Friday, April 1, 2011

Fan Noise on the Oppo BDP-95

Just as I was strongly leaning to buying a second one...

The fan noise of the Oppo BDP-95 is a serious issue.  While not very noticeable from a distance, in the quietest living room condition (no AC or refrigerator running) it is noticeable, just barely noticeable, from the listening position, which is about 6 and a half feet from the new equipment stack currently having the Oppo on top.

It is just barely noticeable in the quietest room condition, at about the same level as the barely audible whine from the computers in the second bedroom down the hall (I'm still working on that) and particularly noisy trucks on the freeway 2 miles away.  So it's not loud, but still not acceptible either.

Close to the player, the noise is quiet strong within the first foot, then decaying rapidly.  (But still, as I said, just audible from listening position.)

The fact that it produces an audible noise means that it cannot serve as a high end component in-front-of the loudspeakers.  It might be OK somewhere else, like in the back corner where the Denon 5900 is right now.  But why have a component with signal to noise ratio of -135dB when it produces audible physical noise?

The Oppo actually seems to have quieter mechanism than the Denon, and might actually be quieter playing discs.  Tests will have to be done.

If I do keep an Oppo in the living room and get a second one for the originally planned video hub in the Kitchen...  The Oppo fan noise will either have to be fixed or the player moved to a less critical location.

I think the corner-back location seems to cover up DVD-player noises, which is why the Denon is there right now, and the Masterlink (which has fan and hard drive whine).  It may well work fine for the Oppo there.

But then the cabling/ADC issue is not solved as I was thinking in the past couple days.  A different approach is needed.  One of the following:

1) Use the existing MSB ADC in the back of the room.  While not as good (I think) or as nice as the Lavry, it still works pretty well, about as well as I can test with RMAA/Juli@through the balanced input.  The problem has been lack of gain, but with a 6dB boost from balanced outputs on the Oppo, it becomes much less needing of a booster-preamp (the currently defunct Aragon 28k having previously been used in that capacity for the unbalanced outputs of the Denon 5900).

2) Run approximately 25' balanced audio cable from the Oppo in the back corner to the Lavry in front.  With Belden 1800F at 13pf/ft, this is dooable, consider less than 300pf capacitance, which should not be a problem for the balanced outputs of the Oppo.

3) Buy a second Lavry AD10.  If I am spending hundreds of dollars on balanced cables and a new $380 balanced audio switch, that money might be better invested in a second super quality ADC.  I have no problem switching numerous digital inputs on my Tact.

I would probably not be moving the Denon 5900 to the front of the room either, because of the aforementioned drive noises (it's still quieter than a 2900 and much quieter than a 2910).  So even if I don't buy second Oppo, I'm pretty much stuck with back-of-the-room location.

I think my intial testing of balanced cables (due to arrive next week) will be front of room because I am working on a packing project in the back of the room.  Then I will likely move the Oppo to the back of the room and use the short balanced cables for a balanced connection to the MSB PAD-1 ADC.  At that location, Denon and Oppo could be compared using the MSB, to help decide how important it would be to have second Oppo, and memory of the previous use of Oppo with Lavry might help determine how important a second Lavry (or long cables and switch to use the current one) would be.

****

On modifying the Oppo, I have no plans to do that, but it might well be possible.  It wouldn't be entirely surprising if Oppo introduces an upgrade fan or fan controller.  The BDP-93 is fanless, and the only differences being the much larger audio board (probably of little consequence for heat) and it's linear power supply.

The fan sounds much noisier than current SOTA in computer fans, which are essentially inaudible.  Typically a very low noise sleeve bearing or magnetic or hydro bearing (ball bearings are the noisiest) is speed reduced to the minimum necessary speed (often 1000rpm or lower), then noise is reduced down to 10dBA or less.  At such low levels, lack of fan tonality may be more important than actual dBA reading. Scythe is a leading manufacturer of super quiet fans, and there are many others.  Sleeve bearings must be kept horizontal (fan blows air out the back, not down to the floor).  There is now a large literature on this subject and the competition to make the quietest fans has been intense.

The Oppo BDP-95 seems to have been designed in a vacuum of awareness of the importance of minimizing fan noise and existing available solutions to the fan noise problem.  The fan seems of pedestrian quality and has distinct tonal clicking sound.

Another solution might be to operate the player with cover off, or with linear power supply made external.

The existing noise could also be reduced by having damping on wall behind player.  But even with that, I fear it would be too noisy in the front of the room, where it can be placed within 1ft of the best ADC I have, the Lavry, and it's nice to keep the Lavry AD10 in the front of the room for testing other stuff, like tuners.


5 comments:

  1. Had the same experience as you with the Oppo BDP-95. Great player, but too noisy for critical listening in an open rack. I think they designed it primarily for home theater installations rather than audio enthusiasts.

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  2. Thanks, anonymous. However, in later posts, I decide it's just too good not to be in my best audio system. I worked the fan noise a bit and got it 6dB lower by moving equipment and adding sound absorber.

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  3. Am considering now whether to keep it and try some of the same fixes (acoustic treatment behind the rack), or return it and buy another player. But finding something comparable will be very costly. For me, that probably means a McIntosh MCD301.

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  4. Maybe my memory fails me, but I don't remember a fan in my Masterlink. My Masterlink is quite noisy, but it's not the original CD-R drive - I replaced it some time back with one of the few drives it would take, which was very inexpensive ($27 IIRC), but it's probably not a great drive.

    Unfortunately, I don't think this made money for Alesis and it's been discontinued, so they're not supporting it and they haven't replaced it. But I still use it quite often.

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  5. Hiya,

    Thank you for this. I too find my Oppo BDP-95 fan intrusive. May I ask what you did to cut down the noise? What material did you use as a sound absorber and how did you implement it?
    Thank you, M.J.

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