uO_c 8hp ornament and crime.

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Altitude909
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Re: uO_c 8hp ornament and crime.

Post by Altitude909 » Tue Jun 16, 2020 4:12 pm

half of U10 doesnt appear soldered and the top of U4 looks suspect

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Re: uO_c 8hp ornament and crime.

Post by Bartimaeus » Tue Jun 23, 2020 12:10 pm

anyone in the usa got a spare pcb/panel set?

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Re: uO_c 8hp ornament and crime.

Post by emmaker » Tue Jun 23, 2020 4:49 pm

Bartimaeus wrote:
Tue Jun 23, 2020 12:10 pm
anyone in the usa got a spare pcb/panel set?
https://synthcube.com/cart/index.php?ro ... ption=true

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Faye
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Re: uO_c 8hp ornament and crime.

Post by Faye » Thu Jun 25, 2020 4:31 pm

Quick question regarding the version 1.1 PCB: In the diptrace file the capacitors C22, C25, C26 and C27 are 330pF, while in the BOM they are 560pF.
Which is correct?

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Re: uO_c 8hp ornament and crime.

Post by emmaker » Thu Jun 25, 2020 8:28 pm

Faye wrote:
Thu Jun 25, 2020 4:31 pm
Quick question regarding the version 1.1 PCB: In the diptrace file the capacitors C22, C25, C26 and C27 are 330pF, while in the BOM they are 560pF.
Which is correct?
Even though the O&C and uO&C are different either. Look at the original O&C schematics.

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Re: uO_c 8hp ornament and crime.

Post by Faye » Fri Jun 26, 2020 1:02 am

Thx

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Re: uO_c 8hp ornament and crime.

Post by Faye » Sat Jun 27, 2020 4:31 pm

So I just finished soldering most components on uO_c. Teensy, screen and hardware are not mounted yet.
First I want to measure some voltages. When I look at the schematics, I'm having a hard time to recognize what is supposed to be a reference voltage exactly. Is it only the voltages labeled with "Aref"? What about "3V3_A (powa)" and "3v3+D" as example? Should my multimeter read 3.3v too on these points at any time when the module is powered?

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Re: uO_c 8hp ornament and crime.

Post by emmaker » Sat Jun 27, 2020 5:38 pm

Faye wrote:
Sat Jun 27, 2020 4:31 pm
So I just finished soldering most components on uO_c. Teensy, screen and hardware are not mounted yet.
First I want to measure some voltages. When I look at the schematics, I'm having a hard time to recognize what is supposed to be a reference voltage exactly. Is it only the voltages labeled with "Aref"? What about "3V3_A (powa)" and "3v3+D" as example? Should my multimeter read 3.3v too on these points at any time when the module is powered?
Schematic isn't done well and sucks (or at least the one I have does). Looking at this saw the node of C20, C19 and R13 isn't connected to VREF_2v5 from U2.

When powered with out the Teensy you should be able to measure:
  • +/-12V, about +/-11.4 past the diode bridge.
    +5V
    3V3_A
    AREF_-5, this is from U6
You will not be able to measure:
  • 3V3+D - It comes from the Teensy, won't be there until the Teensy is plugged in. Don't forget to cut the power trace on the Teensy before you plug it in.
    V_bias - This will probably won't be there. It's unclear from the data sheet where VREF_2v5 comes from in the DAC8565 (U2). If it needs 3v3+D it won't be there.
Jay S.

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Re: uO_c 8hp ornament and crime.

Post by emmaker » Sat Jun 27, 2020 5:40 pm

emmaker wrote:
Sat Jun 27, 2020 5:38 pm
Faye wrote:
Sat Jun 27, 2020 4:31 pm
So I just finished soldering most components on uO_c. Teensy, screen and hardware are not mounted yet.
First I want to measure some voltages. When I look at the schematics, I'm having a hard time to recognize what is supposed to be a reference voltage exactly. Is it only the voltages labeled with "Aref"? What about "3V3_A (powa)" and "3v3+D" as example? Should my multimeter read 3.3v too on these points at any time when the module is powered?
Schematic isn't done well and sucks (or at least the one I have does). Looking at this saw the node of C20, C19 and R13 isn't connected to VREF_2v5 from U2.

When powered with out the Teensy you should be able to measure:
  • +/-12V, about +/-11.4 past the diode bridge.
  • +5V
  • 3V3_A
  • AREF_-5, this is from U6
You will not be able to measure:
  • 3V3+D - It comes from the Teensy, won't be there until the Teensy is plugged in. Don't forget to cut the power trace on the Teensy before you plug it in.
  • V_bias - This will probably won't be there. It's unclear from the data sheet where VREF_2v5 comes from in the DAC8565 (U2). If it needs 3v3+D it won't be there.
Jay S.

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Faye
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Re: uO_c 8hp ornament and crime.

Post by Faye » Sat Jun 27, 2020 7:40 pm

@emmaker thanks so much for the detailed reply. I'm so glad that I asked, instead of starting to look for bad soldering. In this case, everything is fine on my module and I can proceed with the build. :) Thank you!

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Re: uO_c 8hp ornament and crime.

Post by apfEID » Tue Jul 14, 2020 6:15 pm

I have a fully built and working uO_C 8hp, but it doesn't have the standoffs between the main board and the front panel near the top of the screen, so anytime a button is pressed, the screen moves away from the panel, etc, which isn't great, but looking at it out of the rack, holding the ends of the panel and pushing in the encoder, it's really the panel bending not the pcb so maybe it's not super important.

I'd like to fix this, what parts do I need? I already tried to order them based on looking at a parts list but now that I have what arrived, I don't see any way to get them to stay in place, as there's nothing for the screws to latch into...
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Re: uO_c 8hp ornament and crime.

Post by Altitude909 » Wed Jul 15, 2020 5:39 am

use the parts in the BOM or equivalent parts, if you didnt use the standoffs from the start, you will need to remove the display otherwise you wont be able to get the height right

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Re: uO_c 8hp ornament and crime.

Post by apfEID » Wed Jul 15, 2020 8:41 am

I already tried to do that myself but I didn’t succeed at buying the right parts so if someone can point me at exactly the parts to buy for that aspect of the build, I’d be grateful.

I have washers, standoffs, screws, but nothing that the screws could grip to stay in place.
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Re: uO_c 8hp ornament and crime.

Post by KittenVillage » Wed Jul 15, 2020 8:57 am

You may be able to get M3 or M2.5 nuts from a local hardware store. (I've found them at Home Depot in the states.)


apfEID wrote:
Wed Jul 15, 2020 8:41 am
I already tried to do that myself but I didn’t succeed at buying the right parts so if someone can point me at exactly the parts to buy for that aspect of the build, I’d be grateful.

I have washers, standoffs, screws, but nothing that the screws could grip to stay in place.


Eurorack is an exercise in delayed desire.

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Re: uO_c 8hp ornament and crime.

Post by cau5tik » Sat Jul 18, 2020 6:59 pm

I hope it's OK that I ask a question about the full-size O_C here, but this is the thread I could find in the DIY forum and this piece seems to be the same between the two. I'll make references to the uO_C schematic to try to keep this as on topic as possible.

I'm pretty new to this, so please let me know if I'm in the wrong place or need to do more legwork before asking questions. I couldn't find an existing answer to this question.

According to the voltage reference screenshot in the O_C build guide I should be seeing 5V across R39 (2K), which represents the -5V offset from the LM4040 (U6). However, I'm seeing 7V across R39. All of the other checks in that linked image are reading properly.

I've gone ahead and replaced R39, and reflowed C28 and C23, and U6. This hasn't made a difference. I'm seeing 12V over C28 and 5V over C23. The LM4040 has one side with one leg and one side with two. If I measure across both legs on the side with two, I get 5V. I've attached a picture of my board. I've also double checked my parts to verify that I did buy the 5V LM4040.

My questions are:
  • According to the O_C build guide, it seems like I should be seeing 5V across R39 and 7V across C23. Is that correct?
  • Am I measuring across the LM4040 properly?
  • I read in the datasheet for the LM4040 that the max soldering temp is supposed to be 500F, but my iron had been set to 650. Could I be that I've fried it?
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Re: uO_c 8hp ornament and crime.

Post by emmaker » Sat Jul 18, 2020 7:42 pm

cau5tik wrote:
Sat Jul 18, 2020 6:59 pm
I hope it's OK that I ask a question about the full-size O_C here, but this is the thread I could find in the DIY forum and this piece seems to be the same between the two. I'll make references to the uO_C schematic to try to keep this as on topic as possible.

My questions are:
  • According to the O_C build guide, it seems like I should be seeing 5V across R39 and 7V across C23. Is that correct?
  • Am I measuring across the LM4040 properly?
  • I read in the datasheet for the LM4040 that the max soldering temp is supposed to be 500F, but my iron had been set to 650. Could I be that I've fried it?
viewtopic.php?f=17&t=160325&hilit=Ornament+and+Crime

You can tell you're using the uO&C schematics because of the designators, bad idea, the circuits are slightly different.

You aren't measuring things properly. You are measuring across the 2K resistor and what you are reading is correct. You have ~-12V on one end and -5V at the other so the difference is going to be ~7V. Put your DVM gnd/minus end on ground and measure both ends of the 2K resistor with the positive lead. One should be ~-12 (-12 with a diode drop 0.6/0.7V) and the other should be -5V.

Most solder we use wants 650F and as long as you didn't hold the iron on the part for an extended period of time it should be fine.

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Re: uO_c 8hp ornament and crime.

Post by cau5tik » Sat Jul 18, 2020 8:00 pm

Thank you so much for the reply!

I tried using the designators from the uO_C schematics since there aren't designators on the O_C. I've definitely followed the O_C BOM/guides.

I can see how I was measuring improperly now! When I look closer at the voltage test points on the O_C build guide I can see that the arrows on that photo are indicating a certain side of the various components there. I thought I was supposed to be measuring across those components rather than measuring between a certain end of the component and ground. That makes a lot more sense!

Thanks again! :D

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Re: uO_c 8hp ornament and crime.

Post by bawbag » Sat Jul 18, 2020 9:54 pm

Regarding the BOM, is there any particular reason why the 1uF MLCC caps are recommended as 50v? I have 25v caps on hand, but I'm unsure as to their suitability.

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Re: uO_c 8hp ornament and crime.

Post by charonme » Thu Aug 27, 2020 11:43 am

My uO_c PCBs didn't have pads for the supervisor and the pogo pin, so I had to resort to this:
Image
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Heptaphasis - DIY 3HP 7-phase quadrature sine LFO

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Re: uO_c 8hp ornament and crime.

Post by col » Thu Aug 27, 2020 4:28 pm

charonme wrote:
Thu Aug 27, 2020 11:43 am
My uO_c PCBs didn't have pads for the supervisor and the pogo pin, so I had to resort to this:
Image
Interesting, I wonder if that will work on Radio Music?

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Re: uO_c 8hp ornament and crime.

Post by charonme » Sat Aug 29, 2020 10:42 am

col wrote:
Thu Aug 27, 2020 4:28 pm
Interesting, I wonder if that will work on Radio Music?
It should, does radio music have similar startup issues like uO_c?
spotify, bandcamp
Heptaphasis - DIY 3HP 7-phase quadrature sine LFO

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Re: uO_c 8hp ornament and crime.

Post by col » Sat Aug 29, 2020 7:23 pm

charonme wrote:
Sat Aug 29, 2020 10:42 am
col wrote:
Thu Aug 27, 2020 4:28 pm
Interesting, I wonder if that will work on Radio Music?
It should, does radio music have similar startup issues like uO_c?
Yes, I have two of them (Radio Music) and they won't start in a Arturia Rackbrute 6U, they start fine in my DIY case with a linear PSU though. I got a couple of spare mic803 on my last Mouser order, will give it a go.

is the resistor soldered to a pad?

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Re: uO_c 8hp ornament and crime.

Post by charonme » Sun Sep 06, 2020 1:07 pm

col wrote:
Sat Aug 29, 2020 7:23 pm
is the resistor soldered to a pad?
yes, the white cable leg is soldered to the reset pad as per the uO_c schematic
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Heptaphasis - DIY 3HP 7-phase quadrature sine LFO

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Re: uO_c 8hp ornament and crime.

Post by snowtires » Sun Sep 06, 2020 4:53 pm

Anyone have extra pcbs for sale? I can't find one for the uO_c anywhere

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Re: uO_c 8hp ornament and crime.

Post by emmaker » Sun Sep 06, 2020 5:33 pm

snowtires wrote:
Sun Sep 06, 2020 4:53 pm
Anyone have extra pcbs for sale? I can't find one for the uO_c anywhere
Depending on what panel you want Synthcube might. Their website isn't that great for looking this up. For example they don't have board+panel but do have boards and panels separately for the same price as the combo.

https://synthcube.com/cart/index.php?ro ... ption=true

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