Way Huge pcb...

[amz-fx]

Motorola MPQ3904   is the actual device.

Correct Mr. Huge?  

regards, Jack

[bobbletrox]

Next; the Red Llama Overdrive  

*JOKE*

[Tim Escobedo]

The most interesting thing about this whole exercize for me is that i took Jack's and R.G.'s remarks on the first two pages to mean that they had eliminated the possibility of a transistor array and had something truly unusual.

I must say, I was kinda disappointed.  

[Joep]

I guess the MPQ2222 and MPQ3904 contain 4 of the 2N2222/2N3904 transistors? So using separate trannies within the specs of the chip will get you there.

Is somebody able to fill in the partlist, according to the pin numbering in my schem? Some of the values are hard to read read.

Bye,

Joep

[amz-fx]

I must say, I was kinda disappointed.

Considering that it took less than 24 hours to get the chip identified, I was happy...  the pin config just happened to match the standard quad opamp layout and the logical idea was that the chip was being powered up in some unusual fashion, but certainly nothing was eliminated.  It didn't match the arrays I had in the databook handy but once I dug out an old RCA manual and found the CA3138, it matched up exactly and I knew that was the chip style.

The MPQ3904 is the one used, though the MPQ2222, CA3138 or MAT04 would all work in this circuit....  sort of like subbing 2N5088 for 2N3904s...

regards, Jack

[Joep]

Hi All,

I made a few corrections to the schem I published.
- The first transistor had the wrong pinnumbers
- Added C1
- I fixed the "black box" symbols with transistor symbols.

Check my previous post here
http://diystompboxes.com/sboxforum/viewtopic.php?t=18837&postdays=0&postorder=asc&start=50

Bye,

Joep

[bobbletrox]

--

[amz-fx]

bobbletrox,  the very bottom right pad connects to a resistor then the other end of the resistor is not connected on your drawing.  It should connect to that large pad to its left.

regards, Jack

[MR COFFEE]

Hi Jack,
The pictures are great, but the values are hard to decipher. Could you post a parts list from your unit?

I'd be glad to add them to Joep's schematic.

Thanks,

[Peter Snowberg]

I sure got fooled.

I was thinking the same thing Paul Perry was about using protection diodes, but the picture of the top didn't seem to agree with that.


You could use separate transistors, but the cool thing about the arrays is that they're all VERY matched. With discrete devices your mileage is going to vary quite a bit. I'm imagining that while absolute Hfe is important, the relative Hfe is probably just as important between a couple of the devices. Maybe I'm totally wrong too.

What a cool thread.

Take care,
-Peter

[smoguzbenjamin]

Hmmm. Any 2 transistor packages around?

[idlefaction]

heh, it was a good effort, but that pic of the top of the board hasn't got enough detail to get the values.  if someone actually has a swollen pickle, i'd suggest grabbing joe's schem and the pic he did with the component numbers, and listing out all the values.

don't forget the caps  

i'm most interested in the tone control cos Mr Huge's is the best BMP tone control i've heard!    i like the clipping in my BMP moreso than the pickle tho, i've staggered the bass response to go from not much in the earlier stages to normal in the last stage.  totally different sound, it's not apples and apples.

[bobbletrox]

bobbletrox,  the very bottom right pad connects to a resistor then the other end of the resistor is not connected on your drawing.  It should connect to that large pad to its left.

regards, Jack

It looks like those two pads are connected by a jumper...so I just left it like the original.

[amz-fx]

It looks like those two pads are connected by a jumper...so I just left it like the original.

There is a pcb trace under there...

I'll post a parts list, but only if Mr. Huge has no objection.  Otherwise you could use the part values from the BMP.

regards, Jack

[bobbletrox]

There is a pcb trace under there...

Oh!  Ok...fixed it.  

[Chris R]

It looks like those two pads are connected by a jumper...so I just left it like the original.

There is a pcb trace under there...

I'll post a parts list, but only if Mr. Huge has no objection.  Otherwise you could use the part values from the BMP.

regards, Jack

maybe it could by by email/pm request only.

Chris R

[MR COFFEE]

Bobbletrox,
I believe the PCB you have drawn up is reversed - is that intended so folks can use PnP methods? Jack's post has been reversed, presumably to make tracing easier, and your layout matches Jack's picture.

[Mr.Huge]

Aloha All,
Like I’ve said before… I have no problem if you reverse engineer and create YOUR OWN schematic and PCB… But…
Please cease and desist the distribution of Way Huge Electronics copyrighted material.
Copyright laws protect the PCB layout that has been posted (didn’t you see the “C”?). Please remove the Swollen Pickle PCB layout (trace side) from the site post haste.
Thank you.
RG you can post a parts list but please … (everyone)… refrain from using my trademarked material and copyrighted material without any disclaimer that say it does not belong to you. Posting copies of a PCB layout (that is protected) without written consent is illegal.
You guys need to be more careful.  
-Mr. Huge

[idlefaction]

right!  anyone got a pics of the guts of a Line 6 Pod?  

[bobbletrox]

I took the PCB layout down  :oops: