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Bronze Member Username: InviernoPost Number: 28 Registered: Feb-04 | This is a follow up to the hiss and related issues I had with a NAD T773 that was promptly replaced by the dealer. With the new 773 I have not had any of the previous problems with it powering off spontaneously, giving me an occassional crackle through the speakers, having very loud hissing through headphones, etc. However, out of the box, with nothing hooked up, it did still hiss more than I would like, in all surround modes and at all volumes, but more so in stereo mode. The hiss was less the previous 773: in stereo mode I could now hear it 3 feet away instead of 4. Since the other problems weren't present I did some experimenting. With my standard connections to it made, through the OSD I turned off *every* input, digital and analog, which was not currently hooked up. THE HISS IN ALL SURROUND MODES EXCEPT STEREO DISSAPPEARED!! The hiss was still present, at the same level, in stereo mode. This is problematic, since that is the mode I use the most. I did also have some hiss when the DVD player was on pause (instead off off), but that I can attribute to the DVD player, not the receiver. This all implies that at least part of the problem was RFI / EMI at the unnused analog connectors. Since turning off the inputs worked for the digital modes it makes me wonder if Stereo mode is still seeing the analog inputs and therefore getting more hiss. I believe Stereo is by default an analog bypass mode so this would make sense -- can anyone confirm Stereo is an analog bypass mode? Of course, I'm running Stereo with a digital coax connection only so that doesn't make complete sense. I am planning on plugging all the analog RCA connectors (and maybe the video too) with either RCA shorting plugs (http://www.tweakshop.com/Shorting%20Plugs.html) or Cardas RCA Caps (http://www.amusicdirect.com/products/detail.asp?sku=ACARRCAC). Has anyone tried either of these with NAD AV receivers? Anyone know if NAD AV receivers have trouble with shorting plugs, since supposedly some pre-amps don't "like" them? Thanks in advance and I'll keep you all posted as to how this goes. (As a complete aside, this 773 also has the trigger switch on the back "inside" the box, instead of exposed, though it can be reached with a pen -- I'm assuming this is by design, but would like to hear from other owners to confirm.) |
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Bronze Member Username: Gatt767Malta Post Number: 25 Registered: Feb-04 | As regards to the Trigger switch its the same on all NADs with this switch |
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New member Username: PatronPost Number: 2 Registered: Apr-04 | Seems to me that YOU are the only one with this issue. You should get a different brand. Stop "complaining". Fix your issue directly with NAD, get your money back and get something else. My 773 is "perfect" Respectfully. |
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Bronze Member Username: InviernoPost Number: 30 Registered: Feb-04 | I'm not certain that the issue is actually with the NAD. RFI / EMI is a tricky issue and can effect quite a bit of delicate circuitry. It's quite possible that a "perfect" 773 when brought to my location would exhibit the same symptoms. Then again, it could be the unit. I do a bit of ham radio, and have noticed quite a bit of noise in a variety of frequency ranges in this area. This is with a big antenna TRYING to pick up signals, of course. If I travel a few blocks away from home the noise is gone. A friend with more electronics and radio knowledge than I thought that some specific element of the local power lines (I can't remember what) was causing the problem, but as the power is functioning and no one else has a noticeable problem we weren't able to get them to fix it. Thus, I have at least a possibility that local conditions could be adversly effecting the unit. So the Cardas RCA Caps or old fashioned RCA shorting plugs seems like a good way to test this since the 773 should be reasonably shielded inside but the inputs are exposed. Which puts me back to the actual question: Has anyone tried either of these with NAD AV Receivers? Any known problems with NAD and shorting plugs? |
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Bronze Member Username: InviernoPost Number: 32 Registered: Feb-04 | Well, I tried the Cardas RCA Caps. No change whatsoever in the noise level. I'll try the RCA shorting plugs (only on analog inputs) and see what happens. |
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Silver Member Username: AirforceonePost Number: 111 Registered: Feb-04 | Hey patron, why don't you go F$#@! yourself. Invierno's a nice guy and I don't know who the he!! you are, nor do I care. What's classic is that you signed that crap post of your's "respectfully". I won't blow smoke up your butt by doing the same. Disrespectfully, AF1 |
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Silver Member Username: AirforceonePost Number: 112 Registered: Feb-04 | BTW, I made the same mistake you have as far as posting like an idiot when I first came here. The people here are nice and forgiving about it as long as your posting style changes. |
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Bronze Member Username: InviernoPost Number: 34 Registered: Feb-04 | Not good news. With RCA caps, the 773 on its own power circuit, with no inputs, only front speakers hooked up, and every other circuit in the house turned off the level of hiss from the front speakers is still the same. I had originally thought I could live with the hiss, till I realized recently while listening to some stirring music that I could hear the hiss from my listening position when playing the music loud (at -10) during quiter sections. I'll try the RCA shorting plugs when they show up, and my dealer is checking to see if a possible service bulletin related to noise and voltage drops was done on my unit or not. See https://www.ecoustics.com/electronics/forum/home-audio/13874.html for the thread on this. If the service bulletin was already done or if doing it doesn't fix the problem then my solution will be something other than the 773. AIRFORCE: Have you already posted a general review of your NAD 973 amp? I am considering going with a NAD 973 amp and maybe a Rotel RSP-1068 pre-pro if the fix doesn't work. Though my wallet might implode... If you haven't posted a review, are you still happy with the 973? How is the noise floor? How loud are the fans, compared with the 773? Any other issues or concerns? And did you finally decide on a pre-pro? |
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New member Username: PatronPost Number: 5 Registered: Apr-04 | Mr(s) invierno(a) I am sorry If I said something offensive to you. Hey if you need some money please let me know, doors are open. remember open door policy. |
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Silver Member Username: AirforceonePost Number: 113 Registered: Feb-04 | Invierno, I haven't posted a review since the only way I've used the 973 is hooked directly to my Denon 2900. I CAN confirm without a doubt however that the noise floor is non-existent(no humm or hiss at all). You'll be very happy in that regard. Fans are there and rather loud. Louder than the 773 from my memory. This is kinda tricky since my family and friends say they can't hear them. In any case, I can hear them from the listening position during quiet scenes. I haven't done it yet but this is another advantage of the seperates option: you can stash the 973 pretty much wherever your imagination or living arrangements allow. I'm thinking about stashing mine in the attic above the listening room and running the cables down through the ceiling. Then I can laugh the laugh of the fan noise killer. As for a pre/pro I still haven't done anything. If I had to choose one right now I'd still have to go with the B&K REF50. For the money being asked it's a great value. The REF50 originaly cost 3500 dollars and can now be had for under 2000. There are some people over at AVS who paid 3000-3500 for the REF50 who are still pissed at B&K for lowering the price so much. I'm also tempted to get the NAD163 since Darren(who had the original 773 buzz problem) says it works and sounds great with no noise floor issues. By the time I can afford any of these though summer will be almost over and NAD will probably be coming out with a "164" so I figure it will be between the newer NAD vs. the B&K. In case you missed it I'll post a link to Darrens review of the 163/973 combo: https://www.ecoustics.com/electronics/forum/home-audio/15267.html There's another review of this amp. When I find it I'll post it. Take it easy. |
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Silver Member Username: AirforceonePost Number: 114 Registered: Feb-04 | Here's the other review. Pretty interesting. Reading these reviews is making me sick. I want a pre/pro yesterday!! Anyway, here it is: http://www.hometheaterspot.com/htsthreads/showflat.php?Cat=&Number=568562&page=0 &view=collapsed&sb=5&o=&fpart=1 Hope it all helps. If you have more questions, or I didn't fully answer the ones you did ask, let me know. |
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Silver Member Username: AirforceonePost Number: 115 Registered: Feb-04 | Her's a link to the front page of the forum that was posted in. http://www.hometheaterspot.com/htsthreads/postlist.php?Cat=&Board=nadpsd&page=0& view=collapsed&sb=5&o= |
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Bronze Member Username: InviernoPost Number: 35 Registered: Feb-04 | Thanks for the info Airforce. You said the 973 fans were louder than the 773. Could you say by how much? Twice as loud? I can have it in a cabinet with a closed front and open back to control fan noise somewhat, but twice as loud would be pushing it and I can't have it in the attic myself. I'm still hoping they can resolve the issue with my 773, but want to plan ahead in case. |
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Silver Member Username: AirforceonePost Number: 116 Registered: Feb-04 | I wouldn't say twice as loud. You should be fine with it enclosed like that. That's the way I'd like to do it but my entertainment center is full so the amp just sits out alone....making the fan audible. Good luck getting the 773 taken care of, I hope it works out. More questions let me know. |
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Bronze Member Username: InviernoPost Number: 41 Registered: Feb-04 | The third 773 arrived and I listened to it at the dealers. Like the previous two 773's it also has a hiss that can heard at least 5 feet from the speakers, at any volume. At high volumes / reference level the hiss can be heard 10+ feet away -- at the listening position. This is in stereo mode only, as before. So this is either a design issue or NAD has a large batch of 773's that hiss in stereo mode. I had decided to give NAD 3 tries with the 773, so I have now given up on NAD's current AV receivers. They sound wonderful (barring the hiss) but I'm not willing to keep replacing units, even if NAD is. Since I'm beyond my return date for the dealer, I'm getting the NAD T973 amp and will get a non-NAD pre-amp. I had tested the T773 with a Rotel pre-amp hooked to the T773 so it was used solely as an amp. No hiss in any modes. So the amp side of the 773 at least seems to be working fine, which hopefully means the 973 amp will work well. |