Ok I've been gong a long time and haven't been keeping up much. About 18 months ago I had the 950 and sent it back due to hiss issues, Have these been resolved yet? Thanks

Craig

Wow, the hiss issue. It has been a while...

History for newer forum members: the original 950's (from spring 2002) exhibited a background hiss on some systems. Not everyone was affected -- it typically required a system with very efficient speakers. Outlaw halted shipments around May and spent the summer making some changes to the analog signal path, which resulted in the "red dot" revision that August. This provided a lower noise floor and resolved the problem for many users, and shipments resumed. A few users still reported problems with hiss, including our forum regular soundhound. Outlaw continued to work on design changes, and that December began shipping all new 950's with the "blue dot" revisions to the analog section. Existing owners could send their 950's in and have them upgraded to "blue dot" or exchange their units for a "blue dot." As of December 2002 (roughly eighteen months ago, give or take), both Outlaw and the 950 user community agreed that the hiss had been eliminated.

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gonk -- 950 Review | LFM-1 Review | Pre/Pro Comparison Chart | Saloon Links

The 950 doesn't hiss in everybody's system. But in my home theater and in some other customer's home theaters, even the blue dot version hisses somewhat noticably, although the blue dot version hisses less than earlier 950's did. For me the hiss isn't too bad, but it's definitely noticable. However, the latest Sherwood pre/pro is said to be dead quiet by comparison.

Best,

Will

I think if you were to use enough gain and speakers that are sensitive enough, you would find some degree of hiss in any system. After all, some electrons are going to be moving around randomly no matter what you do at operating temperatures. (I'm ruling out absolute zero as a possibility. )

When I first got my 950 (blue dot), I was also concerned about hiss. The receiver my 950/770 combo was replacing was one step away from Onkyo’s very best unit at the time the Onkyo was made. So I did two comparisons. In one instance, I connected the Onkyo directly to the speakers vs. the 950/770 connected to the speakers. In the other instance, I left the speakers connected to the 770, and checked the 950 vs. the Onkyo connected by the line outputs as a pre/pro. In all cases I used the same source unit.

I had always thought the Onkyo to be very quiet. However I found out differently. If I'm remembering correctly, I would score it like this ...

Hiss Comparison, source device not playing, subjective listening, for various volume level settings, using points scoring, lower score is better:



Points:

0 = absolutely no hiss detected at all
1 = near zero, ear within ½ inch from dome tweeter in order to hear hiss.
2 = very slight, ear within three inches of dome tweeter in order to hear hiss.
3 = noticeable, ear within two feet of dome tweeter in order to hear hiss.
4 = borderline, hiss heard from half way to the listening position, very quiet room.
5 = objectionable, hiss heard from the listening position, very quiet room.

*High volume does not mean absolute maximum gain. I considered this a level at which no one would listen without damaging one or more components of a system.

In my comparison, the Onkyo beat the 950 in only one instance – directly connected to the speakers, volume at minimum. Since I can’t listen to any source at this level, a zero volume level comparison is basically useless. I compared this anyway because I was curious.

In every listening level instance, the 950 was a better pre/pro match to the 770 than the Onkyo, with regard to hiss. This comparison satisfied me on the 950 hiss issue.


[This message has been edited by bestbang4thebuck (edited August 03, 2004).]

My experience going from a Sony receiver (used as a pre/pro) to the 950 was the 950 hissed much more, but nevertheless sounded better and more lifelike than the receiver it replaced.

Prior to the 950's blue dot revision, reports of hiss (excluding ground loop hum issues) were common enough to lead Outlaw to make their revisions. Since the blue dot revision was released, such reports seem to have dried up (and an online forum like this one is an effective way to draw out problems). I think Will may be overstating the level of hiss that may be found in current production 950's.

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gonk -- 950 Review | LFM-1 Review | Pre/Pro Comparison Chart | Saloon Links

I don't think that Will is overstating the issue. I bought a 950 last fall and sent it back because of hiss. Has there been an update to the 950 since then? The only way to know if it is too noticeable is to try it in your system.

I was one of the original complainers of hiss in the 950 with my 106db/watt horn speakers. Before the blue dot version of the 950 was released to the public, Outlaw sent me one to test in my system to see if the hiss issue had been solved - it had been to my satisfaction.

I seriously doubt that anybody else here has speakers with sensitivities in excess of 106db/watt such as I have, and if they are hearing hiss, there almost certainly has to be either a setup/calibration problem or a problem with another component in the signal chain.

I appreciate your analysis of the hiss issue, but it would not explain why I heard no hiss whatsoever when I went back to my 6 year old Denon receiver and then installed an Aragon Stage One. Every other part of my system was identical with that exception. The amplification was first by ADCOM and then by M200s. But, it doesn't matter unless its noticeable on your system, to your ears.

Nevertheless, I bet that if you were to do some gain structure measurements, the problem could turn out to be in some other area than the 950. I've done literally thousands of measurements for noise, distortion etc on audio equipment with lab instruments over the years - the 950 as it now stands is actually very quiet in a properly calibrated system at more than ear-against-the-tweeter distances (a totally unrealistic test). If it weren't quiet enough, I would not be using it since I am probably less tolerant of noise than anybody else, and certainly have speakers that are the "worst case" in revealing noise in upstream components. Read some of the posts I did when the 950 was first released - I slammed it for it's lack of meeting specs and it's audible noise in my system.

Also, keep in mind that some preamps have a DAC muting feature which cuts all output when the digital to analog converters are not processing a signal - this gives a false "silent" noise floor that can be easily mistaken for less self-noise than when the preamp is being operated normally with signal. The only way to tell the actual noise contribution under normal operating conditions for sure is to un-mute the DACs in the absense of signal, somehting that is not easily done by end users.

[This message has been edited by soundhound (edited August 05, 2004).]