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At least it’s all original
- Thread starter GAD
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This is the Maverick I bought. It’s in gorgeous condition but that’s gotta go.
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Also, if you’ve ever wondered why circuit boards or even turret boards were invented…
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Oh, much easier to work on that arrangement. Guild used circuit boards in most of the higher powered amps starting roughly with the beige amps. Serviceability is much easier with the Mavs and Thunderstar basses, and you don't develop conductive component boards, like Fenders frequently do. I have a 66 Vibrolux with a conductive board, and I've been dragging my feet on correcting that, because it's so freaking much work.
Give me a point to point Guild any day!
Give me a point to point Guild any day!
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Danelectro.
<shudder>
AcornHouse
Venerated Member
I had a ‘55 Gibson GA-9 amp that didn’t even use terminal strips (the brown strips with solder tags you can see in the above pic.) Everything was tied directly to the tube socket pins. It was even grounded through one of the socket pins.
One of the quietest (hum-wise) 50s amps I’ve ever owned.
One of the quietest (hum-wise) 50s amps I’ve ever owned.
Guildedagain
Enlightened Member
This is your brain on tubes ;]
Opsimath
Senior Member
To me this looked like a pile of leftover parts. But it looks like all the parts are connected to other parts.Also, if you’ve ever wondered why circuit boards or even turret boards were invented…
Did all this come out of one, um, thing? Amp maybe (since this is the amp section)?
There are those of you among us possessing the higher intelligence to be able to decipher this?
Opsimath
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A 2-prong plug means that there's no ground. When there's no ground if a component in the amp goes bad and shorts to the chassis then floating ground of the amp will find a path to true ground whenever it can, and that path will likely be you.
It happens like this: current comes in from the wall, shorts to the chassis, the guitar is plugged into the amp and uses the amp's chassis as ground, but when you hold the guitar and reach over to touch something that has an actual ground, then the current from the wall will go from the chassis, to the guitar, to the strings, to your hand touching the strings, *across your chest (including your heart)*, out your other arm to the true ground. Example:
Yardbirds singer died in 1976, electrocuted by his guitar.
Wow, I just read that the lead singer of the Yardbirds died in 1976 from being electrocuted in his basement, when his guitar was not grounded. Really? I have been playing away and never realized this before. 1. Could it happen today? 2. What do you do to prevent it? 3. How about if you have an...
letstalkguild.com
Oh, and the path to ground might just be you standing barefoot on the floor.
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BTW if you've ever wondered why it's OK for modern power tools to have only 2-prong plugs it's because they're double insulated.
Rich Cohen
Senior Member
Even though my father was an electrical engineer (made radios for the Defense Dept.), and I worked at his company in my youth, I never understood how electrons merely passing through such components as capacitors, resistors, thermistors, etc resulted in holistically creating the said purpose of the overall unit. Can someone explain it to me? GAD?
All I know is that it takes a circuit to me an amp, and other electronic devices.
All I know is that it takes a circuit to me an amp, and other electronic devices.
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It's all physics and math. Also circuits behave very differently when considering AC vs. DC. DC circuits can be relatively simple to understand while even the simplest AC circuit (like the one in an electric guitar) can be maddeningly difficult to understand. That's why there are endless debates about how/why different pickups sound different or if/why vintage capacitors sound different and so-on.
Resistors (pots) slow down electrons
Capacitors store electrons (and can also block DC while filtering AC frequencies)
Inductors (pickups) convert changes in magnetic flux into voltage
Put those three together and you get a guitar circuit. Simple, right? Hardly. This creates something called an LCR circuit, and here's a snippet from Wikipedia on how they work:
That's some not-so-basic math because the behavior of the circuit changes based on the frequency of the signal passing through it. Not only that, but a slight change in the values of any of the components and the resulting signal will be different. Now add to the equation the differences in wire thickness, wire length, the way the wires are wound, and that's just the complexity in the pickup(s).
In its simplest form, an electrical circuit is about electrons wanting to go from source to ground. The path they take to get there is where the magic happens, and when it comes to AC circuits, the more I learn about them the more I believe in magic.
Resistors (pots) slow down electrons
Capacitors store electrons (and can also block DC while filtering AC frequencies)
Inductors (pickups) convert changes in magnetic flux into voltage
Put those three together and you get a guitar circuit. Simple, right? Hardly. This creates something called an LCR circuit, and here's a snippet from Wikipedia on how they work:
That's some not-so-basic math because the behavior of the circuit changes based on the frequency of the signal passing through it. Not only that, but a slight change in the values of any of the components and the resulting signal will be different. Now add to the equation the differences in wire thickness, wire length, the way the wires are wound, and that's just the complexity in the pickup(s).
In its simplest form, an electrical circuit is about electrons wanting to go from source to ground. The path they take to get there is where the magic happens, and when it comes to AC circuits, the more I learn about them the more I believe in magic.
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After all that I don't think I answered your question.
Electronics are kind of like lego, tinkertoys, erector-sets, or other "build" toys in that you have a pile of parts, and if you put them together one way they build something, and if you put them together in another way they build something else. What they build is up to the designer. In some cases that's simple, and in some cases it's not.
Old guitar amplifiers are actually pretty simple, and the simpler they are the better they often sound. The key to a guitar amp is to (duh) amplify an AC signal. That means increasing its voltage. In old amps this is done via vacuum tubes, and in many modern amps it's done via transistors. How those work is a page of text in and of itself, but they're just another component in the chain.
When I was working on my TunderStar Bass amp I took the schemtatic and color-coded it so I could follow the signal:
When you learn to read a schematic, what looks like a convoluted mess becomes one or more signal paths. Each tube in the schematic is an amplifier or rectifier (converts AC to DC) so with an oscilloscope you can see the signal and test that it should be what the schematic says it should be.
The amp has a three-way switch on it and I added colors to visualize how the signal changed based on the switch positions:
Again it's all physics and math. Change any of the component's values along the signal chain and you can affect the tone of the signal coming out of the speakers. By changing values of components you can make the amp louder, softer, distort more or less, have less or more bass, treble, etc., or make it just screech.
The real geniuses can visualize all of this in their heads and tweak an old Fender amp and turn it into something John Mayer pays $100,000 for. Those geniuses are also often quite mad.
I'm not an Electrical Engineer (EE) so I can usually fix them and not die (tube amps have hundreds of volts DC with big current - they are quite dangerous to work on), but I'm no designer.
Electronics are kind of like lego, tinkertoys, erector-sets, or other "build" toys in that you have a pile of parts, and if you put them together one way they build something, and if you put them together in another way they build something else. What they build is up to the designer. In some cases that's simple, and in some cases it's not.
Old guitar amplifiers are actually pretty simple, and the simpler they are the better they often sound. The key to a guitar amp is to (duh) amplify an AC signal. That means increasing its voltage. In old amps this is done via vacuum tubes, and in many modern amps it's done via transistors. How those work is a page of text in and of itself, but they're just another component in the chain.
When I was working on my TunderStar Bass amp I took the schemtatic and color-coded it so I could follow the signal:
When you learn to read a schematic, what looks like a convoluted mess becomes one or more signal paths. Each tube in the schematic is an amplifier or rectifier (converts AC to DC) so with an oscilloscope you can see the signal and test that it should be what the schematic says it should be.
The amp has a three-way switch on it and I added colors to visualize how the signal changed based on the switch positions:
Again it's all physics and math. Change any of the component's values along the signal chain and you can affect the tone of the signal coming out of the speakers. By changing values of components you can make the amp louder, softer, distort more or less, have less or more bass, treble, etc., or make it just screech.
The real geniuses can visualize all of this in their heads and tweak an old Fender amp and turn it into something John Mayer pays $100,000 for. Those geniuses are also often quite mad.
I'm not an Electrical Engineer (EE) so I can usually fix them and not die (tube amps have hundreds of volts DC with big current - they are quite dangerous to work on), but I'm no designer.
Rich Cohen
Senior Member
GAD, I think I get it. The problem is the whole thing starts with electrons. Can you give me an analogy of how the electron interacts with the various components in the circuit? How about a painter's palette? Apologies for me denseness. Is it a predictable science, or more an art?
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Yeah, it can be witchcraft and magic.
Rich, Here's a good link: https://www.freeingenergy.com/understanding-the-basics-of-electricity-by-thinking-of-it-as-water/
In short, it helps a lot of people to think of a circuit like water pipes. Thus, with pics from that link:
Different components change the characteristic of the "pipe". Adding a resistor makes it more difficult for current to flow, much like sand in a pipe would affect water (assuming for the moment that the water wouldn't just wash the sand away). I prefer to think of a resister as a slight crimp in the hose or pipe. This a simple circuit can be seen as an analogy to a simple circuit of water:
In this pic, if you increase the resistance, the water will flow more slowly. Similarly, the light bulb will shine more dimly.
In a DC circuit, a capacitor acts like a battery, and electrons pile up inside it (more or less) until something causes the capacitor to empty. Think of a bucket that fills until a certain point after which the bucket tips over and dumps its content.
If you can imagine a sort of Rube Goldberg machine made with pipes and gates and buckets, then you can kind of visualize the electrons in a simple DC circuit.
Rich, Here's a good link: https://www.freeingenergy.com/understanding-the-basics-of-electricity-by-thinking-of-it-as-water/
In short, it helps a lot of people to think of a circuit like water pipes. Thus, with pics from that link:
Different components change the characteristic of the "pipe". Adding a resistor makes it more difficult for current to flow, much like sand in a pipe would affect water (assuming for the moment that the water wouldn't just wash the sand away). I prefer to think of a resister as a slight crimp in the hose or pipe. This a simple circuit can be seen as an analogy to a simple circuit of water:
In this pic, if you increase the resistance, the water will flow more slowly. Similarly, the light bulb will shine more dimly.
In a DC circuit, a capacitor acts like a battery, and electrons pile up inside it (more or less) until something causes the capacitor to empty. Think of a bucket that fills until a certain point after which the bucket tips over and dumps its content.
If you can imagine a sort of Rube Goldberg machine made with pipes and gates and buckets, then you can kind of visualize the electrons in a simple DC circuit.
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Things can also get crazy. Imagine a hose that has a three-way adapter so you can connect three hoses to one. What happens to the water?
Well, the amount of water flowing (the current) stays he same, but now its been split over three paths, so each of those paths gets 1/3 the current. But what if you put a resistor (sand or a partial crimp in the hose) into one of the three? Then the other two hoses will get more water than the crimped hose. How much more? That depends on the crimp. All of this can be measured and predicted.
What if you wanted the water to come out REALLY fast? Like... a pressure washer? Well, you'd connect the hose to a compressor powered by an engine. This is an amplifier! The current stays the same because only so much water enters the system, but the velocity at which the water is moving is MUCH faster on the other side! This is voltage through an amplifier in a circuit.
What would happen if you took the output of a pressure washer and fed it to the input of another pressure washer? Probably bad things, but assuming it works, then you could then increase the velocity of the water again. And again. In a guitar amplifier, this is what's happening. These are called gain stages, and in some modern heavy metal amps there are a lot of them which is why they can produce that creamy heavily compressed distortion.
Well, the amount of water flowing (the current) stays he same, but now its been split over three paths, so each of those paths gets 1/3 the current. But what if you put a resistor (sand or a partial crimp in the hose) into one of the three? Then the other two hoses will get more water than the crimped hose. How much more? That depends on the crimp. All of this can be measured and predicted.
What if you wanted the water to come out REALLY fast? Like... a pressure washer? Well, you'd connect the hose to a compressor powered by an engine. This is an amplifier! The current stays the same because only so much water enters the system, but the velocity at which the water is moving is MUCH faster on the other side! This is voltage through an amplifier in a circuit.
What would happen if you took the output of a pressure washer and fed it to the input of another pressure washer? Probably bad things, but assuming it works, then you could then increase the velocity of the water again. And again. In a guitar amplifier, this is what's happening. These are called gain stages, and in some modern heavy metal amps there are a lot of them which is why they can produce that creamy heavily compressed distortion.