battery powered drum machine/synth rig

[PlanktonSideburns]

just thinking about attaching a couple of 12v drum machine's to a bike to do some mobile busking. im thinking of using a

yamaha dd65:
https://uk.yamaha.com/en/products/musical_instruments/entertainment/dd-65/index.html

and connecting a usb powered midi keyboard to it, which can control the built in instrument sounds (the dd65 has got a yamaha soundchip of some sorts in, so you can do drums and some basic cheesy synth/piano sounds all out of one unit)

the yamaha takes a standard 12v dc power supply,

    12V Switch Mode Power Supply
    750 mA Output

i could use the old fashioned alkaline batteries for the yamaha, and some sort of usb power pack for the usb powered midi keyboard,


but i was looking at these power supplies for cctv systems:

https://www.amazon.co.uk/TalentCell-Rechargeable-3000mAh-Lithium-External/dp/B072HR211P/ref=asc_df_B072HR211P/?tag=googshopuk-21&linkCode=df0&hvadid=309785494452&hvpos=1o8&hvnetw=g&hvrand=9654469932166453235&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9045651&hvtargid=pla-430838397094&psc=1

would i be able to power both the 12vdc for the yamaha and the USB midi keyboard at the same time off this?

the yamaha seems pretty chilled about what 12vdc it receives, - ive plugged random power supplies from routers and other things at it before.

would be a real neat solution if so!

[Twed]

smells great

[PlanktonSideburns]

thanks twed

[buzby]

just thinking about attaching a couple of 12v drum machine's to a bike to do some mobile busking. im thinking of using a

yamaha dd65:
https://uk.yamaha.com/en/products/musical_instruments/entertainment/dd-65/index.html

and connecting a usb powered midi keyboard to it, which can control the built in instrument sounds (the dd65 has got a yamaha soundchip of some sorts in, so you can do drums and some basic cheesy synth/piano sounds all out of one unit)

The DD65 has got a General MIDI implementation using AWM Sample playback (like a PC wavetable   soundcard). However, reading through the manual there appears to be no way to assign the General MIDI voice patches to a MIDI channel from the front panel. You can download General MIDI-compatible SMF song files into it via USB and play them back, or it can play MIDI files back from an external sequencer via MIDI IN -  SMF files have a SysEx data block at the start of the song file that assigns the required voice patches to MIDI channels for that song.

Unfortunately I think this means that without an external sequencer or downloading song files into it via USB, you can't do much by just connecting a MIDI controller keyboard to it other than maybe play a single voice (which would be whatever patch it loads into a particular channel by default, unless the MIDI controller has a front panel input device pre-mapped to the MIDI Program Change command). You would have to make your own MIDI files to load into the DD65 beforehand with one channel that had a voice assigned but no note data so you could then play along by setting the keyboard's MIDI output to the required channel.

the yamaha takes a standard 12v dc power supply,

    12V Switch Mode Power Supply
    750 mA Output

i could use the old fashioned alkaline batteries for the yamaha, and some sort of usb power pack for the usb powered midi keyboard,


but i was looking at these power supplies for cctv systems:

https://www.amazon.co.uk/TalentCell-Rechargeable-3000mAh-Lithium-External/dp/B072HR211P/ref=asc_df_B072HR211P/?tag=googshopuk-21&linkCode=df0&hvadid=309785494452&hvpos=1o8&hvnetw=g&hvrand=9654469932166453235&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9045651&hvtargid=pla-430838397094&psc=1

would i be able to power both the 12vdc for the yamaha and the USB midi keyboard at the same time off this?

the yamaha seems pretty chilled about what 12vdc it receives, - ive plugged random power supplies from routers and other things at it before.

would be a real neat solution if so!

From the DD65 manual it's rated at 19W and uses a PA-5D or PA-150 power supply. These output 12VDC at 2 Amps (for the PA5D) or 1.5 Amps (for the PA-159). This ties in with the 19W as 19/12=1.6 Amps (it needs this much power as it has an internal amp and speakers). This means the 12V 750ma PSU you are using will not supply enough power for the DD65 at full volume (as it can noly supply half ithe DD65's required current).

The Lithium battery pack you have linked to has a maximum supply current rating 3A which is OK for the DD65, and has a capacity of 3000mAh (i.e. 1 hour at 3 Amps). If it was only powering the DD65 it would have enough capacity for 2 hours play at full volume. Adding the MIDI keyboard to the 5V USB output would reduce that time, depending on how much additional current the keyboard draws.

[PlanktonSideburns]

Hey buzby, thanks for that very informed response!

there appears to be no way to assign the General MIDI voice patches to a MIDI channel from the front panel.

thats true that you cant assign it on the dd65, but i found that if i connect a midi keyboard to it via midi cable, you can change the assigned midi voice patch via the keyboard, using the program change command, - so the drum machine stays working like a drum machine, and youve got the whole of the rest of the soundset of the yamaha to play with on the synth!


so its the inbuilt powered speaker thats doing the most of the draw - would it still be drawing power if the volume was turned down and i used a separate battery speaker for the sound?

ive got two little 25key master keyboardds, a dd65 and a dd55, im thinking of mounting it all on a bycicle and having it as some sort of portable yamaha jam station. i wonder if i can charge the lithiums of a dynamo?

[Twed]

im thinking of mounting it all on a bycicle and having it as some sort of portable yamaha jam station.

smells great

[buzby]

thats true that you cant assign it on the dd65, but i found that if i connect a midi keyboard to it via midi cable, you can change the assigned midi voice patch via the keyboard, using the program change command, - so the drum machine stays working like a drum machine, and youve got the whole of the rest of the soundset of the yamaha to play with on the synth!

I thought as much.. If you prepare some MIDI song file sint he way I described (by deleting the note data for one track that you can then play manually) then you could have full accompaniment too. Note that the General MIDI standard has 32-note polyphony, so the DD65 can only play 32 simultaneous notes across all MIDI channels (this includes the percussion section too)

so its the inbuilt powered speaker thats doing the most of the draw - would it still be drawing power if the volume was turned down and i used a separate battery speaker for the sound?

Depending on the class of amplifier it's built in amp IC is , then yes, current draw is somewhat relative to the volume level. There will be a baseline fcurrent that it always uses even with the volume turned down to line-level output, but you will have to find that out from trial and error as maximum power consumption is the only figure they re required to publish.

ive got two little 25key master keyboardds, a dd65 and a dd55, im thinking of mounting it all on a bycicle and having it as some sort of portable yamaha jam station. i wonder if i can charge the lithiums of a dynamo?

The battery pack you linked to requires a 12V DC 0.5A regulated power supply to recharge it. The output voltage from a bicycle dynamo can be either 6V or 12V, varies with speed, and is AC rather than DC, so requires rectification to get a DC voltage out of it. It would then need to go into a DC/DC Boost converter circuit that would output a 12V regulated voltage but the current would vary with your pedalling speed. Unfortunately as far as I can see nobody sells such a device for bike dynamos, so you would have to make one yourself. You can buy off-the-shelf dynamo-based USB chargers that can supply 5V at up to 0.5A though.

[PlanktonSideburns]

Ooh firing up some midi files could be fun, will look into it!

Ordered the battery, will give it a go and see how it goes for battery life

[boki]

smells great

Sniff a lot of bicycles do you mate