The Audio Equipment Corner

[ejman]

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Originally Posted by ERD50 I've never really owned any high-end tube equipment (just turned out that way, I didn't necessarily avoid it), but here's my take on it from what I do know. For me, "obsolete" is a tricky word. Tubes amplify, and they still do that, so they are not "obsolete" in that sense. Transistor amplifiers (and now the switching amplifiers) have many advantages in size, cost weight, consistency, etc. None of those really have much to do with how they sound. Measurements can tell us a lot, but the question is, are we measuring the right things? The whole psycho-acoustic area is exceedingly complex and non-obvious. Tubes generally have certain characteristics, and some of these characteristics result in poorer measurements in some areas. But those characteristics (or others) may sound good to you. If they do, enjoy! Similar to the debate over LP vinyl versus CD or other digital audio. In many ways, an LP measures way worse. But there are some attributes that some people like. I'm certainly not going to argue with them about which they prefer, and they don't need to justify it. If you like LPs listen to LPs! But I won't accept factually wrong info either - LPs have wow-flutter, the signal is run through all sorts of phase-shifting effects between the RIAA filters and the cartridge reactive elements. A friend of mine would always complain about how active circuits had phase-shift, but seemed to think cross-overs in speakers were somehow different, because there was no op-amp in there. I never got that. Tubes in a guitar amp are a whole 'nother thing. Tubes distort differently, and most who love the sound of a screaming guitar would agree that tubes sound 'better'. -ERD50

By and large I agree with your post but it does seem strange that generally accepted desirable technical parameters such as low harmonic and intermodulation distortion seem to get a pass with a lot of tube amps that have distortion in the order of 10 times or more that of SS equipment. Come to think of it the same applies to LP's vs CD's as you pointed out.

Yet when I listen to my tube amp vs the SS, I hear a larger deeper soundstage (performers are more "present" as solid beings on the soundstage) but I don't actually hear a distorted sound. Maybe my hearing is just not good enough to detect that level of distortion.

[steelyman]

I'm not an audiophile. I have Peavey and Roland amps and enjoy playing with people in the room. The iPod takes care of the rest.

[ERD50]

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Originally Posted by NW-Bound Your methodology of speaker testing with strings surely had not crossed my mind.

Actually, strings can be used very effectively to fine tune your speaker/room interactions. And you don't even need the speakers to be active!

I forget the details, and a quick search didn't bring it up, but the approach is to fix a string at the speaker source, and then pull it taught between that point and the point your ears would be at when listening. Then you add a specific number of inches to the string (I'd have to look it up), and fix it at your ear position (it will now be loose). Now pull the string tight into a triangle and see if you can touch any wall or floor at any point with the string. Any point you can touch indicates a point that will reflect and smear the sound. I need to do some work on my listening room to reduce some of these early reflections, but have not found a solution with reasonable SAP (spousal approval factor).

I'll also need to search, there is a very interesting test tone track I've used, I think it was from a Stereophile test CD. Most of those test tracks are pretty straightforward, frequency sweeps, IM, etc. This was very different. IIRC, it was a short repeating blip of a tone, maybe 7 times - like someone very quickly repeating the same key on an organ/synth, and then it would rise in freq and repeat that freq 7 times. The odd thing was, you would hear the 7 tones distinctly, and it would all be very boring, until you hit certain frequencies, and then they suddenly, and very obviously, all jumbled together. The first time I did it, I thought for sure the CD was recorded that way, or skipping or something - but they were all distinct when I used headphones. So it really made me think about how much the room can mess with the sound, and not just broad frequency peaks/troughs.

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Not being a musician, I looked up the Web and found that a tenor could get as high as a C5, and that's 523.25Hz. Hmm... I did not know the human voice is so modest, although it is said that with overtones, read harmonics to me, our tenor can yell out up to 1.5KHz perhaps.

But the harmonics/overtones go so much higher. And singing voices make all sorts of 'noise', from the sibilants (CHecK! - CHecK! - CHecK! - tesssssst! - tessssst! - tesssst!) to air rushing sounds, probably beyond our hearing range.

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Originally Posted by MichaelB When I was a mostly dysfunctional high school teen I made a short lived deal with my folks that allowed us to sit together in the living room after dinner. They watched TV, I listened to music with headphones. One night I noticed they were staring at me, with that "killer x-ray vision" think usually reserved for married couples. Turns out I was singing along, aloud, to Steppenwolf "The Pusher". It didn't end well.

Hah! Had a very similar experience, and I was going to give the same answer others did - it's an anti-drug song! Our garage band would play that one, great tune. Now I feel sorry for NW-B if that wasn't a part of his youth, and he cannot appreciate it now. Some great 'psychedelic' guitar work on that song (and I never could figure out how a guitar could 'sound' psychedelic?).

Could'a been worse - it could have been the F-I-S-H cheer from the Woodstock album!

-ERD50

[ERD50]

Quote:

Originally Posted by ejman By and large I agree with your post but it does seem strange that generally accepted desirable technical parameters such as low harmonic and intermodulation distortion seem to get a pass with a lot of tube amps that have distortion in the order of 10 times or more that of SS equipment. Come to think of it the same applies to LP's vs CD's as you pointed out. Yet when I listen to my tube amp vs the SS, I hear a larger deeper soundstage (performers are more "present" as solid beings on the soundstage) but I don't actually hear a distorted sound. Maybe my hearing is just not good enough to detect that level of distortion.

It seems strange, but when you understand a bit more about music and sound, it makes more sense.

Like many things, being ten times better in one area might not be significant, if the thing being measured does not sound 'bad' to us at 10x.

(I think I mentioned this in one of the other threads) The relatively high distortion in tubes is "harmonic distortion", and is weighted to even harmonics. That type of distortion tends to blend in with the harmonics already present in the music. And it can, subjectively, make the music sound 'better' - a little fuller. Some will argue that it is not 'accurate', but who are we kidding - unless it is live, acoustic music, it isn't 'accurate' anyhow, it's all an illusion. If someone prefers their illusion with a little more second harmonic, who is in any position to tell them they are wrong?

A 'warm' tube sound (maybe from a little high end roll off, or that 'warm' even-order distortion) might sound better than a solid-state amp with speakers or a room that is too 'bright'. So maybe the room or cross-over should be worked on, rather than say one amp is 'better' than the other - but if you getthe results you like, does it matter?

Well, I should go finish up what is hopefully the last of my cassettes to digitize, my current audio project (then clean up the recordings, edit and such). A few of these are recordings broadcast over FM radio of local concerts I attended, so they have some nostalgic value. A few are tapes I made with a Fostex 4-track cassette, and a small MIDI studio back in the 1980's.

-ERD50

[eytonxav]

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Originally Posted by Nodak Here's my vintage stereo system. The pre-amp is newer but speakers and amp I purchased in 1972

Nice! McIntosh was really the cadillac of amps and pre-amps back in the day. My budget back then could only support dynakits.

[Nodak]

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Originally Posted by DFW_M5 Nice! McIntosh was really the cadillac of amps and pre-amps back in the day. My budget back then could only support dynakits.

I saved for a long time to put together the $1500 those cost at the time. It was worth it though they're still working very well. The amp was recently serviced by Mc and I re-foamed the woofers but no other problems.

[ejman]

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Originally Posted by Nodak I saved for a long time to put together the $1500 those cost at the time. It was worth it though they're still working very well. The amp was recently serviced by Mc and I re-foamed the woofers but no other problems.

Money well spent since Mac erquipment seems to hold its value forever. As a previous poster, I also went the Dynakit route at about the same time frame. My Dynaco SCA-80 is long gone (although I had a lot of fun putting it together).

[NW-Bound]

Well, I like to talk with ya'all about more audio stuff, and to exchange some ideas. But sadly, my effort to revive my 40-yr old speakers has run into a snag. The bipolar caps in the crossovers have indeed dried out, and the responses are all goofy.

I found out the above by measuring the electrical outputs of the crossovers, not the acoustic output of the drivers with a microphone. Amazingly, the speakers still sound half-decent. How could that be? The human ear is so tolerant, or should I say so inaccurate.

Anyway, knowing about this problem, I cannot stand it and must be logging off to look to order replacement caps. I will come back when the order is placed.

[eytonxav]

I still have my Revox A77 tape deck which is in great shape, but unfortunately this is one piece of audio equip that quickly became obsolete due to new and better technology.

[Mr. Paul]

I always thought that when I retired I'd have a turntable set up in a listening room.

Now I do ! Kinda mid grade compared to some of the gear here ... Harman Kardon table, Rotel pre-amp, Sunfire amp. Stars of the show are the Dunlavy SC-IVa speakers.

I have a pair of Little Advents in the garage ... hooked up to an old cheapo Panasonic receiver and I just love the combo.

Here's a question ... what are some of your favorite high quality recordings?

Sinatra at The Sands ... w/ Count Basie
Mark Knopfler ... Sailing to Philadelphia
Bob Marley and The Wailers ... Uprising and Survival
Muddy Waters ... Folk Singer

Those are a few that come to mind right away.

[ejman]

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Originally Posted by DFW_M5 I still have my Revox A77 tape deck which is in great shape, but unfortunately this is one piece of audio equip that quickly became obsolete due to new and better technology.

Some say that a good quality tape on a good tape deck (Which I believe your Revox is) will actually sound better than just about anything else. I really enjoy my Pioneer 701 bought new in 1979 and still going strong.

[eytonxav]

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Originally Posted by ejman Some say that a good quality tape on a good tape deck (Which I believe your Revox is) will actually sound better than just about anything else. I really enjoy my Pioneer 701 bought new in 1979 and still going strong.

It was considered a studio grade machine, but not sure about how it would stack up today.

[Keim]

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Originally Posted by NW-Bound Well, I like to talk with ya'all about more audio stuff, and to exchange some ideas. But sadly, my effort to revive my 40-yr old speakers has run into a snag. The bipolar caps in the crossovers have indeed dried out, and the responses are all goofy. I found out the above out by measuring the electrical outputs of the crossovers, not the acoustic output of the drivers with a microphone. Amazingly, the speakers still sound half-decent. How could that be? The human ear is so tolerant, or should I say so inaccurate. Anyway, knowing about this problem, I cannot stand it and must be logging off to look to order replacement caps. I will come back when the order is placed.

Think Auri Cap, NW-B! You won't regret it.

[Nodak]

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Originally Posted by ejman Money well spent since Mac erquipment seems to hold its value forever. As a previous poster, I also went the Dynakit route at about the same time frame. My Dynaco SCA-80 is long gone (although I had a lot of fun putting it together).

That SCA-80 is really a very nice little amp. I put one together to use while I was saving for the Mc equipment. Used it for a couple of years and then sold it for a profit.

[Keim]

I know I've shown it before. But, since we now have an audiophile thread I'll put it here. I built this system from Bottlehead.com kits, and some internet speaker designs. Naturally, I modified them a little from OEM design. Cost me about $1500, including phonograph. It sounds outstanding. The amp is a 2a3 based SET amp. Pre-amp uses 12au7s. Phono preamp uses 6dj8s.

[ejman]

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Originally Posted by Mr. Paul I always thought that when I retired I'd have a turntable set up in a listening room. Now I do ! Kinda mid grade compared to some of the gear here ... Harman Kardon table, Rotel pre-amp, Sunfire amp. Stars of the show are the Dunlavy SC-IVa speakers. I have a pair of Little Advents in the garage ... hooked up to an old cheapo Panasonic receiver and I just love the combo. Here's a question ... what are some of your favorite high quality recordings? Sinatra at The Sands ... w/ Count Basie Mark Knopfler ... Sailing to Philadelphia Bob Marley and The Wailers ... Uprising and Survival Muddy Waters ... Folk Singer Those are a few that come to mind right away.

I must say I've never heard of Dunlavy SC-IVa speakers referred to as mid-fi equipment. For those that are not familiar with these puppies, they measure 72" H by 12" W by 18" D. Weight: 190 lbs ea and their price ranged between $8,000 and $9,000 depending on finish (these are late 90's prices). Good taste in equipment as well as music.

I enjoy Sinatra a lot and have quite a few of his recordings although unfortunately a lot of his original mono recordings were reissued as "electronically enhanced for Stereo" which in my opinion ruined them.

[ejman]

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Originally Posted by Keim I know I've shown it before. But, since we now have an audiophile thread I'll put it here. I built this system from Bottlehead.com kits, and some internet speaker designs. Naturally, I modified them a little from OEM design. Cost me about $1500, including phonograph. It sounds outstanding. The amp is a 2a3 based SET amp. Pre-amp uses 12au7s. Phono preamp uses 6dj8s.

Beautiful! Those speakers must be quite efficient to be able to work with a SET amp. I've always been curious about SET's but never been able to listen to a good setup using them.

[Keim]

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Originally Posted by ejman Beautiful! Those speakers must be quite efficient to be able to work with a SET amp. I've always been curious about SET's but never been able to listen to a good setup using them.

I fell in love with SETs the first time I heard them. At times, when the moon is right, the recording is good and the planets align, this system has "you are there" abilities. Not all the time, but enough.

I've never heard my speakers called beautiful before . Bright, easy to see, loud-yes. Beautiful-no! They are about 95db. The speakers have a VERY simple first order crossover. Simplicity is the key to everything when it comes to SETs. They are all about ensuring a few watts of very high quality power. The amps put out about 5 watts. With that sensitivity they get pleasantly loud. The stereo is in the basement, and I can hear it in the other end of the house on the main floor when cranked.

[NW-Bound]

I've got to take a break from what I have done!

I had a hell of a time with my measurement set up. Things just didn't make sense. The low-pass to the woofer still passed signals up to 20KHz. What the h***? So, I had to rush out to the nearby Fry's Electronics to get some bipolar caps to do some substitution because this was driving me mad. Then, when I got home and resumed poking around that crossover (a 3-way job, 2nd order each section with some auxiliary padding for impedance control and attenuation), I found that I had picked up the wrong point for the frequency sweep. Arghhhh!

And then, I saw that the excitation from the amplifier was not flat but varying 1 dB or 2 across the band. What the h***? I thought I swept it a few days ago and saw that it was flat from 6Hz to 60KHz. After fooling around for a while, I recalled that it was another amp that I used. Damn! I am getting senile. This current amp is older, and its tonal control is not really flat when set to flat.

So, I hauled out that other amp. Now, it's not flat either! Arghhh!!!!

Then, by playing with it after a while, I found out that its output was not flat until I cranked up enough volume to get a couple of watts out of it. When outputting very low signals (I do not need a lot to check out the electrical outputs of the crossover, compared to the 1W output for acoustical measurements), the darn thing is not flat either. This is a more modern amp with a sound processor chip that has all the volume/balance/tone control built-in. And then, I had to disable the default "surround enhancement thinggy" for it to be really flat.

So, after discovering all these problems, I was so pooped I turned everything off to get away from it for a little while.

Anyway, I will look into these Auri caps, but suspect that the price will be more than what I want to put into these old speakers I am working on.

[NW-Bound]

Hey, by the way these old speakers I am trying to revive have sensitivity of 96dB @ 1W supposedly. They do sound like it, as I get room filling sound with only a few watts, as shown by the real-time power indicator on one of my amps.