[sdiy] Unstability of oscillators and psychoacoustic qualities

[harrybissell]

Hej Magnus....

Better make the psychoacoustic tests "double blind"  (which means, i presume
everyone gets poked in BOTH eyes...).

I bet (without any knowledge) that the results show that there is no correlation
between oscillator stability and perceived quality / lack thereof...

I base this comment on the continued existence of the BBD... whose specs clearly
show....
;^P

H^) harry

Magnus Danielson wrote:

> Dear all,
>
> If you recall, much have been discusses about the unstability of oscillators
> and that this or that oscillator sounds "cold" where as this and that
> oscillator sounds "warm". Similar aspects have also been attributed to filters.
>
> Now, in one end we know that unstability in frequency is a bad thing, since
> then we need to retune the damn machine. The classic is the MiniMoog which you
> had to turn on at least half an hour before the gig start, and if you forgot
> you have a hell to keep it in tune all of the time.
>
> Another aspect is that a certain unstability is claimed to make the sound more
> "alive" or "warm". The lack of this unstability is also claimed to make the
> oscillator "cold". It is interesting to note that certain filters is also
> claimed to be "cold" or "warm", such that a "cold" oscillator can be
> compensated with a "warm" filter.
>
> So far I am mostly summing up what have been discussed on this list and many
> others over the years I've read them.
>
> Now, in my professional life I work with stability of clocks in many signals
> from 4 kHz up to 2.488 GHz. In that line of work there is well established
> methologies to measure the unstability of oscillators and signals. Many will
> know this as jitter and wander where as other will know it as phasenoise and
> Allen deviation. There is great tools to measure these things and I just
> happends to have access to one of these frequency-counters on steroids that
> can do this.
>
> However, what is the goal of measurement? Well, I would like to learn what form
> of unstability which sounds "cold" and which sounds "warm". I.e. it would be
> nice to quantify by both reasoning and by measurement/listening-test what is
> "cold" and what is "warm". Interesting would also to know when things go
> overboard from "warm" to "too damn hot".
>
> Have people dug into this allready?
>
> I've considered doing this for quite some time, but I just discovered that I
> got alot of free time ahead of me, so why not do something usefull of it?
>
> Cheers,
> Magnus - you know, that crazy Swede...