tejas

I want to share details of my audio project in relation to the topic of connecting an external amplifier to a Teensy. In my setup, I interfaced the Teensy 4.1 with an external amplifier using its MQS output pins. This implementation may also be...

With line out from teensy to channel 3 of the amp, I’m setting both CH3 and master to 50%.

Update: I have connected line out, which works great!

Thanks for going through the amp specs! Here is my sequence of things to do (when teensy is on battery power). Please correct me. 1. Set sgtl5000 volume() to 0.5. I like to keep it fixed for my application: 2. Connect teensy audio shield...

Thanks for the clarity! There are situations when I am completely on battery (both teensy and roland). I’d be glad to use the headphone jack for those occasions. What should I keep the sgtl5000 volume() to in that case? I’ve been keeping it at...

Go with the default setting first. With pretty much all electronic stuff, your best path is almost always to first get it working the simplest way. Just to set realistic expectations, if the default setting works fine (eg, no obvious problems...

I can potentially solder an output jack directly to the audio board. The board, however, has two of the nine pins unnamed. I’m assuming they are ground. The amp data sheet states input level as -20 dBu. However, its own line out is rated at +4...

Also, how should I decide the value for lineOutLevel()? I can keep it at default, but want to understand how that's decided.

I'm convinced. Now, for connecting the line out, I have found this AC97 on amazon. https://a.co/d/e158eOy Would the output jack on this work as such (without any modification)? This should be the standard connector for PCs.

Hello everyone, Is there any advantage of using the audio shield's line out over its headphone jack for connecting an external amplifier? I've been using the headphone jack for this purpose so far, with sgtl5000 volume() set to 0.5, and have not...

Thanks for the directing me to that thread! I glanced through it and realized that the issue is somewhat beyond my bandwidth at this point.

That depends on device implementation. It might work in asynchronous mode, it might adjust its DAC clock to host, it might implement resampling. It is generally easier for output device to adapt.

I get it. Is there a practical way to avoid the artifact though? Why do USB speakers in general not have this problem? (Teensy is acting like a USB interface here.)

That makes logical sense to me. However, the sampling rate is 44.1kHz at both ends. Do you mean that there might be a slight difference even then? It reminds me of an experiment that I did once when I played a sine of 440 Hz on two computers...

Yes, but the reason I was asking is that the audio from Teensy without any equalization didn’t sound the same as that from the computer.

There is no nearby phone nor is there an SD card on Teensy. The artifact sounds like a glitch. Let me share a recording.

That helps. Yes, I’m referring to sgtl5000. Thank you!

Hello, I have noticed that the audio output sounds different from the headphone jack on the audio shield of teensy, as compared to when it is sent to a computer to record and play. I’m using the 7 band parametric eq function in the code. I’m...

Hello! I’ve noticed that my audio sounds clipped after raising the levels of the 7 band parametric eq. As a best practice, what should I keep the overall amplitude of the audio so that it doesn’t clip even after all the eq parameters are max...

Hello! I’m using teensy as a simple audio output device for my computer. It works fine. However, after every few seconds I hear an artifact which sounds like a scratched CD (compact disk). I’m not sure of the cause. Any ideas to fix it? I can...