Ground loop issue is what brought me to this channel originally. Was driven half-demented by an irritating hum/buzz coming from my turntable and couldn't figure it out. I was at quite a loss. But Paul's How To website helped me greatly: now no issues at all. So thanks again, Paul!

Hum and hiss are two entirely different animals. Hum is a relatively simple matter too diagnose and fix. Hum is 60 Hz getting into your system. Common causes are ground problems getting into your amp. Just disconnect everything from your amp, if it's still humming get your amp fixed. Now add everything back - one at a time to isolate the source. One time, for me it turned out to be the cable input and an isolation transformer had to be installed on the line.

Thanks, good one. Excellent recap of Mr Ed. Excellent vocalization of the hums. And you're helping me cope with the hiss in my phono stage....

Just when i needed it! Great video, keep em going!!

Great as always!

Paul, when I was repairing valve amplifiers and radios back in the late 1960s, some items had Hum Nulling Pots in them. They were called "Humdingers" in the trade. Your excellent presentation brought back some good memories!

I needed to hear this one Paul! So refreshing to hear a "so what" from one OCD audiophile to another. I just got a pair of REL subwoofers and heard a slight hiss when I put my ear next to the driver. My wife looked at me like what the hell are you doing. Sometimes I think we can drive ourselves crazy scrutinizing every single detail. It's great just to step back and enjoy realizing the things that just don't matter. Love your content.

O, that was useful, finally someone explained it in simple terms and in details! Thank you!

@davidlewis8124

2 жыл бұрын

👌✌️

mains hum that you hear in the speakers doesn't come from the transformer, it comes from the power line; if you had no transformer, you'd still hear it, if all yo had was the generator, you'd still hear it; the solution is a voltage regulator that removes ripple and noise from the transformer or power supply

I have two balanced power isolation transformers. One is a Furman IT-1210 that supplies all power to my home electronic music studio. It is totally silent in operation, which is fortunate since it is rack mounted and about 36 inches from my DAW seating position. I also have a similar IT made by Equi=Tech that I use to supply power to all home theater electronics. That unit makes an audible mechanical 60 Hz hum. Fortunately, the latter IT is in a ventilated but enclosed cabinet so the sound is not audible from any listening position. In both instances the units completely eliminate any possibility of ground loops that would cause a 60 Hz hum in a line level audio signal. They also totally electrically isolate all connected equipment from mains electrical noise, spikes, etc. Both the studio and the theater occupy the same room (at opposite ends). The powered studio subwoofer also serves a dual purpose as a second sub for the home theater 9.2 audio setup (they would never be in simultaneous use). Because the studio sub is at the opposite side of the room from the theater electronics it cannot be plugged into the same IT as the rest of the theater gear and I was getting a ground loop hum. I solved the problem by using a wireless audio transmitter to send the theater sub output to the studio sub input. Because my studio amp doesn't have a sub output the speaker level outputs are connected to the speaker level sub inputs which then has an internal crossover to send the speaker level signal to the stereo speakers. The wireless connection from the theater system is input to the line level studio sub input. Those strategies for the analog audio combined with a quality DAW digital audio interface (RME Fireface 802) with a high quality Word Clock source that synchronizes several other A/D/A converters has resulted in very clean and noiseless recording and playback in the DAW system.

I always come back to this guy haha. All my issues have been resolved so that good

I loved watching Mr. Ed. Every Sunday Night.

I agree good question with an honest answer👍👍

About your humm 60hz vs 120Hz. If you convert AC to DC with a diode-bridge, you double the frequency. Because you just flip the negative sinus-wave to positive, so your frequency doubles from 60hz to 120Hz, our here in my country from 50Hz to 100Hz.

Dave Jones from EEVBlog did a series on this, it ended up being (inherent noise of) the silicon inside the integrated amplifier (on self-powered studio monitors) nothing power/placement could fix in that example.

@BogdanSerban

5 жыл бұрын

That only applies to integrated amplifiers. Discrete ones generally don't have this issue.

A ground loop is precisely what picks up 50/60 Hz hum from transformers. It can be minimized by keeping cable routing away from the transformers, and also by running cables together, rather than spread out. Buzz, which is harmonics of 50/60 Hz power, is usually from capacitive coupling to the AC line (mains), and there can be many sources of this. Many hifi components have small filter capacitors from chassis to both sides of the AC line, and there are parasitic capacitances as well. If all components had exactly the same parasitic coupling to the AC line, then the cables connecting them together would have negligible shield currents, minimizing the problem. But this serendipitous case rarely occurs, and generally there are noise currents in cable shields. The effect can be minimized by having very good ground connections between component jacks and cables, i.e., free of dirt, oxidation, and being mechanically tight. Ultimately, use of balanced signals is the best way to avoid this particular noise source, but sometimes less extreme measures such as running heavy ground wiring from all component chassis to a common star point can be a solution. Hiss is white noise, and its source is primarily the thermal energy present everywhere; it cannot be eliminated, only reduced, preferably below the threshold of hearing. Any electronic component which exhibits electrical resistance produces some thermal noise - not just silicon devices, but even passive resistors. It can sometimes be reduced by optimizing gain balance along the signal chain, but for the most part it must simply be designed out by using good design practices. From the owner's perspective, it can be managed by selecting components of high quality, and applying them as they were designed to be used.

@davidlewis8124

2 жыл бұрын

You are a genius + explain everything in terms so it's easy to understand. 👌✌️

Hi Paul. You say if you can't hear it when your in your seat then it dosen't matter. Well just knowing it was there would drive me bonkers. I want as little noise as possible coming from my speakers when the amp is on. I have spent 1000's of dollars on my equipment and I expect QUIET from my amp.

@marianneoelund2940

4 жыл бұрын

If "just knowing it was there" drives you "bonkers," then there is no solution for you. Noise is always present. You need to be more practical. If you don't hear the noise from your listening position, there is no point in taking measures to reduce it.

@f430ferrari5

3 жыл бұрын

@Helter Skelter. You probably spent more on your wife. You expect quiet from your wife? 😂🤣

Very good explanation Paul. Quite some years ago I was the proud owner of a Threshold Stasis Preamp/PowerAmp combo. I also had access to military grade parts and pieces ( resistors, capacitors, discreet transistors ). Some of the projects I worked on involved low level analog amplification. So here goes: 1: Connect the Threshold Power Amp to the speakers and put a military grade 100ohm resistors across the inputs. Power up and place ear directly next to the 3-way speaker ( 92db for 1w input @ 1khz ) and listen for hum and hiss from all three drivers. Nothing. I couldn’t hear anything. 2. Connect the Threshold Preamp to the Amp using very good, at that time, 18in Monster Cables. Put 100ohm resistors across the Preamp line inputs. Set volume control completely counter clockwise. Place ear next to speaker. I hear nothing from all speaker drivers. Rotate volume control to totally clockwise. Place ear next to speaker drivers. Yup, I can hear just a little tiny bit of hiss. Step back a meter or so and I hear nothing. 3. Build an over the top preamp ( no Phono input ) out of military grade components. Tantalum caps, glass caps ( very expensive ), military grade resistors ect ect. Ordered some super super low noise transistors from Texas Instruments. All discreet parts. Externalize ( a foot away ) the fully regulated power supply with huge Tantalum caps with glass .1uf caps in parallel across them. A simple gain stage preamp that would select one of three inputs. If you remove power from it it takes about 10-minutes to actually turn off. Design was close and tight. All aluminum chassis. Replace Threshold preamp with my “Glass PreAmp”. I actually wrote this title on it. Place 100 ohm resistors across two of the R&L inputs, connect to Threshold power amp with the 18in Monster Cables. Rotate volume control completely counter clockwise. Place ear next to speaker. Nothing. Rotate volume control completely clockwise. Place ear next to speaker. Nothing. :-) I beat Nelson Pass’s design. I still feel pretty good about that.

@jonathansturm4163

5 жыл бұрын

You put my feeble efforts to shame. Have an upvote!

@marianneoelund2940

4 жыл бұрын

"Military grade" resistors still have noise. Esoteric capacitor types are not needed to control noise. Low-noise design starts with matching source and input impedances for low-level inputs, selecting silicon devices with low noise energy and appropriate noise voltage/current ratios, then maintaining low impedance to an extent that is practical, through subsequent stages. Low-noise designs are application-specific, that is, an amplifier designed for low noise figure with a specific source and signal range, may not be optimal in other applications.

@wilcalint

4 жыл бұрын

@@marianneoelund2940 I always point to this project as an example of elegant circuit design: en.wikipedia.org/wiki/Voyager_program

@wilcalint

4 жыл бұрын

@@marianneoelund2940 Little bit of a boost here. Yours truly constructed, did not design or deploy, the test fixture for what is best described as the “compass” for the moon lander. That project was around 1966 and executed in a test bay in a lab run by MIT/GE/USN. Undergrads are cheap labor. Free in fact. The “compass” was also used, and its primary purpose, was in the warhead of a nuclear weapon.

@marianneoelund2940

4 жыл бұрын

@@wilcalint The Voyager craft are amazing machines. I'd love to see circuit design details.

Keep power and audio interconnects separate, cross at 90 degrees, if you can. Regarding hiss, optimize your gain staging. Poor gain staging is one of the major factors in excessive noise.

I love Mr Ed, saw it on nick at nite back in the late 90s

would love to hear more about these ground loops

The answer is that the inherent noise floor is relevant to the sensitivity of the speakers and the gain in the preamp barring any faults like ground loops etc. Given that a turntable playing a record is mechanical and the cartridge is sensitive to noise it would be bizarre to have dead quiet playback.

Reminds me of the joke where the lady goes to the doctor, and says "Doctor. It hurts when I do this", so the doctor says "well then stop doing that". Same here. Stop sticking your ears right up, next to, the tweeter, and you won't hear it anymore. Duh!

@jonathansturm4163

5 жыл бұрын

And that reminds me of: "Bono, whilst playing a gig in Glasgow, got the whole crowd to be silent and then began slowly clapping his hands. He got the crowd to clap along for a while, the stadium quiet except for the rhythmic clapping… After a short period Bono spoke, saying that every time he clapped his hands a child in Africa died … Suddenly, from the front row of the venue a voice broke out in thick Scottish brogue, ending the silence as it echoed across the crowd, the voice cried out to Bono “Well stop fucking doing it then!!” Snopes says it's false, but it is funny...

@amb3cog

5 жыл бұрын

@@jonathansturm4163 No it's not funny. It's mean spirited, and ignorant. Like you!

@jonathansturm4163

5 жыл бұрын

@@amb3cog You are undoubtedly correct. I shall immediately cancel my sponsorship for a child in Africa through World Vision. What was I thinking of?

@phreakinpher

4 жыл бұрын

@@amb3cog Yay, the internet!

hello paul great video about audio hum and hello from australia but i am from uruguay

I kind of like the hiss coming from my DIY speakers. It is relaxing. I only hear it when I turn the gain that high or put my ear close to the speaker though so who cares.

What about the same noise from the midrange and low hum from det woofers?

I started to notice a slight hiss from my right rear surround earlier tonight while the room was quiet. Google said the most common cause is from over driving the speaker so I went into the levels and EQ and brought that speaker down slightly and it got rid of it.

The horse's registered name was Bamboo Harvester , It was Allen Lane tht did the voice of mr ed . We watched it allll the time . Lol

Hi Why would i have louder hiss from right channel than left please? and how do i track which component

Allan Lane made more than 100 movies and TV shows from 1929 to 1966, playing bit parts as well as starring roles -- many of them on horseback. As "Rocky" Lane, he made more than 30 Westerns with his horse Black Jack. But his most memorable role might be as the voice of the talking horse on TV sitcom Mister Ed. A horse is a horse, of course, of course, And no one can talk to a horse of course That is, of course, unless the horse is the famous Mister Ed. Go right to the source and ask the horse He'll give you the answer that you'll endorse. He's always on a steady course. Talk to Mister Ed. Lane didn't sing the jingle -- that was Jay Livingston (1915 - 2001), who co-wrote the song with Ray Evans (1915 - 2007) -- but he was the voice of the palomino who would only converse with his owner, Wilbur, played by Alan Young. Mister Ed was Lane's last role. He voiced the part from 1961 - 1966 but received no screen credit. According to Wikipedia, the producers said the voice belonged to "an actor who prefers to remain nameless." When the credits rolled, they just said: "Mister Ed … Himself." After the show became a hit, Lane asked for but never received credit. He retired after the show went off the air and died 40 years ago today in Los Angeles after a short bout with cancer. He was 64.

@ZadakLeader

5 жыл бұрын

:( that's sad

@Peter_S_

5 жыл бұрын

Thank you for the additional information.

@sixstringsdown1

5 жыл бұрын

And he is funny to!

@marianneoelund2940

4 жыл бұрын

Now there's a fascinating set of trivia. "Mister Ed" was one of my favorite shows when I was young. Thank you for contributing your research.

Sources of "hum" can be swept for and found with the extendable antenna of a compact handheld AM/FM radio set to the AM band!!!....just DON'T contact the metal antenna to an energized circuit!!!...although you may be able to put some heat shrink tubing on the tip for close proximity safety!!!😁👍🏻

@DennisDWest

5 жыл бұрын

By a show of hands, how many people in this forum own an am/FM radio?

@fookingsog

5 жыл бұрын

@@DennisDWest 😂👍🏻...Somewhere!!!😂😂😂

@fookingsog

5 жыл бұрын

@@DennisDWest ...actually I think I have an AM/FM/Shortwave!!!😁👍🏻

Paul I have quick question. I am using Naim XS2, RME ADI-2 and raspberry pi+digione combo. And I have cinema system as well. Both in the same place. When I connect dac to amp using interconnects I got lot of noise even if I turn off the dac. I researched the issue and what I understand is Naim has a ground connection but doesn't pass ground signal to rca, rme doesn't have grounding thats my problem I guess. I have figured out if I connect an interconnect cable between preouts of my cinema receiver and unused rca port of my naim amp I would solve my issue and that works. Is it good practice or not? Another option I considered using a ground wire from extension to amp's unused rca port. Am I doing something wrong?

@marianneoelund2940

4 жыл бұрын

Finding and correcting noise issues due to grounding can be difficult. If you have a solution that works, then it counts as "good practice." Enjoy your system and don't worry about it.

Help! I have a big hifi stereo with a loud hiss (not hum or buzz) when i have it on radio or blue tooth. Its loud enough that i have to turn the music up considerably to not hear it anymore. Im very unfermilliar with components and lingo but ide really like to fix this so i can enjoy quality sound without having to crank it up all the time.

A lot of misconceptions about hum and buzz have been solved by Paul here. Most people think a lot of noise floor just comes from their music recordings themselves. Honestly I used to think that, but it had to do with my mains power situation. At first I thought it was my amp!! I was wrong. I had a pathetic power conditioner and dirty ass AC mains. Nuff said. :)

If you want to hear funny pitch meetings check out screen rant here on KZread. Most hiss and noise is faulty components or poor shielding in my experience.

@ONIKdeftones

4 жыл бұрын

Not really even new Amplifier causes Hiss and it depends on how much Gain it has. I believe hiss is ok because don't listen to music while putting my ears close to the tweeters I sit on my chair and enjoy it so hiss is not a problem but hum/buzz is which can be eliminated somehow I guess.

But isnt this what you try and avoid, you use good cables with batteries and all sorts of things to avoid noise but an audible hum and hiss is ok? doesnt make sense to me, arent you trying to get the most pure sound possible?

@blandondwyer4360

2 жыл бұрын

Thanks

Probably the first time Paul admitted the power regenerator does not eliminate the hum. I think the major problem is manufacturers do not want to build custom made transformers and they do not even cover them any more inside the power amp; they order something cheap from China. I recently bought a new Luxman amplifier and I sent it back the next day because of a hum, but my older Sansui and Quad amplifiers do not hum at all even when I put my ear to the unit close. Probably the design and quality of components is the most important factor; a separate power line as well

@jamesplotkin4674

5 жыл бұрын

Certain your Lux didn't have a cooling fan making noise? I believe the OP was noticing hum over his speakers, not mechanical from within the unit.

@Watcher4111

4 жыл бұрын

Exactly. I have full made in japan vintage gear and hiss and hum doesnt bother me. Signal to noise ratios are above 100 db ( amp 124.4 db, pre 106 db) so theres no hiss at normal volume

why is there no dolby noise reduction on an Amplifier? Like a Cassette deck dolby b or c?

@marianneoelund2940

4 жыл бұрын

Dolby noise reduction only operates on noise that accrues between the encoder and decoder, such as "tape hiss." It does not reduce noise that was already present in the original signal. For the latter, autocorrelators can be used, but they will only treat noise up to the input of a power amplifier, not noise added by the amplifier itself. Minimizing noise coming from the amplifier is just a matter of choosing a high quality model, and also making sure it is receiving signals at an appropriate level that can make full use of its S/N ratio.

I tri-amp and have vintage active crossovers. Each channel makes use of two crossovers. I originally hooked it up as the user manual instructed. I ran the signal into the woofer-to-midrange crossover, then ran the midrange signal into the midrange-to-tweeter crossover. A simple change made a big difference. I ran the signal into the midrange-to-tweeter crossover, then ran the midrange signal to the woofer-to-midrange crossover. It cut the hiss in half. Hiss can be caused by resistors, as well as semiconductors. Sometimes you can detect the offending device by freezing them (one at a time). I've looked into replacing opamps with newer low noise components. This may be fraught with problems. The new chips are likely faster. This may improve transient response, which may good. It may also cause the circuit to oscillate at inaudible frequencies. Capacitors can be added, but then you're getting into more complex mods. Replacing a noisy transistor carries much lower risk. Hum can be sometimes be reduced by re-routing cables. Keep power cables away from signal cables. If they have to close, try to eliminate parallel runs. Use balanced lines if your equipment supports it. If you have some equipment, you can trace the signal through the circuit and see where hum is introduced. Re-routing wires can sometimes get rid of hum. Internal power lines should be twisted and run in the corners of the chassis. Mu-metal shields can sometimes be installed. Foil capacitors may have been installed backwards; the outer foil should be at the lower (ground) potential. Check out _Mr Carlson's Lab_ KZread channel. kzread.info/dash/bejne/p4qfrNOqitXVfpM.html

God, this all brings back memories. I've done a number of low noise amplifiers. None in the audio spectrum. One of the sources of hiss in circuits are thermals. Not the actual stable temp but the change in temp. One technique was to enclose the low level circuit in a little oven. Heat the entire circuit to a constant lets say 80C and leave it there for an hour or so. No thermals and the circuit gets really quiet. I seem to remember some audio preamps using this technique.

@jonathansturm4163

5 жыл бұрын

Well that's a new one on me! I always thought thermal noise was best combated by cooling. I do enjoy the learning here...

@marianneoelund2940

4 жыл бұрын

@@jonathansturm4163 You are correct that thermal noise drops with temperature. Thermal noise due to a resistance: Vn = SQRT(4kRTB) where k is the Boltzmann constant, R is resistance, T is absolute temperature and B is bandwidth. The anecdote about "quieting" a circuit by heating it to 80C is nonsense.

@jonathansturm4163

4 жыл бұрын

@@marianneoelund2940 I suspect that Bill’s talking about a different type of thermal noise than we are thinking of. His comments are almost always sensible and cogent. Not to mention grounded in real research!

Why don't you then make the transformer a separate box instead of mounting it inside the amplifier?

@Paulmcgowanpsaudio

5 жыл бұрын

Yes, this can be done and we did it on several models we've built in the past. It's expensive for that second box and not everyone wants more boxes.

I had a 300 watt sunfire amp that had a hiss and bob carver said the same thing ,it drove me nuts ,I here'd a krell 250 watt that had none ended buying the krell amp

@marianneoelund2940

4 жыл бұрын

I can assure you that your Krell amplifier has noise as well - it's just at a low enough level that you don't notice it. There is no way to eliminate noise, but as you have found, choosing quality components can make it low enough for practical purposes.

@conradva6776

4 жыл бұрын

@@marianneoelund2940 well I'm sorry to say the krell is not audible at all, the sun fire is a good amp but even at low listening you could hear hiss at 4' feet from the speaker [ I can put my ear right at the speaker 1" inch away with krell can't hear nothing

@marianneoelund2940

4 жыл бұрын

@@conradva6776 "Inaudible" is not equivalent to "zero." Human hearing has a threshold, which by the way goes up substantially if there is any other sound source in the room. I'm happy for you, that the Krell works that well, and I believe you are making an excellent recommendation - but no amplifier can achieve zero noise.

As I have gotten older and have more disposable income to spend on my audio hobby, I have noticed that the more expensive and exotic pieces of equipment that I have purchased are also more "fickle". Back in the days of purchasing Pioneer, Kenwood, NAD receivers, JBL, Knight, and NHT, TCM speakers, I never heard any hum, hiss, or buzz. Now owning equipment that cost 10-20 times more, I hear noise. Is it me?

@InsideOfMyOwnMind

5 жыл бұрын

It is not you. The big major brands are designed by many people and are designed more conservatively in terms of the main problems people are likely to complain about. With high end gear a given product is designed buy a much smaller group and sometimes one person does the whole thing. This can lead to "good enoughitis" when you don't have people to bounce things off of so much.

@UberPilot

5 жыл бұрын

Most high end stuff is kind of junk. Maybe not junk but seriously flawed.

@UberPilot

5 жыл бұрын

Larry Niles How about, tends to buzz more and is less reliable. Ask me how I know this. BMW spends hundreds of millions on advertising and is 23 in reliability. That’s from their own club magazine. Perception and reality are rarely the same thing. Don’t have any experience with PS Audio.

@InsideOfMyOwnMind

5 жыл бұрын

@@UberPilotSome things among others PS Audio has going for it. They are at the size where people are depending on their survival. One of the founders is still there. They are still small enough that reputation is more immediate than say a Pioneer or a Kenwood. Each person's fear of screwing it up goes a long way towards quality. If you are just an employee number and some garbage escapes QC who cares? When a company is as transparent as Paul indicates PS Audio to be there is less fear for the buyer. In fact I think they should bring more of thier people into the vlogs If I feel like I know the people damn right I'm gonna look to them first.

@Enemji

5 жыл бұрын

InsideOfMyOwnMind - Quite the opposite. Most large companies have teams who at times are so disconnected that it is not even funny.

How about "My Mother the Car", same timeframe or even "My Favorite Martian"?

Wow I thought I was old.

@jonathansturm4163

5 жыл бұрын

@ hifi noob 2018 I'm told you are only as old as the woman you feel. Pity. My ex-fiancée is a year older than me ;-)

Yes it can. /End

Why not put a cap on the transformer to contain the magnetic field?

@marianneoelund2940

4 жыл бұрын

Usually, it's easier to change cable routing to avoid the magnetic field. Don't run interconnecting cables near power transformers, and keep them bundled together. The area between cables, if they are spread out, is proportional to the amount of hum that will be picked up. Sometimes, high-end manufacturers will put extra shielding around their power transformers to minimize stray fields (e.g., Denon's "low leakage" transformers), but if your components don't have this, your only recourse is careful cable routing.

Hum and hiss are artifacts I rarely hear anymore with digital music gear. Still poor shielding or some ground loop issue can cause hum while hiss I’ve only experienced recently from EMI with a nearby smart phone. These artifacts are more common when playing vinyl.

@wilcalint

5 жыл бұрын

If you listen to a lot of old LP, s in the quiet times during playback you can often hear the hum and hiss from the mixing and capture equipment. Ampex 300's added hum and hiss at the capture point. Take if from someone who knows.

@jonathansturm4163

5 жыл бұрын

"hiss I’ve only experienced recently from EMI" I tend to hiss when I hear the word _Sony_ - EMI not so much...

@ThinkingBetter

5 жыл бұрын

Jonathan Sturm EMI = ElectroMagnetic Interference

@ThinkingBetter

5 жыл бұрын

Bill Kenney Yes, actually you don’t need to listen to old LPs to hear the hiss from old master tapes. It’s quite audible on some digital media also of analog recordings done from the 70s or earlier.

@jonathansturm4163

5 жыл бұрын

@@ThinkingBetter I know. My comment was intended as a weak joke. My bad...

The thumbnail for this video would make a great wallpaper for a phone!

Yes i had terrible emi rfi and git a pretty cheap like 46 dollar Duracell conditioner works fantastic should've got 2

What about a Noise Gate to quiet He Hum and hiss? Guitar players use them.

@marcusfred4480

5 жыл бұрын

A noise gate works by muting the signal source when it falls below a certain threshold. Guitar players use it to make the playing of the instrument cleaner. If you insert a noise gate between say a CD source or tape source and your amplifier, all you will do is eliminate any signal coming from that source when the level falls below the set threshold. As soon as it rises above that threshold it will let through all of the hiss and hum that may be present in the recording/amplification of that source signal. But if the hiss or hum is being introduced in the power amplifier stage then nothing but redesign will fix that unless it's just components that have gone bad like leaky filter caps in the powersupply or noisy transistors.

@Geerladenlad

5 жыл бұрын

@@marcusfred4480 yeah I know how gate works. You won't hear the Hiss while the music's playing normally unless it's really bad. Sometimes hiss can be from a really bad recording.

@marcusfred4480

5 жыл бұрын

@@Geerladenlad Absolutely. I agree. A special filter can reduce hiss. Or you can sample the recording and bring it into a piece of software like Audacity and use noise filter to cancel out background hiss. Also I once watched a video on a cassette player (I think made by Pioneer) that does this digital noise filter thing in real time. It' looked quite interesting! :)

@marianneoelund2940

4 жыл бұрын

@@marcusfred4480 Resistors going noisy, especially bulk carbon types, are the usual culprit as equipment ages. I've had to replace a few of those over the years. I haven't seen any transistors go noisy in power amplifiers, but I have dealt with a noise issue due to batch processing problems in a small-signal device that caused excessive flicker (low frequency) noise. That was an interesting problem to find.

Really really low noise amplifiers are used on sonar designs.

@wilcalint

5 жыл бұрын

Nelson was a stickler for low noise in his preamps.

First they hum, then they hiss, then.. they are told to pack their bags and gtfo😉

You can eliminate just about 100% of hum and buzz by remoting the power supply from the amplifier and having an electromagnetically clean space by design and attention to surroundings, but you can never eliminate 100% of hiss because of noise from the granularity of charge at the single electron level i.e. "Shot Noise", the thermally induced charge carrier variations i.e. "Johnson Noise", and the reality that the Universe is filled with 3 degrees Kelvin of background radiation, probably left over from the Big-Bang. The Universe is just a noisy place. The best you can do is design the circuit's gain structure such that the effect of that noise is minimized at every practical opportunity. If you want the ultimate in low noise amplification, you need liquid nitrogen or helium.

@brianmoore581

5 жыл бұрын

Hehehe...hehehe...he said, "Johnson noise". And "shot noise". Hehehe. --Beavis

@johnyang799

5 жыл бұрын

Use low impedance and high current design can eliminate a lot of noise and interference. For a headphone amplifier, it is very doable to design a circuit has noise 20hz-20khz rms of under 1uV. For speaker poweramps I suppose 100uV is good enough.

@wilcalint

5 жыл бұрын

Classic Nelson Pass Threshold Preamps externalized their power supplies. I still own one.

@brianmoore581

5 жыл бұрын

@@wilcalint so do all but the entry level Pass preamps. I have the XP20.

@jonathansturm4163

5 жыл бұрын

@ Peter S Couldn't agree more. I couldn't afford a toroidal transformer for the first amp I built so the PSU had its own separate box at the end of a 300 mm (1 foot) cable. The specified first stage transistors in the phono stage were replaced with super-matched pairs for some (theoretical) improvement in both noise and distortion. I deemed liquid N, or He as unnecessary given my lack of Golden Ears.

easy to eliminate hum and hiss..................................I divorced my wife

AeeeeeDdd 🤣

There are no Hum and Hiss in my home. No, sir. If they sneak in, they could ruin my speakers, in the worst case... And we won't let that happen, right?