The modified, hiss fixed 950s are here. I received an Email today that mine was ready to ship, but since I live very close to their west coast distribution facility, I merely picked mine up on will call.

The unit is now on the test bench of the palacial SoundHound Testing Labs, and I will report on my findings in a bit.

!!!

Very interesting. I look forward to your findings, good sir.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

I just hooked up my system which includes an ATI 1505 and M&K 750 THX speakers and I can hear the hiss a full 8 feet away at my listening position. I just recieved this unit 2 weeks ago. What is the deal? I thought this problem was supposed to be fixed. I'm pretty dissapointed,

Tim

OK: The new 950 has been measured, and installed into my rack.

First of all, I measured the noise level in the same manner that I have done to all the previous 950s I've come across, i.e. Analog DSP mode, with a 20Khz low pass filter in-line with the lab AC voltmeter. The main volume control was at "00" and the trims were at "0". The new 950 measures as follows:

Left Front Out: -82.5dbm
Center Out: -83.5dbm
Right Front Out: -82.5dbm
Left Side Surround Out: -82.5dbm
Right Side Surround Out: -83.0dbm
Left Back Surround Out: -81.5dbm
Right Back Surround Out: -81.5dbm

To reference the same 2 volts as in the specs in the owner's manual, you would add 8.23db to the above measurements. Taking into account the added 8.5db of gain in the new 950, which was attained without any incerase in noise, you could add another 8.5db on top of that, bringing the total to around 99.2db. The readings between the channels are very consistent, which is a good sign.

Does the new 950 meet it's publeshed spec for noise? The spec in the owner's manual for noise in the Analog DSP mode is -98db _"A" weighted_. If you take into account the added gain, and reference 2 volts, then the new 950's noise is -99.2db _full band, 20Khz_. I don't posess an "A" weighting filter, as I don't believe it to be a valid filter for measuring noise on high-end audio equipment (my opinion), and that a 20Khz band limited measurement is the valid one. Therefore Outlaw's measurement and mine are not directly comparable. All I can say is that the new 950 _does_ meet it's published spec, taking into account the added gain, and referencing the 2 volts stated in the owner's manual. The measurement would be somewhat better if I used the "A" weighting filter they used.

Other improvements: the volume and trim controls now act like those in a traditional analog preamp i.e. as you turn the volume control up, the noise increases, as you turn it down, the noise decreases. The previous 950 had a constant noise level, which was "worst case" regardless of the position of the volume or trims, and this is one reason some people such as myself with very efficient speakers (mine are 106db/watt) experienced a problem with hiss.

Now the bottom line in all this is that you can essentially turn down the 950's volume controls, or the trims, or the input volume controls of your power amps, and realize a net noise reduction of at least 8db, due to the gain increase alone.

So, how does it perform in my system?

Well, I got everything hooked up: changing the 950 in my system is "the Mother of all bitches" due to the fact that I have almost every jack on the 950 plugged into something, and my 950 is at the bottom of a stack of 4 other components, a Sony EP-9ES pre/pro, and my Sony DVD player, with a phono preamp and a Smart "CircleSurround" box on top of it all (!)

I calibrated my system for 75db all around using the internal quasi-pink noise generator of the 950. I have volume controls on all my power amps, so I left all the trims at "0" on the 950.

Did I hear any hiss? Well, very, very little compared to my previous 950. Also, the new 950 hissed significantly less than the prototype I had a month or so ago. Where I could hear hiss about 5 feet from my horms with my previous 950, now I can hear the same level of hiss from something less than a foot. Relatively speaking, the hiss is about 3db more than the residual noise of my power amps alone, and they are very quiet. VERY IMPRESSIVE!!!

Will _you_ hear hiss? Most likely not anywhere near as much as the previous 950. The net "real world" decrease in hiss over even the prototype I auditioned is impressive. I think you will be very satisfied.

I have been asked by Outlaw to provide a brief explanation on how to set up the new 950 in those systems that experienced hiss, in order to take best advantage of the decrease in hiss and added gain in the new 950.

For those of you that have volume controls on your power amps, as I do: After you get the new 950 installed, check that all the trims are set at "0". Set the main volume control at "00". Set the mode for a 5.1 or 7.1 configuration depending on if you have back surrounds or not. Activate the quasi-pink noise generator in the "Channel Calib" menu. Using the RadioShack sound level meter, adjust the volume controls _on your power amps_ so that each channel reads 75db "C" on the meter.

If you have power amps without volume controls: Before you dis-connect your old 950, go into the "Channel Trim" menu and write down the trim level settings you have arrived at (hopefully by using a sound level meter ) for all your speakers. Subtrack 8db from this number and set the trims on the new 950 for the new number, i.e. if your previous trim level was "+8", then you would set the trim at "0", if your previous trim level was "+2", then the new level would be "-6", if the previous trim level was "-2", then the new number would be "-10" etc. Do this for all channels.

That's it. Hopefully, now we can put this whole issue to bed, and enjoy the show!


[This message has been edited by soundhound (edited December 20, 2002).]

I would contact Outlaw directly and get a replacement from the new revision.

Why not just dial the system back in at 75db at 00??


brianca..

[This message has been edited by brianca (edited December 19, 2002).]

Of course that can be done. I just wanted to give a foolproof and fast way to re-calibrate the new 950 without going through the trouble of a re-calibration with a sound level meter. You will find that if you do a re-calibration with a sound level meter the trims will have been reduced by 8db.



[This message has been edited by soundhound (edited December 19, 2002).]

WOW. This is fantastic! How can a new buyer be sure of getting this upgraded unit? Does it have a blue dot?

I've already asked how to return my unit for the fixed one, and am awaiting the reply to do so....?

Thanks Outlaw!!!



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Take Care,
merc

[QUOTE]
What is the cost of a Coaxial cable filter and a Monster Power 5000 power conditioner?

Others have reported that they have a noticable hiss even without cable connections and the hiss didn't go away when they put a power conditioner on the line. But most of us don't have a super duper Monster 5000 power conditioner.
--------------------------------

Response:
The power conditioner cost me about $350 online. Admittedly, many Monster products are just fluff and marketing snake oil, but this is not about Monster.

EM interference and ground issues make an impact on noise. In my case the poor "Quality" of the electrical service and the impact of neighbors motors, and appliances probably contributed some part of the noise/hiss. Better power conditioners provide separation (filters) of the A/V component outlets to further reduce their induced noise on each other. The noise I experienced was NOT the low hum often associated with simple ground faults, but much higher (in the 4-10KHz range). I do not know what frequency range is officially designated as "hiss", but it did sound like a snake. And now, hopefully it's dead, and not just asleep.

The bottom line... There seems to be the potential for an "Audi 5000 type" paranoia concerning this 950 noise/hiss issue. People (my clients included) don't like to read about noise. They begin to hear their heartbeat, and intensely search for problems beyond all reasonable limits. EM interference and grounding issues may not be the cause of the perceived hiss for many (or even most) 950 owners, but it probably is worth a serious look. I suspect many others may be looking to find 'fault' with the 950, when the snake is under another rock.


[This message has been edited by AGAssarsson (edited December 20, 2002).]

In my experience, power line conditions have almost no influence on actual, static _hiss_ generated by a particular unit. This type of noise is a function of the noise generated by the various opamps and other audio and video stages within a component. Pops, buzzes etc. are what are manifested by most junk on the power line. In cases where 'hiss' can be attributed to the AC line, it always turns out to be RF interferrence which in most cases goes right through the power supply of most equipment through capacitive coupling in the power transformer. A power line filter such as the Monster, or "Isobar" by TrippLite will filter this out. These filters will also isolate components to filter out any inter-device coupling of high frequency noise. The level of RF interferrence has to be relatively high, such as when you live near a transmitter tower, or someone with a CB transmitter, for it to be heard through most equipment . Occasionally, such interferrence can be generated by appliances which use the AC line to transmit data, such as the X-10 modules, and units which transmit audio/video through the AC line. Also, some light dimmers can generate noise which contaminates the AC power, and is heard as a buzz through the system. The solution for this is to use autotransformer type light dimmers, as most AC line filters cannot filter this noise out.


[This message has been edited by soundhound (edited December 20, 2002).]