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In Reply to: RE: Would you be so kind to point toward one piece of aduio equipment with PROPERLY... posted by carcass93 on June 25, 2009 at 08:05:58
Sure, here are two, old and new, A Xilica 4080 speaker controller / processor operates over a wide range of input voltages, has no sound, or audible pickup when used near xenon and old florescent lighting or next to switching power supplies and amplifiers.
It’s balanced inputs make concerns about exotic cables irrelevant and the market and sales of exotic cables is vastly smaller by percentage in pro.
A McIntosh mx110 tube pre-amp / tuner also had a huge tolerance to RFI and EMI noise and could be used next to the room with an RF induction heater.
In general tube gear, including the tube amplifiers from Grommes where I worked in the 70’s, were very tolerant of line and radiated noise but much less so on the range of line Voltages.
Lastly an example of a sort of audio situation I had to resolve personally.
I was given the task of re-designing and then building and testing the control electronics for an Acoustic levitation system which was to be flown on the shuttle but first on sounding rockets.
The science problem driving this being that there were many materials which reacted with the container when melted or required such a high temperature that there were no containers available.
The solution was to use high intensity sound to position a sample in the middle of a really hot furnace, to melt and cool the sample without contact.
The existing sound source had a capacitive pickup, like a condenser microphone, which was charged to 200Vdc.
The sound source was a resonant bar of titanium, the pickup’s job was to pick up the tiny signal from the vibration at 16KHz and use the pll circuit I designed to lock on to the resonance, keeping it in tune and at a constant amplitude.
This had to be done on shuttle power, which could vary from 24 to 42Volts (28VDC nominal) with a boat load of noise spectrum up to low RF.
Our experiment power was set to 100Amps so the furnace modulator (4 phase pwm) had to monitor a current shunt to regulate at no more than 100 Amps while heating.
Here is a link to that stuff, now 20 years ago.
http://www.springerlink.com/content/42375j4148345603/
Anyway my point was that even when dealing with the most sensitive signals like a “naked” condenser microphone, buried within an extraordinarily electronically noisy environment, you can still engineer around it, if doing that is part of the task.
Unless there are unusual circumstances, the level of conducted and radiated noise in the home is certainly much less than in industrial and many commercial uses of electronics, including audio.
Lastly, keep in mind that in addition to any real change electronically or not, other things can also effect ones perception of a given event.
A simple test which may be useful to help in seperating these.
Sit down and listen back and forth between the two cables which show the largest difference. Pick music that makes the difference obvious as possible and go back and forth.
When you feel it’s the right time un plug them, have a friend come in and have them pick one of the two and plug it in and you listen again, now not knowing which cable it was.
Have the friend switch back and forth making sure you can’t see and he doesn’t tell you which one is in use.
The results of these fall one of two ways generally.
Most often, the audible difference is smaller to much smaller or even gone when you don’t know which is which and you only use your ears.
If there is a difference even if small this way, without prior knowledge, then you are on to something in the engineering side that can be tracked down to a source, ideally before it is sold as a product.
If not, don't feel bad, in fact your in good company.
In the recording and mixing community there is a story told to remind themselves they are not infallible even if they do it for a living.
It goes like this, the engineer spends 10 min doing minute tweaks on an eq or processor strip getting the sound "just right".
Then when sitting back to enjoy, notices the "bypass" button is / was pressed the whole time.
To a very real degree, we hear what we want to hear and only part of that is related to electrons etc.
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