#Electric guitar recorder

42 messages · Page 1 of 1 (latest)

nimble flax
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Well, I've tried to search on this server and haven't found, so will ask here.

I'm a guitar player and have an electric guitar, that sometimes I'd like to record. Microphone recordings are shitty and hard to reproduce later (mostly because electric guitar without amp is quiet).
So, I got an idea - can I create a gpio board for a flipper with audio jack and app to record my guitar when I don't have a proper sound card and laptop nearby?

Approximate plan is to plainly plug 3.5mm jack on the board, and use a couple of pins to transfer guitar-produced signal (mono audio from pickups) to an app in the flipper and record it on the sd card. The recording don't need to be awesome, I just need more or less external-noise-free and normal-volume-level recording. Latency and processing time of the recording isn't important (as soon as buffer fits into memory, heh) - I usually just want to record a note phrase and go on doing other things.

As I'm not an experienced engineer (><), I'd like to ask a couple of questions to someone here.

  1. Have anyone implemented this already? It would be much simpler just to take. I'm fine with buying some stuff for the flipper, but I don't want to buy just separate device for it to reduce every day amount of things to be charged, think about it, etc etc.
  2. How implementable is the idea on a scale from 1 to 10 in theory?
  3. What probably should be on the board between jack and gpio pin output to the flipper? Can I do it without signal amplification (or do it on a software side)? Can I protect flipper from someone accidentally connecting the amplifier output and overloading the channel? (or it's not a problem?)
  4. What other questions / problems I should keep in mind implementing this?

Thanks in advance to anyone answering. 🙂

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Electric guitar recorder

meager burrow
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Why not get a mp3 recorder via 3.5mm AUX?

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Would be a lot less fussing around with hardware/software and much simpler

nimble flax
# meager burrow Why not get a mp3 recorder via 3.5mm AUX?

As I said, I don't want to buy additional device, charge it, remember about it existence, change batteries, take with me, etc etc. Flipper I already take with me together with wifi board, just one more board wouldn't be a problem.

meager burrow
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I did some searching and found this: https://forum.arduino.cc/t/16-bit-sample-store-then-readback-play-finally-store-to-sd/176459

Arduino Forum
16-bit sample & store, then readback & play, finally store to SD

I’m thinking about how to make a 16-bit mono sound sampling system, with playback of the samples sound, and storage to SD card if playback is okay. Wil then take the SD card & put in a PC for some post capture manipulation. My planned architecture - AD7680 16 bit ADC for audio capture, Atmega1284 for control, a bank of 8 23LC1024 128Kx8 SRAMs ...

nimble flax
meager burrow
meager burrow
nimble flax
meager burrow
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It seems like someone else was only able to accomplish 9.4Khz with just the arduino and no ADC

nimble flax
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Ok, I can use adc, no problems. So, the idea would look like jack -> adc -> gpi pins.
I suppose this also resolves the question with flipper protection as in the worst case only adc would die.
Anything else?

hard briar
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you already have a device that you care about, daily, always on you, that is able to record and play high quality stuff natively

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bar that, you'll also need to consider swapping the adc board and hauling it (maybe you want another board sometime?) and a case ror it

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and b. you'll also need to consider playback, if you're using it to jot down ideas... flipper is going to disappoint you, and its file management is not great, you currently can't even sort thr files or create dirs (on flipper itself)

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flipper also has a very, very low sd card reading speed, so both recording time and file dumping time will be limited. also hope you're ok with qflipper for file management and downloading all ideas

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a possibly simpler alternative is to ditch devices and train up your intervals, so you don't have random recordings with random ideas, but simply imagine stuff and do, oh, unison-unison-unison-third and just remember that as something that sounds like beethoven's fifth

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but you know, that has no flipper :p

nimble flax
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If I could just remember everything, life would be much simpler 😂
Thanks for the feedback. I think I'm fine without playback now, probably I can download files to the phone and play there.

If you're talking about the phone as a device to record, then you anyway need external device for the phone (and situation with mic I already explained).

Currently I'm exploring possibility of just taking hardware audio codec and connecting via spi interface

vivid crag
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I know you've repeatedly said not wanting to incorporate ANOTHER device - but I truly think that $40 iRig2 paired with one of MANY music creation apps will provide a far easier, better, faster, more robust solution. However, I am curious (as an experimental creator) what types of "undesired" effects using Flipper in audio creation could cause - and thus be used in production.

hard briar
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if you're ok with the quality the FZ can record at (which will be far, far under what the DAC can supply) isn't the phone's mic enough anyway?

nimble flax
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The difference between the phone and this idea is that the phone have to use mic for sound capture, and I described the problems of mic sound capture for electric guitar already in the original post. FZ can have 3.5mm jack where the guitar would be inserted, so the captured sound could be clean and free of external noise. Imagine it as an iRig device, that mentioned before. 🙂

meager burrow
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It would just be a lot of work to implement it into code vs a turnkey solution

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Cause you'll need a API to convert analog signal to digital and then use a codec

nimble flax
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Why do I need an API? Cannot I take signal from jack to audio codec and then transfer via SPI to the flipper?

meager burrow
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also streaming data via SPI is sloooow

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It might be enough for what you need

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but turning a analog signal to digital is tricky cause I don't know how that would work

hard briar
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you can also record your pickups on the phone's mic input directly, without any iRig like sound card, just with a $5 usb sound card, which works at mic levels (not instrument levels). it's gonna sound darker and roll off your highs, but we agreed high fidelity isn't our target here

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as for audio codec, once you get data in flipper, remember that card write speeds on SPI are not guaranteed and per spec, over SPI, all cards should be treated as class 0

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At 1MHz clock, you can expect a raw data rate of 125kBps, add in some overhead for communicatig with the card and maybe 100kBps is attainable?

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for consumer audio 44.1kHz@16bit, single channel, you'll need 88.2kBps so it might work but it would really depend on wb55's max spi speeds and your card's speeds

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during this time you'll also need to pump data in from your DAC, which is going to use the GPIO spi bus. it might be a bit too involved for a first project, since you'll need DMAs and probably threading, or at least implenting the producer-consumer pattern

nimble flax
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Well, sorry, but you either haven't read the initial post or just impolite and want to show off. 🙂
Yes, I know about harmonics. No, I don't need to record them. I need external noise free sounds to be able to remember notes and recapture the sound later. I would really appreciate any useful comment besides "buy irig" or "lol".
Thank you.

hard briar
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I never said 'buy irig', i said I fail to see how cheap external devices (not irig, generic tiny cheap usb soundcard) for your phone are inferior to a diy external device on a FZ who will barely keep up. mostly interested in this since I wanted to hack the FZ as a portable recorder myself

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i suppose that amounts to 'lol' for you, so i'll stop here, but i'll keep watching if you make anything interesting - as i said, interested in this myself