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Messages - mjg

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General Questions / Re: Anyone built the Parasit Bitbreaker deluxe?
« on: August 27, 2023, 03:47:43 PM »
As some troubleshooting, maybe get a hex file that does something obvious, like flash a led on and off on one pin, and see if you can get that to work with the chip.  If you succeed at that, your upload process is good and should work with any hex. 

General Questions / Re: Why is my Op Amp smoking?
« on: July 03, 2023, 03:48:22 PM »
I was going to suggest peer pressure, because it thought it would make it look cool?  But yeah, the resistors might do it too  ;)

Global Annoucements / Re: Shipping delay/accident
« on: June 16, 2023, 04:24:20 PM »
That sounds like a pretty crap experience all round, wishing you a full recovery Brian.  Take it easy.

Open Discussion / Re: Vintage Lego electronics content
« on: June 07, 2023, 04:06:49 PM »
Mate, if you get that up and working, I'll give you guys $200 right now.  Who does your missus work for - Vinnies or Salvos?

It’s not Vinnies or Salvos, it’s a local charity in Canberra.  They do re-homing of kids clothes, prams, car seats, toys etc to families who need it.

The Lego sale they did last year was fricken amazing.  There was 3 to 4 tonnes of loose Lego, and they also had hundreds of box sets donated to sell. 

Have to say, I didn’t know that sitting in a bathtub and getting buried in Lego up to my neck was on my bucket list, but it’s ticked off now anyway.  Have to take these opportunities when life throws them at you.  ;D

Open Discussion / Vintage Lego electronics content
« on: June 06, 2023, 09:41:30 PM »
Figure this might interest some people here - some 30 year old Lego Technic, with electronics in need of some TLC.

My partner works at a charity, and they have a big 2nd hand Lego sale to raise funds.  I'm helping out by checking some of the kits before they are ready to sell, and came across this one:

It's got connections and controls for 3 motors, and you can program in a sequence of movements to be replayed later.   Pretty neat for its age. 

The heart always falls when you pick it up and can feel the weight of 30 year old batteries still inside. Sure enough, the batteries had leaked and corroded, all over the place. This is usually not something we can sell, especially when they have leaked this badly. This will usually have ruined circuits underneath.

One of the 'C' size culprits:

Some of the damage:

However, I have to admire the design of this controller - the battery bay was almost completely sealed from the other circuitry, with only a tiny amount of leakage getting through to the back of the PCB. The front of the PCB has no damage at all.  There's a little Motorola chip doing the work. 

Hot wiring the controller to a 9v supply shows that everything still functions.  Success!  (Yes, that's my pedal tester doing the heavy lifting, lol)

I managed to pull the battery contacts out and cleaned them off with a small flat screwdriver, and some vinegar. Once I got the corrosion off, it became obvious that the metal has been eaten almost through. You can see daylight through some bits. This isn't going to be useable with these contacts. 

I've ordered some new battery contacts and will put them into place once they arrive. The kit will then go to some lucky person at the sale (it should sell for $200 or so we hope).

Usually we don't have to go to these lengths for a kit, but it was worth it for the potential value vs the fix (and my time, but whatever, I'm having fun).

It was already April 1st in Aus and NZ when they posted it…checks out.

 I’ll have to watch it later, Emily is hilarious.

Open Discussion / Re: Finally leveled up.
« on: March 18, 2023, 03:49:45 PM »
Nice work Jimi!

Open Discussion / Re: When you have a teenage daughter.
« on: January 27, 2023, 12:32:18 AM »
My current trigger is the empty icy pole packets and soft drink bottles littering my kid’s bedroom floor.   The bin is … right … there…

Open Discussion / Re: Cusack's production facility
« on: January 08, 2023, 02:52:40 PM »
I was amazed at the size…how many pedals do you produce per year?

Open Discussion / Re: Merry Christmas I hope you all are warm and safe.
« on: December 25, 2022, 03:33:28 PM »
Those waffles are excellent.  😁

Happy Xmas, I’ll send warm thoughts to all in the northern hemisphere.  It’s fricken hot here. 

General Questions / Re: mitigating noise via ground plane isolation
« on: October 30, 2022, 03:04:38 PM »
 Yeah, that screenshot looks good.  Worth a try anyway!

For the cap on pin 5, given that’s to keep the output negative voltage steady, it probably wouldn’t hurt to put a 100u and a 1u in parallel. Looks like you’d have room to fit both on your layout. 

Anyway, just another hack here, but hopefully this helps :D

General Questions / Re: mitigating noise via ground plane isolation
« on: October 29, 2022, 03:37:35 PM »
An approach I’ve seen is to not put any ground plane underneath the charge pump.  Keep that area of the board completely clear. 

You could also try the LT1054 instead of the 7660, but beware the difference on pin 1.

Not sure if it will help, but if you’re willing to try out ideas put them on the list?

Build Reports / Re: The J.Scott Special
« on: October 29, 2022, 12:39:48 AM »
Cool.  It took me a while to work out what the MBP “Mad Bean Pedals” knobs did.  Got there eventually.  ;D

Hopefully it continues to improve for you.  They really can do amazing stuff with spinal surgery these days.  Best wishes for the recovery.

General Questions / Re: Dirtbaby blend question
« on: October 18, 2022, 02:25:17 PM »
Not sure that the buffers would help, but worth a try.

I think the reason you are going to get some signal is that the blend pot is 10k, so at most you are adding a 10k resistor in the signal path.

First thing that popped into my head, If you really want to kill the signal from one or the other, maybe expose T1 which will let you completely turn down the wet, and do a similar pot to ground for the dry signal, which would let you completely turn down the dry…and sum those together with an op amp.  It means you have an extra control to fiddle with, but it would definitely let you control the mix all the way to silence from either side.

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