Wrench722 Posted March 13, 2009 Share Posted March 13, 2009 I just dont understand Amps. Like push, pull, A, B, tube power? How 4 or 5 watts can sound louder then 100 watts? It all makes my head spin. HELP! Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 13, 2009 Share Posted March 13, 2009 This is going to be fun! [pi] Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 13, 2009 Share Posted March 13, 2009 Boy, where is everybody tonight? I guess they've all gone out. You forgot to ask what a SET is. Since the pros haven't answered I can tell you this much. A push pull has two output tubes per channel. A single ended amp only has one. These two different types of tube amps sound different. Also, some tube amps can switch between these two modes of operation. There are also hydbrid amps which have some tube and some solid state circuits. SET = single ended triode. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 13, 2009 Share Posted March 13, 2009 How 4 or 5 watts can sound louder then 100 watts? It can't (not with the same speaker anyway). Anyone that says that doesn't understand power. tube power? Tubes are highly linear gain stages, but not perfect and they generally don't have a wide enough bandwidth to support simple methods of accounting for the non-linearity. Tubes also require high bias voltages, so you'll normally see transformers at their output...which is really the achilles heel of tubes when it comes to accurate bass reproduction. Like push, pull, An amplifier topology where one gain stage pushes and the other pulls. A, B Different methods of wiring up a gainstage...if you're not designing amps, then all you need to know is that A sounds better than B...and that A also sounds better than AB. However, it might be argued that AB can be built good enough to where you wouldn't be able to notice the difference. The reason for adding amounts of B is higher efficiency....so basically, the amplifier doesn't heat your room as much (great in the summer, lame in the winter). Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted March 13, 2009 Share Posted March 13, 2009 this one goes to 11, it's one louder, innit? Quote Link to comment Share on other sites More sharing options...
seti Posted March 13, 2009 Share Posted March 13, 2009 I have had several PP amps, a couple SS amps, and SET monoblocks. I could find something to like and enjoy about each topology but for some reason my Canary Audio 300B 8wpc SET monoblocks with George Wright preamp beat them all. The soundstage and instrument seperation on the SET was the best so far for me in my room for what I like best. This was also with simple A crossovers and fully hornloaded speakers Belles and Khorns. Since then I have aquired Jubilee clones which are two way with steep slope ALK xovers. These crossovers seem to absorb alot of energy and so far I have prefered NAD solid state with them over my tube amps. This was a surprise for me. It takes abit more juice for them to sound right. There is a million ways to combine gear and rooms. Just don't discount something because it didn't sound right once in one configuration. There are a million ways to skin a cat. . Quote Link to comment Share on other sites More sharing options...
Arky Posted March 13, 2009 Share Posted March 13, 2009 Attaboy Doc, jump right in. This would have been better in 2-channel. btw, hope I learn something. Quote Link to comment Share on other sites More sharing options...
SWL Posted March 14, 2009 Share Posted March 14, 2009 There is a million ways to combine gear and rooms. Just don't discount something because it didn't sound right once in one configuration. There are a million ways to skin a cat.Oh.....so very true. Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 14, 2009 Share Posted March 14, 2009 You forgot to ask what a SET is But which one is better.... SET or PP or... solid state? [6] Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 14, 2009 Share Posted March 14, 2009 You should check wikipedia and Nelson Pass website. Here is something to get you started. 1) The input signal goes plus and minus in voltage. This is because sound in air goes plus and minus in pressure. This is because vibrating things move in both directions. We use a sine wave as an example. Generally -1, 0, and +1 in an undulating curve. 2) Amplifers have the effect of taking the input signal and making it bigger. Power amplifers (the big box) also supply current to drive the speaker. 3) The amplifer box has a power supply. It just converts the power out of the wall socket, which is a sine wave itself at 60 Hertz in the USA, and converts it to d.c. which is a constant voltage. Like a battery cell. It supplies the power to the rest of the works, but it doesn't create power. 4) Despite what is said in 2) the amplifer does not magically enlarge the input. Rather it can just direct the d.c. power from the power supply to the output. The typical analogy is that we can modulate the output of a water spiggot by twisting the handle of valve. The city water supply pressure is the power supply. The thing which twists the handle is the input signal. 5) The electronic 'valve' is a vacuum tube or a transistor. The handle is the grid, or the gate, or the base of the devices. 6) Here is something interesting. Our electronic valves only work in one direction in conjunction with the power supply. The tube or transistor can turn on to work "forwards" in varying amounts. But they don't work (conduct) backwards. So it looks like we're screwed with the sine input. We can only "amplify" half the signal with these devices. If so, the valve is operating in "Class B". The good thing is that when the voltage input is 0 or negative, it does not work. 6.5) This might deserve futher discussion. We can turn the water valve to the left to shut it to "off" Even with a big wrench, we can't turn it "more left" to get it to suck in water (one reason is 'cause the power supply or city water pressure is "one way"). An important concept and part of why things are wired up. You can say that we can hook up the water valve to a suction pump and get water to flow the other way and the water valve can control it. But that is not the case with our electronic valves. It is a fundamental problem. We can turn around our electronic valves but they still have a built in "check valve" which prevents reverse flow. 7) What is said in 6) is at odds with what is said in 1) to the extent we want the output voltage and current to go plus and minus. We need a work around. 8) The typical simple work around is like this. If the input is full negative of the sine wave input, we set the valve for +1/4 flow. When the input is zero, we have +2/4 flow. when the input is full positive, we have +3/4 flow. But when the valve is operated like this, it is called "Class A". At zero input, the valve is "biased" so that it half on. This is not efficient but it works. In fact, most low level amplifers (like in a pre-amp or microphone amp) work this way. Our valves are not linear at the limits so we don't go to full shut off or full on. 9) Because of what is done in 8) we have to capabilty of making the output -10, 0, and +10. That is amplification. We've controling the flow of the power from the power supply to the speaker or load.. 10) We need another work around to translate the 1/4 and 2/4 and 3/4 flow to an output signal which is back to a -10 0 and +10. It is not the magnitude of the numbers but rather the sign. We have to get that 1/4 flow to cause a -10. The easiest is the use of a capacitor feed to the output. Another is to use two power supply circuits so we have negative and positive supply "rails". Complicated. 11) In 10 we still have a problem. The valve (tube or transistor) is still biased "on" to 1/2 when there is no music. And most of the music is actually silence, or low levels bouncing between - 0.01 and +0.01. 12) What to do? We have to step back a moment. Maybe we need two amplifier circuits. We have this flow and voltage polarity issue and above we;re sort of assuming that we can't flip the voltage of the power supply. But we can. It is sort of like putting the battery in backwards. We can control an invereted voltage power supply if we flip the connection to the "valve" also. The valve doesn't know. 13) So now we have two valve devices in the "box". One amplifies the positive side of the input sine wave, when it is positive. The second amplifier amplifies the negative side of the sine wave, when it is negative. Each amplifer is shut off when not needed. That is two individual amps working in "Class B" but together they recreate the input signal when summed. As you can imagine, that is a "push-pull" circuit. One pushes at the positive and the other pulls at the negative. 14) What is said in 13 is a gross simplification. We can screw with the circuit so that the pair of amplifers are not exactly switched to off at a zero signal input. They operate in Class A at low levels and Class B at high levels. This is AB operation. The best of both worlds. Wm McD Quote Link to comment Share on other sites More sharing options...
seti Posted March 14, 2009 Share Posted March 14, 2009 You forgot to ask what a SET is But which one is better.... SET or PP or... solid state? Have you been taking Parrot lessons? [6] There is no spoon. [] Quote Link to comment Share on other sites More sharing options...
Wrench722 Posted March 14, 2009 Author Share Posted March 14, 2009 Thanks guys. Now I am realy confused. Is there read somewhere that will help? Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 14, 2009 Share Posted March 14, 2009 This is getting like the old joke. Little Tommy asks his dad, "Where did I come from?" Dad,stammers and feels responsible to educate his son and then starts with, "Mommy and Daddy loved each other very much and . . . " Then it goes as far as you like about sex and reproduction. At the end, Little Tom is perplexed and says, "Umm, I don't really understand all that. The reason I asked is that my friend at school says he came from Cleveland, Ohio." Wm McD Quote Link to comment Share on other sites More sharing options...
russ69 Posted March 14, 2009 Share Posted March 14, 2009 Don't worry about how an amp is designed. Good amps come in all the flavors. Use your ears to tell you what sounds best for your system. Thanx, Russ Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted March 14, 2009 Share Posted March 14, 2009 Just buy a good Crown amp and don't worry about it! [] Quote Link to comment Share on other sites More sharing options...
seti Posted March 14, 2009 Share Posted March 14, 2009 I thought Wils 1st answer was good. Quote Link to comment Share on other sites More sharing options...
Wrench722 Posted March 15, 2009 Author Share Posted March 15, 2009 Well I guess a A is better and tubes are warmer. Is there just one that stands out from the rest? One that would give you the best of both worlds? Quote Link to comment Share on other sites More sharing options...
seti Posted March 15, 2009 Share Posted March 15, 2009 http://en.wikipedia.org/wiki/Tube_sound http://www.valvesntubes.co.uk/Vavle-amplifer-terminology Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted March 15, 2009 Share Posted March 15, 2009 Just buy a good Crown amp and don't worry about it! or eleven...[:^)] Quote Link to comment Share on other sites More sharing options...
Wrench722 Posted March 15, 2009 Author Share Posted March 15, 2009 Just buy a good Crown amp and don't worry about it! I was thinking about a McIntosh? Quote Link to comment Share on other sites More sharing options...
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