What's on the workbench?

[Robert]

@Robert, I am curious about the Fumble pcb's that JHS was giving out. Did you have any communication with JHS, or did they just order a bunch of PCBs?

It was mentioned but I'm not sure that it has actually happened yet.

 

[Feral Feline]

Hmm so ...

 

[Robert]

This one has been a real treat. FTT goes above and beyond, as always.

The (three) boards are littered with traces that go nowhere. They snake around a bit, then just end.

 

[falco_femoralis]

Are they meant to be a ground trace in lieu of a plane to prevent parasitic capacitance between the traces either side of them? They all seem to be much thinner than their neighboring traces

 

[jessenator]

I've heard that cartographers do something similar. Call 'em "trap streets" where it's either subtly misspelled, or something innocuous so the reader doesn't suffer. Gives them evidence of copying.

 

[Aleph Null]

I've heard that cartographers do something similar. Call 'em "trap streets" where it's either subtly misspelled, or something innocuous so the reader doesn't suffer. Gives them evidence of copying.

There are also false entries in dictionaries for the same reason.

 

[Robert]

Are they meant to be a ground trace in lieu of a plane to prevent parasitic capacitance between the traces either side of them? They all seem to be much thinner than their neighboring traces

They vary in size and aren't connected to ground (or at least not all of them).

Some are in parts of the circuit where you typically wouldn't want little antennas running all over the place.

The one in the first photo, for example, is right here:



Precision tuned parasitic capacitance?

 

[temol]

They vary in size and aren't connected to ground (or at least not all of them).

Are you sure it was there before you started tracing? Maybe it's some new kind of protection? As soon as you start poking around, random blind traces appear...

 

[Feral Feline]

 

[vigilante398]

Are they meant to be a ground trace in lieu of a plane to prevent parasitic capacitance between the traces either side of them? They all seem to be much thinner than their neighboring traces

That was my first thought, at my day job we call them guard traces and use them to separate sensitive signals to prevent crosstalk/interference. But if they're in places that don't make sense and aren't even ground, then yeah it's just there to make tracing more difficult.

 

[Robert]

I mean..... there was an opamp encapsulated in plastic for absolutely no good reason whatsoever.

 

[Robert]

What's with the two yellowed knobs?

Wait just a damned minute..... why doesn't this one have those custom knobs that improve the sound?

I bet if I put the knobs off my String Slinger on this thing even Howard couldn't distinguish it from a real Dumble.

 

[Nostradoomus]

Wait just a damned minute..... why doesn't this one have those custom knobs that improve the sound?

I bet if I put the knobs off my String Slinger on this thing even Howard couldn't distinguish it from a real Dumble.

I mean…not in his current state.

 

[Nostradoomus]

I mean..... there was an opamp encapsulated in plastic for absolutely no good reason whatsoever.

That was a caged opamp, not a free range grass fed hormone free opamp.

I, for one, am shocked it wasn’t in the literature.

 

[Robert]

I, for one, am shocked it wasn’t in the literature.

Please....


"Ultimately, I added a drive circuit that uses a dedicated module before the normal channel circuit and adopted a method to adjust how much signal is sent to the input stage of the normal channel. "

 

[Robert]

That's what we're calling it now when we take three absolutely essential components out of the circuit and place them on a little board covered in plastic...

 

[giovanni]

That's what we're calling it now when we take three absolutely essential components out of the circuit and place them on a little board covered in plastic...

But does it do what the marketing copy claims? Dedicated module for the drive before the normal channel?

 

[Aleph Null]

 

[pbrommer]

I’m now co-opting the phrase: “and adopted a method to adjust how much signal is sent” whenever I install a potentiometer to shunt signal to ground.

 

[jwin615]

So, what's in the custom shop "modules"?