AV2 Hiss coming from speakers
Posted by: dan scott on 18 January 2007
Hi everyone,
Well I went racing home last night with my 175 in the back of the car all excited. Got everything hooked up and got the Nait5i running in unity gain mode on the AV input ready to be used properly (I was waiting on a modified Chord Chrysalis DIN-Phono cable to get this working)
There is a problem however (Pretty big one too!) there is a loud hiss (Kind of like static ish) coming from the all the speakers, the two fronts especially when the nait is in AV unity gain mode. If I put it back to CD (and hence the volume goes down) it goes away. Now I understand there may always be a bit of background noise in a loudspeaker from the power amp but this is a lot and much more than i've ever had from any reciever i've ever used, it's OK in loud sequences but in dialouge or normal TV prgrams it's awful
(Have to say didn't expect a problem like this!)
My Naim setup is as follows -
AV2
Nait5i
NAPV 175
CD5 (Into Nait5i)
Ariva, n-Sats, n-Cent (All on NACA5 and Naim plugs)
All Naim equipment is using the Naim Crabtree mains leads
Any ideas of what I do now? My plan for tonight was going to be to unplug all equipment from the power and the AV2/Nait5i then only plug in the Naim kit and see if I still get the problem. Any ideas anyone i'm really not feeling great here, thought i'd be in home cinema heaven today but sadly not the case....
Posted on: 18 January 2007 by dan scott
incidentally it's all plugging into a Belkin Surgemaster mains bank that goes into the wall socket (I know it's not a megabucks mains filter but I thought some surge protection could be wise for the thousands of pounds worth of equipment plugged in, could this be contributing?
Also i've read some posts about a hum from similar equipment being blamed on double earthing (I don't really understand what that means sorry
)
Posted on: 19 January 2007 by AV@naim
Dan,
-what firmware is the AV2 running?
press and hold OSD button on the remote for 5 seconds. Front panel will show AVC0107/F6.58 for latest firmware.
-do you get hiss on the front channels in DIRECT mode?
if not, this could be indicitave of a faulty DSP module, you should contact your dealer about returning the unit to naim for repair
-you may have an earth loop. unplug all inputs and see if the hiss is still present (if it is still there, then its likely an AV2 fault)
If the hiss is not present when all inputs are unplugged, gradually apply each source device to the inputs and see which one is causing it
Posted on: 19 January 2007 by dan scott
AV@Naim- Thank-you very much for your help, I shall do exactly as you ask this evening.
Incidentally I did some further tests last night and got it all working nicely by running the AV2 out of Analogue Input 3 into the Tuner DIN input on my Nait5i, I set the volume half way at 12 o'clock and turned down the channels coming from the NAPV 175 to match the gain on the front channels from the half-powered Nait5i.
I just wish I could use the unity gain so I didn't have to adjust the volume.
I'll report on the firmware version and I will only plug in the Naim equipment (Not in the nasty Belkin
)
Also I spoke to my dealer yesterday who asked me to send in the Chord Chrysalis he modified to be a reverse DIN-Phono cable (So I could pre-out the AV2 into the Nait5i) He mentioned something about adding some resistors into the cable as the AV2 output is 'un-buffered' so we can also see how that goes.
Have to say though when I had it going last night with the Nait at half volume, Lord of the Rings (Fellowship of the Ring) spec. edition in DTS-ES sounded f*!£"&g marvellous!!!! so thank-you for an awesome piece of kit (Even if they're are a few teething problems, it'd be no fun otherwise!)
Posted on: 19 January 2007 by dan scott
Quick update, the firmware version of my AV2 is as follows-
AV20106 , F658
Please let me know if I need to run any updates etc.
Thanks,
Dan
Posted on: 19 January 2007 by AV@naim
Normally you need a padded lead if the noise is only coming from the front channels.
You suggested noise was from all channels.
The usual test for this is what you have tried already:-
plug av2 reverse interconnect 5:5 lead in to CD input (rather than AV input) and turn volume on pre-amp up half way. If hiss is now not present on fronts, then you need a slugged lead.
BTW: Do you mean AVC0106, not AV20106??. AVC0107 should be available via your dealer
Posted on: 19 January 2007 by dan scott
My apologies, I do indeed mean AVC0106 (I really do need to learn to proof read)
I'll contact my dealer regarding the update file, I take it I can just flash the unit via the serial port on the back to my laptop (IT technician by trade so have no problems doing this myself) Out of interest what will this update provide?, Or is it a general bug-fix without any specific updates as such?
There is noise from all channels but I understand that there will always be some background noise and the nosie from the centre and surrounds (Those connected to the 175) What noise there is from these other channels is perfectly acceptable, it's just the fronts when under unity gain that are the problem area.
Also if I upgraded to a 122x/150x combo in the future will the DIN AV input on the 122x require the reverse 5-5 lead to be 'padded' or is it ok as is?
Thank-you again for your help, nice to deal with a manufacturer who cares what happens after you've bought something, not just about getting you to buy it!
Posted on: 20 January 2007 by Richard Adams
Hi AV@naim
I hope you don't mind if you butt in on yor thread, dan.
I'm having a similiar problem. If I plug my AV2 in to my 552 and enable unity gain I gett a horrendous buzzing coming through my front speakers. I also get a buzzing if I switch to CD input (CDS3 via hiline) that wasn't there before. The buzzing goes if I unplug the CDS3. It also goes if I disconnect AV2. I'm connecting the AV2 to the 552 via standard reverse 5-5 DIN.
Would I benefit from a padded lead? I have no problems when the AV2 is not connected and also on AV when the CD is not connected
Regards
Richard
Posted on: 20 January 2007 by Trevor
I had a similar problem with my 5 meter long lead from AV2 to 552. Put a 22ohm 0.6w resistor in series with the left and right signal cores in the din plug at the AV2 end. Problem solved thanks to Naim Tech Support.
Trevor
Posted on: 21 January 2007 by Richard Adams
Hi Trevor
Mines only a 1m reverse 5-5 DIN, so it shouldn't cause that proplems
Richard
Posted on: 21 January 2007 by Trevor
Hi Richard,
Yes I agree, I understand the resistors were only required if you were using a long lead.
My noise was like radio interference in the background if yous is a buzz / hum it sounds more like earth loop noise.
Regards - Trevor
Posted on: 21 January 2007 by Richard Adams
Hi Trevor,
Mine is definitely more like an earth loop hum. Any ideas how to get rid of it?
Richard
Posted on: 21 January 2007 by neil w
richard
how are your items powered plug/socket wise
neil
Posted on: 21 January 2007 by Trevor
Hi Richard,
All I can suggest is to try and retrace your steps as to things you have done prior to the problem occuring. Added any electrical appliance, replaced/moved any cabling, all mains/audio plugs securley in the correct place, the AV2 Din-Din is the crossed lead and not a straight one etc.
It usually works for me and comes down to something fairly simple in the end.
Regards - Trevor
Posted on: 21 January 2007 by Richard Adams
Hi Neil
Hifi is plugged into one socket via Hydra and AV stuff plugged into seperate socket via 4 way block. So I guess getting another hydra may be an idea. Can you get an 8 way hydra?
Richard
Posted on: 21 January 2007 by neil w
i had this once , when av stuff was at opposite end of room to hi fi stuff, but connected via unity gain
try the av2 on one of the hydra leads if possible
neil
Posted on: 21 January 2007 by Richard Adams
Trevor
Have rplaced and rechecked all cabling, still getting earth hum as above. Worse when phone stage (Art Audio Vinyl One) is plugged in - but only when AV selected - not on other inputs.
Neil
Connecting AV2 to hydra and disconnecting Armageddon reduces hum by about 75% but still very audible when unity gain selected such that quiet passages on DVD aren't watchable still. I'll ring Grahams tomorrow and see if I can get a hydra made up for all my Naim stuff - will need 8 way hydra
Thanks for the help
Richard
Posted on: 21 January 2007 by Trevor
Hi again,
I doubt weather the hydra will cure the problem, im using a 6 way hydra for my audio kit with 2 different 4 way blocks in one wall socket and another socket the other side of the room for AV kit. Is the record output of the pre-amp muted - does this have any effect!! Does disconnecting the various inputs DVD, Sat, TV etc to the AV2 have any effect!!! Does disconnecting the AV2 from the pre-amp at the AV2 end have any effect!!!
I know this seems like straws and clutching but assuming the AV2 or another piece of kit is not faulty it should come down to a lead or connection - it's just finding it.
Trevor
Posted on: 21 January 2007 by Richard Adams
Hi Trevor
If I disconnect the AV2 from the preamp at the AV2 end completely resolves things, unfortunately I can't listen in surround sound. If I plug the DVD5 into the preamp without connecting the AV2 again no problems. If I connect with AV2 connected, hum back. Do you think ilkely problem with AV2-preamp lead or likely something connecting into back of AV2? Cable and Xbox connected via optical inputs so I assume unlikely. NAPV175 connected via Naim 4 pin Snaics and DVD5 connected via Naim coaxial cable (I forget what this is called ? DC1). I'll play around tomorrow and report back.
Richard
Posted on: 21 January 2007 by Trevor
Hi Richard,
What did you do or change for the problem to start???
Trevor
Posted on: 21 January 2007 by David Dever
Could be hum in video ground plane–assuming that your DVD5 connects only to the AV2 (and to no other Naim components).
Posted on: 22 January 2007 by AV@naim
quote:
Originally posted by Richard Adams:
Hi Trevor,
Mine is definitely more like an earth loop hum. Any ideas how to get rid of it?
Richard
-unplug all sources from AV2, does hum go?
-if so gradually plug sources in one by one until hum appears again.
Then you will know which source is causing it and go from there.
Its possible that the earthed CD player and something earthed on the AV2 input are causing the problem
(similar diagnostic can be used on pre-amps too).
Posted on: 22 January 2007 by AV@naim
quote:
Originally posted by dan scott:
My apologies, I do indeed mean AVC0106 (I really do need to learn to proof read)
I'll contact my dealer regarding the update file, I take it I can just flash the unit via the serial port on the back to my laptop (IT technician by trade so have no problems doing this myself) Out of interest what will this update provide?, Or is it a general bug-fix without any specific updates as such?
There is noise from all channels but I understand that there will always be some background noise and the nosie from the centre and surrounds (Those connected to the 175) What noise there is from these other channels is perfectly acceptable, it's just the fronts when under unity gain that are the problem area.
Also if I upgraded to a 122x/150x combo in the future will the DIN AV input on the 122x require the reverse 5-5 lead to be 'padded' or is it ok as is?
Thank-you again for your help, nice to deal with a manufacturer who cares what happens after you've bought something, not just about getting you to buy it!
I'm afraid updates are generally dealer applied.
main fixes:-
-fix for DTS ES/EX issues (missing audio)
-bass mix now works 100% of the time
-wrong mode displayed after pause/unpause fix
did you try the suggestion i put forward? CD input...try this before you commit to getting lead modified
Posted on: 22 January 2007 by Roy Donaldson
AV@Naim, not sure if you can answer this directly, but wondering if there is any update to the DVD5 scheduled for this year ?
Thanks,
Roy.
Posted on: 23 January 2007 by dan scott
quote:
Originally posted by AV@naim:
quote:
Originally posted by dan scott:
My apologies, I do indeed mean AVC0106 (I really do need to learn to proof read)
I'll contact my dealer regarding the update file, I take it I can just flash the unit via the serial port on the back to my laptop (IT technician by trade so have no problems doing this myself) Out of interest what will this update provide?, Or is it a general bug-fix without any specific updates as such?
There is noise from all channels but I understand that there will always be some background noise and the nosie from the centre and surrounds (Those connected to the 175) What noise there is from these other channels is perfectly acceptable, it's just the fronts when under unity gain that are the problem area.
Also if I upgraded to a 122x/150x combo in the future will the DIN AV input on the 122x require the reverse 5-5 lead to be 'padded' or is it ok as is?
Thank-you again for your help, nice to deal with a manufacturer who cares what happens after you've bought something, not just about getting you to buy it!
I'm afraid updates are generally dealer applied.
main fixes:-
-fix for DTS ES/EX issues (missing audio)
-bass mix now works 100% of the time
-wrong mode displayed after pause/unpause fix
did you try the suggestion i put forward? CD input...try this before you commit to getting lead modified
Hi yes I did and it's running very very nicely like that as I type! I've sent the Chrysalis DIN-Phono off to be 'slugged' and have the reverse 5-5 lead into Tuner DIN on my Nait5i with the volume at 12 o'clock and it's perfect!
Obviously i've adjusted the surround and centre channels powered by the 175 to match the gain provided by the 12 o'clock nait and am loving every film!!!
I'm expecting the modified din-phono back either today or tomorrow and will report back with the results.
Also the Belkin surge protector is a Naim-free zone now, I bought a Grahams Hydra yesterday and it is in it's own wall socket. This has definetly helped the background noise also.
Thank-you again for your continued help and I shal;l contact my dealer regarding the upgrade.
Dan
Posted on: 29 January 2007 by dan scott
The slugged lead has arrived and it has partly reduced the hiss, however it is still much worse than just putting the volume to 12 o'clock on the CD or Tuner DIN inputs and using the supplied AV2 reverse 5-5DIN.
Is there anywhere we can go from here, i'm quite happy using the volume at 12 o'clock method and may well be upgrading the Nait soon anyway (202+150 or 122+150 with a bit of luck)
Still any further advice appreciated.
Thanks
Dan
