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  1. H

    Quad 33 Disc Adapter Board

    I would suggest using polystyrene caps as they are extremely stable (no capacitance variation with frequency) and available in 1% tolerances. Since this is a disc input you want accurate values. 63V capacitors will do the trick _ Quad 33 runs off approximately 12V IIRC. 10nF and 1n5 should be...
  2. H

    Dimming bulb on digital circuits

    Measure the voltages with globe in circuit and ascertain if digital circuits are getting the required voltage - if they are you can assume they are working and thus could be protecting the amp from the fault that blows your output transistors
  3. H

    tube life

    On and off is usually harder on the equipment. Valve heaters when cold, have a very low resistance, so at switch-on a larger than normal current flows until the heater warms up. Old filament light bulbs almost always fail at switch-on and this is why. But then again valve heaters dont operate at...
  4. H

    Remote volume control for tuner

    https://www.aliexpress.com/item/1005003472299869.html?src=google&src=google&albch=shopping&acnt=298-731-3000&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&gclsrc=aw.ds&&albagn=888888&&ds_e_adid=&ds_e_matchtype=&ds_e_device=c&ds_e_network=x&ds_e_produ...
  5. H

    DIY isolation transformer

    12VA / 220V = 55mA that is enough to stop your heart. They only way to stay safe when working on mains connected apparatus (valve or solid state) is common sense and knowing what it is you are doing. High voltage is high voltage regardless of where it comes from.
  6. H

    Filter network on cables

    Ha - not going to ask what kind of music is noise! The filter aims to prevent interference from getting into the cable
  7. H

    Filter network on cables

    Attempts to prevent interference getting into the cable and interference getting out of the cable.
  8. H

    Full sound at low volume

    The above measurements show that the difference in sound is die to the listeners ears - which is exactly what the Fletcher-Munson curves measure. Adjusting tone and loudness controls for low(er) listening levels is compensating for how your ears work not your equipment - audio equipment of...
  9. H

    Is all well with Netflix?

    Older Samsung TVs stopped supporting Netflix from today. My TV (2012) gave me a warning a couple of months back. Cheapest solution would be to get a media player.
  10. H

    what is the rarest valve/vacuum tube?

    Audion from 1906. First vacuum tube - I presume they didn't make too many of them
  11. H

    Decware SE84UFO in Wilderness.....

    Use the volume control 😁 Your DEC clips at more than 2V input. Your preamp amplifies the input by 3.89 times. The preamp volume control determines the size of the output signal down to 0V. Set the DEC volume to maximum. Adjust preamp volume to suit your required loudness. If the DEC is...
  12. H

    Some advice regarding sub pre amp

    The AVR is doing frequency splitting so all you need is a preamp with a gain of whatever say, 2 - 5x. You can easily build an op amp based one - google 'opamp circuits' - you'll want the circuit posted below. I would use 3k3 for Rf and whatever you need for your chosen gain for Rin.
  13. H

    Rebuild a Thorens E50 Motor

    According to analoguedept.com: “The easiest way to accomplish a proper alignment between upper and lower bushings is by assembling the motor without firmly tightening the 4 bolts that hold the assembly together. Leave the nuts just barely loose enough to allow shifting position at both upper and...
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    Rebuild a Thorens E50 Motor

    I rebuilt mine about 5 years ago - not as daunting as it seems. You’ve done the hard bit - taking it apart - clean the felt washers and impregnate them with lots of oil, bolt it back together (I think I used 2.5mm nuts n bolts to secure the lower bearing) loosely so you can still move the top...
  15. H

    Cars that were tuned in South Africa

    Chevrolet Nomad
  16. H

    Cars that were tuned in South Africa

    Ford XR6 Interceptor
  17. H

    Plumber reccomendations in Randburg please

    Patrick Bangie 0833426437 did the same fro me blocked bathroom pipes, fixed it all at a very reasonable price
  18. H

    Switched mode power supplies vs Buck converters

    The advantage of an SMPS is that you don't have any low frequency interference. In a linear supply that is around mains frequency 50Hz plus the harmonics thereof - interference at these frequencies is extremely hard if not impossible to eradicate (if you look at a spectrogram of almost any...
  19. H

    Codename Revolver

    Yip, feedback resistances are R11 and the output resistance of the 12AT7
  20. H

    Codename Revolver

    Well done @Ajay-L a testament to your considerable skills!
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