In need of a specific sound-to-light module

[ddlooping]

Hi all

I'm in the process of developing a "guitar-kits" project called **broken link removed**.
One of the possible options for the body of the guitar will be clear Perspex.
(not yet implemented on the options form)
I would like to integrate a sound-to-light module below the scratchplate (pickguard)...

(mockup of the "Ghost" with Perspex body and blue LED lighting)

**broken link removed**

I know that there are sound-to-light kits readily available but I would like one with the following specs:

• works using the output of a guitar pickup (I think it's between 100mv and 500mv)
• needs to be as "transparent" as possible (no detrimental effect on the sound of the guitar)
• runs on one 9v battery
• uses off-board **broken link removed** (I'm not sure how many would be needed to achieve the desired effect)
• be small enough to fit either under the scratchplate - the battery being inside the controls cavity (bottom left on the mockup) - or inside the control cavity
• uses a rotary switch for the following options:
  1. off (totally cuts the module off the circuit and turns the battery off)
  2. fixed light intensity (intensity and color adjustable via a couple of trimming potentiometers on the board)
  3. variable light intensity based on the level of guitar output signal (sensitivity and color adjustable via a couple of trim pots)
  4. variable color based on the frequency of the guitar output signal (sensitivity and color range adjustable via one or more trim pot(s))

It would be great if all these options were feasible but a 3-way mini-switch could be used if only three were available.

The following ones would be the icing on the cake:

• both variable light intensity and color based on the guitar output level
• variable color based on the guitar output level
• variable light intensity based on the frequency of the guitar output signal
• automatic "ramped" color change
• etc etc ...

(I hope the following request is allowed and not frowned upon)
What I'm actually looking for is not a diagram but for someone (preferably UK based for practical reasons) to design and build the module.
It goes without saying (but I'm going to say it anyway) that I would be paying for this someone's services.

Thanks for reading this lengthy post.

 

[ddlooping]

Well, I've contacted qs from "instructables.com" as I'm sure he'd be able to modify his "Musicator Jr." to some of my requirements. **broken link removed**

Still waiting for his reply so I don't know whether he'd be willing to do it or not.

 

[BrownOut]

It's perfectly fine to offer to pay someone to help you out. But you should realize that anyone who has the skills to develop your widget commands a high hourly rate. I have a couple questions:

1) Is this a product that would be marketed, or will it be a "one off" for your use only.

2) Is there an established business who would market it.

I would only consider hiring myself out for an established business who intends to market a product. It's just my preference. For one thing, too many individuals have big ideas, but flake out once they learn how difficult things can be. For another, I seek to be in business for myself, and need to build a portfolio of products that are targeted to market.

 

[ddlooping]

Thanks for the reply, BrownOut.

I answered your questions in bold inside the quote.

... you should realize that anyone who has the skills to develop your widget commands a high hourly rate.

For now I can only speculate on the time it'd take to develop the widget and what the hourly rate would be.
I'd appreciate if you could give me a ballpark figure for both.

1) Is this a product that would be marketed, or will it be a "one off" for your use only.

It will start as a one-off, used with the prototype of the Perspex version of the 5 guitars that will be shown at the **broken link removed** (May 8-9, London UK).
Whether it will stay a one-off or not depends on the demand for the Perspex version of the guitar body.

2) Is there an established business who would market it.

The idea is that it wouldn't be marketed by Delta Guitars but would be offered as an option when choosing Perspex as the material for the guitar body.

I would only consider hiring myself out for an established business who intends to market a product.

I guess that rules you out then, as the business is not yet established and would probably only market the product as an add-on. :-/

It's just my preference. For one thing, too many individuals have big ideas, but flake out once they learn how difficult things can be.

I have already spent a considerable amount of time and money (relative to my purse anyway) to develop the Delta Guitar-Kits concept and have received quite a lot of positive feedback for both the "Ghost" (the name of the actual guitar model) and the concept itself.
I don't intend to give up any time soon but curved-balls tend hit you when you least expect it.

- I have designed the guitar
- I have designed and started making the website (still in early-beta stage)
- I have designed and made the options form on the website
- I am working in collaboration with an established UK guitar maker (**broken link removed**) and a UK pickup maker (Catswhisker Pickups).
- I have 4 of the 5 guitars on order for the festival
- I'm in contact with QD Plastics, a Scotish company and posssible canditate for producing (machining, routing and polishing) the Perspex bodies
- etc etc ...


For another, I seek to be in business for myself, and need to build a portfolio of products that are targeted to market.

Things are moving pretty fast: at the end of December 2009 I started designing a guitar body to use with an old favorite guitar neck of mine.
Less than 6 months later I will have a small stand at the Guitar Nation 2010 Festival.

You will appreciate I haven't had the time (this is not my full-time job) to think about all the different case scenarios, including hiring a skilled electronician to develop a specific widget for a specific version of the guitar body.

My point is your portfolio could end-up containing photos and videos of a Perspex "Ghost" in action. I personally think it could be a welcome addition to any portofolio.
But obviously both parties, you(?) and I, would first have to agree on the terms of our collaboration.

 

[BrownOut]

I looked back over your requirements (the first time I tried, it hurt my eyes) I think we're talking about a microcontroller here at a minimum. Otherwise, it would take a considerable amount of circuitry to accomplish what you want. Another option would be to use a CPLD and ALOT of Verilog. The cool thing about using a microcontroller would be you can make changes, try out different ideas and upgrate without rebuilding the circuits. Battery drain might be a problem. Since you're making this from scratch, maybe consider powering it from the power input to the guitar (I assume being electric, there is a power input, but I'm not a guitarist) This way, it coulbe be made very small and pack in all the features you want.

 

[ddlooping]

I looked back over your requirements (the first time I tried, it hurt my eyes) I think we're talking about a microcontroller here at a minimum. Otherwise, it would take a considerable amount of circuitry to accomplish what you want. Another option would be to use a CPLD and ALOT of Verilog.

Reading "CPLD" and "Verilog" hurts my eyes (head?) too. **broken link removed**

The cool thing about using a microcontroller would be you can make changes, try out different ideas and upgrade without rebuilding the circuits. Battery drain might be a problem. Since you're making this from scratch, maybe consider powering it from the power input to the guitar (I assume being electric, there is a power input, but I'm not a guitarist) This way, it could be made very small and pack in all the features you want.

It would indeed be very cool but the widget has to work on one 9v battery.
An electric guitar does not have a power input (adding one is not an option), only an output for the pickups signal.

I guess I might be asking for too much for the perspex prototype. :-/
I will probably end-up using the cheap-and-cheerful "Musicator Jr." I previously mentionned.

It would be great if it could be slightly modded though:

• swapping the electret microphone for wires to be connected to the guitar output
• (high-brightness) multi-colour LEDs to allow for an overal color selection via trim pots (Red, Green, Blue levels)
• adjustable sensitivity via a trim pot (a guitarist would want for the LEDs to go full brightness now and then, even if he/she had a soft touch/style)
• 3-way switch (off - always-on - dynamic)

Is it something you would consider doing?
If yes, roughly how much would the cost be, both for modifying the circuit diagram and making one widget?

 

[BrownOut]

Well, I'm not in the UK. I still think you're going to have an issue with your 9V battery running down if you're trying to run a bunch of high brightness LED's. I'm sure someone on this site has crunched the numbers. You're guitarists won't appreciate the luminosity running down during their shows.

 

[ddlooping]

I still think you're going to have an issue with your 9V battery running down if you're trying to run a bunch of high brightness LED's.

I have no idea whether high-brightness LEDs will actually be necessary.
I don't know how many LEDs will be needed either.
My guess would be a minimum of two, to give the effect a wider spread.

I'm sure someone on this site has crunched the numbers.

Let's hope they take the time to read and reply to this thread.

 

[ddlooping]

No taker? **broken link removed**

 

[BrownOut]

If you want, I can take the circuit you linked and show you how to put in a switch for some of the effects you want. Then you can experiment and see how happy you are with it's performance.

 

[ddlooping]

If you want, I can take the circuit you linked and show you how to put in a switch for some of the effects you want. Then you can experiment and see how happy you are with it's performance.

Thanks, BrownOut, that'd very much appreciated. **broken link removed**

 

[BrownOut]

In the attached drawing, I've added two switches and a 10K variable resistor to the Musicator. The 10K resistor is R7, and acts as a fader control. The component labeled "Selector Switch" chooses either the guitar input, or the fader control. Any 10K variable resistor will do for R7. R5 is also a variable resistor, and replaces the 470K ohm resistor in the original schematic. The switch "Power Switch" disconnects the 9V.

I have no idea what the levels from the guitar pickup are, and so I'm not 100% sure is this will even work. I encourage you to build it with the standard mic and series resistor at first to get everything working, then try it with the guitar. The Gain variable resistor can be adjusted for varying input level, but if the guitar signal's impedance is too high, a buffer ( or additional amplifier ) might be needed.

Sorry for the weird schematic symbols. My editor doesn't have all the symbols I needed.

EDIT: Error ridden attachment replaced.

 

[ddlooping]

NOTE: There is an error in my drawing. I am in the process if making an edit.

Roger

I have no idea what the levels from the guitar pickup are, and so I'm not 100% sure is this will even work.

Passive guitar pickups normally output a signal between 100mv and 1v (for powerful pickups).
The ones I'll be using will probably be in the 500mv too 750mv range.

Sorry for the weird schematic symbols. My editor doesn't have all the symbols I needed.

Please don't apologize, I fully appreciate you taking the time to help me out.
On my birthday as well.

 

[BrownOut]

Happy birthday! I turned 50 last week. The output voltage from your guitar should be OK, but the other thing is the impedance. You may or may not know what that means, but basically, every voltage source has a characterisitc resistance or impedance. If the guitar output impedance is too high, we might need to make a small change to the circuit.

The drawing has been corrected.

 

[BrownOut]

PS: Use the variable resistor labeled "Gain" to adjust the circuit if the guitar's output it too high.

 

[ddlooping]

Happy birthday! I turned 50 last week. The output voltage from your guitar should be OK, but the other thing is the impedance. You may or may not know what that means, but basically, every voltage source has a characterisitc resistance or impedance. If the guitar output impedance is too high, we might need to make a small change to the circuit.

The drawing has been corrected.

A belatedly Happy birthday to you too, fellow Pisces.
I'm now 46, not far behind you.

Some info about guitar pickups you mind find of interest:

726-750 - Seymour Duncan/Basslines
(paragraphs #742 and #743)

Guitar Pickups Simulation

PS: Use the variable resistor labeled "Gain" to adjust the circuit if the guitar's output it too high.

Ok, will do.

I will go in town tomorrow to Maplin (equivalent to your RadioShack I think) and get all the bits.
I will keep you updated about my progress (or lack thereof ).

Thanks again for your help, BrownOut, it is fully apprciated. **broken link removed**

 

[BrownOut]

Get a couple extra opamps, or a quad package if you can. That way, we can add buffers if needed.

 

[ddlooping]

Something I forgot to ask: the guitar output and the input on the circuit are connected in parallel right? **broken link removed**

 

[ddlooping]

Get a couple extra opamps, or a quad package if you can. That way, we can add buffers if needed.

Ok, will do.

 

[BrownOut]

Something I forgot to ask: the guitar output and the input on the circuit are connected in parallel right? **broken link removed**

It's not really parallel. The ground is wired directly to the lower connection shown on the schematic, and the signal is wired to the top one.