[intlplby]

I want to make something like this:

http://www.soundprofessionals.com/cg...item/ISI-RLM-1

 

[robzy]

I am also very interseted in this.

I was looking into it a while back, but it just all seemed too hard at the time.

Rob.

 

[Icy006]

I was just thinking this! Unfortunately my electronics background is limited to digital logic design. I've been tempted to do this with an FPGA or microcontroller via a A/D converter

Wouldn't have a clue how to add it without affecting sound quality, though. If there is a parallel branch of the line-in to an A/D converter of said digital logic circuit, I can't say I understand the implications of splitting the current flow.

Also, surely there may be an analog-only way to do this. The "power LED cut-off on low power" feature that is on some DIY amps comes to mind. Something like a diode cuts off the current path to the LED if the circuit voltage drops due to low batteries.

 

[intlplby]

i got a bunch of links but i don't know which would be ideal for this if any of them

http://www.zen22142.zen.co.uk/Circuits/Audio/palm.htm

http://www.zen22142.zen.co.uk/Circui...levelmeter.htm

http://home.maine.rr.com/randylinscott/oct98.htm

http://www.aaroncake.net/circuits/vumeter.htm

http://www.ethanwiner.com/meters.html

 

[skyskraper]

lm3915

 

[Icy006]

Wow, the LM3915 looks like tons of fun. Up to 10 LEDs X two channels = byebye battery life! Would be worth it, though, with some tiny low-current LEDs. Looks like the chip lets you adjust everything, and it can drive LCDs or VFDs in addition to LEDs.

I would love to add this to a PIMENTA with a switch to enable/disable it. Anyone know how it could be integrated without affecting audio quality (much)?

 

[skyskraper]

just run it in parallel at whatever point you want to take the reading. i have a few half finished lm3915 circuits sitting around. i really should finish them,...

 

[~n00beR]

Although the links are in Korean, these are good examples, and have circuit digrams.

LED Level meter 1

LED Level Meter 2

LED Level Meter 3

It looks like there needs to be a parrallel signal path for the VU meter, as I wouldn't like all this switching in the signal path.

If you wanted you could make a custom cable, with the parallel signal wires to the VU meter, then the single "passive" headphone cable from there to the phones.

Hope this helps

 

[intlplby]

nononono ack thread hi-jack...... a positive thread hi-jack but a thread hi-jack nonetheless....

this is supposed to be about line-in level monitors for recording with binaural mics

 

[Clown12]

Quote:

Originally Posted by Icy006 Wouldn't have a clue how to add it without affecting sound quality, though. If there is a parallel branch of the line-in to an A/D converter of said digital logic circuit, I can't say I understand the implications of splitting the current flow.

Wouldn't a gp op-amp do this, with a high input resistance to the point of insignificance.

 

[bg4533]

Check out MisterX's PPA

 

[setmenu]

The LM39.. series are great chips I use the 3914 for my voltage meters.

http://www5.head-fi.org/forums/attac...achmentid=4555

Setmenu

 

[intlplby]

is there any difference in a line-in level meter for recording and a line-out level meter that one might use with their amp?

drew

 

[roadbuster]

Why do you guys want little LEDs to light-up to sense the signal level? If you need a rough estimate, aren't your ears good enough? And, if you need something precise, why wouldn't you use a voltmeter?

If you really want to do this, then drive the output signal to four comparators (eg: use a quad comparator package like the LM339). Create your four reference voltages with a voltage divider network (eg: a tree of resistors). Tie the output of the comparators to an LED. Voila: signal meter.

 

[skyskraper]

in the field, what your ears hear arent always what the microphones pick up. a well sortted meter is a valuable tool.