API Line input question
« on: March 23, 2018, 11:32:34 AM »
Hi,
I have a question about a few diodes on the line input in the vintage API desks.
I took a screen grab from another thread here with a clear schematic. D1-4.
My question is: Why are they there at all?



ruffrecords

Re: API Line input question
« Reply #1 on: March 23, 2018, 12:32:04 PM »
The intention is to prevent the input signal exceeding the power supply rails.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: API Line input question
« Reply #2 on: March 23, 2018, 06:15:08 PM »
Thanks Ian.
What would be the practical purpose of this?


The intention is to prevent the input signal exceeding the power supply rails.

Cheers

Ian

john12ax7

Re: API Line input question
« Reply #3 on: March 23, 2018, 09:11:04 PM »
The purpose is to protect the circuit that follows,  perhaps an opamp in this case. Transistors have max ratings,  for example Vcb., which you don't want to exceed.

Re: API Line input question
« Reply #4 on: March 24, 2018, 06:18:29 AM »
Alright thanks!

The purpose is to protect the circuit that follows,  perhaps an opamp in this case. Transistors have max ratings,  for example Vcb., which you don't want to exceed.

buildafriend

Re: API Line input question
« Reply #5 on: April 04, 2018, 05:15:18 AM »
This is called diode clamping