Tuesday, April 12, 2011

Equipment piles must not get too high

In the last few days, I had built up a pile of components near the right speaker.  This pile started with the Belkin power conditioning UPS, which was low enough (lower than the Acoustat interface boxes) that I figured I could put it near the speaker.

I had also piled on the Acurus A250 power amp, which drives my ribbon tweeters.  Sitting atop the Belkin, it simply looks like one unit: a big impressive amplifier.  That's been there since I got the Belkin (and was there even before I got the Belkin actually).

Then last week I added these: the Nakamichi RX-505 (sits nicely atop the Acurus, and the Acurus doesn't even get warm in normal use now), the Kenwood KT-6040 tuner, the Oppo BDP-95 disc player, the Lavry AD10 analog to digital converter, and (just yesterday) the Sony 507ESD CD player (so I can play discs from guests, I only put the cleanest or new discs into the BDP-95).

And yesterday or thereabout I determined that I could reduce the fan noise from the Oppo by moving it down in the pile, to just above the Nak.

Well now, looking at this pile that was up to nearly eye level, I was wondering if that was causing the image to shift to the right.  So I took the Kenwood and the Sony off the top, and it seemed to make little difference to the orientation of the image.  I moved the right speaker back about an inch and that fixed it.  I was listening to a friend's CD of Long Black Veil by The Chieftans.   The effect of centering a female vocal by moving the speaker and lowering the equipment pile was truly magical.

Anyway, I think it's not good to have a pile of equipment up to ear level around a dipolar speaker (in this case, just slightly to the side and behind), so I'm keeping the pile low for the time being.  I think it should be no higher than lap level.  I moved the Kenwood and Sony to a new pile near the left speaker, still no higher than the interface box on the back of the Acoustats.

If I need to do a Denon/Oppo comparison, I can put the Denon in the left pile, replacing the Sony CD player temporarily, or put it in the right pile, replacing the Nakamichi temporarily.  The really heavy components need to go near the bottom.  The Nakamichi is fairly heavy.

I thought again of getting a second Lavry ADC for the single ended components.  Note that the Sony 507, however, sends coax digital to my Tact preamp and doesn't need an ADC.  So the only analog components which need switching are: Kenwood tuner, Nakamichi tape deck, Sony tuner.

After lowering the right pile, the Oppo is again on top (from the top: Oppo, Nakamichi, Acurus, Belkin).  Since moving it down in the pile had reduced fan noise, I remeasured the fan noise.  It actually seems slightly improved, from 22.5dB to 22dB (actually stayed at 21dB for a few seconds).  Perhaps the Oppo was causing slight vibration in the Kenwood sheet metal above it.  My previous measurement with Oppo turned off was 20dB, and I did not repeat that measurement.

Back on Sunday, I finally got around to setting up the Oppo audio options.  It seems funny to me that HDCD was not turned on by default.  I also changed SACD mode from multichannel to stereo, though I wonder if that makes any difference through the stereo outputs.  When I made that change, I was hoping it would reduce fan noise by turning off the multichannel analog outputs and reducing heat.  Most of the heat generated is most likely due to the multichannel outputs.  But it did not seem to make any change to fan operation.

Some people say that the Oppo fan does not run until it gets warm.  However in my experience, with SACD's and HDCD's, the Oppo fan starts running a minute or two after the player is started, and then never turns off.  My room temperature is below 78 degrees.

Though I've tended to obsess about the Oppo fan noise, I also measured one of my quieter Denon's, a 2900, while playing an SACD.  It has no fan noise, but a very obvious high pitched whine, much more annoying than the Oppo hummm, and it measured 26dB at 1 meter.  I have two 5900's and one of them is quieter than this, and the other is noisier.  So even with its fan, the Oppo is quiter than some high end players.

I'd much rather have the Oppo near the front of my living room system than a player as noisy as my Denon 2900.  And it turns out that I really like having a player near the front.  The player near the back of the room is nearly always inaccessible because of junk piled up near the back of the room.

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