[JN] LIght voodoo

Stewart Ono via Sound sound at soundlist.org
Sat Sep 6 17:49:59 CDT 2014


Ahhh, the  explanation for which Einstein won the Nobel prize. I would that
that effect would be too small to be audible to human ears. And no
measurements taken. Curious as the blue light LEDS exhibit little effect.

Then again my ancient Rider manuals claim that Shot noise was due to
electrons hitting the plate structure....

I can see perhaps a slight increase in dynamics, perhaps, but it also seems
that the noise floor has been lowered.

Have to listen more as I only did this  yesterday. Incidentally if any one
wishes to replicate I ordered the 5 MM ultra bright LEDS from Lighthouse
LEDS. No affiliation, but they do give very quick service even through
USPS. Original more yellow/orange LEDS were sourced from Mouser.


On Sat, Sep 6, 2014 at 12:25 PM, Gary Bronner <gbronn at gmail.com> wrote:

> Stewart,
> It's pretty well known that in a vacuum tube, electrons are generated by
> thermionic emission.  It's also known that the emission characteristics of
> a metal are changed by shining light on the metal.  You should get more
> electron generation when you shine light on the filament/cathode for a
> given filament current.  Shorter wavelength light has the highest energy
> and thus will give more of a boost to electron emission.  Going from longer
> wavelengths to shorter wavelength you have
> red>orange>yellow>green>blue>violet.
> Have you checked the tube operating point as you shine the light?  Does it
> move around?  Perhaps you're getting some subtle tuning that is a slightly
> better sounding operating point.
> ---Gary
>
>
> On Sat, Sep 6, 2014 at 3:01 PM, Stewart Ono via Sound <sound at soundlist.org
> > wrote:
>
>> Yeah: tried blue and white. I am suspecting the color sort of matches the
>> filament color and may be adding electrons?.
>>
>> Tried a more  yellow/orange version and could hear some improvement  but
>> not as much as the  more red orange I am currently using.
>>
>> 12 volt DC wall wart is connected to another duplex socket BTW and in a
>> PLC. used the recommended 470 ohm current limiting resistor ( 20 mA per
>> LED).
>>
>> Its weird.
>>
>> I had actually tried blocking off light (toilet paper cores taped over the
>> top) and I thought I heard some improvement there, shielding the tubes
>> from
>> ambient light. I am using the Orange LEDS in ambient light and simply
>> placing them close to the tube bases. THe overall effect is small when
>> applying to one tube but as you pace more down it becomes more audible,
>> and, If I dare say, quite pleasant, giving my system more presence. I
>> first
>> used a single LEd but  then double them up per tube for greater effect.
>>
>>
>> On Sat, Sep 6, 2014 at 11:46 AM, Alex Mitaru <amitaru at gmail.com> wrote:
>>
>> > Just for experimentation sake, did you try with any other color LED’s ??
>> >
>> > thanks, alex
>> >
>> > On Sep 6, 2014, at 2:24 PM, Stewart Ono via Sound <sound at soundlist.org>
>> > wrote:
>> >
>> > > I am appealing to list members for help in a explanation for an
>> observed
>> > > phenomenon (at least I don't think I'm going crazy, not yet)
>> > >
>> > > Started off with a Vincent tube CD player. They place a tube on the
>> front
>> > > faceplate in a well and illuminate the well with orange LED. Talk
>> about
>> > > ugly, but the back panel has a 4 position switch so you can alter the
>> > > intensity and also turn the orange LEDs off.
>> > >
>> > > So for cosmetics sake, I turned off the LEDs (there were 6 in the
>> well)..
>> > > Imagine my surprise to note I had lost some dynamics and detail. It
>> was
>> > my
>> > > expectation that turning off the lights should increase performance
>> not
>> > to
>> > > lose some.
>> > >
>> > > Cut to the present: I purchased a few ultrabright 5 mm orange LEDS and
>> > > hooked them up to a AC wall wart power supply. Placing them at the
>> base
>> > of
>> > > my tubes (6922's and EL 34s) has a noticeable effect on sound. On the
>> > input
>> > > tubes I can not hear any downside: dynamics increase , top end
>> extension
>> > > soars and there is additional detail throughout the FR. On power
>> tubes,
>> > > bass tightens up significantly. Initial feel was that I had lost some
>> > bass
>> > > but I can hear more bass harmonics and  the bass is cleaner and
>> tighter
>> > in
>> > > that regards. Funny after  15 minutes, bass seems to increase in
>> > extension,
>> > > but could be simply my ears accommodating the change.
>> > >
>> > > For experimentation I just lay the Leds on the chassis top, BTW
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