Way Huge - Fat Sandwich  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
Nocentelli
Tube Twister
Information
Posts: 2174
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1004 times
Been thanked: 854 times

Post by Nocentelli »

LaceSensor wrote: Green Rhino
Fat Sammich
Swollen Pickle
Angry Troll
Pork Loin
Supa Puss
Ringworm
!!!

The new Swollen pickle has been traced here at FSB, but I'd love to see guts of the rest.
vanessa wrote: 20 Aug 2007, 17:51 You can't arrest someone for reverse engineering something.

User avatar
LaceSensor
Cap Cooler
Information
Posts: 577
Joined: 02 Jan 2011, 12:01
Has thanked: 47 times
Been thanked: 260 times

Post by LaceSensor »

pretty sure the pork loin is already traced.
ill try to take some pics of the green rhino over the weekend

User avatar
Intripped
Cap Cooler
Information
Posts: 620
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 831 times
Been thanked: 240 times

Post by Intripped »

LaceSensor wrote:pretty sure the pork loin is already traced.
thanks, i totally missed that!

User avatar
lukatosh
Solder Soldier
Information
Posts: 194
Joined: 04 Dec 2010, 02:55
Has thanked: 33 times
Been thanked: 182 times

Post by lukatosh »

Green Rhino Guts please Sir!

Best Regards from chile!!

User avatar
MoonWatcher
Diode Debunker
Information
Posts: 715
Joined: 28 Jul 2008, 12:27
Has thanked: 41 times
Been thanked: 43 times

Post by MoonWatcher »

coldcraft wrote:just got one of these for $65 and it is AWESOME. I will take pictures when I have more time, but I think its safe to say that it is an opamp clipper driving a series of 4049/4069 Inverters. The Presence and Resonance appear to be a Baxandall-type EQ. The Tone control is a simple roll off.
I can make out two pairs of clippers - a pair of silicons, and a pair of LED's.

There's a trio of transistors. In order to have a tone circuit function in a "standard sense" with inverters, I'd think these would be a necessity. The 3rd transistor could be just a low Z out. Or - maybe there's some active tone shaping beyond the presumed Baxandall? Maybe a gyrator tied to something?

So there's the op amp, there's the transistors, there's the 4049 - what's the other long chip in there? None of that stuff should be for switching, because that's all on the separate board w/all the SMT stuff.

I see a lot of small ceramic caps that I'm assuming are primarily for attenuating treble. It looks like this circuit is more complexly crafted than one might realize from just using the pedal. I sort of can imagine parallels (in a design sense) with the Pork Loin. Doesn't the PL use a mosfet on its input? Maybe that is what is going on here, and maybe the pair of canister-type transistors are some sort of pre-emphasis circuit?

It's kind of amazing that this one hasn't been traced sooner. Really slick work. Tripps is an amazing dude.

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

Surprise!
Attachments
Fat_Sandwich.png
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
zedsnotdead
Breadboard Brother
Information
Posts: 121
Joined: 13 Dec 2012, 02:27
Has thanked: 31 times
Been thanked: 52 times

Post by zedsnotdead »

:applause:
Ty!

User avatar
jubal81
Breadboard Brother
Information
Posts: 94
Joined: 01 Apr 2011, 01:29
Has thanked: 48 times
Been thanked: 30 times

Post by jubal81 »

Way Cool. Planning on doing a layout, Coldcraft?

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

no, sorry, feel free to do that if you want.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
Nocentelli
Tube Twister
Information
Posts: 2174
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1004 times
Been thanked: 854 times

Post by Nocentelli »

coldcraft wrote:Surprise!
Thanks! Is the 4049 actually powered? There's no indication on the schematic, but I kind of assume +9v to pin 1 and grounded pin 8. Just breadboarding this beast now, and I've got to the end and really have no idea.
vanessa wrote: 20 Aug 2007, 17:51 You can't arrest someone for reverse engineering something.

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

yes it is. sorry i left off the standard power filtering.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
Nocentelli
Tube Twister
Information
Posts: 2174
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1004 times
Been thanked: 854 times

Post by Nocentelli »

Got massive squeal and self oscillatiion with the drive pot on just about anything above zero. Everything else seems to work ok, though. I have a 1k from +9v to the 4049 pin 1, like the red llama. It's very late, so I'm using headphones but i'll have another play around tomorrow.
vanessa wrote: 20 Aug 2007, 17:51 You can't arrest someone for reverse engineering something.

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

try bypassing the Pin 1 (9v) with a large electro to ground
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
MoonWatcher
Diode Debunker
Information
Posts: 715
Joined: 28 Jul 2008, 12:27
Has thanked: 41 times
Been thanked: 43 times

Post by MoonWatcher »

Nocentelli wrote:
coldcraft wrote:Surprise!
Thanks! Is the 4049 actually powered? There's no indication on the schematic, but I kind of assume +9v to pin 1 and grounded pin 8. Just breadboarding this beast now, and I've got to the end and really have no idea.
Take a look at what the makeup is of the 4049 - it's mostly a Red Llama, but it uses triplets of inverters for each stage. But the cap values with the Llama are the same as is used with the Fat Sandwich. It must make a ton of treble frequencies to have both a 270pF and 220pF cap in the negative feedback loops at the tail end of the circuit.

User avatar
stevo83
Information
Posts: 37
Joined: 06 Feb 2010, 23:28
Has thanked: 8 times
Been thanked: 6 times

Post by stevo83 »

Thanks for the schematic guys.

Interesting circuit with a lot going on; 3 stages of clipping/distortion etc.

Is there a reason for the CD4049 inverter stages stacked in parallel, more gain?

User avatar
MoonWatcher
Diode Debunker
Information
Posts: 715
Joined: 28 Jul 2008, 12:27
Has thanked: 41 times
Been thanked: 43 times

Post by MoonWatcher »

stevo83 wrote:Is there a reason for the CD4049 inverter stages stacked in parallel, more gain?
I think it's for less noise.

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

if I had to guess, that would be what tripps did in the Red Llama MkII as well.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
zedsnotdead
Breadboard Brother
Information
Posts: 121
Joined: 13 Dec 2012, 02:27
Has thanked: 31 times
Been thanked: 52 times

Post by zedsnotdead »

Didn't know there was a llama MKII... whats the main diffenreces for MKI? Is there a schematic/layout?

User avatar
coldcraft
Diode Debunker
Information
Posts: 725
Joined: 11 Jul 2009, 01:00
Has thanked: 41 times
Been thanked: 81 times

Post by coldcraft »

no, not yet. there is no difference from the outside, but I bet tripps just paralleled the inverter stages like he did here.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

User avatar
MoonWatcher
Diode Debunker
Information
Posts: 715
Joined: 28 Jul 2008, 12:27
Has thanked: 41 times
Been thanked: 43 times

Post by MoonWatcher »

coldcraft wrote:if I had to guess, that would be what tripps did in the Red Llama MkII as well.
I think the MkI's had the old Fairchild CD404NUBCN which was pretty good. The one by Texas Instruments - the "UBE" has a lot more hiss.

Fairchild has ceased production of a non-SMT CD4049UBCN, at least for export to what I'd assume are most countries.

The Rotagilla pointed out that the MkII had a MC14049UB by ON Semiconductor, and that the noise with it was lower, too. But no one traced that out, and no one thought to look for 6 100R's.

I think Texas Instruments is the remaining large company that distributes the 4049U worldwide with the through hole style. If the parallel configuration is to lower noise, it might be because WHE (or I guess Dunlop) is expecting to exhaust their inventory of chips by ON Semiconductor?

I think Rohm may make a 4049U, but it may not be manufactured in the numbers that a company like Dunlop might require. I just don't know.

Maybe it's just good design principle as opposed to how it's typically been done - connecting the unused inverters to either ground or V+. I also wonder if it's a way to reduce the need to limit current to the 4049.

Post Reply