midiphy Eurorack Expander Modules

[latigid on]

Hello, Peter made an awesome video (4k quality!) demonstrating the assembly of the following modules

• Euroceiver (line driver receiver in the rack), power distribution
• A1 Expander (AOUT based on MAX5500)
• D1 Expander (DOUTX1 for gates plus protection)
• D2/D3 Expanders (likewise for clocks and triggers)

Feel free to use this thread for any discussion or troubleshooting. Have fun building your modules! 

 

 

Edited September 12, 2019 by latigid on

[TK.]

Thanks a lot Andy and Peter for this great work! 

Based on this video tutorial I built up my modules yesterday, all are working fine, almost no troubleshooting was required. :)

Now I need a case (I ordered a 4ms Pod40X in the hope that the modules will fit into this case without special measures)

Best Regards, Thorsten.

[latigid on]

Awesome, have fun with the CV! A small case is a sensible idea as it can keep the modular addiction contained :)

Thank you for the framework and codebase to enable development of these modules.

Best,
Andy

[Againsistm]

Hi, I just finished the euroceiver module and like to test if it functions with the  led etc. Is it already possible to test the module because when i put the usb in there i don't see the led going on while the led is good while checking with a multimeter. Thanks, niels

[latigid on]

What is the jumper setting with J5? Choose USB to power it this way.

(check the +5V rail is not shorted to 0V)

[Againsistm]

Hi,

Jumper setting is the same as in hawkeyes video. Just wanted to test the module only with the usb power but do you also need to supply power by the eurorack psu rail? Sorry still really noob with eurorack, this is my beginning with it ;-) i thought powering only by usb is enough. 

[Againsistm]

Ha now i understand the jumper was wrong. Everything working now, no need of an eurorack power (yet). Thanks going further now with building ;-)

[Againsistm]

Hi,

I like to start with the dacs but looking at the pcb's i see that the bridges are really close to eachother. Is this normal? I Guess using flux will not solder a bridge but just asking ;-)

Cheers niels

[latigid on]

Hi Niels,

These pins are intentionally bridged; see also http://ucapps.de/mbhp/mbhp_aout.pdf (amplifier circuits now a bit different and available on the transmute8 page). The next run of PCBs will indicate this a bit clearer. On the plus side, no need to unbridge these if there's too much solder!

Have fun building!

Best,
Andy

[Againsistm]

Good to know Andy, will try. Thanks again

[Againsistm]

Hi, another question. I am also busy with the matched resistors and looking at peters video he uses auto range on his multimeter to get 2 decimals. Whatever i try with my fluke 87iii i always get 1 decimal. How are you getting 2 decimals when measuring the resistors?  I Guess it should work with a fluke right? Maybe not the right question for this board but since you are far better with electronics then me maybe you can help me. Cheers niels

Edited September 23, 2019 by enveevee

[latigid on]

Try to hold the yellow backlight button down for a second or so. At least this is how it works for my 87V meter.

[Againsistm]

25 minutes ago, latigid on said:

Try to hold the yellow backlight button down for a second or so. At least this is how it works for my 87V meter.

Thanks man! works with the 87iii as well . Still trying to get an accurate reading every time because when I try several times I still get some difference of 0.01 

[latigid on]

!! Thanks for the beer!

0.01kOhm = 0.02% of 50kOhm, so pretty well matched already. Probably the offset current of the TL074 has a larger effect, but still it is nice to try and match as best as you can. Plus, we will calibrate each analogue channel on the SEQ individually. 

[Againsistm]

Hi,
I finished building the boards and like to test them out. I order a eurorack case and psu but i did not receive them yet.
Is it possible to power all the boards with the usb power. I tried it but didn't get any Lights on the other boards. Peters video and other screens only show eurorack power so i am in doubt.
Cheers Niels 

[latigid on]

Hi Niels, you would need some sort of +/-12V power supply for the modules. Do you have any old 12V wall warts or other PSUs around? You might be able to rig up something.

Best,
Andy

[Againsistm]

Just now, latigid on said:

Hi Niels, you would need some sort of +/-12V power supply for the modules. Do you have any old 12V wall warts or other PSUs around? You might be able to rig up something.

Best,
Andy

Hi Andy, nice to know, i will make something in the meantime . What exactly is the use of the usb power on the first board?

[latigid on]

The SRIO (J8/9) and J19 SPI require some sort of +5V, the source of which is selected by J5 (or SJ5). So the USB (power only) can be one of those sources, otherwise it can be regulated down from the Eurorack +12V or passed through the DB-25 cable, though I don't recommend the latter as the wires are quite thin and there will probably be a voltage drop.

[lukas412]

Has anyone tested out the tracking on these yet? Are they better/worse than previous version of mbcv modules?

thanks,

Luke

[lukas412]

Just now, lukas412 said:

Has anyone tested out the tracking on these yet? Are they better/worse than previous version of mbcv modules?

thanks,

Luke

Ok just started watching the tutorial vid looks like its really accurate! 

[Hawkeye]

10 hours ago, lukas412 said:

Has anyone tested out the tracking on these yet? Are they better/worse than previous version of mbcv modules?

@lukas412 recently TK. came over for a visit, for a long walk and also to grab his new set of these modules! :) We performed a tracking test in conjunction with a purely digital oscillator on a MIDI controlled synth and could not really hear any problem at all over many octaves. That is, if you perform good calibration, which is explained in the video tutorial in chapter 64, here: https://www.youtube.com/watch?v=dD8VeSuTKWI&t=5561s

Have fun and many greets!
Peter

[lukas412]

Thanks Hawkeye! Just placed my order for the kits!

[Hawkeye]

@lukas412 awesome! Hope you will have lots of fun buildling and using your new modules!

Best regards!
Peter

[Againsistm]

Hi,
I installed all the modules and like to calibrate but when i power on the a1cv board all leds are all lighted red and when meassuring voltage all inputs have 5v. Do you know in what way to look? 

Gates board is working fine, only my first channel 1 led is always burning (only when connected with my midibox) but you can see it's triggering. All other channels are working like a charm.

Cheers niels

Edited September 30, 2019 by enveevee

[latigid on]

1 hour ago, enveevee said:

I installed all the modules and like to calibrate but when i power on the a1cv board all leds are all lighted red and when meassuring voltage all inputs have 5v. Do you know in what way to look? 

+5V or -5V? Inputs or outputs? You mean you can't change the voltage of the outputs?

 If you followed the tutorial, the LEDs should glow red with negative voltage. Or did you use different LEDs?

How are you sourcing the +5V on the Euroceiver? Still over USB or with the regulator/jumper?

 

From the description, I think the DAC is not outputting any voltage, so the transmute8 board defaults to the -5V offset. This could be caused by 

• no +5V power
• AOUT not configured (select module type AOUT)
• cables/improper board-to-board connections/cable in wrong J19
• missing RC1 jumpers

Even without any transmute8 board connected, you should be able to measure voltage from 0-2.048V from the output header when running through the calibration procedure.

 

1 hour ago, enveevee said:

Gates board is working fine, only my first channel 1 led is always burning (only when connected with my midibox) but you can see it's triggering. All other channels are working like a charm.

Can you measure a voltage on the jack output? Maybe the gate output is configured as inverted on the AOUT SEQ menu? You can try another octal board. Check the soldering around R1/LED1/IC1.