I run 50 amps of balanced power to two Cinepro amps, an SE Gold and a 2K5II. With the volume at max there is hiss only when you put your ear right up to the speaker 1 or 2 inches away. That's quiet enough for me.
I run a Yam DSP A-1 as processor, to 4 IRD MB-100 monoblocks, as well as a single Marantz MA6100 block. Speakers are Paradigm Studio 40's, Studio CC, and two surround ADP 350 dipoles.
Absolutely dead quiet. I could thrust my head through the grill cloth at max gain and hear nothing. Not recommended, but I have sampled it a few times, and silence.
I run two dedicated circuits (12AWG,15A), and run a few aftermarket power cords, as well as some Belden 83802 DIY power cords. Use a PS Audio Juice Bar for the blocks and the sub. Had very, very low hiss with this setup. 6" away kind of gentle woosh hiss.
Added two (rather expensive) cryo'd duplex outlets (Hubbell 5362's) recently, and the noise floor dropped below ground.
Unbelievably quiet. Absolutely no noise, no haze, no HF smear. The noise floor literally dropped 40db. Allows me to hear all the detail at less gain. Nice at night when the family is in bed and my system is running. Could not do this before the outlets.
John, IME, any hiss, noise, is going to be amplified with gain. The more you can lower your noise floor, the more prominent your high/low frequency level will be reproduced, the faster your transients will be. Noise is hash, robs the signal content of subtle audio detail and sudden dynamics. Lose the amplified garbage hitching on the AC and you cut through to the tonality of the signal. You can hear a much smoother, a silkier HF reproduction. My amazement was the separation of the musical instruments I heard after I added the cryo'd outlets. Music came to life. My experience with these cryo'd outlets was such that they should be considered a component, not a "tweak".
I also have the same Parasound 1205A with AVR-3802 as pre/pro setup. I also noticed increased hiss after upgrading to the separate amp. The parasound, sensitive and powerful as it is, simply exaggerated a pre-existing condition. If the system with reciever pre outs to amp connected only isn't dead quiet then your problem is at the wall outlet. If not you need to isolate the component that is the source of the distortion which in my case was a combination of all my video stuff; TV, VCR, Cable and DVD.
so many reasons why something like this can occur. it's entirely possible that or the s/n, thd, etc. coming out of the 3802 outputs has issues. other reasons may have to do with mismatched output levels and input levels of the combinations one chooses. perhaps the following will serve as an illustration. Consider a Classe SSP30 mated to something like an Adcom GFA 7500. The GFA 7500 only needs 1.14 volts for full output, however the output of the Classe equipment is in the vicinity of 5-7 volts. If the GFA 7500 had input level controls, this wouldn't be an issue. It doesn't however. What the specs are on your equipment, I don't know.
Let me preface by saying the hiss in my system at its worse is only audible from a foot or two away from the speakers. I have nothing but the highest of praise for the 3802/1205A combo. The sound is incredible.
Chu According to Parasound, 1.2 V is what it takes to attain full volume on the 1205A, And according to Denon, the analog output on the 3802 is rated at 1.2V. It appears they match so I don’t think this is the source of the hiss.
I also don’t believe it’s a grounding issue. But the 1205A has a ground lift switch in the back that separates the signal ground from the chassis/earth ground of the amplifier. This is an internal version of the ground loop isolator that Chu & John mentioned. I haven’t tried it and Parasound recommends this only as a last resort because it leaves the sensitive parts of the amplifier vulnerable to transient volt surges. I’m not sure if anybody sells Transient Voltage Surge Suppressors (TVSS) for line signals. Hopefully the external ones recommended by Chu and John have built in TVSS.
okie dokes so no mismatch. the ebtech box simply inserts between the two components and it's not the same as the 'ground lift' switch, which would definitely be a last resort. nasty things those hisses...once you zone in on it, it seems sometimes to be worse than it is...best of luck in whatever you do
Even though Outlaw did extensive testing of the 950 pre/pro in house before they shipped the 1st one to customers, and even though they had 4 beta testers with a variety of equipment, bam, the very 1st 950 hissed in approx 10% of systems.
So they regroup and release the "red" dot (equiv) model. I got one of those. Hissed in my system. I had a combination of Def Tech and Vandersteen speakers. All speakers hissed to about 2 ft, except my rear center, a DT CLR 1000B which hissed out to 4 ft. Acurus amplification.
Benchmark for me was the Sony TA-E9000ES which only exhibited hiss if you stuck your ear right up against the speaker, and tilted your head just so...
After a little while, it came out that the "2nd" version of the 950 hissed in maybe 1-2% of setups, and that Klipsch speakers highlighted it (extremely sensitive), and Acurus amplification highlighted it.
I did lots of testing with my unit. The most interesting was that I compared gear plugged straight into a wall AC outlet vs running through balanced power. No difference. I definately get other benefits with balanced power, but in this particular case, hiss wasn't one of them.
Another interesting data point was that I switched from 2 Acurus A200x3 amps (6.1) to 1 A200 plus 1 A200x5 (7.1) in the middle of this. Hiss was identical with either setup.
So Outlaw amazingly regroups once more, and releases the "blue dot" (equiv) unit. (Shipping since Dec 17th.) I now have one of those. The hiss was reduced by 75% so that my worst speaker was cut down from 4 ft to 1 ft. Quite acceptable for me.
So my conclusion was that there can definately be an interaction between components that causes hiss, but yet still if any one piece of gear is imo to be considered "audiophile" quality, it shouldn't cause any more hiss than any other component in any system. If that makes sense.
Thank you Kevin especially for the information about the balanced power isolation transformer and its inability to lower your system hiss. I know now not to go down that very expensive road.
Chu, you're right about the ground lift switch on the 1205A not being the same as Ebtech's hum eliminator. They differ in that the ground lift separates signal ground from chassis/earth ground while Ebtech's unit separates the signal itself from its ground. Both designed to eliminate ground loops.
well i suggest it primarily because you could probably pick one up locally, and if it didn't work, return it for a full refund. for trying out ideas, mail order simply sucks.