Gefen Digital Audio Decoder (GTV-DD-2-AA)

I had tried some other models sold here at Amazon, with intermittent success. TV does not have headphone or pre-amp [line out] output to feed my cordless headphones. And my main reason for the adapter is to be able to quietly listen on headphones to early morning over-the-air news broadcasts etc. when the rest of the house is asleep...Learned the hard way that my TV's optical output ONLY put out Dolby Digital, so whatever I used had to handle that type of signal.Some of the clones [i.e. ones using non-licensed circuits that copy the real Dolby circuits] have problems when the broadcaster's signals have problems - other units' audio output signal will drop out until hard power reset is done.Now we get to the Gefen unit. This device uses a licensed version of the Dolby Digital decoder.Difference shows in both cost (hey, manufacturer has to pay licensing fees!) and stability. Once the unit is fully turned on, over-the-air signal disruptions MIGHT get a muted output for a second, but then sound comes back.Background: I have a number of devices indirectly controlled by the TV i.e a power bar that senses when TV has been turned on - power bar then applies power to certain outlets in the power bar, and one of controlled outlets powers up the power supply for the Gefen unit.The gotcha mentioned in the review title refers to the stability of the power bricks used to supply voltage. In tests, confirmed with oscilloscope and meters, it appears that all of the commonly available units (including the one shipped with the Gefen) can take up to 3 seconds before a stable DC power output is achieved.Symptom: Turn TV on, and sound does not come out until DC power into unit is unplugged for a few seconds. Once DC gets cycled, unit is very stable...My original thought was that the TV's fiber optic output was taking too long to come on line and/or settle. Made a little project device that basically set up a time delay to apply 120V to the power cube... no joy, same result.After some thought [plus measurements mentioned earlier], and using another power cube to experiment with, I used time delay trick to control DC output FROM the brick [that is, wait 5 seconds before unit gets DC power] instead of delaying the 120V power to the power brick/cube supplying it. In other words, let power brick warm up, THEN allow power to go to Gefen unit.Issues fixed...In retrospect, I think the issues with off-the-shelf power supplies may be the main factor in some premature Gefen failures, and possibly some of the signal problems other users have had. I'm guessing that the Gefen units MAY get damaged because they try to start working too soon...I believe the Gefen design has to modified/improved to squeeze in a time delay circuit on the incoming power circuit - i.e. slow down application of incoming DC power to the adapter's audio circuits until it is stable. The adapter might increase in size, but I suspect product losses/returns due to premature failures will be less, and savings will offset cost of redesign.My option/fix (a home-built time-delay circuit) is unavailable to most consumers...

UPDATE...January 2012The longer I use this product, the more I want to kick myself for not doing the homework I describe below. The most irritating quality of this product is the time it takes for it to recognize input signal then begin outputting it to my Vizio sound system. Sometimes it takes a few seconds...sometimes almost a minute. If power is cut to the device, getting it going again is dicey. It finally got to the point where I simply took it out of the loop and if I want to watch over-the-air TV I just use the Panasonic TV's exceptionally crappy speakers. I am very close to replacing the whole shebang--Vizio sound bar, Sony sub, Gefen converter--with a system that decodes Dolby signals from the get-go. I can't say this enough--DO YOUR HOMEWORK! As a result of all this, I am lowering my grade by another star to three out of five. Does what it's supposed to, but not very well, and for an exorbitant price.Original review:I needed this device because (a) I did not read the instruction manual for my Panasonic TC-P42S1 plasma TV thoroughly before buying a sound system to attach to it, and (b) the Vizio sound system I attached to it does not decode Dolby Digital signals. Had I read the instruction manual for the TV, I would have realized that ATSC signals fed through the Panasonic and out the optical digital output are done so only in Dolby Digital, and that there is no option in the TV's audio setup menu to change that. With that knowledge, I could have selected a different sound system for my TV...one that does decode Dolby Digital signals. Could have, should have, would have...but didn't. All these variables presented themselves when I disconnected my cable television service and went with an over-the-air antenna. I had audio signal just fine from everything but antenna-sourced signals which, of course, are ATSC. It was then I realized the shortcomings of my A/V setup, and subsequently researched to find the solution: I needed a digital-to-analog audio converter (DAC). And not just any DAC--it had to be specifically tasked for Dolby Digital signals. This need increased the cost of the device by at least $40 and as much as $70 depending on where one looks for their electronic goodies. My guess is that Dolby's licensing requirements are the cause of the increased cost, along with some additional engineering required to handle Dolby signals in addition to "standard" PCM signals. In any event, the little box works as expected and sends clear analog audio to my Vizio sound system. My only real gripe with the device is that the analog output is not quite as strong as it could be, but it still plays plenty loud. I would complain about the price more, but in reality I could have prevented the expenditure by popping a few more bucks for a TV with selectable audio output, or by selecting a different sound system. As it is, I'm not terribly heartbroken--the savings I realize from having no cable for one month will offset this expenditure.

I was afraid this device would die on me soon when I bought it as some other reviews have said. But I hooked it up 2 years ago, and it's never been disconnected since, and still works exactly as it should!I do have a UPS protecting my home theater, and we've had a few blackouts, but the battery kicks in and I get to safely shut everything down. Maybe that's helped?

Sauteuer aber es hilft bei meinem samsung TV dessen audioausgang digital 5.1 surround sich nicht auf stereo umstellen lässt, wer denk sich sowas aus.ein analog Ausgang beim tv und kopfhörerausgang gibt's auch nicht, genauso idiotischdeshalb war ich auf der suche nach einem solchen converter von digi 5.1 auf analog stereobisher arbeitet er ganz ordentlich außer gelegentlicher kurzer Tonaussetzer

It does work.Most of the time.Stereo signals are not an issue, but lots of boxes do that.But every now and then when doing what you buy this box for (handling Dolby multi-channel), it seems to run out of steam and take a little break, before carrying on.

Habe heute den Gefen Digital- Analog Wandler an meine Stereoanlage angeschlossen.Leider gibt es häufige Tonaussetzer an meiner Stereo- Anlage,Werde den Wandler zurücksenden!