is the voice coil ,as it only suitable for moderate power operation. Typically the voice coil windings part from the aluminium former when overloaded. A repairer has to carefully dismantle the cone assembly from the speaker frame and inspect the assembly. It is a highly skilled task to remove a blown coil ( if this is indeed the fault) from the polypropylene cone and fit a suitable replacement and achieve a performance that complements the original design.
  6. The point I wanted to make is that a L pad in conjunction with the appropriate crossover network will allow electrical damping of a tweeters Fs which is so often neglected by the majority of designers. The simple answer is that the series resistor in an L pad will be lower for the same attenuation level than a series only resistor. If for example a -6 dB pad were required to adjust a dome tweeter with a 92 dB sensitivity to a bass/mid speaker of 86 dB sens. then the pad alone would provide a damping factor of 1 in the working range of the tweeter ( and considerably more at the Fs of the tweeter). For this case, the // resistor will equal the tweeters nominal impedance and the series resistor would be half of the nominal impedance. A series resistor, only would equal the tweeters' impedance and result in twice the impedance being presented to the xover network, which is an added complication.
  7. It is definitely the wisest procedure to have the Spendor SD-08 looked at by a specialist repairer, as your first option. If there is a major problem, such as an overheated voice coil which would require a replacement to be fitted, then it would be prudent to supply the good speaker as well for measurement ( T & S parameters) to enable exact matching to be achieved. Repair work is normally cheaper than buying Spendor replacement drivers.
  8. A valid question, Ittaku. A - 3dB pad is a common value and the series resistor would be around 2.3 ohms for an 8 ohm impedance tweeter; (the // resistor being 19.4 ohm). The xover network design should be one with an inductor connected from the input to the 2.3 ohm resistor and the opposite terminal of the tweeter. This indicates the use of a series first order network or a parallel second order network to ensure that the tweeter is damped below the crossover frequency. This is an effective design method and it is better than trying to tame the resonant frequency of a tweeter with an LCR network that invariably will be out of whack given that the tweeters Fs will vary with temperature and ageing.
  9. "L" pad attenuation as shown in the reference from mwhouston from the previous post, is the best method of correcting the sensitivity level of a tweeter. A series resistor reduces damping and is not effective in reducing impedance variations. The human ear can just detect pressure level changes of around 1dB under controlled conditions at the mid-range frequencies and given the normal manufacturing tolerances of speakers, a resistance variation of 0.1 ohm is unlikely to be noticed.
  10. VanArn

    Speaker Cabinet Builder

    Did you supply a full set of plans for the intended enclosure design, so that an estimation of material and labour could be given ? Remember that Aranmar use CNC machinery and this requires data to be fed to the computer to meet exact requirements and one of, custom builds are expensive , if production runs are not involved.
  11. There has been an ongoing issue with the Yamaha NS 1000 woofers. Basically the magnet front and back plates can shift causing the voice coil to become jammed in the magnet gap. It can be caused by glue failure especially if the speakers have received a heavy jolt when transported. Care will be needed to extract the cone assembly for re-use and even so damage to the voice coil may not be able to be fixed and a replacement woofer may then be needed. Were you advised of any problems with the NS 1000,s at the time of purchase?
  12. I associate the speaker with Douglas Hi Fi, a store that once operated in Melbourne. They were a house brand intended for the budget market.
  13. VanArn

    Speaker Cabinet Builder

    The address for Aranmar Acoustics is 63 Southern Road, Mentone. If a complete drawing plan is not available for the proposed enclosure then John Woodhead provides a service which includes measuring the parameters of the speaker drivers and finalising the design.
  14. Early stereo phono cartridges were often rated for an output level based on a 1 cm/sec. groove velocity at 1kHz. At a later date, 3.54 cm/sec became the standard reference figure. The Leak preamps would have been designed around the available cartridges that were typical for the times and these in the main are of a higher output than the models available today. This is because improvements in tracking performance and flatness of response etc have been part of the design criteria, at the expense of some loss in sensitivity. As far as I can recall, the manufacture of the Point One, ceased around 1964.
  15. Apologies are in order. I have located the Owner's Manual on the Hi Fi engine site and it reveals that, dual ganged 100 kOhm trim pots are fitted on the pickup, tuner and extra inputs to preset the gain for matching levels. While this is a convenient feature, carbon pots are not low noise devices and the tolerances are not precise. Perhaps, disconnecting the trim pots and replacing them in the input circuits with modern metal film resistors would be a worthwhile step.
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