Can I easily increase voltage to drive a meter?

[Crazy_Fool]

I could return the device but it would just look too cool on a pedal board to not try to make it work...

I had the idea that I could make a spiffy little meter that would dance when I hit the strings on my guitar. I found one that is digital but with an analog appearance. It's 1V but can be scaled up. My thought was that I could try different guitars and scale it appropriately. It arrived and I realised that this one is DC voltage not AC like I narrowed by filters for. There is no AC one that's this small and cool looking. My question is - what is the easiest way to ramp up guitar pickup mV to get to the range of 100mV to 1V DC? I'm pretty decent with a soldering pen, components fabricating off small boards so schematics to go with ideas are very welcome.

This device will not be in the audio path at all. It will run off an isolated output and the DC voltage to power it will run off of an isolated source as well.

Thanks in advance!

[Enzo]

Your guitar is part of the signal path. You want a circuit to boost the 100mv signal to a volt? How about the amp itself. Find a spot in the amp that has the signal level you want and sample the signal level there.

You want to take your (essentially) AC signal and make it DC? Insert a diode in series.

[The Dude]

Not knocking the idea- might be a fun little project, but my first thought is,...... who spends that much time staring at their pedal board?

[Crazy_Fool]

Not knocking the idea- might be a fun little project, but my first thought is,...... who spends that much time staring at their pedal board?

Well I'm starting a great new job in a week after too long of just looking after the kids during covid and etc. So just finding a way to burn off a little steam and it's better than pacing...

[Crazy_Fool]

Your guitar is part of the signal path. You want a circuit to boost the 100mv signal to a volt? How about the amp itself. Find a spot in the amp that has the signal level you want and sample the signal level there.

You want to take your (essentially) AC signal and make it DC? Insert a diode in series.

This is by design to be on the pedal board and if I do it right it will be just a tap from the raw guitar signal due to where it's positioned.

I'm actually seeing that in DC out without rectification or anything else the signal is incredibly weak e.g. < 1mV. What I want to so is find a super simple way to rectify the super weak signal and then boost it. If I remember correctly DC to AC is DC divided by 1.4. I want to then take that super weak signal and boost it to the point where weak pickups and a light touch are in the range of ~100mV and hot pickups and an aggressive attack are in the range of 1V. For this I don't care about if the sound is ugly and nasty. I just want a signal where the voltage is representative to what's coming out of the guitar but in the range of the meter.

Does that make more sense?

[Jazz P Bass]

I am not all sure that your idea is going to function as you would like.

If I understand correctly you want a display of the guitar signal level.

If you strike one note & let it ring out, then the meter stands a chance of displaying it.
But striking a chord?

What information are you trying to get and why?

[Enzo]

So pretend you are making a new pedal. Put an op amp in a box to boost the signal level to what you want. There are various "VU meter ICs" on teh market, pick one and use it.

Do yo have anything with a meter on it? A mixer, a tape deck? Play your guitar into it to see what drives the meter. I think you will find a guitar signal is more logarithmic than you might think. The dynamic range can be large. In other words you may find that your play might have to be fairly loud to fill the meter, but if you back off much then the lights don't come on. If you boost the gain so light play fills the meter, then get any louder and the lights just stay on full constantly. SO to make it visually intersting, you need to scrunch up the scale. COmpress it.

I assume a digital VU meter rather than a moving needle. And I am assuming you want eye candy rather than something with actual practical use.

[J M Fahey]

I could return the device but it would just look too cool on a pedal board to not try to make it work........ It's 1V but can be scaled up....... scale it appropriately. It arrived and I realised that this one is DC voltage not AC like I narrowed by filters for. There is no AC one that's this small and cool looking. My question is - what is the easiest way to ramp up guitar pickup mV to get to the range of 100mV to 1V DC?

START by showing "the device"
No clue about it, the display, sensitivity, polarity, or power supply needs. Not even size.
How are we supposed to know?

I suppose you only have pedal standard +9V supply available; there are some pedals which include a guitar signal to DC converter, for their own use, typically a compressor or oe of those cheesy 80īs Autowahs.

Knowing your needs , some of them could be modded for the job.

You will have to design your own board, or build it on Veroboard or equivalent.

Meanwhile read this:
https://www.deeptronic.com/electroni...time-settings/
for a general idea on what you need.

[eschertron]

What I want to so is find a super simple way to rectify the super weak signal and then boost it

To be more in line with the physical realities of rectification diodes, you'll want to BOOST the signal, then rectify it. A minor point, but will save some frustration.
An opamp, couple resistors, and a diode. Look at the most simple OD pedal design, and go from there. ditch the tone-shaping, keep the gain. Drive your meter from that.