Axiom Home Page Forums General Discussion Advice from Axiom Owners For those of you with external amps - floor noise

I recently went with an external amp to test out the differences between receiver power compared to external. So far my findings have been extremely positive but since I am fairly new to this I was curious what is acceptable floor noise when using external amps. If I have the volume half way up and mute the sound I can hear hiss about a foot away between my speaker and ear. What are you seeing with your external amps? I just don't know what is the acceptable standard when it comes to floor noise. I'm using RCA connections from a Marantz SR7010. Thanks

Make sure the volume of your television is zero.

I use an Integra M504 external amp with a 9.2 AVR for front L/R. No hiss.

are you using XLR or RCA connections?

Spiroh, what you are hearing is more correctly called "thermal noise", the residual random noise generated by active electronic circuitry. Assuming you don't have ground loop hum or buzz, the "hiss" from well-designed power amps or the power amp section of a receiver shouldn't be audible more than a foot from the speaker and you certainly wouldn't hear it from a normal listening distance.
Some receivers will generate more thermal noise than a separate power amplifier because of the more densely packed circuitry.

Typically, separate preamps are quieter than the preamp sections of a receiver, especially those with phono inputs, moving magnet or moving coil.

Regards,
Alan

Alan, you're a treasure to have on these boards!

I would say I cannot hear the thermal noise more than a foot away. Does this thermal noise affect sound quality at louder volumes? I guess my debate is do I sell the SR7010 to go to the AV7702mkii to be able to go from receiver with builtin amp and only rca output to a pre-amp with XLR outputs.

What Alan said. You can put a resistor on your kitchen table and measure the voltage across it as a result of intrinsic and extrinsic noise. Intrinsic from thermal fluctuations and extrinsic from stray fields.

To answer your question, a signal to noise ratio of over 85dB referenced to a 1 Watt output into the rated load with the inputs shorted and measured over a band from 20Hz to 20Khz at maximum gain is a figure your ears won't object to.

If you are really concerned about the noise, drown your amp in liquid nitrogen.

Does that help ?

At louder volumes the signal to noise ratio improves. Don't worry about it and enjoy the noise...I mean the music .

No thermal noise from my 25+ year old Integra M504, or Yamaha M80s. My newer anthem 5 channel amp ... no noise. Oh, my 5 wpc distortion generator (thanks Alan you treasure you) no hum, no thermal noise.

Good luck with your amp.

That beast's noise is imperceptible!

http://likemagicappears.com/site-content/uploads/2014/10/M-504-Specs.png

Mojo, the M504 is a wonderful beast, but the Yamaha M80 is a much more powerful Beast, but first 30 watts pure class A, stable at 2 ohms.

250 wpc continuous into 8 ohms 380 wpc dynamic/8 ohm, 850 wpc dynamic/2 ohms, bandwidth 10 Hz - 100 KHz 0.03% THD. A MONSTER

Spiroh, there are no practical benefits to using XLR outputs in a domestic environment unless your living space is besieged by local RF and power-line interference. There is no improvement in fidelity or sound quality with XLR connectors -- only suppression of possible interference and hum.

XLR connections were designed for broadcasting, sound reinforcement, and studio applications for long microphone cable runs and equipment interconnection, where cables are run hundreds of feet and may cross power supply cables from remote generator trucks. In the vast majority of home applications, they are not necessary. Most were added as an up-market sales ploy to lure gullible audiophiles into buying expensive gear that appears "professional".

And 2X6, despite your enthusiasm for vacuum-tube distortion generators, it makes as much sense to use tube amplifiers in modern-day high-fidelity systems as it would be to use a tube-operated computer or HDTV set (the former would fill an entire room with heat-generating electronics requiring its own dedicated cooling system).

Of course, many rock guitarists like the sound of vacuum-tube distortion layered over their guitar's output, but that's a different discussion.

Regards,
Alan

It's one thing to be opinionated, Alan, it's another to be arrogant and contemptuous. I have several solid state amplifiers, which I like. Kenwood KA9100, Yamaha M80, Integra M504, Odyssey Khartago, Anthem PVA, They have their strong points. I've used them all with Axiom speakers and various sources (Sony ES CDPs, Ah! Njoe Tjoeb, Marantz NS, MMF 7.1 turntable). I have an Antique Sound Labs MG S1 15dt, 5 wpc SET integrated tube amp. (tested at 8wpc with 6550 tubes.)

My best sounding system, is the tube distortion generator. We have a southern California jazz/audio group. My opinion as to the superiority of this tube amp to the others is shared by most of the others in our group. That is not to put down solid state, but to make the case, based on real world experience, that the tube amp simply reproduces music that many observers conclude sounds more life like.

I particularly like playing Mussorsgky's Pictures from an Exhibition, Royal Philharmonic Orchestra, Rene Leibowitz conducting, and watching the impact of the stunning attack of the French Horns on the listeners. Female vocals, are simply, sweeter, and more life-like. I find the music more involving.

Now, I know your tastes are very elevated, and it must be difficult for you to suffer those who have not attained your level of audio snobbery. That was made apparent to me when I sent you a CD of Ed Gerhard's music as I thought some of the cuts showed off Axiom speakers very favorably. When I did not hear from you I contacted you and asked whether you had received the CD. You informed me that you had but the music was not to your taste.

I got your measure then, Alan. Anyway, I like my heat producing distortion generator for music reproduction. I prefer solid state for my computers.

Enjoy the music.

That was predictable.

You brought it up and started it, 2X6.

Hi Mark, that sounded like Donald Trump!

No offense intended.

Wow! What with the month I've been having, I had to check the post dates to be sure I was in the present.

See, newbs, this is what it used to be like around here, sometimes daily. Only back then, ten people would have been in this fray by now. The joust is dead. Long live medieval re-enactments!

Peter may be correct to find it predictable, but I find the familiarity of it to be somehow nostalgic. Yes, I do have an appointment before the week is out.

One of these days I have to find some tube gear and hook it up to my M80s and Dreamcatchers. I'd really like to hear what it sounds like. Silly me...I grew up with a ton of tube amps in high school and took them for granted. I had a chance to take so many home. I think many of them were just thrown in the garbage .

2x6 ... It is ok for you to like the tube sound. Your amplifier generates about a 6% THD at its rated power, which translates into a distortion floor of about -24 dB, which is quite audible in the all important midrange portion of the musical spectrum (200-2000 Hz).

As an example, in this range, at 90 dB at a listening position, a pair of M80's will have a distortion floor of about -48 dB, compared to your amp's floor of -24 dB.

A good solid state amp will have a distortion floor of about -60 to -80 dB, depending on the amp - well below that of the speaker, and inaudible.

At this -24 dB level, your tube amp will be adding typically 2nd harmonic distortion, which will be quite audible. It's also, for many listeners, quite pleasant - it is that "warmth" people will tube amps discuss.

Alan's description of the amp being a "distortion generator" may be abrupt in its delivery, but it is quite accurate.

That entire post was pure arrogance so it is interesting that he's calling out people for their perceived arrogance. He must be one of the very few who has zero additional noise when using external amps. Lucky him.

I always marvel at the list of equipment that graces so many of 2x6's posts. It's been so long since I've read the words "Ah! Njoe Tjoeb" -- it really took me back to the food old days. )

He has a ton of "noise" or to be more accurate, distortion. Distortion can sound quite nice. All you have to do is listen to my EP600v2 to find out how nice it can sound .

I will add myself to the list of people here that have outboard amps with ZERO noise. And for what its worth we all must like distortion since the M80's are criticized for comb filtering due to their design. And for whats its worth there are a few people that come off as pretentious and critical around here and for the most part I just ignore them . I find finger pointing in bad taste, both by 2X6 and Alan, come on grow up guys, most of us here are out of grade school.

I'd say the most practical aspect is the click-in connection. I've had way-too-tight RCA connectors that have been impossible to pull off without doing damage. It's been a while, but it has caused me grief. I don't currently use a pre-pro, but one of these days I hope to revisit that sort of setup, and then I can pull out my XLR interconnects again that have been sitting boxed up. Right now the only XLRs I have are the cables between subs (since I have four).

I use XLR also, these days there are a lot of wires and cables behind a typical HT setup and it seems like a good idea to me to take advantage of the noise rejection XLR provides. Whether it makes a difference I cant say but it certainly does no harm.


Richard

XLR cables aren't expensive these days. Unless you choose the Corinthian Leather ones.

I prefer the ones with fine Valencia Vinyl. They lend a crispness to the music.

Some solid state amps sound very good. Some, with similar THD specs sound not so good. I suppose if you pump enough negative feedback into the circuit, you get good specs, but poor sound quality. I've heard tube amps which are very 'plummy,' a characteristic some equate with 'tube sound.' A good tube amp does not sound plummy but does have a distinctively rich, warm, 'musical' sound. (To my ears). The new MacIntosh, Prima Luna, ASL, VAC and many other new tube amps are not plummy.

I list some of my solid state amps to make the point that my opinions cocerning solid state amps are not based on something I read as opposed to my experience.

I have a system in every room (except of course baths). I have one tube amp, and a bunch of solid states. Including my garage, car wash system, I have 5, 2 channel rigs. I like them all. Except for 1 very sweet system with Dahlquist M905s, and one with the magnificent Thiel CS3.6s (Home Theater system), they all use Axiom or Axiom made speakers.

Frame of reference.

Ha! You're finger-pointing at them for finger-pointing. That's Rich! Hey, I know it's corny, but it's a double entendre and a pun at the same time! I had to go for it.

BTW, Richard, you wrote, "Most of us here are out of grade school," not "the REST of us here..." That means you think there are others. Don't make me guess. No, really, don't make me do that.

I'm off to play a round of golf ... really.

As you might expect ... tour blades and persimmon wood woods.

Before I go, you can get a decent sounding hybrid tube amp from Monoprice for $150. I picked one up and a pair of used maple M3V2s as a gift. Sound quality? Silly good for the price.

You may want to try one. You might like it.

Hmm maybe I will for my m22's.(office setup)

Richard knows that I am, in spirit, still in grade school .

Phil, I am very surprised to hear you don't have systems in your bathrooms. Get on that .

Bob stop pointing your finger at my fingers that are pointing back at me. Sheesh

Richard, my index finger is so arthritic, that if I were to use it while I admonishing you, you'd think I were pointing to the guy directly to my left.

I'm sure your wrist could compensate.

I tried it and it works. Arthritics have no excuses.

My finger smells funny.

I know, Mojo, but I have a rule against taking electrical appliances into the bathtub.

I do have a cool JBL blue tooth speaker, but I haven't figured out how to get FOX News from my phone.

Sorry to hear that Bob, old age sux. I have tinnitus and trust me that sux. But life is still better now than when I was young and broke and I DGAF what people think .