Signal level indicator bulb for a spring reverb

[bandus]

Happy holidays everybody,

I'd like to install an output signal level indicator bulb for a Telefunken Echomixer spring-reverb effect, is there any way to easily set up something like this? I'd like to have it just for the look of the flashing light, not for indicating clipping or anything measurable or scientific. 

The output of the effect maxed out is about 0.8VAC peak to peak, what kind of indicator light would be needed for this modification and how to wire that in?

Any help would be highly appreciated! 

Here is the schematic, the output is on the upper right corner:
https://archive.org/details/sm_Telefunken_Echomixer_Schematic/mode/1up

[Dormammu]

Need specificly bulb, or LED will also fit ?

[bandus]

It would be good to have something vintage looking, since it's a 60s made device. So a bulb would fit better for this project, I think.

[Dormammu]

What kind of lamps do you have?
Voltage, current consumption.

[idy]

Welcome to the forum.
We don't know how much you don't know.
You will not be driving a lamp or LED directly off your signal.
You will have to add a buffer so you have an output that won't load your effect or introduce "hash" when an LED turns on and off.
Then you will have to boost that signal (because .8v won't drive a lamp or LED) and rectify it to be DC.
As to looks, there are plenty of ways to combine a vintage style bezel with and LED. Easier to drive, much less current.

[PRR]

> output signal level indicator bulb

Must it be an OUTput level? The only strong signal in there is the reverb driver. Which IS the direct signal. You "lose" the reverberated signal level, but that is rarely more than the direct sound, unless you palm-mute very abruptly.

[bandus]

> output signal level indicator bulb

Must it be an OUTput level? The only strong signal in there is the reverb driver. Which IS the direct signal. You "lose" the reverberated signal level, but that is rarely more than the direct sound, unless you palm-mute very abruptly.

This looks nice, thanks! What kind of LED is needed for this one and why are there two in the circuit?

[anotherjim]

I'd second Paul's suggested LED circuit.
You need 2 because it's an AC signal and it will be better if the LEDs load each polarity equally and it will reduce flicker. Stuff them in a Fender amp-style pilot lamp holder for a retro look. Any LEDs can do, but rectangular type for VU meter stacks fit side by side neatly.

More work than you probably want, but the ultimate retro IMHO...
http://boginjr.com/electronics/lv/magic-eye/

[bandus]

> output signal level indicator bulb

Must it be an OUTput level? The only strong signal in there is the reverb driver. Which IS the direct signal. You "lose" the reverberated signal level, but that is rarely more than the direct sound, unless you palm-mute very abruptly.

Thanks, I've tried this configuration and it worked! Thanks for your help, really appreciate it!
Now I have to figure our how can I make it look more old-school.