Lightbulb Tube Simulator?

Essen · #1 02-15-2010, 02:05 PM

A question: Does the "tube sound" come from the fact that the strings within the tube are glowing? If so, correct me if I'm wrong; Wouldn't it be possible to get the same sound by amplifying the signal, and then send it trough a small flashlight lightbulb?
I must say, I really don't know what I'm doing.

Anyone think this would work?

Taylor Livingston · #2 02-15-2010, 02:08 PM

It would not work. A lightbulb and a vacuum tube are very different. Even things with tubes don't always have the "tube sound" people are looking for, because they're run on low voltage or the tube is just used as a clipping diode.

Sometimes amps do send sound through a light bulb. It can done as part of a limiter, or to provide some soft compression, or alternatively some soft expansion. Technically this might contribute to something you might call "tube sound", but in general not.

But luckily there is no shortage of actual tube distortions and preamps in this world.

Mingus Addict · #3 02-15-2010, 02:09 PM

GregDunn · #4 02-15-2010, 02:14 PM

A vacuum tube glows because an element inside it (the heater) is hot enough to emit visible light. The heater causes electrons to be emitted from the cathode and captured by the anode. The electrical signal you apply to another element (the grid) inside the tube modulates this current, which is then taken as an output. The "tube sound" is a result of nonlinearities in the modulation of the output current.

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

Taylor Livingston · #5 02-15-2010, 02:14 PM

Quote:

Originally Posted by Mingus Addict

Let's try to be kind, here.

I think it's detrimental to the progress of knowledge if we discourage people from asking questions by making them feel dumb.

rcubed · #6 02-15-2010, 02:17 PM

I've had some success with running some tubes at 9V for a good overdrive sound without using clipping diodes. It's definitely possible.

Mingus Addict · #7 02-15-2010, 02:28 PM

Quote:

Originally Posted by conical johnson

Let's try to be kind, here.

I think it's detrimental to the progress of knowledge if we discourage people from asking questions by making them feel dumb.

You're right, but every now and then I fail to behave myself.

In my own defense, I restricted myself to smilies.

Essen · #8 02-15-2010, 02:45 PM

I wasn't planning on using a flashlight instead of a tube amp. (don't worry) I'm just playing around with electronics, I want to build something with my limited supply. I barely understand how a fuzz face works, even though I've built one.

Mingus Addict · #9 02-15-2010, 03:00 PM

If you want to gain a better understanding of electronics, and you've already built a pedal from a kit or something of that nature, I suggest getting into pedal modifications. I think using a circuit, altering it, and then using it again, is a good way to start drawing connections between circuit components and what they actually do.

A fuzz face is actually a great circuit to experiment on if you're up for it. Search google for fuzz face mods. Doing something like adding a tone control is very easy, and it will help you understand how tone controls in most any stomp-box usually work.

**251** · #10 02-15-2010, 03:06 PM

Quote:

Originally Posted by Essen

A question: Does the "tube sound" come from the fact that the strings within the tube are glowing? If so, correct me if I'm wrong; Wouldn't it be possible to get the same sound by amplifying the signal, and then send it trough a small flashlight lightbulb?
I must say, I really don't know what I'm doing.

Anyone think this would work?

ROTFLMAO

There is more to Physics & Electronics than you think. Consider getting a copy of this:

http://www.amazon.com/New-Way-Things...6271467&sr=1-1

- or - at least put this in gear before you engage your keyboard:

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

8-)

Essen · #11 02-15-2010, 03:24 PM

I really wasn't implying that a tube is a lightbulb. I've read the Wikipedia article, and I understand that a tube can be used to amplify a signal. I get that, though I don't understand the process.
It didn't say anything about what changes the sound. So instead of buying a book, I posted my question here. I'm not looking for a degree in physics, I'm just looking for a better understanding of it all.
And that's more than I can say for a lot of people I know.

Taylor Livingston · #12 02-15-2010, 04:00 PM

Essen, don't let the haters discourage you. There was a time for each of us when we didn't know what we now do. And we currently are all much less knowledgeable than we will be in the future (hopefully). Anyone who sees fit to laugh at someone because they don't know everything should start by laughing at themself.

WalterBush · #13 02-15-2010, 04:16 PM

Check out these titles. They're a great starting point; I own the first two and have built my way through about half the circuits contained in them. They all sound good, are reasonably simple, and will help you understand how electronics for audio applications work...or don't.

http://www.amazon.com/s/ref=nb_sb_ss...ronics+project

Lots of people who build pedals, amps, etc for a living got their start with the first book shown.

**251** · #14 02-16-2010, 09:47 AM

Quote:

Originally Posted by Essen

I really wasn't implying that a tube is a lightbulb. I've read the Wikipedia article, and I understand that a tube can be used to amplify a signal. I get that, though I don't understand the process.
It didn't say anything about what changes the sound. So instead of buying a book, I posted my question here. I'm not looking for a degree in physics, I'm just looking for a better understanding of it all.
And that's more than I can say for a lot of people I know.

I was just trying to help. If you understand the basic operation of the vacuum tube now, go back & read your OP. Can you see the humor? 8-)

Kosko · #15 02-16-2010, 09:53 AM

According to the article tubes are actually lightsabers

DaZombieWoof · #16 02-16-2010, 09:57 AM

I recall one tube simulation approach being driving a very small transformer into saturation. That was going for an approximation of output stage distortion. Then there is SWR's Interstellar Overdrive which created a mini tube amp optimized for bass and dialed down the output to run monster power amps. It also was a 6 watt class AB rig.

Preamp tubes distort another way. Vacuum tubes tend to have a smoother and longer transition into clipping/distortion. Solid state power amps could get real ugly when they clipped, hence Peavey and their Distortion Detection Technique (DDT). Had a real old Peavey amp without it and it was lovely until it clipped. Then it was hideous.