Schematic Voltage Question

[jcruppe]

http://www.el34world.com/charts/Schematics/files/ampeg/ampeg_r-12r_212r_50h_reverbrocket_ri.pdf

I believe this is the schematic of the Ampeg Reverberocket Reissue. In the boxes that contain the proper voltage to ground readings there are labels like Clean 1.3Vrms and Dirty 1.42Vrms. Of course I have seen voltage to ground before but not these. Is this something that I need to be concerned with?
 
Thanks in advance.
 

[sluckey]

Those are signal voltage readings based on a 25mv 1KHz signal (probably sine wave) applied to the guitar input jack. They can be useful for signal tracing thru the circuit.

[jcruppe]

Is that something one would use an oscilloscope for?

[HotBluePlates]

There are 3 voltages listed. Clean, Dirty and a DC voltage. In places where there is 0vdc or it doesn't apply, they simply list "-".

This reissue amp has a clean channel and a dirty channel. You are a tech with a malfunctioning amp. Customer says the clean channel works, but the dirty channel is acting "weird". You have 23 other amps to fix this week, and you are paid per amp fixed, not by the hour. How do you find the issue quickly?

You can inject the signal indicated to the input jack and measure the AC voltages indicated while the amp is on the dirty channel. If you find a reading that's very-wrong (0.5v instead of an expected 6.8v), then you can stop and check relevant d.c. voltages and see if there is an obvious bum-part in the area.

It's about giving you a tool to see what's normal vs not-normal fast so you can find the particular section that's acting up.

[jcr]

It's about giving you a tool to see what's normal vs not-normal fast so you can find the particular section that's acting up.

Thanks, makes sense. I hadn't ever seen that info on a schematic before.