Building my first x0x.

Discuss x0x construction and related issues

Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.
Locked
VerreyckenGerd
 
Posts: 13
Joined: Tue Feb 28, 2012 12:30 pm

Building my first x0x.

Post by VerreyckenGerd »

hi all,

I am new to the x0x community and recently ordered my b0x from x0xsh0p.

Heard about the x0xb0x many years ago somewhere on the internet. People where writing about firmware updates all the time so I believed the thing was DSP driven for many years. Stupid heh...
Now that I have finally discovered the box has a full analogue audio path and even better a reverse engineered 303 circuit I decided it's definitely worth to build.

The kit from SubStyler arrived very well packed and all most everything is labeled seperatly.
It also came with some "special parts" in a bag containing some alternative transistors, resistor and caps witch should improve the sound.

I am gonna spread the assembly over some spare time here and there in the evenings. Could take some time to finish. Maby gonna design my own faceplate since I have build a 3 axis CNC mill a few years ago with some friends.

The power supply and VCO are already built and running fine.

To calibrate the VCO I used a lab power suply with fluke 79 (only 4000 digit) multimeter and my PC running Audio Phonics Guitar tuner freeware that I use for tuning my other equipment / guitar.

The provided pots seem very sensitive to make a perfect tuning. Has anyone replaced them with multiturn trim pots?

I have also looked at both waveforms with a scope. Square looks more square than on the adafruit construction manual pics probably due to the bag with "special parts". Thanks for that subStyler!!

As a final test i "played" the VCO trough several CV sources
Doepfer Dark Energy CV out, Novation Basstation CV out and MFB Kraftzwerg CV out.
It sounds linear and musically to my ears....

I'll keep you guys updated about the remaining steps.

Greetings,

Gerd

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: Building my first x0x.

Post by antto »

welcome
if you're running windows, there's a win32 VST plugin which helps tuning the VCO (here but watch the tutorial video first)
but you should do this fine-tuning at the end, when the x0x is fully assembled

as for the square wave, it usually doesn't look like a real square at all, and it's exact shape varies with frequency alot, so don't be surprised about it ;]

have fun :mrgreen:

VerreyckenGerd
 
Posts: 13
Joined: Tue Feb 28, 2012 12:30 pm

Re: Building my first x0x.

Post by VerreyckenGerd »

Finished the x0x succesfully !

Mistakes I have made and debugged:

1.) Shorted a little ceramic capacitor on the sequencer 5VDC line (oversoldering). The powersupply survived it.
2.) 8 buttons didn't work. A pin of the corresponding convertor IC was bent to the inside.
3.) Swapped the 2 stereo potmeters. Tansplanted them in there right position.

Things to do:

1.) Fine calibration (it however already sounds quite right from initial VCO calibration) f
2.) Post a demo video.

Greetings,

Locked
Please be positive and constructive with your questions and comments.

Return to “Making x0x”