Hey everyone. I am in the process of downgrading from the Naim AV2 to an Arcam AVR-300 for various reasons and I am having a problem calibrating my speakers. This afternoon, I tried out an Arcam AVR-300 along with my Nait 5i and Naim Ariva speakers (very efficient) and could not for the life of me calibrate levels to match the centre and surround speakers which were monitor audio gold speakers for comparison sake. The Nait 5i, set in av passthru mode, just set my SPL meter to over 85 dB even with the speakers set to zero on the Arcam (lowest level possible). By comparison, even with the Monitor Audio speakers set to +10 (powered by the Arcam), I could not match the SPL of the Arivas powered by the Nait 5i - they were still 5 dB too low. I know that the Monitor Audio speakers are less efficient but this just seems wrong to me.

Does anyone have any suggestions on what I may be doing wrong? Is there a resistor I can add to my Nait 5i inputs to cut the output somewhat?

All advice appreciated.

Thanks.

Well, just read how to reset the Arcam and I can now adjust speaker levels below 00 so will recalibrate in the morning (too late right now as family is in bed) and see how things go.

Just another Friday night "duh" moment.....

Now - if I can only get rid of the HUM I have whenever I use the av passthru mode. Strangely enough, this HUM does not exist when other inputs are used such as CD or Tuner.

Any suggestions?

The hum is most likely being caused by an earth loop. Try plugging in the various bits of hifi to different sockets. Alternatively (and most likely), the problem is caused by one of the unearthed units such as the TV. Try unpluggiog the TV from the Arcam to see if that's what's causing the problem. If it is you could apply attenuators on that unit to reduce and possibly remove the hum.

quote:

Originally posted by markusp:

Now - if I can only get rid of the HUM I have whenever I use the av passthru mode. Strangely enough, this HUM does not exist when other inputs are used such as CD or Tuner.

Any suggestions?

-how long is interconnect from AVR-300 to nait5i?

-is AVR-300 mains earthed?

-is it naim branded lead?

Thanks for the help so far fellow Naimers. I was mistaken in my assessment of the sound. It is not a hum but rather a loud hiss that increases dramatically as the volume is increased. Funny thing is, the hiss only happens on the AV input of the Nait 5i - when I use CD etc., the hiss is not present.

Av@naim - the interconnect between the AVR-300 and the Nait5i is made by Linn and is 1 metre long (rca to rca).

The AVR-300 is indeed earthed and interestingly enough, when I lifted it's ground switch, the problem increased quite a bit.

I've read through a number of forums last night and it seems I need an interconnect that has resistors built into it to cut down on interference pick up. Will this eliminate the hiss?

Thanks..

when you plugged your AV processor in to CD input (and got no hiss), did you set the volume accordingly (as it would be on AV bypass mode on Av input)??

Setting roughly 1/2 volume on any other input is about the same. Do you get hiss then on CD input?

If not then you may need to slug your leads between AV processor and nait5i

Ah! I think it's like a buzz rather than a hiss right? I've had this before and found it very difficult to get rid of, but changing the connections and the plug locations does help.

Not sure quite how to describe the problem. I quess it could be considered a buzz but I think hiss more acurately describes it.

AV@naim - I have set the volume on the CD input accordingly (1/2 valume) and get virtually no hiss on the input. As soon as I switch the AV input, bingo - very loud hiss.

I have ordered a slugged lead from my dealer (he has to make it) and should get it sometime next week. Will report back then as to whether or not it corrects the problem.