F5 Bias display

[john65b]

Hello all! Just built an F5 with +/- 30v SMPS and sounds great.

Now the chassis I put it in has two VU meters...I don't care to see the dancing needles, but would be great to see if the bias has drifted from across the room (my OCD acting up)....If I use a series 800 ohm resistor on the VU across the emitter resistors, I am right on the clip line...

So question is, would a constant voltage (around .45vdc) kill a VU meter?

 

[Zen Mod]

you're good

just put 10-100uF directly across instrument

more, it'll dance less

 

[john65b]

Putting that cap across VU meter (instrument) also puts it across the emitter resistor... Maybe I draw I diagram?

 

[Zen Mod]

there is, as you said, 800R between instrument and Rss

go figure

 

[john65b]

Ah, yes, forgot that I have that 800 ohm series resistor (duh),

 

[Zen Mod]

🙂