Tube Screamer Dungeon

Part Seven: Transistors & Opamp

Welcome to part seven of my exploration into converting the electrical schematic of the Ibanez’s TS-808 Tube Screamer guitar effects pedal into a functional dungeon map. To those needing to catch up, I’ve placed links to all previous installments at the bottom of this page. For those who don’t, it’s time to explore transistors and the opamp.

We’ll start with NPN bipolar junction transistors labeled on the map, rooms Q1 & Q2. NPN bipolar junction transistors (BJT) act as switches or amplifiers in electrical circuits. There are three parts to a BJT: base, collector, and emitter. In the TS-808, electric current flows into the base (P) between the collector (N), and emitter (N); NPN. As the level of current increases in the base relative to the emitter, the transistor becomes active and the current flows from the collector to the emitter.

The TS-808 uses two 2SC1815 NPN bipolar junction transistors. They are black, half-cylinders with three metal leads protruding from the bottom. On the curvature of the half-cylinder is an indented circular dot. On the flat side is the component’s markings.

The “Q” rooms carry features from the component. The walls are matte black with a circular indentation in one wall. The markings on the transistors are present on a wall opposite wall as the circular indentation. Lastly, the doors for these rooms are smooth shiny metal that open when touched.

To represent the NPN bipolar junction transistor’s function, the door used to enter represents the base. The other door is the emitter. The collector is represented by the 9v connection. 9v connection? Remember back to Part Two: Design and Refine. There, I had three 9v connections I didn’t know what to do with. I pushed them aside and promised to incorporate them into the dungeon later. Well, it’s time to bring them in. After entering the room the exit door will not open until power is hooked up to the collector. Its power source is missing. The 9v power source is a giant button battery that nests in the wall; the circular indentation. Player characters will discover them as they journey through the dungeon. Once the exit is powered, the emitter door will automatically open allowing characters to exit. Once they exited, the door will close behind them.

Dual-opamp
Our last component to discuss is the JRC4558D dual-opamp. It’s an area I was putting off until last. Depending on the way we choose to interpret this component it might lead to complications with the map. But first, what is an opamp? An opamp (operational amplifier) amplifies voltage in a circuit. In the TS-808, the opamp is an integrated circuit, i.e. a microchip; a compress electrical circuit made of resistors, capacitors, and transistors. The chip has its own electrical schematic and is mappable. Below is its electrical schematic.

If I expand the dungeon using the schematic layout of the opamp, the two JRC4885D rooms on the map get replaced with a series of resistors, capacitors, transistors, and one diode room. It would add 54 rooms. Reconfiguring the map to fit these new rooms is not practical and therefore is not going to happen; I’m done tweaking and reworking. One option is to make them pocket dimensions inside the JRC4885D rooms. But still, 54 rooms? That’s a lot. A better option is to leave the rooms alone. Treating them as two rooms and ignore the make-up of the opamp. It’s the simplest solution and the direction I am choosing. I will build an optional JRC4885D dungeon map to use as a pocket dimension in a future article. For now, the JRC4885D rooms will remain super simple as single rooms with no pocket dimensions.

Alright, so we have two rooms. What will the player characters find inside these rooms? The opamp amplifies voltage. I’ll alter the amplification from voltage to safety. The JRC4885D rooms become safe rooms where characters can build up their strength and heal their wounds without the threat of attack. The first JRC4885D room the characters encounter comes right after the input buffer section of the schematics. I’ve had thoughts of making the input buffer section a character funnel. The first JRC4885D room will allow the players to safely rest and level up to the next level. The second JRC4885D room is centrally located allowing the player characters to use as needed.

Incorporating the characteristics of the opamp, the walls of the rooms are a flat black. Stenciled on the walls are the chips’ markings which have no meaning to the player characters. In the first room, an etched circular indentation on a metal door marks position “one” of the microchip. The contents of the room will revolve around comfort and resupplying the characters. An arch outcropping in the room which could easily be mistaken for a large fireplace holds the key to the players’ heart’s desire if the judge lets them. The arch is a material generator. It can reproduce simple organic and inorganic objects if the adventures can get the internal AI to recognize them. The arch in the first JRC4885D room is very limited in the number of items it can produce. It’s power cells are running low. Since Mutant Crawl Classic characters do not receive additional equipment upon reaching level one, the items it does produce are at the discretion of the judge. As a judge I’d give them some basic equipment and weaponry from the Dungeon Crawl Classic Tables 3-1 Weapons, 3-2 Ammunition, 3-3 Equipment, and if I’m feeling extra generous 3-4 Armor. In the second JRC4885D room there is a 9v connection. The arch will not function until it receives power. And after that, it will be up to the judge to decide how long it lasts and what it will produce. The power source is different from the “Q” rooms. The battery needed to power this room resembles a common 9v battery only larger and heavier. These are throughout the dungeon for the player characters to find.

So that completes this part of the build. Thanks, for sticking with me in the dryer and technical parts of the Tube Screamer Dungeon. In our next Part, Part 8: Bad to the Bots we put aside the dungeon map for a while and take a look at the service bots that maintain the dungeon. Thanks for following my journey and I hope you return.

~Stephen Pennisi

To see my journey click on the links below:
Part One: Proof of Concept
Part Two: Design and Refine
Part Three: Moving On Up
Part Four: An Isometric Point of View
Part Five: Capacitors as Elevators
Part Six: Diodes and Resistors
Part Seven: Transistors & Opamp
Part Eight: Bad to the Bots
Part Nine: And Artifacts For All
Tube Screamer Dungeon – Part Ten: Block Party

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