Berkeley III repair board checks out

[R.G.]

I got back word from the first adopter of the Berkeley III repair PCB. It works.
Whew!! :lol:

The board fits the same mounting holes as the original, has the same circuit as the original [as far as I can tell - more on that below], includes the power supply and filters on the PCB, so the chassis caps can be left there are pretty bits of "originality", not hooked up, and ... it work!

The board hooks to the same pots, jacks, etc as the original, and in general just bolts in. The wires were re-routed to one side of the PCB, not all around it, so it can be flipped up to work on the bottom/solder side when/if service is needed.

So old Berk 3s can now be fixed without poring over the old PCB. Step 1 in the replacement process is "Clip off all the old wires at the controls, unscrew the original PCB and remove it. It is no longer needed."

Well, OK, you do have to solder new parts on the PCB, but hey, that's the fun part, right??

[soundmasterg]

I got back word from the first adopter of the Berkeley III repair PCB. It works.
Whew!! :lol:

The board fits the same mounting holes as the original, has the same circuit as the original [as far as I can tell - more on that below], includes the power supply and filters on the PCB, so the chassis caps can be left there are pretty bits of "originality", not hooked up, and ... it work!

The board hooks to the same pots, jacks, etc as the original, and in general just bolts in. The wires were re-routed to one side of the PCB, not all around it, so it can be flipped up to work on the bottom/solder side when/if service is needed.

So old Berk 3s can now be fixed without poring over the old PCB. Step 1 in the replacement process is "Clip off all the old wires at the controls, unscrew the original PCB and remove it. It is no longer needed."

Well, OK, you do have to solder new parts on the PCB, but hey, that's the fun part, right??

That's awesome R.G.! I am sure that there are a lot of people that use those amps that will be very thankful for your efforts. I haven't forgotten about what I am supposed to do with the UL amp board for you. I am sorry it has taken me so long since I last reported back to you with any progress. Life and its many complications has gotten in the way, but I am still planning on getting the board up and running to test. I was able to source some of the original trem parts that were used on those amps, and I can share more of that with you in an email or PM. I'm hoping to get back to populating the board and interfacing it with my power amps that I planned to try with it before the end of the year. I'll let you know.

Greg

[R.G.]

Sounds good. Well, I hope it will

I fully understand about life happening to you while you're trying to get other things done. Do it when you can; music is for making happiness, not obligations.

Which makes for a good story. The Berk 3 board was something I did a few years ago, but was missing a few critical bits of information - like the pesky location of the hole in the dead center of the board - so it never got completely finished and prototype boards ordered. The first adopter contacted me, said he'd read about this being a possibility and wanted to get one, whatever it took. I 'splained the condition to him, that it needed some touchup and tinkering, then boards ordered, then some very brave soul to populate and test the first one, as I'm unlikely to have time to do that anytime soon. He volunteered on the spot, so a couple of weeks later the boards got ordered, and a couple of weeks after that he was soldering in parts.

Fortunately, we got the hole locations right, and there were no gross issues with the board itself. I hosed up the values on a few parts, but we got those corrected quickly, got the DC conditions set up right, and he able to fire it up.

... upon which it emitted an ear-splitting siren shriek. Oops. We dug through it for a couple of weeks and found out that there are at least two versions of the driver transformer in the Berk 3 with the same color leads but flipped polarities. The thing was shrieking because it was giving positive, not negative feedback. Flipping the two primary leads fixed that, and converted it into a real, no-fooling working Berk 3.

I found out several tidbits that are NOT in the Thomas service literature, but nothing that invalidated the board. It was a real happy thing.

So maybe there's now hope for ...my... old Berk 3 hulk that's had to wait its turn. This is starting to sound like another issue of the story of the shoemaker's children going barefoot.