Cliff switching jacks and the schematic?

[joekelly9692]

Hey gentlemen. ...

I'm trying to gain a deeper understanding of my guitars signal path through the hi and lo inputs on my lite 2b... progress is slow lol...

Is there any links on those cliff switching jacks and what there lugs all do and how the parallel wiring changes our impedance?..

[geoff 1965]

hello Joe,

18wattLite2b (1).gif

the inputs on the lite2 are single & parallel not Hi & Lo,if you look at the schematic the preamp tube has 2 "triodes" and the input jacks connect to each half but notice the signal path of the parallel jack connects to the signal path of the single input so when you plug into the parallel jack you have signal going to both halves of the preamp tube "parallel".
plugging into the single jack breaks the connection with the parallel jack so you only have signal into one triode.
the lite2b is a modded version of the marshall 18watt normal channel,here's a schematic so you can compare i.e.notice the tonestack and capacitor/resistor changes.

18wattLite.gif

[geoff 1965]

hey Joe!
more food for thought for you! have a look at the inputs on this spitfire schematic,different again from the other schematics.
both Hi & Lo signals are "parallel" with the Hi passing through the 2 68K resistors into the grids of the preamp tube.
the Lo signal passes through 1 68K the other 68K goes to ground acting as a voltage divider which lowers the signal.

tt-spitf-schematic.pdf

hope this helps you with understanding amp schematics,"be warned" it's addictive! i used to get off on pictures of Raquel Welch but now it's tube amp schematics!

CKS_1033_0023.jpg

mmmmm! maybe not!

[joekelly9692]

Great info Geoff..... I'm finally able to make sense of the signal path on schematics. ..to begin with I could not tell where the signal can. Can't and would go lol.....

Deffo addictive ....