[AudioI] AudioInjector and Guitar

[Joseph DiVerdi]

I have some of this kind of work on my website. Here is an example of an amplifier (and much more) I installed in a bass guitar including (relevant to this discussion) a pickup amplifier and final low impedance output buffer which is capable of driving looong cable lengths with high fidelity. The guitar details can be found at <http://xtrsystems.com/music/20201222%20bass%20guitar/20201222%20bass%20guitar.pdf> Other relevant items (including my planned installation of a Ultra audio-injector (another of Matt's fine products) and a raspberry-pi into a big amplifier and speaker system. One possibility for this is a Sonic-Pi application for synthesizer. Another is for looping. Big goals, limited time to work on them.

The guitar electronics were intentionally designed to operate on a single (9V) battery knowing full well there would be some power on/off transients (clicks). This was a prototype project (perhaps "throw away"). Two batteries would help or a negative rail DC generator. One of the helpful aspects is that the line voltage output is so high that I had to construct an in-line 10x attenuator that sits at the amplifier input (helping control line impedance and minimizing frequency roll-off, reducing line noise and the on/off transients).

I'm happy to discuss electronic circuit design in this context or others. I have been doing this stuff for many years and enjoy sharing the experiences.

Joseph

On Sun, 20 Feb 2022 3:42 PM, Matt Flax via People wrote:
> *** Caution: EXTERNAL Sender ***
> 
> Do you know any circuits online of guitar preamps which are known good ?
> 
> One idea is to design one up - possibly using the Pro soundcard first - because of its available power rails and low noise design and the AIABS inteface which would make it reusable.
> 
> We could work through the design of a preamp there seems to be some interest.
> 
> Matt
> 
> On 21/2/22 09:37, hugh crawford wrote:
>> I was really excited to see this because I thought maybe somebody had figured it out. Imagine my disappointment to see that it was pointing back to me. I have not actually figured this out. I am dealing with six extremely low power output single coil pickups and the noise is six times worse than one would get from a regular setup so it’s sort of worst case scenario here.
>>
>> I am also building the actual guitar so I have been occupied with a multitude of other problems.
>>
>> Some ideas that I am considering but have not yet tried are to run the guitar signal through some sort of effects box, a booster for instance, that will do impedance matching and deliver a more useful signal to the audioinjector.
>>
>> In my case I’m thinking of trying six cheapish noise gates since hardly ever am I playing all six strings at once.
>>
>> Another idea involves using a high impedance Phono preamp as a buffer.
>>
>> My advice would be to build your device, then if necessary visit your friendly guitar store and try out different stomp boxes as buffers. That’s what I plan to do soon now that they are open to in person business.
>>
>> On Sun, Feb 20, 2022 at 1:46 PM Matt Flax via People <people at lists.audioinjector.net> wrote:
>>
>>     Hi Harold,
>>
>>
>>     Some people in the past have build guitar rigs, there is most likely good information here :
>>
>>     https://lists.audioinjector.net/pipermail/people/2020-December/000157.html
>>
>>     http://forum.audioinjector.net/viewtopic.php@t=5797.html
>>
>>
>>     You can also contact those people directly if you don't get a response here.
>>
>>
>>
>>     Matt
>>
>>
>>     On 20/2/22 07:02, Harold Désert-Legendre via People wrote:
>>>     Hello Audioinjector Users,
>>>
>>>     I bought the audioinjector soundcard (stereo in/out via rca connectors) in order to build a guitar looper pedal. Will I need to adjust the guitar signal in term of gain? Or Can I directly plug the guitar  into the soundcard (just physically transforming jack into rca).
>>>
>>>     If anyone has experience with it, thanks for sharing your feedbacks!
>>>
>>>     Regards,
>>>
>>>     Harold
>>>
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>>
>>
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>>
> -- 
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> 
> 
> 

-- 
Joseph A. DiVerdi, PhD, MBA
XTR Systems, LLC
ChemIntelligence for Hemp & Cannabis
+1.970.980.5868 - www.xtrsystems.com/
us02web.zoom.us/j/9460709393