Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How Tube Amplifiers Work

robrobinette.com

Post reply on HN
Print view View original

71–75 of 75 posts

Re: How Tube Amplifiers Work

#71

Post by kjs3 »

tomasphan wrote: post #58
disruptthelaw wrote: post #45

When a webpage loads that looks like it was made in the 90’s, no ads, and is too wide for mobile so I have to drag from side to side, I know the content is gonna be legit.

I got two ads that took up 2/3rds of the screen :(

Yeah...and I like how if you hit the 'hide ad' arrow, it veeeery slowly scrolls out of the way. Keep it classy. And don't put a 'donate' button and then pack the page with so many ads I have to use an adblocker[1] to actually view the content in a non-rage-inducing way.

[1] yes, yes...I know...always use an ad blocker.

Re: How Tube Amplifiers Work

#72

Post by leptons »

JKCalhoun wrote: post #69
marpstar wrote: post #62

Earlier quoted context omitted.

This is what has kept me from working on amps. I'm comfortable working inside of pedals (9v) or with USB-powered circuits, but anything with a large transformer just seems a lot scarier.

It depends on the "power" of the project. I was building ½ Watt Darling hi-fi amps that never had more than about 225 VDC or so running through them. But by all means, you never touch it when plugged in, you use chopsticks if you need to poke/debug a live circuit (you keep one hand in your pocket, etc.).

225VDC will kill a person, but it entirely depends on the current that can be delivered. As little as 50mA can kill. Your 1/2 watt amp probably won't but I don't know the details of the power supply.

Re: How Tube Amplifiers Work

#73

Post by fsckboy »

kazinator wrote: post #30
fsckboy wrote: post #27

Earlier quoted context omitted.

> That cannot possibly be true. Not knowing what exactly is going on with the charge carriers at the subatomic and quantum levels is not the same as not knowing how the amplifier works since everything that happens inside a transistor is exactly what is going on in a quantum sense, you've described "not knowing how it works". You cannot understand a bipolar transistor without quantum effects, it's the thing that crea…

You can empirically drive the equations that apparently govern the macroscopic behaviors, right down to details like temperature sensitivity, and the Early effect, without having a detailed model of what is going on at the atomic and subatomic level. Then what makes an amplifier work is explained by those equations. And for that not even the full detail of them is necessarily required, depending on what aspect of the…

empirical equations are driven by data about devices. they didn't have any devices, they were inventing the first ones.

Re: How Tube Amplifiers Work

#74

Post by bogomog »

dmitrygr wrote: post #32

> WARNING: A tube amplifier chassis contains lethal high voltage even when unplugged--sometimes over 700 volts AC and 500 volts DC. I promise you it does not contain AC when unplugged :)

But capacitors may hold high voltage DC, if there's no path to discharge them.

Re: How Tube Amplifiers Work

#75

Post by bogomog »

TomMasz wrote: post #63

Tubes are definitely inferior to transistors in a lot of ways, but nothing sounds like them (FETs come close). Plus, there's the comforting glow of those little glass bottles that just seems right.

My favorite, kind of ironic, advantage of tubes over transistors is that it's easier to source replacements.
Post reply on HN