Regarding the question on the diode effect. For those that missed it or don't recall it George explains it as follows:
The diode effect that George references and that the LSA eliminates is clearly something designers of some well known preamps understand and can hear. Here is a quote from one:
FWIW - The custom Shallco switch referenced above is used in his top of the line preamp that uses gold contacts, with a double-spring-loaded wiper. Highly superior and much more costly compared to other switches.
The designer also had this to say about the LSA:
Anybody want to take a guess at who it is? I doubt anyone will question his knowledge on the subject.
The (diode thingy) "diode effect" is bought around by very fast music transients from the source, CDP or phono, which can be in the order of 100's of volts per micro seconds (volts per uS) these happen as the name implies in micro seconds.
When we view a static (constant) 1k-10k square waves on an ocilloscope all looks fairly fine going through a good pot (Alps Bournes ect).But it's when you pulse the waves at micro seconds (transients) an then store it on a very good super fast digital storage ocilloscope play the micro second pulses back frozen in time, and magnify the corners of the waves it's then you see the ringing/occilations effect of the light wiper contact on the conductive track of the pot, (I have named it for want of a better word, "dynamic contact bounce")It's the wiper being ever so slightly bounced on the track.
When pressure is applied to this wiper (with in my case a wooden skewer) so the wiper presses down hard down on the conductive track, the ringing occilations stop when doing the same test. When a soldered resistor is in place of the pot it's not there either, when a Lightspeed Attenuator is in place of the pot it also is not there either.All pots no matter how good bounce to a certain degree this is why they all sound different, they are all fundamentially flawed.
The diode effect that George references and that the LSA eliminates is clearly something designers of some well known preamps understand and can hear. Here is a quote from one:
Having done some audition in this regard (we 'switched', if you will pardon the pun, to our custom Shallco part about 15 years ago as a result of some of these auditions), the difference in contacts that George is describing above is clearly audible.
Its my opinion that the volume control is what shoots many preamps down (especially preamps with remote control) before they can even get off the runway. One of the consequences is that the majority of line stage technologies are in a deplorable state- I don't fault anyone for thinking that a passive might be better.
FWIW - The custom Shallco switch referenced above is used in his top of the line preamp that uses gold contacts, with a double-spring-loaded wiper. Highly superior and much more costly compared to other switches.
The designer also had this to say about the LSA:
I had the opportunity to compare the Lightspeed against one of our own preamps and I have to say it was the most neutral passive I have heard.
Anybody want to take a guess at who it is? I doubt anyone will question his knowledge on the subject.