The Real Lightspeed vs Eva - no monkey bottoms!

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Comments

  • uglymusicuglymusic
    That's really a question to address to Paul Hynes and the Australian guy (taps side of head to no avail) who designed the original Lightspeed circuit.

    I have the boards and I'm assembling them into a piece of hi-fi with the help of my assistant @Jim.
  • AlanAlan
    George Stanscheff (apologies foe typos)

    I wonder if his reticence is due to his sharing Col's KISS ethos, with no switches at all in the signal path. Perhaps a motorized pot would have some noticeable bearing on the power supply?

    That sounds weird, but the EVA benefited from a better PSU (no reason why it should), and Col reckons green LDRs are better than red. Its all hoodoo AFAIAC.
  • uglymusicuglymusic
    I'll be addressing the PSU issue at some stage, too.

    Tomorrow, we'll be attempting to get it all together and working. The tweaks (and possibly nicer cases) will come along later.
  • anubisgrauanubisgrau
    i've tried a number of LDR based attenuators/preamps, possibly everything that exist both ready made or aimed for DIY-ers, except for Dartzeel thing and Paul Heynes boards.
    HiFiGeorge's Lightspeed is good as long as you can provide good impedance matching. My experience is that a huge number of power amps simply have no input impedance high enough for the LS which can spit up to 4-5k output impedance out. That's far too high for universal use.
    That and a huge overall variations of output impedance makes use of buffers almost obligatory. You may use a final touch of transparency but you gain amazing solidity and drive no bufferless LDR can have unless you precisely match source and power amp impedances via LDR. 
    my 2-3 cents....
  • uglymusicuglymusic
    All NVA power amps are designed for use with passive pre-amps, so they're great with LDR attenuators.
  • uglymusicuglymusic
    I thought I should give you an update on the Lightspeed construction

    We had a late start for various reasons, and then spent hours trying to make sense of how to build the thing. There are notable gaps in the information provided and no step-by-step instructions. We ended up calling Paul Hynes and @Jim renewed his old contact from years back.

    We now think we have all the info we need, but we ran out of time.

    More follows... ;-)


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