Operation of Basic Synth Example

[es314159]

All the release examples work great with my guitar. I'm trying out the Basic Synth module but I'm confused about how to connect it.

• Does it need DC power as well as the USB-MIDI connection to my computer (Mac)?
• Does the sound come out of the pedal's output jack or is it sent back to the computer?
• Do I need additional software on the Mac to act as a USB host?
• I also have a midi keyboard. Can I control the Hothouse Basic Synth with just the midi keyboard without the computer?

I've tried multiple configurations, played with the Mac's Audio Midi Setup App, and Bome Network App, but I'm not getting any sound (the Hothouse/Daisyseed does show up in the MIDI Network). Any help would be appreciated.
Thanks.

[clevelandmusicco]

Excellent questions.

Does it need DC power as well as the USB-MIDI connection to my computer (Mac)?

Yes. The Hothouse has analog audio circuitry that buffers the Daisy Seed's audio I/O. A 9V supply is required to operate that circuitry. This little blurb from the Hothouse Build Guide explains a bit more:

The Hothouse uses operational amplifiers to buffer the audio in and out of the Daisy Seed. These operational amplifiers are powered by the 9V supply. So, the Hothouse cannot produce sound without the 9V supply.

With a USB cable plugged in but no 9V supply, you might be able to get the LEDs on the Hothouse to light up (depending on what code you have flashed on it). This is because the 5V supplied by USB is sufficient to power the Daisy Seed itself, but you will never hear sound coming from the Hothouse without a 9V supply powering the operational amplifiers.

The next question is somewhat related:

Does the sound come out of the pedal's output jack or is it sent back to the computer?

The sound comes out of the pedal's audio output jack. A snippet of the code shows the output signal being assigned to L and R out:

void AudioCallback(AudioHandle::InputBuffer in, AudioHandle::OutputBuffer out,
                   size_t size) {
    // Stuff omitted ... 

    out[0][i] = out[1][i] = flt.Process(osc.Process()) * env_out;
  }
}

So, you'll need to connect the Hothouse's output to something like an amplifier or your audio interface's input(s) to hear the sound. (Just like with the other examples.)

Do I need additional software on the Mac to act as a USB host?

Admittedly, I can barely spell Mac 😜, so I am not familiar with the native audio/midi tools. That said, it seems this is supported without additional software: Set up MIDI devices using Audio MIDI Setup on Mac

If both the Hothouse and your MIDI keyboard are visible as MIDI devices, you would connect the keyboard's output to the Hothouse's input, which will have a label like "Daisy Seed Built In MIDI 1" (or similar). If you get this far, it's more a matter of getting the hang of the Mac tools than something to do with the Hothouse or the Daisy Seed. A quick spin around Reddit confirms you're not alone in needing a little help with MIDI on Mac, so maybe try there?

I also have a midi keyboard. Can I control the Hothouse Basic Synth with just the midi keyboard without the computer?

Note information is read via MIDI over USB, so you will need a USB host such as your computer, or a commercial or DIY solution. Since you are using your Mac, you already have a USB host, but if you want to better understand how all that general MIDI stuff works for the sake of learning, the links above are a good start. This and this might also be helpful. The upshot is that gaining this knowledge is applicable not only for using the Hothouse, but using ANY MIDI device in general.

Let us know how it goes!