Of course the APC is anything but sinusoidal in its output. As has been discussed up to 1KHz or so the dirtier the better seems to help.
Absolutely... I mention GPS whenever I hear a comment along the lines of "what does that stuff have to do with real life"... That and quantum mechanics - without that where would we be with electronics. People should know that the phone in their pocket relies on all that stuff they may think is irrelevant.
Exactly. Amongst other things we make power monitors that check the voltage, current, phase, power factor, frequency and spectral content of the waveforms. This is mainly for large 3 phase installs, either for the utility of the customer - making sure they are getting what they pay for. In industrial scenarios, power can get pretty shitty. However, I've run a lot of tests in my own domestic environment. My environment is pretty potentially noisy - loads of switchers, amateur radio gear, boosted wifi links, LPR stuff.... Oh, and audio... All easily turned on and off as I also do pre-compliance emc measurements. What I find here is, despite all that, remarkably little phase shift or distortion to waveshape. The biggest problem is voltage variation.
Where in the overall system is this residual jitter you hear? There are a number of potential sources, bu mostly they are resynced out of a system as the jitter is less than the sampling window....
Again, with all this experience here, and expertise, has no one ever heard an SPDIF cable change also change the subjective sonic presentation enough so as to be noticed??
Step up, and share your experiences?
Let me add it is fine with me IF this was due to a known or presumed engineering reason - just IF it has ever happened to you??
(seems like the room got very quiet suddenly? How many dBA are we measuring now?)
Sorry, I have not heard a difference between SPDIF cables, optical or otherwise. The same goes for all wires, except obviously faulty ones. Never have, even when my ears were still fresh.
Edit: this was also at times when I was very dissatisfied with the sound I had, and tried all kinds of fixes to improve it. To no avail, it was the speakers as I found out. More specifically, the diffraction pattern created by most loudspeakers.
Last edited:
Thanks for that George....I'm going to use that one in future, lol.
All good advice.
In this case I have shut down all the RF functions, and removed a bunch of apps....I ought to learn more about Android 'rooting' and strip it down as far as possible.
As it is, it works as a very fine audio player (Flan and Wav), and the portability is ace.
The at will sonic changes that I speak of are independent of internal software/hardware overheads and are perfectly repeatable...ie in seconds I am able to flick between two different 'signatures' that each remain until deliberately altered.
Dan.
I am happy to believe people who claim the system sounds best late at night. In many areas mains voltage will be higher which could make a difference to sub-optimal designs and of course ambient noise is lower.
Plus you are likely to have a single malt/beer/glass of wine in front of you and music sounds best after a drink, despite the droopy hairs it causes.
Plus you are likely to have a single malt/beer/glass of wine in front of you and music sounds best after a drink, despite the droopy hairs it causes.
The Bybee devices have to be soldered in line, with the cable, so HOW can you move them up the cable?
Something is not right with the scenario!
Not serious true believers in the high end myths you and others like to promote.
Testing op-amps for noise late at night is always few db lower than day time testing.
I figured the APC wasn't the cleanest power around but it worked well enough on the show floor. I actually had some people listen, then ask "what is the secret?"
I'm not really worried about some khz harmonics on the power feed. Mostly the Mhz stuff is what I would hope the APC can nail down. It did what it had to do at a decent price and is grab and go available at the basic office and computer stores.
I figured the APC wasn't the cleanest power around but it worked well enough on the show floor. I actually had some people listen, then ask "what is the secret?"
I'm not really worried about some khz harmonics on the power feed. Mostly the Mhz stuff is what I would hope the APC can nail down. It did what it had to do at a decent price and is grab and go available at the basic office and computer stores.
Power quality from various backup devices
Turns out the smartUPS is a true sinusoid. Must check which version I have... Might be worth doing some testing with it. Of course the stepped waveform of the backups might produce cleaner DC in your equipment.
Turns out the smartUPS is a true sinusoid. Must check which version I have... Might be worth doing some testing with it. Of course the stepped waveform of the backups might produce cleaner DC in your equipment.
Most every time I have had a "wow!" moment with a neat audio circuit an EE will point out all the empty part of the glass. Debbie downer!
It did what it had to do. T.H.E. Show went smooth this last time. The time before that my DP-51 TT was going crazy because of line fluctuations. Your dig with the stepped waveform only applies to it running in offline mode. Another try at Debbie downer.
http://www.kerrywong.com/2013/08/21/ups-transfer-time-measurement/
I've attended a great many professional symposia, commonly as a janitor to mop the floor.
(my mind is always undressing, even shrinks, but also expands)
I'm a night critter, everything sounds best after dark.
You are right up to the point where the step away from convention has to be made to get something cool and groovy. Usually when I have pushed a circuit into uncharted territory I have mostly gotten quizzical looks, chin scratching and then the "well, you have to be careful of this and that. Need to do a sim...."
A great designer quote "just build it and see what it can do" That was Keith Barr. He did some of his best work on his boat in the open ocean.
- Status
- Not open for further replies.