How to avoid hum and hiss to speakers from amps.

If you are already experiencing this, you've got one of what could be many problems.

1) Tubes could be bad or going bad

2) You've got ground / AC polarity issues or very noisy AC mains

3) You are picking up higher than average quantities of RFI or EMI

4) The gain of the system is TOO high

5) The equipment is poorly designed i.e. very low signal to noise ratio.

As a side note, if you've got audible noise of any type coming through the speakers at or slightly above normal listening levels, you'll never achieve the results that most "audiophiles" desire. Without a black background, you lose detail, dynamic range, imaging is not as vivid, notes are blurred, etc... It is not abnormal to have a VERY small amount of audible hiss coming out of the system with the gain cranked wide open. On a good system, you can put your ear to the speakers with the gain wide open and barely hear any noise at all. Just don't forget to turn the gain down before playing some tunes : ) Sean
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Two friends had been complaining about a hum through the speakers. Both problems solved with a power conditioner.

Unless you have tried your system with and then without a power conditioner, you will be concerned about nothing at all. One factor to take into consideration is the sensitivity of your speakers. The more sensitive they are, the more likely they are to increase any noise that is picked along with cables, then from the amps etc... I myself I gone through a drastic set up change, from medium sensitive speakers (88db) and a powerful amp, 200 watts per channel, to a set up that is low in power: I have toyed with 9 watts set from a pair of 300Bs, then to a passive preamp/op amp(solid state) driven integrated rated at 20 watts/47 Labs Shigaraki integrated and now, I am currently running an entirely battery powered set up, the Final Music 5 and Music 6...independent from any wall/line problems. This set up goes to a 96.5 db sensitive full range horn loaded speaker. Even from the battery driven gear, I get some hiss. I need to be seriously close to the driver, my ears, I mean...there is some hiss because of the gain that the preamp provides. I believe that this may be caused due to the sensitivity of the speaker. When I ran the 20 watts/channel Shigaraki into a pair of Epos ES11, rated 89 db, crossoverless...That set up was quiet, because of the sensitivity being lower. I had to increase the volume a lot more to get decent level sound.

All this points to one fact, sensitivity of the speakers will determine what noise you will be able to hear. Of course, a combination of badly designed cables also can introduce some hum to the set up. Another factor that will add to the noise problem is the type of amp you use...a tube amp that is not properly designed or with defective tubes can be noisy.

From experience, this past 3 months, I can tell you that unless you are not careful, a sensitive set up as you plan, can pick up noise and hum problems. This past two weeks I had my share of frustrations due to a hum that my powered subwoofer produced.

I went crazy trying to pinpoint the source. I realized it was the product of three different pairs of speaker wires (different brands) as well as two different pairs of interconnects (RCA ones, from Audioquest to other sort of expensive ones.) I was finally able to reconnect the set up without the sub humming or introducing artifacts to my set up today, after having plugged in a pair of Analysis Plus speaker cables with spades/banana adapters I had laying around.

PS: By the way, I have a BPT 2.5 deluxe edition, to which everything else expect the Final Music 5/6 are connected and to be very honest, I have not noticed a major improvement as reviewers and other users have noticed. Perhaps this was due to the fact that my former set up might have been quieter than most of the other gear out there.

You should not be too concerned by something you have not experienced. If and when you set up system up, if you encounter a problem, there are ways of solving it. Expensive cables and interconnects might actually introduce, instead of resolve some noise problems.

Balanced interconnects also help because they require less overall gain and seem to keep out unwanted noise vs. RCA. I know you really can't do that from a turntable but the more you can connect balanced the better off you are.

I think every SET amp I've ever heard of has some hum...especially if the heaters are AC right? No power conditioner is going to help...been there done that...and in my case the amp always sounded best right into the wall.
Right now I'm using a Final Labs 6 amp (batteries) with an autoformer for volume control.....dead quiet...I mean ear to the cone and nothing....I'm amazed at all the stuff I've been missing all these years...I do miss the beatiful glow of tubes.............
Steve

I agree that using tubes with very high sensitivity speakers can make for a noisy system. Tube based systems typically have higher gain and ANY noise that is generated is easily reproduced through the higher than average sensitivity speakers. Havng said that, i've had systems that were VERY quiet with speakers that were rated at 104 dB's @ 1 watt. Like anything else with audio, you have to work at it. Sean
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Nice to hear from someone else who has gone the DC way, with the Finals. Steve/Brooks, can you elaborate about the type of autotransformer you use as volume control? What about the speakers.

Judging from the responses, I'm wondering how much hum and hiss we're talking about. Volume turned up full I can hear the tweeters buzzing but not much at regular listening levels unless my ear is near the speaker. Is it the complete absence of noise or just getting rid of what can be heard at "normal" levels that's trying to be avoided? I have always lived with a bit of noise but never imagined that it could be gone.
My earlier post was for an annoying ac hum that could easily be heard at regular listening levels.

Hiss is a characteristic of tubes. Try different ones. Some will hiss less, but they all do it. It is mostly an annoying academic problem because music at any reasonable level will mask the hiss.

Hum is a grounding and shielding issue. Experimaent with different ground configurations. Unfortunately some of the grounding configuration is in the equipment circuitry. Hopefully the designer got this part right.