What’s on *YOUR* workbench?

KR Sound said:
I fixed this dude today for my friend. The cymbals and high hats weren’t working and the toms had a decent hum.

It’s a Korg Rhythm 55 or KR55 drum machine.

It sounds exactly like it looks.

View attachment 93590

Opened it up and found some corrosion that had affected several joints and grounds. I even replaced an IC that was known to have been a culprit sometimes just in case. Replace a few caps that were in the corrosion and removed as much of the green stuff as I could. I had to make some wire runs to connect where the traces had been obliterated.

Main corrosion in the cymbal/high hat circuit:
View attachment 93591

Corrosion on ground and input cap:
View attachment 93592

My repair:
View attachment 93593

Upper board with new IC10:
View attachment 93594

Lower board was fine.
View attachment 93595
Click to expand...
What caused the corrosion just on that one spot, leaky cap?
 
jimilee said:
What caused the corrosion just on that one spot, leaky cap?
Click to expand...

Good question. I took that 10u cap out and it measured 16u. I’m surprised it even registered. And the 10u at the power input still registered 10, but had corrosion on one leg so it got replaced as well.

My friend said the seller told him it had been sitting around for 20 years probably. I did find a dead cockroach in there ¯\_(ツ)_/¯

That was the culprit, right next to IC9:

IMG_1693.jpeg

I also like how they locked down the trimmers after they were set. Or variable resistors?
 
lowpitch said:
How does it compare to the more common BJT treble boosters? Rangemaster, Brian May Booster, Naga Viper and what have you.
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I only have a Rangemaster. With Range set to zero they sound similar. But once you start turning the Range pot the sound gets warmer, fuller.
Also - there's a bit more grit with the Omega. And a bit more hiss. Omega has higher output level than my Rangemaster.

KR Sound said:
I forget what you’re using to shield your I/O wires. Do you find it makes a difference? Well obviously you do, or else you wouldn’t it. Anyway, I need more coffee.
Click to expand...

It's Tasker microphone shielded cable (C118). I use shielded cables out of habit. I used to make a lot of high-gain preamps where shielding was definitely recommended. And that's how it stayed... it's hard for me to say now if there's a difference because I don't use anything else :)


Thanks for your comments!
 
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First test bend with the press brake. Right out the gate I’m trying to work with 3d printed dies to achieve a mar-less bend as I would like to work with stainless steel. The die is made with regular pla 100% infill. It surpassed my expectations and seemed to have left no marring. This is looking promising! Now to calibrate the machine for accuracy and I’m going to try a full sequenced bend operation! IMG_3756.jpeg
 
So, an update on my post of last week about totally overhauling my rig to use most of my DIY pedals and run everything on a MIDI switcher. I figure I will be finished with this project around 2027 or so.

The controller and the three loop boxes arrived. I built a stand to hold all the pedals (it started life as 3 stackable shoe racks from Walmart that I glued and bolted together and then fortified with mending braces at all the joints. I put silicone tape on the slats to try to keep everything from sliding around.

IMG_5126.jpeg

Now I’m in the midst of all the wiring. So much freaking wiring. I purchased about 160 feet of cabling from Redco and I’m in the middle of creating and routing 72 (!) cables and power. So many freaking cables. And I’m really really slow. Anyway, I ran out of jacks and so had to take a break until my shipment from Tayda gets here tomorrow.

IMG_5125.jpeg

In the downtime, I worked on baking the decals for my next three pedals – an AionFX Lumitron (Mutron III), a PPCB ABY box, and a PPCB Triad Distortion (just a Rat with mods, but my first Rat).

IMG_5127.jpeg

Mike
 
And the award for Most Variety in Capacitor Choice goes to....
1000006671.jpg
I did it on purpose... There's more toan in the number of colors and compositions of caps you use!
Finally getting back to building after a few hellish weeks. KOing some @jessenator PCBs.
Didn't realize the 2 Mylanta caps on the top left were MLCC until after I soldered them. They're CGW though so I may let them stay if they behave.

That's all for tonight. One more (missed) film and electros and pots tomorrow.
 
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