Amplifiers - PeachParts Mercedes-Benz Forum

TN-W124 Diesel · #1 08-28-2002, 10:27 PM

Dumb question but I will ask anyway, Are all amps really in mono and the processor or whatever turns it into stereo?? I see some ads on Ebay say mono amps, why would anyone buy a mono amp? music sounds dead in mono ..and are there really much difference in TUBE amps or preamps vs solid state, for as sound??

rickg · #2 08-29-2002, 12:28 AM

This outta get good! The 'ol tube amp vs solid state amp debate. Almost as good as the synth oil vs dino oil debate!

Hard core audiophiles hold that tube amps have a "smoother" sound, and have more ability to put out the rated wattage at a wider range of frequencies. Both claims, IMHO, are subject to too many variables. (Speaker quality, type of music listened to, ect.) But, let's see what this stirs up from all the "experts"

Mono amps are for the really hard core audiophiles that want a totally seperate amp system for each channel of the stereo. A lot of this stems from wanting seperate power supplies and complete "channel seperation". I really have no experience in this area, as to whether this is an improvement that is actaully detectable to the ear. But there are those that claim they can tell, just as with tube amps.
I saw a report in Stereo Review magazine back in 1979 where they took a cross section of stereo amps, from cheap to really expensive. Then in a controlled enviroment, they had a panel of random people listen to a set selection of music, played thru different amps with the same speakers. The listeners had no idea which amp was being used at any particular time, only that the amp had been swithched at a given time. Not one person could tell which was the $2000.00 dollar amp and which was the $100.00 amp! Everyone had about the same success at picking which amp was which as one would have at a random guessing match.
The real difference comes in when you really push the amp. A cheap amp rated at 100 watts RMS will not hold up in the Bass range vs a good high end amp with the same rating. My Haflers will blow any of the Technics, Panasonic, Sony, ect out the door in that area.
So depends what you want from your system. If you only listen to average music at average sound levels, get an average system. If you want to blow your neighbors away with bass that'll make your vision blurry, you gotta spend more. But as to tube vs solid state, do the research and make your own determination.

That Guy · #3 08-29-2002, 01:05 PM

Actually, Mono Amps are used for subwoofers since bass is nondirectional it is always in mono.

Anything above 80-100 hz will require stereo amplification but beneath that everything is Mono. This is why you can have a subwoofer as opposed to only subwoofers.

TN-W124 Diesel · #4 08-29-2002, 07:08 PM

thanks for the education, I might get a tube amp to drive my second set of speakers though..just for kicks. I really like the old Carver & Phase Linear equipment of which sound great on my Infinity IL 50 & 25's.

rickg · #5 08-29-2002, 09:53 PM

Quote:

Originally posted by That Guy
Actually, Mono Amps are used for subwoofers since bass is nondirectional it is always in mono.

Anything above 80-100 hz will require stereo amplification but beneath that everything is Mono. This is why you can have a subwoofer as opposed to only subwoofers.

That's true for the most part now days. But seperate sub-woofer amps have only really come into wide use in the past ten years or so. A subwoofer amp will usually have inputs for both channels to internally combine the signal, including a built-in low-pass filter. And they will often have a self-switching power function.
A mono-amp on the other hand, is a whole differant thing, or at least they are intended to be. They are intended to be used as seperate power amps, one for each stereo channel, and need a seperate pre-amp to feed them. Usually refered to as a "mono-block amp", they have been used this way in high-end stereo systems for 50 years or more now. The most popular for years have been the McIntosh amps, many of which were and still are tube amps.
My first exposure to a system like this was back in about 1978. I went over to a friends house. His dad had these huge "cabinets" in the living room, one in each corner. They each had a large McIntosh amp sitting on top of them. I learned about Klipschhorns then. What a system! I've since seen many systems set up like this.
With a lot of new recivers today now having sub-woofer outputs, a mono-block amp will work good in this application, and I think that's what most of them are used for anymore. That's how I hook up my Hafler power amp to my Harmon Kardon surround-sound reciever. Sounds awsome!
There are lots of good high-end stereo web sites. Try these:
http://roadsters.com/audio/
http://www.trueaudio.com/index.htm
http://invalid.ed.unit.no/%7Edunker/horns.html
And long as I'm tooting my horn, here's a pic of my folded horns I built 20+years ago.
Have fun!

Kyle Blackmore · #6 08-30-2002, 01:22 AM

Wooaahh,what big speakers you have Rick

JCE · #7 08-30-2002, 02:45 AM

My latest 'Invention and Technology" (Fall 2002, vol 18, no.2) just arrived with a bunch of useful info on this topic. Vacuum tubes are still a $100 million/year worldwide industry! Apparently, any time REALLY high power, or high voltage surge resistance, or Electomagnetic interference rejection is needed, vacuum tubes are superior to solid state. Solid state devices running at high power outputs produce heat comparable to vacuum tubes, and still can't pump out the large power (water cooled vacuum tubes are used at radio and television transmitting equipment.)

Also, tubes are much more resistant to overloads without damage than solid state devices. Photomultipliers, microwave oven and relay magnetron tubes, radars, pulse weapons, etc. have never been succesfully replaced by solid state devices, and high power/high frequency devices and certain components of communications satellites work best and most reliably with tubes.

Tubes are used in a lot of electric guitar amps because solid state devices can't produce the full range of special effects and feedback control that tubes can do.

During Desert Storm some military field units dumped their solid state radio equipment in favor of tube types that can better withstand certain types of interference. Military satellites use vacuum tubes also because of their resistance to damage from electromagnetic pulse radiation from anti-satellite nuclear devices.

The concept of hifi sounding better in tubes than in solid state form is almost off in the realm of religious conviction. Individual hearing has more variation than the solid state vs. tube devices according to the article, which concludes that none of the systems are perfect, that there are aspects to hearing which haven't been modeled or tested enough to apply to audio components yet, and that it is a matter of individual preference. Vacuum tube amps are called 'warm', and solid state amps 'cold or brittle'. They state that most people can notice this subjective sound difference, but that it is impossible to measure objectively (in numbers) because of a variety of physical, physiological, and psychological barriers. (Their examples were that the same sound, such as fingernails on a blackboard, effects different people differently, and even the same person is effected differently at different times. They further state that while you can compare 2 pictures side by side, looking at them each at the same time, you can't simultaneously compare 2 identical sound amplifier sources, as they interfere/blend with each other. Switching amplifiers rapidly doesn't work very well either, they claim, as "humans are not capable of accurate short term memory of sound events").

This all may be a moot point, however. In 1999 researchers at Cambridge University used solid state device manufacturing techniques to build the nanotriode - a vacuum tube 100 millionths of a millimeter across, which seems to offer the operational/durability advantages of a vacuum tube and the size/current/manufacturing cost advantages of a solid state device!

rickg · #8 08-30-2002, 10:22 AM

I think it's kind of like compact disk vs old fashioned records. There's alot of classical music buffs that won't go to CDs because they sound cold compared to records. I just like not having all the pops and such from even the best cared for records.
Have they been able to get rid of the 60 cycle hum that all the old tube amps used to have? Seems even the most expensive amps still had a hum you could hear during soft passages of music. But of course there is the hiss that solid state amps put out. Pick your background noise I guess.

G-Benz · #9 08-30-2002, 10:28 AM

Quote:

Originally posted by rickg
And long as I'm tooting my horn, here's a pic of my folded horns I built 20+years ago.

I guess you can just crank up the amp and stand in front of the speaker instead of using a blow dryer in the mornings!!!:p

rickg · #10 08-30-2002, 12:31 PM

Clears the sinuses too!

mikemover · #11 08-31-2002, 04:03 AM

Tubes are still VERY much preferred for high-quality guitar amps, and any professional recording studio will have an assortment of nice tube compressors, pre-amps, and microphones. It's not always a matter of better/worse, just different.

Mike