leo
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Post by leo on Nov 8, 2007 23:02:39 GMT
Only time I'd consider using a traffo on the output of a dac is if its a step up transformer used with a current out dac. I won't be rushing to try it either seeing that the decent ones are too bloody expensive
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Nov 9, 2007 0:34:56 GMT
what's an in-line audio transformer? Series connected line level audio transformer.The entire audio signal passes directly through the device Cool.In essence if you connect a digital sourece to the primary (input side of the trafos) of a 1:1 (a tad less than unity gain being a passive device) line level audio transformer where both the analog "hot" and analog "ground" connect to the primary and you FLOAT the secondary (the output side of the trafos) you have just TOTALLY disconnected ALL DAC grounds from the final analog output signal so any digital ground noise (RF) that is present is 100% eliminated. A side (AND FREE DAMMIT !) benefit is you can add a simple DPDT switch to the trafos primary for instant polarity flip (phase inversion) switch AND at the same time add a gentle rolloff of (depending on trafos) aliasing AND in the case of a NOS DAC get rid of the nasties that reappear in the far upper regions even if the NOS DAC has an inherent rolloff in the audible band depending on the trafos from 30khz up. Think of it as a digital "band aid" that can in a pinch cover most superficial wounds no matter the size. 1-isolated ground 2-polarity inversion 3-anti-aliasing/ultrasonic/RF filtering cinemag.biz/line_input/line_input.htmlI have this one built into my passive control center (notice i did NOT say "passive preamp" ) : cinemag.biz/line_input/CMLI-15-15B.pdfThough initially for digital sources i find having a phase invert option to be handy though there are some limitations like having a highish output impedance source "look into" an input impedance of 18K.Fine for any SS source i know of,not so very for many passive resistor output DACs or some CDP tube output stages where an additional buffer stage may be needed or even (gasp !) an output stage redesign to get the Z below 2K ohms or so a VERY good read that sort of goes to topic in a roundabout way : www.jensen-transformers.com/an/ts_guide.pdfwww.jensen-transformers.com/iso_aud.htmlfunny thing about digital ground noise is you never notice it until it is gone then when it is back (removing the trafos) is about as irritating as it gets (for ME anyway ) so the "band-aid" is useful for all things digital including portables and especially ANY digital audio computer feeds which have the absolute worst backgrounds of any wanna be prime time audio devices
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leo
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Team wtf is it?
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Post by leo on Nov 9, 2007 0:57:43 GMT
Any plans regarding diy projects Rick? we have been a bit slack on here lately
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Nov 9, 2007 1:40:56 GMT
Any plans regarding diy projects Rick? we have been a bit slack on here lately Man,to be honest I have not even THOUGHT about electronics in a very long while (posting here is my first revisit of the hobby) and in fact have liquidated most of my lab gear and tools.I have a box full of electronics and audio trade mags totally unread,all my "bits and pices" bulk stored in boxes and my personal system is down to entry level gear having liquidated some months ago so I have to actually THINK on the subject to bring forward anything coherent rather than my previous "on cruise control" the topic being current thus having prominance in my brain-a brain that I can delete content from never to be seen again to casual thought but like with a hard drive THERE with enough digging though potentially with some "bits" missing or scattered to be recronstructed over time as the previous task takes precedence again
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Nov 9, 2007 1:57:29 GMT
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leo
Been here a while!
Team wtf is it?
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Post by leo on Nov 9, 2007 2:01:48 GMT
Any plans regarding diy projects Rick? we have been a bit slack on here lately Man,to be honest I have not even THOUGHT about electronics in a very long while (posting here is my first revisit of the hobby) and in fact have liquidated most of my lab gear and tools.I have a box full of electronics and audio trade mags totally unread,all my "bits and pices" bulk stored in boxes and my personal system is down to entry level gear having liquidated some months ago so I have to actually THINK on the subject to bring forward anything coherent rather than my previous "on cruise control" the topic being current thus having prominance in my brain-a brain that I can delete content from never to be seen again to casual thought but like with a hard drive THERE with enough digging though potentially with some "bits" missing or scattered to be recronstructed over time as the previous task takes precedence again At least your back on here Rick Hope you can get yourself sorted mate!
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Post by charleyphogg on Nov 10, 2007 22:42:27 GMT
Thanks for the links and valuable info SandyK, Leo, Miguel, Rick , Rowuk and all.
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Post by hiflight on Nov 15, 2007 15:35:58 GMT
Well here are some alternatives at various prices. There are many more, so this is an small list: - $100 Silverstone EB01 - $175 Lite Dac-AH non oversampling dac - $250 Fubar II USB Dac by Firestone Audio - $300 HeadRoom Micro Dac (2006 and older) so use for $250 - $399 Spitfire Dac by Firestone Audio - $500 Musical Fidelity X-Dac V3 - $700 Ultra Micro Dac by HeadRoom I stopped at $700 because that at the moment is my limit. However check the Cambridge CD 740C. You will be surprised. I purchased the Ultra Micro DAC from HeadRoom, and am extremely pleased with the flexibility, multiple switchable inputs and especially by the smooth, natural sound of this upsampling DAC. It is used at the present for decoding my optical inputs and feeding them to my Earmax Pro. So far, I has outperformed my previous DACs. I would highly recommend this DAC. PRO: Small size, multiple switchable inputs, superb sound. CON: AC only, rather pricey. HiFlight
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mrarroyo
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Post by mrarroyo on Nov 15, 2007 20:53:31 GMT
Ron (HiFlight) good to see you posting here. Welcome aboard!
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