My son has a binocular microscope for his cartridge repairs/mods - tried it, didn't work for me alas (btw: there's a not-so-steady-anymore hand
to take into account as well). Thanks anyway for the uplifting tip.
I've read enough disturbing reports by pro circuit designers to stay away from SPICE and the like. My WYSIWYG-like statement lacked nuance,
that's true, but transitional phenomena e.g. are difficult to be measured correctly, and consequently just as difficult to predict/calculate/simulate.
And my experiments were on so called linear PSUs; btw: there's practically nothing 'linear' really in the operation of these classic power supplies.
As a result they are noisy, and hard to tame. Your average designer, however thinks, an overkill of microFarads + 'tripods' will easily cure this ...
Audiots frequently spend big bucks on external power supply 'upgrades' - on top of the just mentioned cure, these contain big transformers
with rediculous VA specs. While this might make sense for a power amp with underrated internal PSU, such upgrade PSUs for phono-amps are
outrageous ! We have performed in-depth listening tests here, and concluded that the advertised pros - improved bass response and dynamics -
didn't make up for the apparent loss of overall-quality: the music seemed robbed of its liveliness. Some team members stated: "As if an elephant
is sitting on the sound".
If you would want to consider RCA's Dynagroove technology* as a kind of early dithering, I would be with you, but calling RIAA equalisation
distorting the signal ... Changing the tonal balance in no way fits the definition of distortion. It is in fact a perfectly rational adaptation to the medium.
Its primary objective was optimizing playing time - so maybe one could call it a form of (physical) compression. The second aim, however is to
diminish and limit distortion - i.e. tracking distortion ! The famous ADC XLM cartridge from the sixties arguably was one of the most agile ever,
but it was not free from tracking distortion, of course. Here the question arises, how one is to discern between distortion caused by the vinyl
registration process, and distortion from the cartridge tracking the groove with its needle.
My son has done quite a bit of research in improving suspension in phono cartridges; he was surprised to find, how much there still is to be
gained in terms of tracking distortion this way - the experiments were done with state-of-the-art commercial carts.
(to be continued)
Ray
* dynamics at the end of the Pink Panther theme by Mancini e.g. really are impressive, but ... sure, it's just an effect - no HiFi.
To the list of analog turntables (and vinyl records) problems vs CD you can add poor channel separation, lower signal to noise, far less dynamic range, low frequency limits,
groove wear, warping, inherent vulnerability to acoustic feedback, tracking problems, and less resistant to injury and corruption.
As for reproducing square waves, as far as I know, no instrument other than electronic synthesizers produce anything that approaches the fast rise/fall times of a square wave.
That said, there are several groups that I like that use(d) synthesizers.
As for degrading eyesight I'm reliant upon my bench binocular microscope just to solder 1960's tech like DIP ICs and through hole.
My spare parts are so old that I have to remove the unwanted oxide layer from them (just like my brain).
I don't like too much SPICE in my food.
Analog turntables - Don't get me started! The analog signal is distorted prior to recording so it can be reverse distorted for playback to support the RIAA equalisation.
And also seem to also ignore other distortion influences such as wow and flutter, stylus/cartridge momentum and contact friction variations
Like oscilloscopes, sound should be sampled at about 5x or more than the desired maximum bandwidth.
And how does one get a speaker to playback perfect square waves?
