Well this is frustrating ...

[Deke609]

Success! Success! Success!

The breadboard of the stock Beepre took forever but it worked! Hooked it up to the SII-45 and NO HUM!!!!  And look at the thing! A complete rat's nest - an invitation for hum at every turn.  And there was no question it was working and producing sound b/c the microphonics of the rat's nest build were crazy (but clear, without buzz or hum -- just that beautiful Beepre "ping" and resonance)

So something went wrong in the previous iteration of my Beepre - I again suspect a short somewhere caused by a metal shard (swarf from all the drilling). But who knows -- and frankly, at this point, who cares.  Now I can turn my attention to doing some proper breadboarding and then begin the actual rebuild in the new and bigger alumininum chassis (with CLCLC HV filter, dedicated LV trafos with CLC filters before the LM1085 board, cooling fans, snubbers, tons of copper shielding, and giant Nichicon 22mF 80V cathode resistor bypass caps -- in short: the works!) 

I am a happy guy tonight 

cheers, Derek

[grufti]

It looks like you took me up on the Wago clips. Aren't they just amazing for prototyping? You bought a bunch!

[Deke609]

It looks like you took me up on the Wago clips. Aren't they just amazing for prototyping? You bought a bunch!

I did indeed! I picked up a cheaper knock-off version after you posted about them. I think it was a 75-pack, most of which are doubles that are only good for connecting 2 wires. They work really well. What I most like about them is that you don't have to clip the leads of components and so everything is reuseable for the permanent build.

cheers, Derek

[EricS]

Congrats, Derek!  I've had a few problems over the years from stray single strands of wire, curly aluminum corkscrews, or a rogue solder bead that rattled around inside the chassis.  I have found an air compressor to be a useful device before final assembly.

Now the fun starts of getting it back into a chassis.  This is where I am, just now ordered the aluminum top plates after being tied up with work for weeks.

[Deke609]

Thanks Eric! Yeah, now the real fun begins. I've got a lot of metal work to do. And still need to settle on a layout. I think I'll build it in a wooden enclosure before making any cuts in the new aluminum.

cheers, Derek

[Deke609]

And +1 to PB's trick of using flat ceramic 4 pin sockets for breadboarding (mentioned in Eric's 300B build thread). As PB mentioned, you can insert 4 pin tubes from the bottom. Just remember to swap left and right pin wiring - maybe not such a big deal for pins 1 and 4 (filament) if you're using AC heating, but you don't want to mix up grid and anode! 

cheers, Derek