[Project] Music Thing Radio Music 4hp sample player

Tombola · Post by **Tombola** » Sun Nov 30, 2014 2:18 pm

[video][/video]

This is the main thread for my new project, the Music Thing Radio Music Sample Player.

It's a 4hp module that behaves like a Voltage Controlled FM Radio or a Shortwave Radio, but is actually playing files from a SD Card, without the problems of actual live radio reception.

Why would anyone want a radio station in a modular synth?

Features
- 4hp x 40mm deep
- All through hole, no SMD soldering, including what I think is the world's only through-hole SD Card holder
- Samples stored as 16bit 44.1k mono .raw files on hot-swappable Micro SD cards (up to 32gb)
- 16 banks, up to 75 files in each bank
- Playback is 12 bit, 44.1k, AC coupled
- Based on a Teensy 3.1 microcontroller
- 75ma current draw

Controls
- Station pot (and CV Input) This is how you choose which file to play from the current bank. It works exactly like a radio tuning knob. Like real radio stations, the files loop endlessly and continue to play in the background - they don't re-trigger each time you select a new station. If you turn on the module and wait 5 minutes, then switch to a channel playing a 30 minute long radio recording, it will be 5 minutes in.
- Start pot (and CV input) This sets where the file will start playing from from if you press the RESET button.
- Reset Button (and trigger input) This restarts the current track at the point set by the Start pot.
- The module creates a settings.txt file on the SD card. By editing this, you can change how the module behaves; how quickly pots respond, how clicks are suppressed.

Status
- Here is the wishlist for kits from Thonk
- Software is stable (issue log)
- Rev 2 PCBs are available and will soon be prototyped for the Thonk run
- Hardware designs and my code is all CC-BY-SA licensed

Details
- Manual
- Documentation including build documents, BOM etc
- Suggested audio
- Hardware and Software details

[soundcloud url="https://api.soundcloud.com/tracks/179087720" params="auto_play=false&hide_related=false&show_comments=true&show_user=true&show_reposts=false&visual=true" width="100%" height="450" iframe="true" /]
https://soundcloud.com/musicthing/radio ... ndom-drums

https://soundcloud.com/musicthing/radio ... dom-voices

Like this project? Donate some money to Resonance FM so I have something interesting to listen to in the car

Tombola · Post by **Tombola** » Sun Nov 30, 2014 2:27 pm

Questions and answers from the other threads, so everything is one place:

Windspirit asked:
1) will this be open source also? If so I may make a whole row for myself :p
> Yes, it is CC-BY-SA

2) with a fast enough clock can you "scrub" the sample position with a saw tooth wave?
> ...ish. If you edit the settings.txt file you can get the module to respond in a fast, raw, noisy way without the affordances that normally make it a bit more smooth.

Stainers asked:
Is there anyway you can get it to keep memory of all settings after a power cycle?
> It retains the current bank (which is set by pushing/holding reset) but not the play position

Waveglider asked:
Does that mean that once you trigger a station, leave it, then come back- the playback position will have followed in real time and it picks up at the current position rather than the position where you left off?
> Yes, that's the idea

B-Art asked:
I mean i really like the whole radio concept and think its awesome for long samples and recordings (conceptual yes!) but i was also planning on using it as a one-shot sampler. For various reasons.
>You can probably do this - ie fill up a folder with one shot samples, choose a sample by voltage, then trigger it from the start using the reset trigger.
>Would be easy enough to add a 'don't loop' option on the SD card if that turns out to be useful.
>OR if you have any arduino coding chops, it's very easy to hack the firmware - you can use the normal Arduino language and upload via a USB cable

SpunRaddish asked:
Do we have ways to write to SD cards in modular yet as a function of sample recording?
> And got a long reply from Teensy creator Paul Stoffregen

Taylor12k asked:
is it an fm radio that samples it's own stations?
does it sample outside sources?
>is that it's a sample player with a radio-like interface.
>So you can load up a bunch of Conet Project samples and it's like the easiest SW radio ever.

Spip · Post by **Spip** » Sun Nov 30, 2014 3:20 pm

Really nice !

Any idea of when ?

Will it be a DIY kit ?

NS4W · Post by **NS4W** » Sun Nov 30, 2014 3:29 pm

I'm already collecting samples to put in it!

lintfresh · Post by **lintfresh** » Sun Nov 30, 2014 3:34 pm

Stand out work as always, Tom.

A few questions if I may:

I'm assuming you're using the onboard PWM for audio output as I don't see a DAC. I'm curious how you feel about the audio quality trade-offs and what factors led to this design decision.

Is the code written using the teensyduino tools?

Tombola · Post by **Tombola** » Sun Nov 30, 2014 3:46 pm

lintfresh wrote: I'm assuming you're using the onboard PWM for audio output as I don't see a DAC. I'm curious how you feel about the audio quality trade-offs and what factors led to this design decision.

Is the code written using the teensyduino tools?

The Teensy 3.1 has an on-board 12-bit DAC.

I've been very happy with the sound - it's probably more Akai S900 than Pro Tools HD, but it's full range, loud and clear, as you should be able to hear in the audio demos.

Yes, it's all Teensyduino - I've modified a couple of functions in the library a little bit, but it's basically stock, so is really easy for anyone with basic arduino skills to get started.

knob_alchemist · Post by **knob_alchemist** » Sun Nov 30, 2014 3:56 pm

Interesting project....will be my next build....

windspirit · Post by **windspirit** » Sun Nov 30, 2014 3:58 pm

Are the problems with the v1 pcb outlined in the github? I am not very patient

EDIT: nvm, I was being lazy, I looked it up myself. Thank you tom for another amazing module!

executiveBlaster · Post by **executiveBlaster** » Sun Nov 30, 2014 4:14 pm

great work

valis · Post by **valis** » Sun Nov 30, 2014 4:20 pm

Very cool!

More questions..

1) Can it run on +/-15V
2) Do you envision one will be able to buy just the circuit board without the euro panel?

Thanks!

ClausF · Post by **ClausF** » Sun Nov 30, 2014 4:32 pm

Great!

Tombola · Post by **Tombola** » Sun Nov 30, 2014 4:40 pm

valis wrote:Very cool!

More questions..

1) Can it run on +/-15V
2) Do you envision one will be able to buy just the circuit board without the euro panel?

Thanks!

+-15v should be fine but untested - it's TL07* op amps and a 78L05 feeding the Teensy

This is a pair of super tight boards - there are no mounting holes, no screws/spacers connecting the front and back boards, just panel mounted pots and headers/sockets connecting the two boards - so it might be harder than some other designs to hack into a different format.

OTOH, it's so tiny, you could probably make a quad sample player in one of the big formats.

If you did want to do that, the Teensy has more grunt than is being used here - I think people have got it playing 4+ separate .wav files simultaneously from one SD card, so with an outboard DAC it might be possible to do a quad/poly version...

mxmxmx · Post by **mxmxmx** » Sun Nov 30, 2014 5:02 pm

Tombola wrote: If you did want to do that, the Teensy has more grunt than is being used here - I think people have got it playing 4+ separate .wav files simultaneously from one SD card, so with an outboard DAC it might be possible to do a quad/poly version...

people have indeed done this. but doing more than stereo with separate outputs wouldn't be feasible with i2s devices (which most decent audio DACs are), and SPI/DMA isn't currently supported by the API so .. possible maybe, worth the trouble probably no.

MrNovember · Post by **MrNovember** » Sun Nov 30, 2014 5:24 pm

Definitely interested in this
Really want a Mikrophonie too
I just need as many weird sound sources as possible apparently

Tombola · Post by **Tombola** » Sun Nov 30, 2014 5:53 pm

mxmxmx wrote:
Tombola wrote: If you did want to do that, the Teensy has more grunt than is being used here - I think people have got it playing 4+ separate .wav files simultaneously from one SD card, so with an outboard DAC it might be possible to do a quad/poly version...
people have indeed done this. but doing more than stereo with separate outputs wouldn't be feasible with i2s devices (which most decent audio DACs are), and SPI/DMA is currently supported by the API so .. possible maybe, worth the trouble probably no.

Ah, got it.

mxmxmx · Post by **mxmxmx** » Sun Nov 30, 2014 6:04 pm

Tombola wrote:
mxmxmx wrote:
Tombola wrote: If you did want to do that, the Teensy has more grunt than is being used here - I think people have got it playing 4+ separate .wav files simultaneously from one SD card, so with an outboard DAC it might be possible to do a quad/poly version...
people have indeed done this. but doing more than stereo with separate outputs wouldn't be feasible with i2s devices (which most decent audio DACs are), and SPI/DMA is currently supported by the API so .. possible maybe, worth the trouble probably no.
Ah, got it.

ups. typo - i meant to write "SPI/DMA isn't currently supported by the API so ... " . anyways, it's perfectly possible to stream several files so adding additional clock inputs will be an easy mod.

Thonk Support · Post by **Thonk Support** » Sun Nov 30, 2014 6:29 pm

Will be doing panels in the same range of colours as the Spring Reverb, White and Black PCB and Aluminium. Oh and with four choices of button colour, couldn't resist

oscillateur · Post by **oscillateur** » Sun Nov 30, 2014 6:40 pm

Will there be an already built version ?

Post by **Joe.** » Sun Nov 30, 2014 8:10 pm

Monobass wrote:Have started purchasing for the first run of kits. January definitely seems possible right now.

The mailing list doesn't specify how many kits people are interested in. I definitely want two please.

makers · Post by **makers** » Sun Nov 30, 2014 8:17 pm

I've already got an unused Teensy 3.1. It would be great to have a PCB/panel option sans the Teensy.

Ras Thavas · Post by **Ras Thavas** » Sun Nov 30, 2014 8:54 pm

A question that I'm sure the answer will be "no" to, but have to ask anyway-

Would two of these with the same "stations" saved on their cards stay remotely in sync after a "reset" pulse? I ask as two thoughts come to mind; stereo files and timing pulse tracks.

I'm actually more interested in the second option, I know this isn't supposed to be a sampler, but I'd like some way to sync up the stations with the rest of my modular beyond the reset input.

NU · Post by NU » Mon Dec 01, 2014 2:08 am

If anyone in North America would be willing to build an extra one for me, please let a dude know.

Tombola · Post by **Tombola** » Mon Dec 01, 2014 2:22 am

Ras Thavas wrote:A question that I'm sure the answer will be "no" to, but have to ask anyway-

Would two of these with the same "stations" saved on their cards stay remotely in sync after a "reset" pulse? I ask as two thoughts come to mind; stereo files and timing pulse tracks.

I'm actually more interested in the second option, I know this isn't supposed to be a sampler, but I'd like some way to sync up the stations with the rest of my modular beyond the reset input.

If you want to build a stereo version, you'd just need:
- An outboard DAC for 2 channel audio - mxmxmx's Eurotrash project would be a good place to start in terms of schematic. OR you could use PWM pins
- Then you'd need to get my code playing stereo .wav files vs .raw, which shouldn't be a huge piece of work. Again, mxmxmx has done most of the work here: http://forum.pjrc.com/threads/24793-Aud ... #post55274
- A bit more panel space, and at least one SMD component - thats why I didn't do it.

meatbeatz · Post by **meatbeatz** » Mon Dec 01, 2014 10:26 am

genius!

337is · Post by **337is** » Mon Dec 01, 2014 10:30 am

I read about this last night but couldn't watch the video at that time ... mind blown. Watched the video finally this morning. Gobsmacked! Can't wait to build one. Added my name to the Thonk notification list. Incidentally, thanks for making stuff to build that isn't SMD ... my vision doesn't go that small!

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[Project] Music Thing Radio Music 4hp sample player

[Project] Music Thing Radio Music 4hp sample player