I want to build an amp selector (two amps a/b, one cab)

[Chuck H]

... and reduce effective input resistance to 250k.

Right. I knew there was something I was forgetting to mention. And this CANNOT be worked out with low capacitance cables.

[vintagekiki]

That Leo Fender and Jim Marshall had used computer emulation, there wouldn't be Rock & Roll, nor Jimi Hendrix.

Twisted question
How created the first amp for an electric guitar?

[Jazz P Bass]

"How created the first amp for an electric guitar? "
Copied the RCA Receiver manual?

[Helmholtz]

Copied the RCA Receiver manual?

Or maybe an AT&T/Western Electric circuit?
https://books.google.de/books?id=fvU...cation&f=false

Would love to see the original patent.

[vintagekiki]

"How created the first amp for an electric guitar? "
Copied the RCA Receiver manual?

No

[vintagekiki]

Or maybe an AT&T/Western Electric circuit?
https://books.google.de/books?id=fvU...cation&f=false

Would love to see the original patent.

In the time of Jimi Hendrix, that book did not exist

1)

http://www.gibson-prewar.com/gibson-1936-e-100-amp/

http://www.gibson-prewar.com/gibson-1940-eh-185-amplifier/

[Helmholtz]

In the time of Jimi Hendrix, that book did not exist

...and that proves what?

BTW, how does this Fender history stuff relate to the amp selector topic?

[vintagekiki]

The first guitar amp was created by soldered several capacitors, resistors and 2 tubes.
That's history, everything else is technology.
At that time there was no nightmare (computer emulation), handbooks were a rarity, schematics created in the head became a reality. Only 2 controls (volume, and cut) 2 tubes and 12 ”

This is real vintage sound which we now unsuccessfully try to process and emulate in various ways.
It is up to the musician to make the most from it.
The first serious schematic is audio amp from the legendary All American Five.

https://frrl.files.wordpress.com/2009/01/aa5_genericschematic.jpg

http://www.gibson-prewar.com/gibson-prewar-amplifiers/

https://www.vintageguitar.com/1804/antique-guitar-amps-1928-1934/

https://www.thegearpage.net/board/index.php?threads/who-made-the-first-amp-as-we-know-it.828467/

Although early prototypes exist, the first commercially produced guitar amplifier was made by Fender in 1947

[vintagekiki]

About Miller effect and Miller capacitance

... Miller effect.

https://www.aikenamps.com/index.php/what-is-miller-capacitance

https://www.diyaudio.com/forums/tubes-valves/325865-miller-capacitance.html

http://www.valvewizard.co.uk/gridstopper.html

http://deewm.com/Webcache/The_Valve_Wizard/Grid-Stoppers_and_Miller_Capacitance/Grid-Stoppers_and_Miller_Capacitance.html

https://www.sweetwater.com/insync/miller-effect/

http://www.mit.edu/~klund/papers/jmiller.pdf

[vintagekiki]

Miller Effect

... ...

http://www.r-type.org/articles/art-129h.htm
Miller Effect