500 series blue face 1176 rev A - Help thread

[Electrobumps]

Always measure resistor with DMM before populating with alligator clips to the resistor leads. Don't touch leads with your fingers while measuring because your body can add resistance. Resistance will change in circuit most of the time meaning trying to measure once soldered to board could give you inaccurate reading. One would have to lift a leg of the resistor to get accurate reading in circuit. Not ideal. Just be familiar with color code you should be fine. https://eepower.com/resistor-guide/resistor-standards-and-codes/resistor-color-code/# Carbon Composition 5% at best.

I like to use a multifunction tester. I find it much quicker and easier than a DMM for testing parts. They are all over Ebay, Amazon and Ali express. That is a US link but you will easily get one in Germany.

https://www.amazon.com/Treedix-Tran...DAifQ==&sprefix=TC1+component+,aps,143&sr=8-2

 

[roofRob]

So, here I am- trying to squeeze in way too big a part I:



I guess it can be wired in/above place with wrapped resistor-legs, once psC4b and its neighbour have been relocated to the bottom side of the PCB…



squeeze in way too big a part II- I guess, it‘s hopeless (unless brute force stripped off the case):



and so I‘ll wander off asking to buy in the black market…

 

[roofRob]

Hey!
I was trying to be extra smart (which I also know I‘m not, d‘uh) and soldered R64 from the bottom (and also before the switches like the manual says).
Now it appears the solderbulb might touch the casing of the 20 ratio switch, but I can‘t really tell…

What would that connection yield? Sound (hum, noise, explosions in the sky) or nothing to worry about?

From the looks in the manual it might already be the same situation, though the resistor is sitting on the pcb top side between the switches…

 

[sam system-d]

Hi there,
Has anyone been in touch with David lately ?
I can't get in touch with him although I ordered a U76A last mounth, so far no answer, no news from him.
I was looking at his schematics, I can't find anything explaining his +30v/-10v board. If you can help me there I can probably try to design my own pcb.
Thanks.

 

[roofRob]

Awesome!
So after a year long hiatus, where everything else was more important and also the long awaited DC/DC converter had arrived twice, I could finally finish the build and it turned on and play immediately!
Very rewarding...

The only bummer being the small knobs, I had ordered from Hairball, are too big- at least for input/output next to each other. I found what I think are even smaller ones somewhere else and will order in the near future.

But the unit is working so far.
Bucketlist check.

 

[MiamiBoy]

Daaaamn..! No, those are wrong. Looks like they're the ones for the full size rack version.
I see that the kit doesn't include the small knobs anymore. That's where I got mine from.

 

[roofRob]

Yeah well, that had been the case since I've had the very first look. But I was actually under the impression I'd just needed to order the small knobs extra- which are still too big apparently.
Whatever- I found some elsewhere.

 

[MiamiBoy]

Okay. If you look at mine, those are the correct sizes. They’re about the same size wide, as the hex-nut below it (see pic).
I’m glad you found them elsewhere