Author Topic: Way Huge pcb...  (Read 60405 times)

amz-fx

Way Huge pcb...
« on: February 12, 2004, 06:58:14 PM »
Here is the bottom of a Way Huge pcb...



What's so interesting about this?  The IC is unmarked but from the layout I can guess that pins 4 and 11 are for the V+ and V- power connections...  but if you can locate the IC in the middle of the board, you'll see that neither of these pins are connected to anything!!!

Anyone want to take a guess what's happening here???

-Jack

Steve C

Way Huge pcb...
« Reply #1 on: February 12, 2004, 07:24:08 PM »
Hey, the other side of the Swollen Pickle!

Ry

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Way Huge pcb...
« Reply #2 on: February 12, 2004, 08:02:28 PM »
My guess would be that it's a suprious component thrown in to stop people from tracing the effect and making clones.

Please let me know if I'm wrong, but I can't think of a way that an IC could work without electrons flowing...

Ry

Mr.Huge

Way Huge pcb...
« Reply #3 on: February 12, 2004, 08:09:56 PM »
I can!
But it's so much fun to watch y'all struggle with such a simple little thing.
-Mr. Huge
BEN:   Mos Eisley Spaceport. You will never find a more wretched hive of scum and villainy. We must be cautious.

LUKE:   But I was going into Toshi Station to pick up some power converters...

VADER:   I find your lack of faith disturbing.

amz-fx

Way Huge pcb...
« Reply #4 on: February 12, 2004, 08:48:03 PM »
Quote
Please let me know if I'm wrong, but I can't think of a way that an IC could work without electrons flowing...

You're wrong...  :)  hint - there are bias resistors on the inputs and outputs...

actually I played around with an idea like this but never got it working well...

-JACK

Rory

Way Huge pcb...
« Reply #5 on: February 12, 2004, 08:50:52 PM »
Its not acting as a transistor?

Steve C

Way Huge pcb...
« Reply #6 on: February 12, 2004, 10:06:56 PM »
I'm going to go out on a limb and say it's acting like a rectifier?

Peter Snowberg

Way Huge pcb...
« Reply #7 on: February 13, 2004, 01:27:30 AM »
Very cute Mr. Huge. ;)

I think I know what the trick is, but I would need to see the top to confirm my suspicion.

It's not the sort of thing you would want to do with a chip that supplies any real power if I have it correctly.

This is the first time I've seen the concept used in an actual product.

Take care,
-Peter
Eschew paradigm obfuscation

KarbonHed

  • Guest
Way Huge pcb...
« Reply #8 on: February 13, 2004, 05:17:59 AM »
Is it something like a 4007 with the individual mosfets used as clipping "diodes"?

Paul Perry (Frostwave)

Way Huge pcb...
« Reply #9 on: February 13, 2004, 05:45:49 AM »
Since some chips have 'protection' diodes from input & output pins to power rails, if you leave the "official" power pins disconnecrted, sometimes yu can get the chip to work.
I had a logic chip in a turned pin socket once, and one turned pin collar was missing! the chip leg (V+ as it happened!) just floated there, while the chip acted a bit flakey.

Dan N

Way Huge pcb...
« Reply #10 on: February 13, 2004, 07:41:46 AM »

amz-fx

Way Huge pcb...
« Reply #11 on: February 13, 2004, 08:26:04 AM »
Most of the opamp sections have voltages like this:

Inverting input:  0.67v
Noninverting:    25mv
Output pin:    4.7v

The inverting input is essentially a diode drop above ground and the noninverting is connected to ground through a 100 ohm resistor, so it's not surprising it is almost 0.   The pullup resistor on the output and the internal circuitry are balancing the output near 1/2 V+.

Knowing what the opamp could be is the key to understanding this...  :D

regards, Jack

Paul Perry (Frostwave)

Way Huge pcb...
« Reply #12 on: February 13, 2004, 08:46:03 AM »
This is why I was glad mr Huge didn't post the schematics... this way we're going to LEARN something! :D

Ed Rembold

Way Huge pcb...
« Reply #13 on: February 13, 2004, 10:12:37 AM »
a 4069 perhaps?

Ed R.

Aharon

Way Huge pcb...
« Reply #14 on: February 13, 2004, 10:37:09 AM »
If I want to know what's inside of an effects box I go and rent it for $10 a month at my local music store.
Aharon
Aharon

RDV

Way Huge pcb...
« Reply #15 on: February 13, 2004, 10:44:24 AM »
Most boutique builders sand off the old ICs or smother them in goop, so renting does you little to no good.

Regards

RDV

Chris R

Way Huge pcb...
« Reply #16 on: February 13, 2004, 10:46:20 AM »
4069 hex inverter has a different pinout than most 14 pin quad op amps..

which would mean.. that the unused pins on the 4069 were

output #2 & input #5


Aharon

Way Huge pcb...
« Reply #17 on: February 13, 2004, 11:40:06 AM »
"Most boutique builders sand off the old ICs or smother them in goop, so renting does you little to no good. "
RDV


Some do some don't,older effects certainly don't have that problem.
Aharon
Aharon

Ed Rembold

Way Huge pcb...
« Reply #18 on: February 13, 2004, 12:07:23 PM »
My only other guess would be a transistor array chip,
making it a BMP like thing?
I dunno,  love the surface mount pulldown R.


Ed R.

Mr.Huge

Way Huge pcb...
« Reply #19 on: February 13, 2004, 02:04:26 PM »
You are very wise Grasshopper.
But answer me this… Why does the universe appear to have one time and three space dimensions?
Ha..HA..HAHAH…HA!
-Mr. Huge
BEN:   Mos Eisley Spaceport. You will never find a more wretched hive of scum and villainy. We must be cautious.

LUKE:   But I was going into Toshi Station to pick up some power converters...

VADER:   I find your lack of faith disturbing.