More Minibrute

So, someone has been in this machine before, and rather brutally broken the connectors. This is what the connector looks like once all of the hot glue (!) has been removed. 

Looking at the other end of the 34 pin cable, I think the hot glue is original; it looks like when they manufacture these things, they hot glue the connectors as an added protection against falling apart? 

So as far as I can tell, someone wanted to get into the machine, has hacked away at the hot glue on the other end of the connection, and in the process have destroyed the connector latches. When they were done, they kind of pressed the assembly together again, hoping for the best. So unsurprisingly, the connector and socket have drifted apart, causing the beast to cease to function. This 34 pin cable is the main interface between the digital board (where the keyboard scanning, CPU, Midi etc is) and the analog board - where the sound comes from. 

Now I have implemented a hack of my own, which is not something I am too proud of but it is a bit of a bugger getting 34 pin 2mm surface mount sockets to suit - so herewith my hack ... 

It works a lot better! Not perfect, but we have some sounds. I also found what was the reason for someone having a go at getting inside the beast. The analog board is covered in a heavily corroding mess of dried diet coke. So, I am gradually working around the board with isopropyl alcohol, and a toothbrush. 

And we have some more sounds ... it kind of makes noises, seems to be largely controllable. The LFO doesn't seem to make any difference to sounds at the moment, but the keyboard all works, the filter filters, the main oscillators and vibrato, pitch bend and the amazing arpeggio all seeem to work. There is some cosmetic work as well  a couple of missing knobs, the slider knobs are all pretty worn and shabby. 

But, all in all, good news - it lives! 

Arturia Minibrute

 Struck again on an Internet auction site - this time an Arturia Minibrute. 

"Turns on but no sound" says the seller. Ah well, might be something silly. Worth a shot especially at a third of the average selling price for a second hand one. 

So, it needs the odd replacement knob or two, and its a bit scruffy. 

And there is a missing screw on the bottom plate. And all of the other screws are loose .. oh dearie me, someone else has been in here. At least it is as described, power light comes on, but nothing - like NOTHING comes out of the jack. 

I was trying to work out how to listen to it, put a short jack cable into the sound interface on the huge 27 inches of loveliness. Moving the boards around to put some insulating material between the digital and analogue boards, and I thought I saw something flash. Was that a burst of sound? Then I saw how badly mangled the "main connector" was on the digital board. Clearly someone has been in this beast before, decided to  try to get the connector out and has broken the retaining clips. Then they decided to stick the connector together with a hot glue gun - badly. 

So I have checked to see if the usual places sell a mating pair of 34 pin, 2mm IDC plugs and sockets. The quickest and most reliable thing to do would be to replace the IDC connector on the cable (using the tried and tested method of a vice to compress the connector and cable together) and replace the motherboard one. I am finding it difficult to locate one of the surface mount kind for the board though. 

Should I solder the 34 connections of the cable to the board ? 

Virtual cameras in Zoom and Teams

 Just leaving this here to remind me how to get Teams to work with an OBS virtual camera again after an update: 

*****UPDATE*****

As of version 1.3.00.28778 the process has changed and the above workaround is no longer valid.  In order to get this fix working on the latest version of Teams, additional commands will need to be entered.  Keep in mind, these commands are relative to where you have Teams installed, so if it is in a different location, you'll need to adjust the file path accordingly.  So as it stands currently here are all of the commands (must be entered one by one and not pasted in one big block) that will need to be entered:

xcode-select --install (only if you haven't already)

sudo codesign --remove-signature "/Applications/Microsoft Teams.app"

sudo codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper.app"

sudo codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (GPU).app"

sudo codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (Plugin).app"

sudo codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (Renderer).app"

Lockdown Loaf

 So, I decided during this kind of lockdown that I would have a go at breadmaking. I'd ordered up the ingredients from Sainsbury's last week just in case i felt like it. 

For today, I had put a casserole in the slow cooker this morning and I jiust fancied some olive bread to go with it, so I decided to make some. Here's my first effort at a loaf ...

New lab has a new iMac

 Well, new to me anyhow. Working all day on a small Macbook (though I love it for performance and battery life) is bad for the eyes, so I have furnished the lab with a pre-loved iMac 27 inches ... 

Access to the Lab is now improved ...

So instead of walking across a series of stepping stones embedded in mud, we now have some proper decking outside the lab. It is huge. Well done, Kris - it really does look spectacular. After this, the next steps will be some tidying up at the bottom, and the rockery / wild garden / pond .. looking forward to some post lock-down family gatherings here.

Fixed the Cambridge P500

Another one off the list of things to sort out .. turned out to be one of the darlington output transistors. They have integrated emitter resistors, and one had gone from 0.22 ohm to something in the hundreds of ohms, so it got replaced. While I was there I checked all the caps (no problems) and I replaced all of the heat sink compound, as there was pretty much none on the transistor I changed. Actually I changed both on that channel to make sure I had a matching pair. Applied power, and success! Sound in both.

There's quite a lot of discussion on t'Internet about the bias current, but I found in the spec for the trannys themselves that they recommend 40mA. So I put some meters on, looking for 17.6mV across the two 0.22 ohm resistors. They seemed to want to settle at 20.4mV which is close enough.

This is a budget amp, so I wasn't expecting too much, but the heatsink is a bit pissy and it feels cheap. The whole amp is not worth saving, really but it might do for a bench amp at a push. At least it is now off my bench so I can move on down the list of things to be repaired.