usb-isolator-assembly-guide for more info, including scope noise shots.
Separating grounds and feeding known quality power plus regeneration of USB data is very nicely beneficial to audio systems also IMlimitedE.......I promise that I will do the blind testing when I get a roundtuit.
BTW I grabbed this board primarily for T&M purposes, with audio system usage a fringe benefit.....it's looking like I need another one or two.
Dan.
Separating grounds and feeding known quality power plus regeneration of USB data is very nicely beneficial to audio systems also IMlimitedE.......I promise that I will do the blind testing when I get a roundtuit.
BTW I grabbed this board primarily for T&M purposes, with audio system usage a fringe benefit.....it's looking like I need another one or two.
Dan.
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Cool, it should be quite useful to you.
I am using a transformer type 12V DC plug pack to power the module, and retaining the switching 5V on board regulator stage........for now.
There is discussion of fitting a 5V 3 pin regulator, or direct feeding from an external 5V supply.
For now my A system and digital recordings collection have just been rebirthed.
Dan.
I am using a transformer type 12V DC plug pack to power the module, and retaining the switching 5V on board regulator stage........for now.
There is discussion of fitting a 5V 3 pin regulator, or direct feeding from an external 5V supply.
For now my A system and digital recordings collection have just been rebirthed.
Dan.
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Just coincidentally this morning I was at a ham-fest and got an APC UPS for very cheap, no battery, but have just ordered a battery for € 17. I wonder how much an UPS completely separated from the mains will clean up my measurements? Any experiences?
Jan
For those interested I have been trying a modification to a budget CD player. The mods are in the digital domain, not the analogue side of things. Its been interesting.
Its all here,
http://www.diyaudio.com/forums/loun...-trying-some-modifications-budget-player.html
Its all here,
http://www.diyaudio.com/forums/loun...-trying-some-modifications-budget-player.html
Ha! Good question, I'll see if I can find out. The user guide only says: 230V RMS +/- 8%, 50Hz +/- 1Hz. Doesn't say what the wave shape is, but there's no visible heatsinking so probably piece-wise sine. Rats - didn't think about that one!
But we'll see.
Edit: yep, stair-case sine. Ohh well, I can always get one of those USB isolators
Jan
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Low dissipation amplifier
Low dissipation amplifier
Thank you Jan
If not the analysis of M.J. Hauksford (attached), the analysis of Dimitri http://www.diyaudio.com/forums/attachments/lounge/367658d1377455546-john-curls-blowtorch-preamplifier-part-ii-dimitri.jpg
would have been enough to cover any ‘new’ approach.
Thanks for the warning
No I am not sure Pavel and it is very embarrassing that I never thought that such a possibility exists with the in-built sound card I use on this PC.
I will repeat at least part of the listening test with an outboard card that does 24bit (USB M-Audio Audiophile) and I’ll report back.
George
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For brown-outs and black-outs, a UPS is invaluable.
As a filter, they are well neigh useless. Unless that's a totally new breed device, it works not as a pass-through, but as a parallel power supply, which will cut in within a few milisecs of lost power at the input. Too short a time for your PC PSU to notice.
And that, Brad, is what they were made for, and they generally do a very good job of it. For how long depends on the capacity of the onboard accumulator and your power eequirements, but by and large, even the smallest of them give you at least 5 minutes of autonomy to normally shut down the PC.
A local manufacturer used to offer a UPS with all the required electronics packaged into a fairly small case, for one to use in conjunction with a car accumulator. Given their capacities of 130, 150 and even more Ah (mostly for trucks, delivery vans, etc), the actual autonomy could extend to even several hours. Unfortunately, that system adds the "benefit" of accumulator chemical fumes right up our noses, which is hardly good in closed space situations.
A local manufacturer used to offer a UPS with all the required electronics packaged into a fairly small case, for one to use in conjunction with a car accumulator. Given their capacities of 130, 150 and even more Ah (mostly for trucks, delivery vans, etc), the actual autonomy could extend to even several hours. Unfortunately, that system adds the "benefit" of accumulator chemical fumes right up our noses, which is hardly good in closed space situations.
Scott, are you SURE it's still up to the advertised 1000W? I ask as a precaution, IME those batteries they use inside tend to lose power fairly fast, I've seen cases where nominal 1,000 was down to 200 or less after 5 years. Of course, you could go for better quality batteries, Pansonic makes some really good ones, but that soon turns into a very high end operation, price wise.
Just for kicks, try it out, see for yourself where you stand. If it's a year or two old, don't bother, it'll probably be still near to its specs.
In my case I don't think its the lower noise per se I am after, but rather to isolate it from the mains with all it's attendant junk. I would just run the test equipment from the UPS, and see if that lowers the noise floor, and gets rid of some of the problems stemming from ground loops when connecting a DUT and a sensitive analyzer to the same mains.
Jan
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In that case just use an Isolation xfmr, not toroidal. No need for the extra circuitry of an ups which may or may not cause more noise. Use that part of the budget to get one with more isolation resistance.
Toroid's have too much pass band, who needs it for power!
Yeah, I can't imagine the junk on the mains could be much worse than a stepped sine. And even if you had the most pristine sine, consider all the junk that's created when you rectify it. And I would suggest the isolation transformer be balanced.
se
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