The importance of guitar amp input circuits

[Reeltarded]

EXAMPLE OF A GOOGLE SEARCH ON AMP GARAGE FOR TUBE SOCKET:

tube socket site:ampgarage.com

Anything else is misery.

[Jana]

If you want to know the theory, learn the theory.

[roberto]

^ this

[SoulFetish]

Ugh, this thread blows. Is there a mercy kill feature for this? I know the theory, i've read the books. Love them. I was looking to help people out who may be new at it or want to talk about the actual theory. I find that reading and dialog about what was actually read is much more helpful than telling people just what to read.

[SoulFetish]

The google search tip is solid though. Its a helpful bit of info

[pops]

Sorry, i thought it was a good idea.

[jelle]

I disagree that this thread blows. All the information is in this forum. And RDH4 is plain wonderful.

[Jana]

In the first post, you mentioned wanting "a tutorial covering the importance of radio frequency suppression, signal to noise, microphonics, shielding, miller capacitance(and how it relates to series resistance, cable/shielding capacitance), etc."

Then later you said that you "know the theory, [and have] read the books" and was "looking to help people out who may be new at it or want to talk about the actual theory."

I suggest you write this tutorial and post it.

[gingertube]

Here ya go.
http://www.valvewizard.co.uk/gridstopper.html
I use 10K grid stop with an added 470pF on the input stage on all amp builds, as per Merlin's advice.
Cheers,
Ian

[pdf64]

That seems fine provided that what's feeding the amp input has a low source impedance, eg a buffered pedal.
How about when a guitar is plugged straight in and the volume control is rolled down a little; doesn't the effective Rg become ~100k-250k, and the treble roll off excessive?

[R.G.]

Frequency response questions aside, vacuum triodes input-clip more softly when driven from a low impedance source.

This is because when the grid goes positive, the grid goes from near-infinite impedance to a few K quickly. A low impedance source can drive this change in impedance with less distortion than a high impedance source.

This is completely aside the clipping mechanisms of cutoff, current limiting, or running out of plate voltage.

[teemuk]

Roberto, I did use the search function. Im not sure reading through 15 pages listing non specific threads to see if 20 of them contain bits of info is very efficient or practical.

Well, but that's what searching and researching is about: You browse through a huge assortment of material, most of it more or less useless for your research, only to find tiny fraction of information that happens to be relevant.

Everyone who searches the forum, or searches any information, pretty much faces this. That's why it's called "searching" not "finding" in the first place.

I don't know why you expect that someone else does it for you and then summarizes the results in one or two clever phrases? You want discussion, do the research and give us something to discuss about. You want answers to questions? Well, they are answered but you probably should search for those answers...

[Jana]

Yes, but--that involves reading and stuff.

[vibratoking]

God dammit, I just want the info I want. And I want it now. If you all would only just post what I want to hear, this would be a good thread. But now it sucks.

Kinda reminds me of the guitar amps as copper pipes thread. Sorry I said that. Now you'll have to search for it and it might not come up at the top of the list...then what? I'm damn near useless.

Maybe there should be an RTFP (read the fucking posts) sticky or a DAFS (do a fucking search) sticky or maybe have a quiz that must be passed before you are allowed to post at all. Has anyone else noticed the degenerative trend? I think it started when I got here. Or was it Miles?

[Jana]

It started on Sept. 7, 2008.