electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
 Forum index » DIY Hardware and Software
BassBoy US$29 Midi Monosynth
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 2 [38 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: 1, 2 Next
Author Message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 11, 2011 1:03 pm    Post subject: BassBoy US$29 Midi Monosynth
Subject description: Anybody else buy one of these?
Reply with quote  Mark this post and the followings unread

http://www.mikroe.com/eng/products/view/658/bassboy/#order

Well, it works...almost. I get a lot of stuck notes and incorrect notes or notes that don't sound at all using an M-Audio 49 keyboard. I'm hoping that my particular BassBoy is somehow defective. I'd hate to think this was a 'normal' device. Too bad, since it is pretty cheap. Not worth returning for my money back since shipping was US$25.

Anybody have better success than me?

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
JovianPyx



Joined: Nov 20, 2007
Posts: 1248
Location: West Red Spot, Jupiter
Audio files: 161

PostPosted: Mon Apr 11, 2011 2:23 pm    Post subject: Reply with quote  Mark this post and the followings unread

Interesting. Do you have access to a different keyboard? Or scoped the MIDI logic output before it goes into the uC? I've heard of more than one odd MIDI thing happening due to grounding that shouldn't be there. I'm wondering why it costs $25 to ship it...
_________________
FPGA, dsPIC and Fatman Synth Stuff

Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
Back to top
View user's profile Send private message Visit poster's website
TheAncientOne



Joined: Dec 26, 2006
Posts: 146
Location: United Kingdom

PostPosted: Mon Apr 11, 2011 3:15 pm    Post subject: Reply with quote  Mark this post and the followings unread

He's shipping from central Europe, and using DHL, to avoid too many 'losses in transit'. The $25 covers up to 5Kg, so a group buy might be a good idea.

On the 'bad MIDI' problem; here are a few thoughts.

1) bad/high capacitance cable

2) low output on the Keyboard

3) bad opto on the Bassboy board

Hinton Instruments Website has a lot of good info on MIDI cabling and testing and is well worth a look. His simple testers are well worth making, as are the timing test adapters.

Hope you get it sorted, it seems a very cool project.

Best wishes

Mike

_________________
Mike
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 11, 2011 4:05 pm    Post subject: Reply with quote  Mark this post and the followings unread

OK, I switched keyboards and it worked just fine. The M-Audio 49 is my go-to keyboard for testing and seems to play all my other midi stuff just fine. The other keyboard that did work was a Doepfer MKE unit. Hmmmm. It's bad enough I have a project queue...now I have to add diagnostics to a module and keyboard! Crying or Very sad
_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
JovianPyx



Joined: Nov 20, 2007
Posts: 1248
Location: West Red Spot, Jupiter
Audio files: 161

PostPosted: Mon Apr 11, 2011 4:16 pm    Post subject: Reply with quote  Mark this post and the followings unread

Cool, that would mean that there's likely nothing wrong with the bass machine itself.

I had another friend with a similar problem which turned out to be an inexpensive USB to MIDI adapter that had a funky ground connection which caused something like what you described. Maybe check how the "bad" keyboard is wired internally? What's even more frustrating is I'll bet you can find equipment that will work just fine with that keyboard.

And as TheProf wrote, cables can be a problem as well. (mine are mostly home-made).

Heh, and Dan, why do you think you should be excluded from the herd of people (myself included) that have such queues? Smile

_________________
FPGA, dsPIC and Fatman Synth Stuff

Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
Back to top
View user's profile Send private message Visit poster's website
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 11, 2011 6:51 pm    Post subject: Reply with quote  Mark this post and the followings unread

Scott, well it's not as cool as just about everything you're working on, but it is cheap and dirty and does make a nice bass voice. The slide/portamento effect can be initiated with legato playing but if you leave a note down, play a second note then release the second note, the first note does not sound again, so it's not as monophonic synth-like as I prefer. I have yet to set up the cc controls for filter, etc. so I can't tell you how those work. Apparently, they are using a "moog" algorithm for the filter...we'll see. They may want to change that to "transistor ladder" to avoid possible trademark issues.

Another possibility is that the opto-isolator pull-up resistor may not optimized. I remember working on TH's Midi to CV-Gate/Trigger unit and having to change the value to get it to work with everything I had. I had similar problems Tom verified the schematic. Maybe it was the same M-Audio kbd? I don't remember, it was a couple years ago.

The unit ships from Serbia. It was fun tracking the shipment thru eastern Europe. Nowhere do they mention they are in Serbia. I wonder if they think there's still bad feelings from the Balkans war? I think there are a lot more issues in the world to worry about now.

I think The Prof is right. Group buy is the way to go. Maybe someone from each country can organize one

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
egasimus



Joined: Feb 11, 2011
Posts: 112
Location: Bulgaria

PostPosted: Mon Apr 11, 2011 10:27 pm    Post subject: Reply with quote  Mark this post and the followings unread

^ Offtopic: Not really bad feelings from the wars, but Eastern Europe isn't exactly prospering, and there is a general mistrust for EE countries - at least in Western Europe. It's because impoverished EE citizens often emigrate to Western Europe countries, and by 'impoverished EE citizens' I mean mostly gypsies who want to live off social welfare aids and petty crime. This sort of gypsies. So that's probably why Serbia isn't mentioned anywhere.
Back to top
View user's profile Send private message
TheAncientOne



Joined: Dec 26, 2006
Posts: 146
Location: United Kingdom

PostPosted: Tue Apr 12, 2011 2:36 am    Post subject: Reply with quote  Mark this post and the followings unread

I remember 'Sasha', (I'm not sure of he's on here - he does more on MIDIbox), complaining about the endless official paperwork and costs of exporting from Serbia when I helped with his modified x0xb0x project, (he did the panels and modified PCB's, I sorted out a parts bulk buy). I wonder if he's using DHL to cover all that, too? Is Serbia still subject to trade sanctions?, I know it was at one time.

Back to the MIDI problem. If it's a non-optimised opto resistor, (good thinking Dan!), then you'll have to trot out the SMT kit. It's a new product, and it might be he's not that familiar with production spread; a slightly low sensitivity on the opto might hit a limit somewhere if the resistor is sub optimal.

Same goes for the keyboard. The orginal MIDI spec calls for drive from a transistor or TTL open collector output. A lot of more modern devices use a pin of a micro processor, sometimes these can be a bit marginal on current drive. I had a similar problem with a friends portable groovebox, (can't remember the model - could have been a Yamaha). A loop check revealed it wasn't capable of delivering the specified current. With good sensitive optos in The devices he was driving, it worked fine, but failed with a few older units. My solution was to add a small buffer, and use the spare stages in the chip to drive LED's. I do that with some of my home made MIDI gear for another reason, the driver chip is there because it's easy to replace if some kind of bad wiring problem kills it, (this is me playing safe for when equipment goes out live; a CD4049 I can change, a programmed PIC or AVR is another matter), though I may be over worrying about this!

You could check by putting MIDI splitter in line with the M-Audio and seeing if the problem went away. If you haven't got one, there are quite a few designs around - the parts cost is trivial, and they perfboard up easily.

A few thoughts anyway.

_________________
Mike
Back to top
View user's profile Send private message
egasimus



Joined: Feb 11, 2011
Posts: 112
Location: Bulgaria

PostPosted: Tue Apr 12, 2011 5:52 am    Post subject: Reply with quote  Mark this post and the followings unread

Trade sanctions? Not anymore, I think, but they aren't in the EU, either, which does indeed make shipping costs to pretty much anywhere quite prohibitive, thanks to various customs taxes.

Have you heard about the case when (sometime in the mid-20th century I guess) the customs service of some country took a bunch of perforated cards which contained a computer program for a 'bulk item', so they took a 'sample' from them, as law required them to. Took the debugging team a while to find out why the program didn't work Laughing
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 18, 2011 11:00 am    Post subject: Reply with quote  Mark this post and the followings unread

http://www.mikroe.com/eng/downloads/get/1621/bassboy_manual_v102.pdf

I've been looking at the midi in circuit here. Is it just me or does that 10K pull up resistor on pin 5 of the CNY17-3 seem a little high? On a 5V circuit, I usually see something in the 1-2K range.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
JovianPyx



Joined: Nov 20, 2007
Posts: 1248
Location: West Red Spot, Jupiter
Audio files: 161

PostPosted: Mon Apr 18, 2011 12:31 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hi Dan,

That's a pullup on an open collector transistor. In my opinion, 10K should work and so should 1K.

I would look at the the collector pin with an Oscope - when the MIDI signal is present, the signal should ideally be a nice rectangular waveform from near 0 volts to near 3.3 volts. If it's sharp/crisp like that, it should work.

That resistor basically sets the gain of the transistor where the higher the resistance the higher the gain, but lower collector current. The circuit receiving that should ideally have a fairly high impedance and should not load it. If it looks sloppy, as in a slow rise or slow fall, you might try other values (such as 2K or 1K) and see if that improves it. Seeing the difference on the Oscope will tell you whether you are improving it.

I don't have a datasheet for that optoisolator - what you need to do is look at the collector current rating. 1K at 3.3v will allow 3.3mA to flow. Make sure that the current allowed by the pullup won't violate max Ic (collector current). If it's below max, it can still work very well - and won't blow the IC.

_________________
FPGA, dsPIC and Fatman Synth Stuff

Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
Back to top
View user's profile Send private message Visit poster's website
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 18, 2011 4:31 pm    Post subject: Reply with quote  Mark this post and the followings unread

Scott,
Thanks for the suggestions and tips! I guess Iĺl have to drag out the old o´scope. It might be a little while before I get back at this.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Alex_BG



Joined: Apr 21, 2011
Posts: 10
Location: Belgrade, Serbia
Audio files: 3

PostPosted: Thu Apr 21, 2011 4:52 pm    Post subject: Reply with quote  Mark this post and the followings unread

If you look at the schematic, the base of the phototransistor is connected with a 100KOhm
resistor to ground. That improve CNY17-3 speed (rise 5.6uS/fall 3.6us) instead of 6.4uS/123.6uS without resistor.

www.jaycar.com.au/images_uploaded/optocoup.pdf
http://www.digikey.com/Web%20Export/Supplier%20Content/NEC_51/PDF/cel-AN3011.pdf?redirected=1

I`ve tested with FT232R MOD+ROLAND DRIVERS, Ploytec GM5 USB Midi Interface,
Soundblaster MIDI interface and MOTU UltraLite mk3 MIDI OUT and work without any error.
Back to top
View user's profile Send private message
rosch



Joined: Oct 03, 2009
Posts: 162
Location: germany

PostPosted: Fri Apr 22, 2011 2:08 pm    Post subject: Reply with quote  Mark this post and the followings unread

hey Alex,
nice synth, i like it!

will you release the control board soon?
Back to top
View user's profile Send private message
Alex_BG



Joined: Apr 21, 2011
Posts: 10
Location: Belgrade, Serbia
Audio files: 3

PostPosted: Sat Apr 23, 2011 10:43 am    Post subject: Reply with quote  Mark this post and the followings unread

I'm a bit tied up right now, but the project will be finished eventually.

The idea is this:
it has 12 pots, where 4 pots can be either pot or switch.
it will work as midi merger, recieving notes via midi input, and will send notes together with midi cc values from pots itself to midi output.
Sasha (midibox.org) is completing the sequencing part of xoxbox, and integration of this pot board will be very easy, but can also work as a standalone midi pot control.

IMPORTANT:


Sincere apology to everyone who already bought older version of bassboy

After the ports initialization, the state of the ports cannot be read immediately, so the information about the state of the ports can be wrong. Is it a atxmega bug or problems appeared from production process itself, there is a chance that bassboy doesn't read the state of playing mode & channel mode pins correctly. This can be resolved in following way (this applies only to version SSP 1.0; in newer version a time delay has been added): add a resistor network 10k SIL5 - see picture below.


front.jpg
 Description:
 Filesize:  96.64 KB
 Viewed:  148 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

front.jpg


Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 25, 2011 7:50 am    Post subject: Reply with quote  Mark this post and the followings unread

Alex,

1. Welcome to the electro-music.com forum! welcome

2.
Quote:
If you look at the schematic, the base of the phototransistor is connected with a 100KOhm
resistor to ground. That improve CNY17-3 speed (rise 5.6uS/fall 3.6us) instead of 6.4uS/123.6uS without resistor.

I suspect my initial problems were due to my M-Audio keyboard that I used for testing. Bassboy worked quite well with my Doepfer MKE unit. I really like how the fingered portamento (slide) works.

3. Really looking forward to the controller board! This will really make this unit shine. I tried to test it with my Alesis Photon X25 keyboard, but the LCD stopped funtioning and I couldn't program the knobs to correctly control the BassBoy! All I could get was a little filter and volume control.

4.
Quote:
After the ports initialization, the state of the ports cannot be read immediately, so the information about the state of the ports can be wrong.
Thanks for the fix. Looks simple enough, especially since the rest of the unit is already assembled.
_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Mon Apr 25, 2011 11:02 am    Post subject: Reply with quote  Mark this post and the followings unread

Alex,
One other quick question about the planned control/pot board: would it be possible to change the cc number for the pots?

I'm asking because of another project I was involved with:
http://electro-music.com/forum/topic-21634.html
could certainly use pots for changing reverb, chorus, filter, portamento, etc.

If not in a menu, I suppose we could change the firmware to match GM Midi specs? Just a thought, it could make the pot board a product on its own.

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Alex_BG



Joined: Apr 21, 2011
Posts: 10
Location: Belgrade, Serbia
Audio files: 3

PostPosted: Sun May 01, 2011 10:06 am    Post subject: Reply with quote  Mark this post and the followings unread

Yes, it`s configurable via MIDI and look like this...

Aleks

p.s. knobs in the game...


knobs.jpg
 Description:
 Filesize:  81.11 KB
 Viewed:  154 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

knobs.jpg



ControlB.pdf
 Description:

Download
 Filename:  ControlB.pdf
 Filesize:  16.02 KB
 Downloaded:  164 Time(s)

Back to top
View user's profile Send private message
Alex_BG



Joined: Apr 21, 2011
Posts: 10
Location: Belgrade, Serbia
Audio files: 3

PostPosted: Thu Jun 23, 2011 10:01 pm    Post subject: Reply with quote  Mark this post and the followings unread

Test patterns ( LIVE MODE jumper )


Seq01-TG VIRUS.mp3
 Description:

Download
 Filename:  Seq01-TG VIRUS.mp3
 Filesize:  472.13 KB
 Downloaded:  227 Time(s)


Seq01-TG VIRUS.mid
 Description:

Download
 Filename:  Seq01-TG VIRUS.mid
 Filesize:  4 KB
 Downloaded:  168 Time(s)


Seq02-DJ ABADROZA.mp3
 Description:

Download
 Filename:  Seq02-DJ ABADROZA.mp3
 Filesize:  190.5 KB
 Downloaded:  236 Time(s)


Seq02-DJ ABADROZA.mid
 Description:

Download
 Filename:  Seq02-DJ ABADROZA.mid
 Filesize:  3.41 KB
 Downloaded:  148 Time(s)


Speedy J -Ping Pong seq.mp3
 Description:

Download
 Filename:  Speedy J -Ping Pong seq.mp3
 Filesize:  912.75 KB
 Downloaded:  196 Time(s)

Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Sat Jun 25, 2011 6:40 am    Post subject: Reply with quote  Mark this post and the followings unread

Nice samples Alex! How is the control/pots board coming along?
_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Alex_BG



Joined: Apr 21, 2011
Posts: 10
Location: Belgrade, Serbia
Audio files: 3

PostPosted: Sat Jun 25, 2011 10:50 am    Post subject: Reply with quote  Mark this post and the followings unread

Because my health status momently it is not good ( i have operation of left knee ) that will be move for later. With best regards, Alex
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Sat Jun 25, 2011 11:26 am    Post subject: Reply with quote  Mark this post and the followings unread

OK, hope you get well soon, Alex!
_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Cynosure
Site Admin


Joined: Dec 11, 2010
Posts: 692
Location: Toronto, Ontario - Canada
Audio files: 39

PostPosted: Thu Sep 22, 2011 10:36 am    Post subject: Reply with quote  Mark this post and the followings unread

Did you ever get the pots working with this. It seems like a great sounding bass synth for the price. The only reason I haven't ordered one yet is the cost of shipping.
Back to top
View user's profile Send private message
Dan Lavin



Joined: Nov 09, 2006
Posts: 620
Location: Spring Lake, Mi, USA
Audio files: 21

PostPosted: Thu Sep 22, 2011 6:35 pm    Post subject: Reply with quote  Mark this post and the followings unread

Cynosure:
you may want to propose a group buy for, say Ontario, then the shipping won't be so bad. If you can't handle the buy yourself, maybe someone else could step up?

_________________
Synth DIY since 1977!
Back to top
View user's profile Send private message
Cynosure
Site Admin


Joined: Dec 11, 2010
Posts: 692
Location: Toronto, Ontario - Canada
Audio files: 39

PostPosted: Thu Sep 22, 2011 7:05 pm    Post subject: Reply with quote  Mark this post and the followings unread

Not a bad idea. I know of at least one other person who would be interested.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 2 [38 Posts]
View unread posts
View new posts in the last week
Goto page: 1, 2 Next
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use