DIY Mutable Unsuccessful Builds

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: lisa, luketeaford, Kent, Joe.

Post Reply
soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Thu Jun 11, 2020 11:48 am

Yes. I'm powering it off of a MI module tester with a wall wart (I'm not sure if that's relevant information). Sorry for the lack of numbering. The one I referred to as "left" is IC6 (so 2 outputs have the normalization signal). And IC7 has one output with the normalization signal (OUTA) and the rest seem to be constant.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Thu Jun 11, 2020 11:58 am

IC6 should have normalisation signal on 3 of its outputs (pins 1, 8 and 14) IC7 should have it on pins 1 and 8.

This could be where the problem lies.

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Thu Jun 11, 2020 1:14 pm

cnicht wrote:
Thu Jun 11, 2020 11:58 am
IC6 should have normalisation signal on 3 of its outputs (pins 1, 8 and 14) IC7 should have it on pins 1 and 8.

This could be where the problem lies.
I've checked IC6 and all outputs are as expected after I reflowed the pins again. IC7 is still missing the signal on pin 8. Also, the input and output of IC8 read as ~0V as well. I've checked the surrounding components for continuity and can't find anything wrong. I might be doing something wrong? I'm not sure.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Thu Jun 11, 2020 2:15 pm

If there's 0V on the inputs of IC8 there'll be 0V on its outputs.

What are the actual voltages on the outputs of IC6 and 7 if you cut out the normalisation signal?

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Thu Jun 11, 2020 3:03 pm

Sorry, should have been clearer... I was worried I had fried IC8 when I put it down initially because of a short that I removed when first troubleshooting the thing myself (hence the obvious 0V comment). Cutting out the normalization signal:

IC6 has pin 1 = 2.79V, pin 7 = 3.28V, pin 8 = 2.99V, pin 14 = 1.63V
IC7: pin 1 = 1.65, pin 7 = 2.35, pin 8 = 3.27V, pin 14 = 3.28V

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Thu Jun 11, 2020 4:01 pm

The calculated voltages should be IC6 1 = 2.8V 7 = 1.65 8 = 1.66 14 = 3.0V IC7 1 = 1.66V 7 = 2.35V 8 = 1.66V 14 = 1.65V

There will be some small discrepancies between the measured and calculated but it appears that some of the op amps are in saturation which is indicative of unconnected components around them.

Check soldering.

intropod_
Learning to Wiggle
Posts: 17
Joined: Wed Jun 21, 2017 9:28 pm

Re: DIY Mutable Unsuccessful Builds

Post by intropod_ » Sun Jun 14, 2020 6:50 pm

Question about Elements: Does the FM knob affect the tone at all if there is nothing plugged into the FM jack?

I have a board that I built myself, and the affect from the unplugged jack / FM knob twisting combo doesn't match up with what I see in VCV rack. I'm not sure if the problem is with my board, or the VCV implementation.

In VCV, the knob does not affect sounding without anything plugged in. But, if you take a dual attenuverter (for instance), and pump a constant voltage into the FM jack, it sounds quite like the physical unit I have (except with nothing plugged into FM in my case).

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Mon Jun 15, 2020 10:36 am

cnicht wrote:
Thu Jun 11, 2020 4:01 pm
The calculated voltages should be IC6 1 = 2.8V 7 = 1.65 8 = 1.66 14 = 3.0V IC7 1 = 1.66V 7 = 2.35V 8 = 1.66V 14 = 1.65V

There will be some small discrepancies between the measured and calculated but it appears that some of the op amps are in saturation which is indicative of unconnected components around them.

Check soldering.
I've resoldered all the surrounding components, reflowed the op-amp, cleared the flux off the board. I've continuity-tested the entire line and connected components, and they're registering as connected, albeit with a very high resistance. What resistance should I be reading from pins 8 and 14 on IC7 to the signal pin on their jacks? Do you have any advice?

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Mon Jun 15, 2020 11:16 am

This isn’t the correct measurement to take.

You should measure the voltages at the outputs of the op amps.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Mon Jun 15, 2020 11:20 am

Also components cannot be connected if they’re registering ‘a very high resistance’.

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Mon Jun 15, 2020 12:44 pm

cnicht wrote:
Mon Jun 15, 2020 11:20 am
Also components cannot be connected if they’re registering ‘a very high resistance’.
I have been measuring the voltages. I was curious if there was another metric I could use to pinpoint the problem, as I have tried resoldering everything that's linked to the pins including removing, desoldering/cleaning the pads, and then resoldering. The resistances are in the Mohm range (and I can see why it was a bad way of determining connectivity), so I will stop including that information.

I'm still running into the floating outputs at pin 8 and 14. The grounded inputs are reading properly, and the input on pin 8 is at 0V and the input on pin 13 is at 0.6V. All other output pins have resolved to the correct values, excluding the two I'm still struggling with.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Mon Jun 15, 2020 4:27 pm

Pins 8 and 14 of IC7 shouldn't be at saturation, do you see varying voltage on these pins if you patch an LFO into either the Morph or Harmonics inputs?

The only possibilities are that there's a bad connection or IC7 is damaged (although this I think is unlikely)

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Tue Jun 16, 2020 12:40 pm

cnicht wrote:
Mon Jun 15, 2020 4:27 pm
Pins 8 and 14 of IC7 shouldn't be at saturation, do you see varying voltage on these pins if you patch an LFO into either the Morph or Harmonics inputs?

The only possibilities are that there's a bad connection or IC7 is damaged (although this I think is unlikely)
I plugged in an LFO and saw no change in voltage on the pins, so it's either of the two things you mentioned. Both still read ~3.3V at each output.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Tue Jun 16, 2020 3:31 pm

To check the soldering of IC pins I use the tip of the tweezers and very carefully try to push the pins to one side. It often shows up any unsoldered pins which look soldered.

If you do this it will be entirely at your own risk.

soupspoon
Learning to Wiggle
Posts: 20
Joined: Thu May 28, 2020 3:45 pm

Re: DIY Mutable Unsuccessful Builds

Post by soupspoon » Fri Jun 19, 2020 10:29 am

cnicht wrote:
Tue Jun 16, 2020 3:31 pm
To check the soldering of IC pins I use the tip of the tweezers and very carefully try to push the pins to one side. It often shows up any unsoldered pins which look soldered.

If you do this it will be entirely at your own risk.
Thanks for the tip! The good news is that nothing bent or broke. The bad news is that the legs on the IC are properly soldered because none of them moved.

User avatar
cnicht
Veteran Wiggler
Posts: 699
Joined: Mon Sep 23, 2013 9:23 am

Re: DIY Mutable Unsuccessful Builds

Post by cnicht » Fri Jun 19, 2020 1:33 pm

Post some high resolution photos of your board?

Still Sound
Learning to Wiggle
Posts: 8
Joined: Tue Jun 23, 2020 11:39 pm

Re: DIY Mutable Unsuccessful Builds

Post by Still Sound » Tue Jun 23, 2020 11:44 pm

Hey guys,

New uBurst build doesn't seem to boot.

When powered, all 4 LEDs just light up, and stay lit orange.

Could anyone point me in a direction to start troubleshooting?

I've built the AI OTA VCF, Turing MKII, RYK M185, and Ornament and Crime. All function, but unfortunately I'm not well versed on electronics.

Any help would be greatly appreciated!

Thanks!

Tony

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: DIY Mutable Unsuccessful Builds

Post by Altitude909 » Wed Jun 24, 2020 5:35 am

sounds like you didnt flash the bootloader and the program

Still Sound
Learning to Wiggle
Posts: 8
Joined: Tue Jun 23, 2020 11:39 pm

Re: DIY Mutable Unsuccessful Builds

Post by Still Sound » Wed Jun 24, 2020 12:49 pm

Altitude909 wrote:
Wed Jun 24, 2020 5:35 am
sounds like you didnt flash the bootloader and the program
Thanks alot.

I didn't receive any build or programming instructions, so I don't even know where to hook an ST Link up.

From what I've seen, most modules have a 4 pin header to connect to. This doesn't.

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: DIY Mutable Unsuccessful Builds

Post by Altitude909 » Wed Jun 24, 2020 1:13 pm

it uses the microjtag header, you'll need an adapter for the STlink. you can build the binaries and program in the vagrant VM or just download them and program with the STlink software

Still Sound
Learning to Wiggle
Posts: 8
Joined: Tue Jun 23, 2020 11:39 pm

Re: DIY Mutable Unsuccessful Builds

Post by Still Sound » Wed Jun 24, 2020 2:47 pm

Altitude909 wrote:
Wed Jun 24, 2020 1:13 pm
it uses the microjtag header, you'll need an adapter for the STlink. you can build the binaries and program in the vagrant VM or just download them and program with the STlink software
Thanks alot.

Not really looking to spend more money on a module that may not work.

I think I'll just scrap this, and get an Arbhar.

Thanks for your help.

Tony

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: DIY Mutable Unsuccessful Builds

Post by Altitude909 » Wed Jun 24, 2020 2:57 pm

well it sounds like it works, its powering up. The 4 lit LEDs are how its supposed to look like before you upload code to it, not sure why you would toss it at this stage. There is no option to uploading code, you're going to have to do that on any MI diy project unless you get a preflashed chip

Still Sound
Learning to Wiggle
Posts: 8
Joined: Tue Jun 23, 2020 11:39 pm

Re: DIY Mutable Unsuccessful Builds

Post by Still Sound » Wed Jun 24, 2020 3:11 pm

Altitude909 wrote:
Wed Jun 24, 2020 2:57 pm
well it sounds like it works, its powering up. The 4 lit LEDs are how its supposed to look like before you upload code to it, not sure why you would toss it at this stage. There is no option to uploading code, you're going to have to do that on any MI diy project unless you get a preflashed chip
I'm sorry. I misunderstood.

If the orange LEDs say we are good to go at this stage, I'll keep moving.

Thanks

Still Sound
Learning to Wiggle
Posts: 8
Joined: Tue Jun 23, 2020 11:39 pm

Re: DIY Mutable Unsuccessful Builds

Post by Still Sound » Thu Jun 25, 2020 6:21 pm

Altitude909 wrote:
Wed Jun 24, 2020 1:13 pm
it uses the microjtag header, you'll need an adapter for the STlink. you can build the binaries and program in the vagrant VM or just download them and program with the STlink software
Is this the correct adapter?

https://www.mouser.ca/ProductDetail/Oli ... dijQ%3D%3D

Thanks again

User avatar
Altitude909
Super Deluxe Wiggler
Posts: 3401
Joined: Wed Aug 24, 2011 5:13 pm
Location: Meesheegan

Re: DIY Mutable Unsuccessful Builds

Post by Altitude909 » Thu Jun 25, 2020 6:25 pm

Yup. Dont forget the little header, I dont even bother soldering those in, just use friction

Post Reply

Return to “Music Tech DIY”