Audio Equipment and Home Theater Audio : Anyone out there using Vacuum Tubes for HT?

Anyone out there using Vacuum Tubes for HT?

Hi All,

The title says it all. Anyone using tubes for home theater? (amps that were built at least 40 years ago or some new production.)

My current setup uses a pair of Bogen HO125 Tube theater amps, made in 1946, these are 125 watt amps that rated that has a absolute max output of 440 watts.

The center channel is a 36 watt Sherwood made in 1962, and this the most detailed and crisp amp I have ever heard.

Rear channel is a Stromberg Carlson 14watt + 14 watt made in 1961.

This system easily outpaces any high end system (and I'm talking about actual home theater stores). There's no comparison.

Re: Anyone out there using Vacuum Tubes for HT?

what for?

what u are going to get?

are they quick? NO

do they produce a lot of heating YES

Re: Anyone out there using Vacuum Tubes for HT?

what for?

=======>All channels except sub bass.

what u are going to get?
More clarity and detialing than anything SS can do. I already own my amps. I built this system from the ground up.


are they quick? No

==========> Only when I use Telefunken 12AX7's in the preamp sections. Any other tube works fine.


Oh, and I played music for a halloween party with over 700 elementary (5 years to 10 years)students and quite a few parents in attendance, using a pair of Peavey SP1 with 15's and a horn, and a pair of SIXTY WATT Precison Electronics tube amplifers, it was loud and clear on the floor, so loud you couldn't talk and no distortion, no clipping.

Re: Anyone out there using Vacuum Tubes for HT?

Hey man, what's the point of $2000 vacuum tube cd players? Sounds like complete idiocy and a vast waste of money to boot. Ditto for tube driven anything else today.

Nothing is more beautiful than nothing.

Re: Anyone out there using Vacuum Tubes for HT?

Youre actually partially correct, it's the actual preamp that makes the difference, if the preamp is tube, you'll get the same sound. SO you can actually take pretty much ANY cd player, and preamp it with a tube preamp, and get the same sound.

I have run the entire gamut, from very high end audio, to 1960's console stereos.

The only advantage SS has is power from a smaller size and less heat. With 18 watts from a stereo tube amp, with inefficent speakers, I can drive people out of the house with no clipping and very little distortion.

Low quality SS amplifiers literally give me headaches. I refuse to listen to SS anymore, only exceptions are the monster receivers from the 1970's.

I have covered over 700 screaming elementary students (5-10 year olds)playing music at a Halloween party with only two monoblock 65 watt Precision Electronics tube amplifers matched with a pair of Peavey SP1. It was so loud you couldn't talk on the floor.

I am tired of the *beep* surrounding digital and how great it is. CD's cut off at around 17khz, and are intentionally compressed. In Dire Strait's Money for Nothing, there's a whole layer of sound effects missing from the beginning of the song because of that cut off.

Re: Anyone out there using Vacuum Tubes for HT?


I am tired of the *beep* surrounding digital and how great it is. CD's cut off at around 17khz, and are intentionally compressed. In Dire Strait's Money for Nothing, there's a whole layer of sound effects missing from the beginning of the song because of that cut off.


What on earth are you talking about? CD's do not cut off around 17kHz. The technical frequency response of CD's is to 22.05kHz, and the lowpass filter used in the mastering process is applied at no less than 20kHz... above the higher limit of adult human hearing, which rests around 17.5-18kHz.

Compression in mastering has nothing to do with digital compression. The former is a method of reducing the amplitude signature of the audio to keep it within the dynamic range of the format (which is 96.7dB for CD and only around 80dB for vinyl). The latter, digital compression, relates to the reduction of data which doesn't always correlate to a reduction in audio information, and does not apply to CD audio at all since the CDDA format is uncompressed 16-bit Linear PCM without exception.



Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

http://georgegraham.com/compress.html

http://en.wikipedia.org/wiki/Loudness_war


http://emusician.com/tutorials/emusic_masters_mastering/

http://www.audioholics.com/education/audio-formats-technology/issues-with-0dbfs-levels-on-digital-audio-playback-systems

http://www.cdmasteringservices.com/dynamicrange.htm


http://www.261.gr/CD%20loudenss%20war.html


http://www.rollingstone.com/news/story/17777619/the_death_of_high_fidelity/print
http://rockmusic.suite101.com/article.cfm/the_audio_loudness_wars

Sugarland's self titled album was unlistenable because of distortion.


If you want further proof, I am using a Shure V15 III cartridge with the correct needle. The preamp is vacuum tube. I can record Dire Strait's Money For Nothing, and you can compare it yourself.

Another example is Train's Drops of Jupiter, at 4:00 into the song, the drummer starts hitting the cymbals. On the all digital copy, the cymbals sound like static in the background, on the vinyl 45 copy, the seperate cymbals hits can clearly be heard.


I also run into the problems with audio levels when going from CD to an analog reel to reel.

Re: Anyone out there using Vacuum Tubes for HT?

This is an entirely different argument you're presenting now.

First you said that the frequency range is limited to 17kHz at the high end, which is false.

You also said that compression is the problem, which is false.

What you're describing and the links you NOW provide are not a problem with the frequency response OR dynamic range of the CD format.

They are a function of bad mastering. The loudness wars began actually in the 1950s, and kept escalating. Phil Spector used his "Wall of Sound" technique to increase the signal amplitude of tracks prepped for radio transmission... but since the 1970s there has been a worsening trend to master audio nearer to 0 dBFS than in the past. The result is that the larger dynamic range of CD is being wasted since the levels are mastered to a constant near the peak dynamic range.

If the audio engineers simply mastered recordings today actually knew what they were doing, CD's would all sound great... and a very few of them do.

But what you're encountering in the analog realm is a tradeoff... you're gaining a noise floor which also reduces the dynamic range, worse than CD's.

My personal preference, though, is 24-bit Linear PCM. This is also a digital format, and it is vastly superior to 16-bit Linear PCM. Where CD audio has 65,536 possible amplitude values per quantization interval, 24-bit LPCM has 12.7 *MILLION* possible amplitude values per quantization interval. This provides a degree of amplitude resolution and dynamic range that makes even the erratic amplitude of cymbals sound pristine, more so than any analog medium can handle.

Note that I say medium... this is very important. Analog is in theory without limit of dynamic range and has no amplitude resolution limits. But the formats that analog is fixed in, whether reel to reel, vinyl, etc. all have compromises whether a higher noise floor, groove width (vinyl) that limits dynamic range, magnetization of playback heads and wearing out of the recording on each successive playback... the available analog media are not up to the task of repeatedly providing the kind of dynamic range and amplitude resolution of digital past the first playback.

A properly mastered digital recording, one that hasn't been "pumped" for radio airplay, plays beautifully.... and even more so if it's 24-bit LPCM versus 16.



Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

Frequency response aside.

If you have heard a true analog to analog live recording of say a classical concert, if was mixed properly, there's a sense of extended range, or "air" or spaciouness that CD's cannot duplicate. It does slightly better when the source is analog.

PM me for the email address, I challenge you to compare the two distinct versions of the Train song I was talking about. If you are into country music, I have Jimmy Wayne's Do You Believe Me Now as a 45 also.

I agree with you about bad mastering, 90% of what's out there is unlistenable, half the time, it seems they can't even get stereo right.

I am using 1940's full range tube theater amplifiers rated @125 watts as my main source of amplification. These amps bring out EVERYTHING that is wrong with CD's today. I have run frequency sweeps on these amps, and my roommate's seven year old screams when it runs above 17khz because it hurts her ears. So I do know what they are capable of.

Re: Anyone out there using Vacuum Tubes for HT?


If you have heard a true analog to analog live recording of say a classical concert, if was mixed properly, there's a sense of extended range, or "air" or spaciouness that CD's cannot duplicate. It does slightly better when the source is analog.


Incidentally, I happen to have done professional mastering. That "air" you're hearing is the noise floor "fuzzing" up the sound, both the noise in the recording as well as the noise resulting from the playback system (a stylus touching a grooved record). While this may sound appealing to you because you're used to it. The problem is that while it "sounds good" to you, it's not an accurate reproduction, it's not a better dynamic range (again, the groove widths of a 33 or 45 limit the dynamic range to about 80dB), AND every successive playback of your 45 will continually degrade the media.


PM me for the email address, I challenge you to compare the two distinct versions of the Train song I was talking about. If you are into country music, I have Jimmy Wayne's Do You Believe Me Now as a 45 also.


"Drops of Jupiter" was mastered poorly. I ran this through an Leq(A) spectrum analyzer and here's what I found: NOTE: The tracks used are both 256 Kbps AAC, but they are from the original master recordings. The format doesn't change the loudness levels they were recorded at. So, for the purposes of this comparison of attributes, these files are more than adequate. The fidelity is not an issue as AAC at 256 Kbps is regarded by most engineers and audiophile forums as acoustically transparent to 16-bit LPCM. If we compared two LPCM files, the bad mastering would be just as evident:

http://images.cinemalogue.com/LeqA/LeqA-DOJ.tiff.html

http://images.cinemalogue.com/LeqA/LeqA-DOJg.tiff.html

"Drops" has an A-weighted average loudness (LeqA) of -12.0 dBFS, unweighted -8.6. This is no better than most of the amplitude-pumped bs recordings mastered since the 1990s to today.

Now compare that to "Celebration" by Kool n The Gang, produced by Eumir Deodato and released in 1980.

http://images.cinemalogue.com/LeqA/LeqA-Celeb.tiff.html

http://images.cinemalogue.com/LeqA/LeqA-Celeb_g.tiff.html

The LeqA value is -19.1 dBFS. This is an example of excellent mastering, and I picked it specifically because it is very emblematic of the quality of sound engineering from some of the bigger mastering houses in the early 80s. Also, it's nearly the same duration as "Drops", about 38 seconds longer.

More importantly, "Celebration" actually sounds quite fuller than "Drops" because it contains layers of instruments and lots of sweetening (a term used by engineers to describe fine tuning the mix to enhance spatial and amplitude dynamics, resulting in nuances that pop out at you rather than a "flat" mix but also having the distinct quality of not drowning out background layers). When the bass drum hits, if you adjust the volume upward, the thump stands out far more than anything in any portion of "Drops", which frankly sounds like it was recorded on crumpled wax paper and engineered by third graders with a potato peeler.

"Drops" is engineered so badly that the lead singer's vocals are almost drowned out by the portions of solo acoustic guitar! Nevermind when the strings and piano and drums come in... it all sounds very flat and I weep for the guy who spent tons of money on "audiophile" equipment only to purchase and play music this awful over his overrated amps and speakers.

Take a careful look at the two graphs. note in the yellow line how the A-weighted average keeps increasing toward the end of the "drops" track. This sort of gradual drift in the AVERAGE is common among newer tracks. However, older tracks while sweetened were downmixed and mastered to a constant average. It doesn't flinch once "Celebration" gets going.

Now look at the blue line, which is measuring the peak level in - dBFS at any given point throughout the track Note how "Drops" is constantly clipping its peak, whereas "Celebration" cycles a LOT and peaks JUST below 0 dBFS through the whole track. The range from the softest to loudest in the "Celebration" track is gigantic, very dynamic.

It shouldn't be the case that the average drifts while the level at any given moment there is only a -3dB difference from peaks to troughs. It should actually be the OTHER way around... a constant average with much larger variance between peaks and troughs... about TWENTY dBFS in the case of "Celebration". Now, just looking at the graphs you can tell which one is going to sound flatter on ANY sound system.

"Drops" looks like crap... and correspondingly sounds like crap. The funny thing is, what this means is that the vinyl copy of "Drops" will sound much worse. Oh sure, it won't manifest itself in scratchy cymbals clipping the dynamic range... but it will sound flat throughout, compared to a track like "Celebration". The noise level of analogue media simply masks most of the junk at the cost of making the entire track sound less intelligible. But your ears get used to it very quickly... especially if you aren't comparing it frequently to properly mastered digital recordings.


I agree with you about bad mastering, 90% of what's out there is unlistenable, half the time, it seems they can't even get stereo right.


Because of the poor mastering and final replication in a medium (vinyl) that can't support a larger dynamic range, even if they output "Drops" to 24-bit Linear PCM it's still going to sound like crap compared to "Celebration"... why?

Garbage in, garbage out.


I am using 1940's full range tube theater amplifiers rated @125 watts as my main source of amplification. These amps bring out EVERYTHING that is wrong with CD's today. I have run frequency sweeps on these amps, and my roommate's seven year old screams when it runs above 17khz because it hurts her ears. So I do know what they are capable of.


The reason your roommate's seven year old screams is because at that age, the eardrums are smaller, as are the hairs in the cochlea. Consequently, they resonate at higher frequencies. As you get older, however, and larger, your hearing degenerates both because your hearing equipment doesn't resonate to the highest frequencies, and because of years of use or abuse which eventually damages the cilia in the cochlea.

It is commonly misconceived by many "audiophiles" (a word that roughly translates to "doesn't know a lick of professional sound engineering") that cymbals don't reproduce well in digital recordings because of their high frequency. But this is absolutely false. Cymbal frequencies don't lie anywhere near the Nyquist frequency/limit. The problem is, as I stated before, dynamic range and amplitude resolution. While analogue media surpass 16-bit LPCM for amplitude resolution, they compromise on dynamic range because of the noise levels inherent to the medium as well as the mechanical limitations (e.g. groove widths on LP or track with/pitch on magnetic tape).

It is important to recognize that the combination of a higher noise floor, and more amplitude pumping at clipping levels is a disastrous combination from a sound engineering point of view, and the result is simply mediocre.

The advent of digital recording and mastering means that your entire argument is somewhat moot. Remember what I said, "Garbage in, Garbage out?" Another way of saying this is that your final product is only as good as the best representation of it at any stage in the process. If you trust "Drops" to be a listenable recording, or any other material from any band since probably 1995, know that almost all recording, mixing and mastering since that time has been done on digital mastertapes. Whatever limitations you think the digital format carries, is therefore present in the final analogue product you purchase.

If you argue that older analogue recordings sound better... they do! But again, that's not because of the analogue medium. That's because of the mastering process I just explained. Listen to THOSE recordings on 16-bit dithered LPCM (CD Audio) and 24-bit (undithered) and you'll see precisely what I mean.

P.S. thats another point... 16-bit recordings have some quantization error inherent in the medium but this is addressed by the process of dithering, or adding barely perceptible noise to the recording (well below the level noticeable in a digital recording) to force amplitude values to register correctly. I could explain this in better detail but it may bore the hell out of you and occupy a couple hours of my time. Basically, any properly mixed and mastered recording is going to sound better in a digital format than analogue.

Lastly, a properly engineered recording, as a mastering engineer once told me, should sound fundamentally good on any playback system. This doesn't mean that a pair of paper cone Kraco speakers will sound as good as my KEF Q-series loudspeakers. It does however mean the opposite of what you think is true. If a recording is engineered right, it will sound great on a mediocre system, and SPECTACULAR on a great system. If a recording is engineered wrong, it will sound bad on a great system, and like utter CRAP on a mediocre system.

Do this... compare a newer recording on an iPhone speaker or similarly limited-range speaker system to an older one... you might even use "Drops" and "Celebration". I will guarantee you that "drops" will sound like mud coming through that tiny speaker, and "Celebration" will sound much clearer. Or do it with any low-fi speaker... the result is always going to be the same. Especially because a good engineer always tests his master on various speaker systems to ensure that it's been mastered within the dynamic range and frequency response characteristics of most speakers. To do otherwise would be, much to my own chagrin, financial suicide.

I personally prefer to master my own recordings to a 24-bit DVD Audio format, which surpasses CD, SACD, Vinyl, tape, everything... but the market for this product is insignificant, and consequently most commercially released recordings are done in 16-bit which is still better than vinyl or quarter-inch reel to reel. (It's a whole other ball game if you're talking 3/4" or 2" mastering reels... but again, when these go down to the final product, forget it, there isnt enough groove width on vinyl or magnetic space on a 1/4" to accomodate a dynamic range better than CD. Anyone who suggests otherwise is selling you snake oil.

But more importantly, even with the ear-splitting 140dB dynamic range, and ludicrously-fine amplitude resolution of 12.7 million values per sample interval, of 24-bit LPCM, if your entire recording is mastered within only -3 dBFS variance from peak, it's still going to sound like sh-t.

Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

Well done,Sir.


But then you get into situations where such Meatloaf's Two Out of Three Aint Bad from Bat Out of Hell, where it sounded like the 2 inch track tape machine either had some really dirty heads, or a worn out capstan pinch roller.

What's even worse is Ami Stewart's Knock on Wood from 1979 on Ariola Records. Every single 45 version of this I have found sounds screechy on the upper levels, and it does on different turntables. Both ceramic and magnetic carts. However, the LP version is fine.

There's no question though, that records have to mastered differntly. Think RIAA curve selector on high end amplifiers and phonos from the 50's and 60's. The bass was intentionlly set to the center of the sound field so that the vibration would not make the needle jump out of the groove. The RIAA curve selector restored the wave to what it should have been oringinally for the listener.

I am familiar with Celebration, and I was using Drops because it was available on 45. I have run both through a 50C5 tube amp(3 watt, single-end pentode @10% distortion) and a 4 inch general purpose speaker that's matched to the output of the amp)and yes, the older analog to analog mix sounds fuller, even with this simplistic ceramic cart set up.

The whole jist of this that basically, the general public is being duped irregardless considering 90% of what's done today is going straight to mp3. (facepalm, if you know what I mean.) The whole situation is steadily getting worse.

Re: Anyone out there using Vacuum Tubes for HT?

There are certainly a few examples of bad recording mixing and mastering in the 1970s and 1980s.... Led Zeppelin's earliest recordings were done "live" (in one room without isolation booths rather than multitrack sessions, as is common today) on a 4-track and consequently had a lot of garbling due to Page's guitar and Plant's vocals bleeding into one another. It was such that Plant had to time his wails to go between Page's guitar licks or it would just sound like a garbled mess!

But yes, the loudness wars are one thing that escalated from the late 1980's onward. However, I think there has also been a general state of decline in the presence of trained engineers and producers amongst many of the ad-hoc folks who have sprung up in basement studios and home studios. I'm not saying that the advent of low-cost digital recording is bad... it's actually better for the industry in the long run. What's bad is that as I get older, younger people care less and less about quality and more about quantity... in all walks of life, not just sound engineering.

It's so hard to find an excellent engineer now that I'm surprised that even the highest paid solo recording artist in the business, Madonna, recorded such an awfully-engineered album as "Hard Candy" which clips all over the place... tack that up to her producer Timbaland who, frankly, doesn't know what the hell he's doing. Oh well...

There are a few exceptions the other way, too. Listen to "Counterparts" by Rush, recorded in 1993, produced by Peter Collins and engineered by Kevin "Don't Call Me" Shirley. This album sounds absolutely astounding for a rock album in the 1990's.. and it is probably Rush's fullest sound for their heavier albums. The track "Alien Shore", one of the best specimens on the album is a little flat, with a maximum variance of peaks of maybe -5 dBFS, but it has a constant LeqA of -14.4 dBFS... which is certainly better than most rock recordings of the time.

With regard to Mp3... there are better formats out there, such as MPEG-4 AAC which utilizes perceptual coding co-developed by Dolby Laboratories (AAC is a direct descendant of AC-3 Dolby Digital). But Mp3 is mostly a compression schema and not reliant so much on ingenious perceptual coding. Consequently, while a 256 Kbps AAC file is acoustically transparent (i.e. indistinguishable) from uncompressed CD audio. 256 Kbps Mp3 is noticeably not.

As long as the recording, mixing and mastering processes remain the same as they had been in the past, the end product on AAC would be great... and I for one welcome the age of digital distribution which evens out the playing field for the independent artist's sake. I foresee an age very soon where record companies will be largely obsolete. In fact, I foresaw it in 1996... when I wrote a research paper on the idea of internet-based music distribution. Incidentally, that was the same year that Apple started development of the iPod.

The advantages of digital distribution and storage are too many to count in one post, but aside from allowing greater exposure of independent artists by breaking the 60-year old distribution monopoly of the big distros (Uni, WEA, BMG, Sony, etc.), generation loss is largely a thing of the past, as is a perceptible noise floor, and retail costs can shrink because gross margin doesn't have to recoup manufacturing and physical distribution... costs go down about 80%. And, most importantly, the reliance on one single as being the marketing vehicle for an entire album of otherwise worthless material is at an end... Now with a-la carte purchasing, every single has to be desirable.

These are all advantages for the creative artist and the consumer of music... which SHOULD give, in principle, the ability to dedicate more time to the craftsmanship that's actually going to stand a chance of recovering its costs in this paradigm.





Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

Where can I get in touch with you personally?

How about some a/b comparisons of some songs and response testing?


When you go back to the 50's, you look at a label like say, Sun (Jerry Lee Lewis, Billy Lee Riley). Compare it to say, Dot, (Pat Boone and later Andrews Sisters), the Sun recording generally sounds balanced and clear, while the Dot recording usually blows windows out because it's three times louder and not necessarily cleaner. Speciality (Little Richard) occasionally sounds overdriven but not nearly as bad as today.

Even more extreme example is Gene Vincent's Be Bi Biddy Go Go on Capital (I think that's it, it's 1 am here. Gene is mostly famous for Be Bop A Lula) this one sounds like it was literally recorded in a garage with a single overhead mic.

But even then, a high quality 78 rpm on a good system blows a 45 out of the water. Unfortunately I do not have any quality 78's with the exception of Why Do Fools Fall In Love by Frankie Lymon but with no way to properly record it.

RCA played games with this during the 50's and 60's with Orthophonic High Fidelity, manupulating the frequency curve for more bass. However, they also had Classical music on Red Seal, which far better fidelity and quality vinyl.

I know that each label had their "sound", think the Nashville sound for RCA in the 70's, and the "Columbia" sound for Johnny Cash in the sixties and seventies.

KISS aside, Casablanca was mostly known for Disco acts such Diana Ross, as RSO was known for Bee Gees and Player.

This trend continued into the 80's with many hair metal bands ending up on Columbia, Geffen, Capitol, and to some extent, Electra and Mercury.

This trend also continues with country,with examples from the 80's such Rosanne Carter's Seven Year Ache, on Columbia to Sylvia's Nobody on RCA. Completely different sound and feel. Then early George Strait on MCA.

I was almost to the point to where I could listen and pretty much tell what label they were on.


This the cart that I'm using for daily listening

http://www.shure.com/stellent/groups/public/@gms_gmi_web_ug/documents/web_resource/us_pro_v15iii_ug.pdf

Your thoughts on frequency response, etc?

Re: Anyone out there using Vacuum Tubes for HT?


Your thoughts on frequency response, etc?


There are a variety of shortcomings of the vinyl format that make the frequency response of a stylus somewhat irrelevant.

Problems ranging from stylus noise, tonearm geometry (a radial stylus transport would be ideal), groove width, changes in groove compression from the outer to inner portion of the record, center pinhole offset, lack of true L-R discrete channel separation in the initial cutting of the master, dust, heat, etc.

Even signal transmission itself is a factor. I've never heard so startling a difference as when I obtained my first receiver with fiber optic inputs. The difference was so startling when watching the opening dialogue in "The Thomas Crown Affair" between Pierce Brosnan and Faye Dunaway in that there was a noticeable noise floor with analog cables, and no noticeable noise whatsoever in the optical transmission. It was most evident in the silent pauses between lines of dialogue... Nothing, absolute silence as the input signal of the dialogue track dropped off. When the input signal drops off with analogue wiring, there is hiss evident that can only be the product of unbalanced (RCA) copper stereo interconnects. Sidenote: I would like to see more consumer equipment using balanced analogue inputs and outputs (alongside the optical I/O), as this is a mathematically foolproof method of removing line noise entirely bypassing the temptation to succumb to the dubious claims of speaker wire charlatans.

This is not to say that it's wise to use a stylus that would add noticeable imperfection versus one with a flat response... but the medium as a whole is, to me, severely limiting.

One thing I forgot to mention was that the loudness wars were not only the result of radio. They did in fact begin in the analogue age much earlier than the 1980s because higher amplitudes have the effect of acoustically masking the noise floor. But in the digital realm in a properly mastered recording, no amplitude gain is needed to mask an imperceptible noise floor. Consequently the available dynamic range at the disposal of a creative engineer who wants to produce an astounding recording is tremendously greater in the digital world.


How about some a/b comparisons of some songs and response testing?


Unless we can use the results of a scientifically-controlled, double-blind testing environment, I do not consider any other kind of A/B or ABX testing to be of any factual significance.

Listening tests are unnecessary though when considering the notable mathematical differences between analogue and digital methods of recording, mastering and reproduction. It should be obvious that if a completely objective spectrum analyzer reads a -20 to -40 dBFS difference in noise floor, that the average Joe can immediately discern the difference between vinyl and compact disk.

Less noticeable might be the differences in amplitude resolution and dynamic range. Frequency response isn't really the issue because, while a gramophone record can achieve a frequency response (theoretically) to 76kHz, both the lack of integrity of the medium through repeated playback and the limitations of human hearing make it a moot point.

The few concerns that there are regarding digital recording have been addressed in Ken Pohlmann's 1985 book, Principles of Digital Audio (a must read), and consequently in most recording and playback systems manufactured at all ends of the price spectrum since the mid-80's. But jitter, frequency response roll-off, amplitude resolution and frequency aliasing (a frequently misinterpreted term) have all been addressed through various innovations developed in the latter 1970s and early 1980s in the development of commercially-available recording and playback equipment.

For the small contingent of audiophiles who claim there to be substantially perceptible flaws in digital reproduction versus analogue, or even between uncompressed digital formats and perceptual coding systems such as AAC and AC-3, I have yet to see a conclusive double-blind study, coupled with objective spectrum analysis results, published in a peer-reviewed scientific/engineering journal.

There's certainly no arguing that some people may simply prefer to listen to the more acoustically inaccurate results of analogue playback in a medium such as vinyl. That's a matter of personal preference, not fact. But, it is worth noting that the characteristics of vinyl can be reproduced IN a digital recording while yet retaining the benefits of digital media (e.g. zero generation loss, lower noise floor, optical transport, etc.). This can be achieved either through signal processing (effects), or by digital replication from an analogue master... as in the case of Ahmad Jamal's "Live at the Pershing" or Miles Davis' "Birth of the Cool"... or, for that matter, Dave Mancini and Denis DiBlasio's "Salt Peanuts" which was engineered and mastered by Jeff Tyzik, director of the Rochester Orchestra Symphony, and remastered digitally by yours truly. :)



Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

Sidenote: I would like to see more consumer equipment using balanced inputs and outputs, as this is a mathematically foolproof method of removing line noise entirely bypassing the temptation to succumb to the dubious claims of speaker wire charlatans.


===>Correct, when I was getting my amplifiers rebuilt for daily use, I insisted that the original balanced input was set up properly with canon inputs. My biggest problem is I do all my recording through the reel to reel from the computer and there is a long ass rca cord between tape deck/phono/computer setup and the rest of the system.

====>Correct also, I'm currently just plain zip/lamp cord on mine. I think spending high $$$ on speaker wire is stupid.

You keep mentioning noise floor. So what is the story about specifications even when these tube amps have a noise floor of -80 db and are essentially dead quiet, even on high efficiency speakers. Here's the specs for the Teac.

Track System 1/4-Track, Two-Channel Stereo or Mono
4 Heads Erase, Record, Forward Play and Reverse Play
3 Motors 1 Dual-Speed, Hysteresis Synchronous Capstan Motor;
2 Eddy-Current Induction Reel Motors.
Reel size 10" and 7inch and 5"
Tape Speed 7-1/2 ips and 3-3/4 ips (±0.5%)
Wow and Flutter 0.06% at 7-1/2 ips (NAB Weighted) 0.09% at 3-3/4 ips
Frequency Response (Overall) 30-28k Hz (±3dB: 40-24k Hz) at 7-1/2 ips
30-20k Hz (±3dB: 40-16k Hz) at 3-3/4 ips
Signal-to-Noise Ratio (Overall) 58 dB
Harmonic Distortion (Overall) 1% at 1kHz normal operating level
Stereo Channel Separation 50dB at 1 kHz
Rewind/Fast Forward Time 160 seconds for 1,800 feet
Inputs 2 Line: 100mV/impedance: 50k ohms
2 Mic:0.25mV(-72dB) Impedance: 600 Ohms or more
Outputs 2 Line 0.3V/load impedance:10k ohms or more.
1 Stereo Headphone Jack: 8 Ohms
Power Requirement 100/117/220/240VAC, 50/60Hz (General export model)
117V AC, 60Hz (USA/Canada model)
220/240V AC, 50Hz (Europe model)
Power Consumption 105W
Dimensions (WHD) 440x488x216mm
[ 17-5/16"x 19-1 /4"x8-1 /2"]
Weight 23kg [51 Ibs] net

Re: Anyone out there using Vacuum Tubes for HT?

The amplifier specifications can only speak for the amount of noise floor inherent to the electronics of the amplifier that could be introduced into the signal. These specifications do not, however, speak for the amount of noise floor in the sound recording itself as a factor of the recording equipment and techniques used, nor do the amp specs speak for the additional noise introduced by the playback device, the playback medium, the transmission of the signal to the amplifier and the internal circuitry of the playback device.

Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com

Re: Anyone out there using Vacuum Tubes for HT?

Okay, so essentially, I'm using a Harmon Kardon AVR 235 as the preamp, with also deals with the 5.1 signal for Home Theater. The 1940's amps are connected to the H/K.

Taking a source such as CD using the optical input, with low noise floor, send it to the amps, then theoritically, even with the 60 year old amps, the noise floor should remain the same with a -80 s/n ratio? Correct?


Wouldn't the noise floor be inconsquential in this case when the overall picture when is taken into consideration for overall performance? Power ratings,etc.

Sorry about that last post, it was a little convaluted.

Re: Anyone out there using Vacuum Tubes for HT?

Well, if the noise level inherent to the amp is -80 dBFS, as imperceptible as that is, there might be some noise insertion present but as to whether the end sum of the noise from the amp plus the noise from the source is *perceptibly* greater than the noise from the source alone... that's debatable.

By comparison, a CD's noise floor is close to -100 dBFS. The difference of 20dB from a level of -100 dBFS is likely to be perceptible, particularly if in a quiet listening environment.

So using a CD to the pre-amp over optical, yes, would be ideal in your case. Since the pre-amp and amplifier are separate, the external analog cabling from the pre-amp to the older amps may introduce some noise and RF interference compared to an optical cable or balanced 1/4" TRS pairs into the amplifier, which would be ideal. However, its the next best thing.

Depends on the ears and the room, too. I can tell you this... in a quiet room, I perceive what feels like a slight change in air pressure when an electronic device such as a CRT is running... so it's very possible that I'd notice the amp noise. But again, I'm just being academic here. It is true that once a track gets going, there will be auditory masking. However, I wasn't so much concerned with you hearing the marginal noise from the amps so much as I was saying that no matter the noise floor on your amps, it isn't going to improve the high noise signal coming from your reel to reel or phonorecord player.

P.S. I've sent you a PM with some information on how to reach me.

Nature abhors a moron. -H.L. Mencken
http://www.cinemalogue.com
Top