tommylion "Lowering the noise floor" 90% of systems these days have enough gain from the source and in the poweramp so a passive pre can be used, this get’s rid of a large source of noise, the "active preamp". Remember what nelson pass said: Nelson Pass, "We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more. Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up. Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control. What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection. And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."
Cheers George |
georgehif90%
of systems these days have enough gain from the source and in the
poweramp so a passive pre can be used, this get’s rid of a large source
of noise, the "active preamp" If your active preamp is a "large source of noise," you really need a better preamp. |
90% of systems these days have enough gain from the source and in the poweramp so a passive pre can be used, this get’s rid of a large source of noise, the "active preamp". Wouldn't that be a moot point if one is using an integrated amp? |
I agree that lowering the noise floor can pay huge dividends. For those interested in super quiet amplification but do not want to go Class D, try one of Linear Tube Audio's (David Berning designed) ZOTL amps. I got a chance to try one in my system and it was amazing how silent the background was--not just "for a tube amp"--but quieter than any amp I've ever had in my system. |
" Wouldn’t that be a moot point if one is using an integrated amp?"
gdhal,
Not really, since almost all integrated amps just have a built in active preamp section. However, integrated amps do eliminate the need for external cables that are required between separate preamps and amps that may help keep the noise floor a bit lower.
dodgelum,
A very quiet tube amp really is unusual, congrats on finding one.
I’ve always loved the sound of a good tube preamp or amp in a system but realized they had to add something to the signal (even order harmonic distortion?) to flavor the sound like most do. Whether this added something adds to the noise floor of a system, I’m not certain.
Tim
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If your active preamp is a "large source of noise," you really need a better preamp.
Why, if you go passive (no noise) and you have more than enough gain without an active pream in 90% of systems. Even the "best" active preamps add their own noises, and as well amplify any input external noise. Cheers George |
gdhal Wouldn’t that be a moot point if one is using an integrated amp? The OP tommylion uses a 2A3 poweramp with an input impedance of 100kohm and very high gain at just 500mV input for full wattage output. There is 2000mV (2v) or more available from any source these days, why add another gain stage with an active pre???. This is a perfect scenario for a passive preamp. Any active preamp no matter how expensive, is a backward step, not just in noise but also sound. http://www.divertech.com/asltulip.html Cheers George |
My system actually exhibits a lower noise floor now after adding tubes to the system. Originally I had only two 12AU7s in my line stage and all was well. After having my SACD player modified by Dan Wright and company, which added two 5687s and a 5AR4 rectifier to the mix things are actually quieter when the digital source is selected than before. I feel secure in giving some of the credit to my PS Audio P5 power regenerator. 2.0% distortion in, .1% out!
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Proper grounding is another way to lower the noise floor. That’s a given for LF hum, but for HF noise it’s a bit more complex. Cheers George |
Here some (uncontroversial) sources of noise or distortion that might not have been mentioned.
1. The induced magnetic field produced by the large transformer that extends outward to all electrical components and wiring in proximity.
2. The mechancal noise produced by the large transformer and direct coupled to the chassis and the circuit boards.
3. Low frequency seismic vibration that is capable of exciting the resonant frequencies of the turntable platter, tone arm and cartridge AND of affecting the laser reading process in CD players, producing jitter.
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I ran a separate power supply from the pole to my house for my audio gear. Separate ground copper pipe 8’ down. I use Transparent power conditioning & Transparent reference power cables. But I think the real difference was getting the power off the house system with motors EMI & RFI. For me the clean power, high grade panel w superior grounding lowered my noise floor immensely. At least now I know any noise issues are with my equipment and room. |
Found this thread looking to reduce room background noise.
@
willemj1
Were you ever able to lower below 35dB? Measured yesterday and that is about where I am at. This is making sure the HVAC system is not running, but that is easy enough to accomplish for an hour or two. Didn't do anything special when building our house, though home theater is in the basement (fully buried to about 3/4 buried in back). There are only two of us so running water isn't a big issue, haven't tried unplugging the fridge to see its' effect but it is a fairly new quiet unit. |
The noise floor of any components and the sum total of the noise are the most underestimated factor in audio to gain sound quality... The problem is some solutions introduce, limitations of their own, a trade-off, a reframing of the sound, a compression of the sound, an active filtering that ressemble an artificial "framing" of the sound... My solution is passive filtering.... With stones and crystals, I obtain a complete transformation of the system...It is not perfect,nothing is,but there is no relation between before and after that...By the way even my power conditioner benefit from the stones...Cables also...etc |
I posted this in December of 2017:
" "I have one word. Cryogenics. Cryo everything! Everything in the signal path and everything not in the signal path. "
I sure hope geoffkait is right about the cryogenics treatment on everything; I’ve got an appointment tomorrow to have my entire body cryogenically treated. Our ears and brains are in the signal path, right?
The doctors warned me that my entire body will become very brittle after the treatment, like fine crystal.
They said a high, sustained tone at just the right resonant frequency or even being nudged or bumped could cause me to shatter into 1,000 pieces.
I’m sure everyone’s in agreement that these risks are definitely worth taking for a bit better system sound, right?
My wife’s trying to talk me out of it but our commitment to better sound trumps any silly marital vows, right?
Okay, all systems are a go for the treatment unless geoffkait tells me before 2 pm that he may have exaggerated just a scooch on this cryo stuff. since the cryo treatment is non-reversible.
Wish me luck,
Tim"
Well, I had my entire body cryogenically treated and I promised an update on the results. I was just released from the hospital last week. I’ve been in what they call their "Super-Duper Complete Body Cryo Treatment Just in Case Isolation Chamber" since I underwent the treatment way back in 2017.
All of my attending doctors were required to remove all of their existing body hair and wore completely sealed body suits with hoses attached that fed oxygen in and and carried exhalation emissions out of my sealed glass room. Any possible ’contaminates’ such as tvs, radios, computers, books, magazines, clothing, telephones or visitors were strictly forbidden. I was constantly being poked, prodded and monitored. My wife divorced me and I’d actually forgotten what colors looked like because everything was white or metallic.
It was a bit difficult to go through and I’m just so glad it’s all over and I’m home again. Thank goodness my very good health insurance ran out. Nobody ever said getting great system sound was going to be easy, right?
Okay, enough of the whining, what were the results?
Well, it’s only been a week, but I think my system sounds a scooch better. Of course, I haven’t heard music for almost 2 years but I doubt that would have any affect. The weird part is I’m now constantly cold and shivering. I can also constantly see my breath, my wife’s gone, I’ve lost all contact with family/friends, I have no idea what’s going on in the world and I lost almost 2 years of my life. But on the positive side, I think my system might sound marginally a bit better, maybe.
Yes, it was definitely worth it, no doubt about it, it was so expensive and painful it must sound better, what was the friggin point otherwise? Uh oh, do you think this could be what’s called the ’placebo effect’?
Tim
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My 'snake oil voodoo crazy upgrade bias placebo' additions have done wonders to my noise floor.
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