Harman Kardon AVR 7550HD (2008 announcement) - Page 44

Hmm... That is very curious. As I mentioned, I unplugged the power from the back of the AVR, not the wall socket, for about 30 mins, yet when I plugged back in it seemed to have reverted back to factory defaults. At least all the source input settings were back to default. I had to reprogram my turn table, Wii, TV, etc...

Not a big deal, but I wonder why it did that. I am on a 2009 version of the 7550 with the HDMI 1.3a, not the upgraded version. Would that matter?

Thanks.

Perhaps it has to be plugged in for while to charge the memory. Is this the first time you have plugged it in?
Mcode should know the answer to this one.......

As I previously posted...
The engineering limit specification of 21 days came out of the Service Manual which means that is the minimum...
The typical average will be significantly longer.


Just my $0.02..

has anyone tried internet radio presets? I could only store 10, not 30 as stated on the manual.

The actual memory used is a CMOS type, no battery is required..
However whenever the AVR has undergone long periods of power ON/OFF cycles there is a relatively small change of corrupting the memory when powering up which simply means the user must rerun the setup configuration routines..

Additionally today in our energy consumption times, many consumers will unplug their system totally when going away on vacations.. So when powering up again, something may happen, low probability but it does happen..

Just my $0.02...

fan noise
my brand new 7550 started having fan noise!

10 internet, 30 AM/FM presets..

Just my $0.02..

That's interesting. On their manual, it says 30 internet!

Yep. I have had mine for about 6 months and the little video fan on the back left side started squealing a few weeks ago. I applied a drop of trumpet valve oil to it and it is now silent.

That is my biggest issue with the unit. Appart from that I love it. Especially the sound.

You know better..
Than to trust what HK puts into the Operation Guide, brochures & website..


Just my $0.02...

my fan doesn't have squealing nosie... it sounds like refridgerator's humming...

My 745 doens't have any sound.

This is incorrect. The 7550HD can have 30 internet radio preset stations. I have nearly 20 on my own 7550 and had the same amount on my previous 7550.


Chris: To set an internet radio preset above and including 10, you must first press "0" then the 2 digit number.
For example, to set a station that is currently tuned/being used to preset number #23, press "OK" then press "0-2-3" Do this quickly.
For presets below 10, simply press "OK" then the preset number desired.
The presets do not have to be set in order, you can choose any number 1-30 for any preset.

I believe this may be missing from the manual in the Internet Radio section (though correctly specified in the AM/FM and XM sections), which would explain your difficulty.

The 'fan noise' problem is normally a squeal, from the small video board fan.

As I mentioned when you asked about the fan problem earlier in this thread, the fan(s) do make noise under normal operation. The main tunnel amp produces a very low, dull noise. The tunnel/amp fan seems to be on at all times at very low speed, however it will ramp up to higher speed when needed.

Can you determine where the noise is coming from in your unit? When looking at the unit from the front, the video fan is about mid way on the left side of the chassis at the very top

If it is a rumbling type sound than it is the larger fan for the amplifier tunnel..
This is triggered by (2) sources, DSP volume level gain and temperature heat sensors mounted on the tunnel...
At certain times this runs @ low speed and sounds like yours may be cogging as it is trying to start to turn..

Though HK needs to respond, my thinking is either the fan is not mounted and torqued down properly to the tunnel. Or just the fan itself is noisy and to fix this may need to be replaced, or perhaps a slight shot of light oil may help. The fan itself was available with a ball bearing retainer and/or a thrust retainer, the thrust retainer is cheaper but I really don't know whats in your 7550HD.

As I posted previously...
After the 7550HD/760/660 were approved for MP start the original design team was terminated and everything shifted to China. And I have seen & heard that certain OE components were revised for less expensive ones to save $...

Hmm.
30 internet radio presets..
Good to know but 10 is enough for me..

But again as I posted previously HK manuals, brochures and website have multiple typos so I don't really trust any of their published specs...
For example, 1 brochure mentioned the 7550HD power as 75W x 7, another place said 85W x 7 and another 110W x 7.. Whatever its power output really is, drives my loudspeaker loudly & kleenly..

If you have more 7550HD questions just keep pushing HK for their response as hopefully someone can answer the technical questions..
Better than me.. As you know I have spent many hours on this forum helping HK users but frankly speaking this burden should really be on HK to support.. Or maybe I should send them an invoice for services rendered..

Just my $0.02..

Unfortunately I had to return my 7750 because HK does not have a replacement for a bad video card. I recieved this unit from HK direct about a month ago and could not get video through it. I really had my eye on this reciever for a long time.

they still have it in ebay for sale.

Call the US office directly!

I was looking for BDP1... nowhere to be found. I just called up someone in their office on the East Coast. They let me order one from them immediately.

question on the stereo mode:

does 7550 have a separate DAC for pure stereo ?
if not, would it be better if I use a good CD player's DAC, and connect analog to 7550 when i listen to classical music?

No..
The 7550HD/760/660 uses the Cirrus CS42528 8 Channel DAC, its specs are quite good 192KHz & 24 bit. Depending upon the brand, age & price class of the CD player it might sound different..

I would say try both and then decide which one sounds better...
But I would bet that the DAC in the 7550HD sounds the best.

Just my $0.02...

so, are you saying when that DAC does the conversion at stereo mode, it doesn't put any additional sound field? just pure two channel digital to analog?

Yup..
The CS42528 is a combination part..
1. 8 Channels of Digital to Analog converters
2. 2 Channel of Analog to Digital converter
3. S/PDIF Tx/Rx

Also since the 7550HD has the unique feature 8 Channel Digitizer, it uses an 8 Channel Analog to Digital converter when the input source of 6/8 Channel Direct is selected. This how the 7550HD (and 760) are able to apply the bass manager and EzSet/EQ II to 6/8 Channel Direct.

Just my $0.02...

question on DAC:

All CD's recorded with sampling rate of 44.1 kHz. Most of the disc players' outputs are either 48khz or integer times 48khz. Only the high end of HK CD player 990 is variable output....

So, if i use the digital output those disc players to send to 7550, the end results won't be 100% fidelity?

two questions on fan noise:

1. without openning the cover, I think it's the smaller video fan. When I first turn it on, I can hear a very low (pleasant) fan humming. After half a minute, this squealinng sound came on. I hesistate to open the cover. Besides the lack of lubrication, do you guys have any unfixable problems with that fan that requires sending the whole unit back?

2. is that usual to have the fan noise coming in the first week of usage?

The smaller video fan noise didn't start on my unit until after about 4 months or so, but it got worse quite quickly and became annoyingly loud. As was prescribed by others, a couple drops of light oil (I used trumpet valve oil that I had laying around) solved the problem.

I have no other issues that would require sending the unit back. I suppose this fan may require this oil service one in a while, but hopefully it will be fine for a few years at least.

What is the manufacturing date?
As mentioned previously the early runs done in mid/late 2009 had issues with the small video fan..

Just my $0.02...

Mine did not have the HDMI 1.4 upgrade so I beleive mine was 2009.

On the rear panel there should be a sticker with month/year..
Another way is to check the serial # last 4 digits, if < 1200 then it is early production.
You should oil the video fan..

Just my $0.02..

Agreed, oil the fan, bit of a pain but worth it for me. It's not just the early models either, the build date on mine is Jan 2010, and well beyond the < 1200. The fan started squeaking after about 3 months, did a little squeak here and there in the weeks before that. Chris I wouldn't be too surprised if yours acted up in the first week. a drop or two of oil and that small fan is back to silent running with superb sound where it counts.

My replacement 2010 unit also did this after a few months. Opening it up and oiling it is easier than unhooking all the wires/cables.

I posted a couple pics on page 41 post #1219 that should help you out. Mine has been nice and quiet since.

Thanks for the pics on page 41. My unit is good so far but in the future if noise appears I will be referring to your pics.

I think I need to go ahead and take care of the fan noise. Thanks for the photo.

Question:
From the photo, the fan is facing/blowing to the side. The blades facing outside. Since the shaft and the body of the fan under the circuit board, how do I oil it? Do I just drop a drop of oil on the center of the blades, where the axis tip is?