Stratus Overdrive Ibanez TS-9 Tube Screamer Overview Stratus Project Link The Stratus Overdrive project is a clone of the Ibanez TS-9 Tube Screamer, which needs no introduction. If you’ve ever wanted to mod the living daylights out of a Tubescreamer, I believe mine is by far the most versatile board you can use—I tried to incorporate all of the best modifications as options. Further along in this document you’ll find component values and notes for a few of the more popular variants. There are two switches available: one for clipping diodes (with enough pads available for any diode combination you can dream of, as well as “comp cut” or diode lift in the middle), and a second one that can be used for any of three other mods using jumper wires. More details on this below. New version 2: The Stratus layout has been completely revamped for easier building. The Mod switch can be assigned via jumper pads instead of running wires across the board. The parts list and numbering is identical. The drilling template is the same but the controls are mirrored. Controls & Usage The Tube Screamer has the same control layout as most overdrive or distortion effects: • Tone controls the treble response of the effect. • Drive controls the amount of gain in the op amp feedback diode clipping stage. • Volume controls the overall output. Modifications & Experimentation The Clipping switch mod allows you to set up a second set of diodes to toggle back and forth from stock. Extra pads have been provided so you can stack two diodes in a row if desired. (The middle two pads are connected in each diode.) If you use a SPDT center-off switch, the middle position becomes a diode lift mode (called “comp cut” on the Fulldrive), but you can also use a regular SPDT if you don’t care about this. See further down for detailed diagrams on a few different diode configurations. The second switch is a peculiarity. I couldn’t pick just one mod, so I made it one-size-fits-all. By using the jumper pads, you can “assign” a mod to it. • The most popular mod is the Bright switch, allowing you to change the response of the tone stack. • The Fat control from AMZ controls the bass corner frequency. • The last one is the Flat Mids switch from the Fulldrive 2, which cancels out some of the “mid hump” the Tube Screamer is known for, TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 1 Parts (Stock Circuit) Resistors Capacitors Semiconductors R1 1k C1 22n Q1 - Q2 2N5088 R2 510k C2 1uF film IC1 JRC4558D R3 10k C3 51pF MLCC 2 D1 1N4002 R4 10k C4 47n D2, 4, 6, 8 1N914 4 R5 4k7 C5 220n 3 D3, 5, 7, 9 jumper 4 R6 51k C6 220n LED 5MM R7 1k C7 1uF film R8 10k C8 100n Potentiometers R9 220R C9 1uF film Tone 20kW R10 1k C10 47uF 25v Drive 500kB R11 1k C11 10uF 25v Volume 100kA R12 510k CX2 22n 1 R13 10k CX3 68n 1 Other R14 100R CX4 100n 1 R15 10k CX5 10n 1 SW1 - SW2 SPDT center off R16 47R CX6 100n 1 R17 10k R18 10k RX1 47k 1 RPD 1M to 2M2 LEDR 4k7 1 Part of a mod. All the parts with an “X” in the number (e.g. CX4) are modifications. See next page. 2 I prefer MLCCs (multilayer ceramic capacitors) here, but the original uses regular ceramics. 3 Important: If you’re not using the Bright mod, you need to jumper the bottom-left and bottom-center pads of the “Bright” jumpers in order for the tone capacitor to be properly connected. See diagrams on next page. 4 Your choice. The stock TS circuit is shown here, but the clipping section is extremely flexible. See the page further down for a variety of ideas. I recommend using sockets so you can experiment. Additional Part Notes • Capacitors are shown in nanofarads (n or nF) where appropriate. 1000n = 1uF. Many online suppliers do not use nanofarads, so you’ll often have to look for 0.047uF instead of 47n, 0.0056uF instead of 5n6, etc. • The PCB layout assumes the use of film capacitors with 5mm lead spacing for all values 1nF through 470nF. I prefer EPCOS box film or Panasonic ECQ-B/V-series. • Potentiometers are Alpha 16mm right-angle PCB mount. • Switches are Taiway (Small Bear) or Mountain Switch (Mouser) brand with solder lugs. I prefer the short- toggle variety, but that’s just a matter of aesthetics. • I recommend using these dust covers / insulators from Small Bear to insulate the back of the pots from the board and prevent shorts. If you don’t use these, use some electrical tape or cardboard to act as insulation. The right-angle pots will make direct contact with the solder pads otherwise. TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 2 Modifications & Experimentation NOTE: In the first 100 v2 PCBs, the “Bright” and “Bass” labels are switched around on the silkscreen. “Bright” should be the bottom-most mod section and “Bass” is the middle. This documentation assumes the correction. Bass (Fat) Mod Allows you to switch a capacitor value to change the bass corner frequency. Include CX2 and CX3 and connect the three jumpers labeled “Bass”. The values given in the parts list for CX2 and CX3 are arbitrary and can be customized to taste. They are switched in parallel with C4, so the total capacitance will be the sum of C4 and the CX capacitor being switched (e.g. 69n for CX2 + C4 and 115n for CX3 + C4). Bright Mod Allows you to switch a capacitor value to change the response of the tone stack. Include CX4 and connect the three jumpers labeled “Bright”. The value given for CX4 is arbitrary, but the idea is that at half of the stock capacitor’s value (220n), it will give you a little more brightness, while the center (off) position will give you even more. The other side of the switch is stock. Note that if you are not using the Bright mod, you need to jumper the bottom-left and bottom-center pads in order for the tone capacitor to be properly connected. Flat Mids Mod Taken from the Fulldrive 2, this removes the mid-hump that the Tube Screamer is known for. Include RX1 and CX5 and connect the two jumpers labeled “Mids”. If you’re using a center-off switch (recommended for the other mods), you will have two “off” positions and one “on”. Other Mods CX6 is for power stability / noise reduction. This won’t affect the sound at all, and so I recommend including it on any variant. Drive control range increase: This is another very common TS mod. By reducing the value of R5, you’ll have more gain at maximum and less gain at minimum. However, you’ll also want to increase C4 proportionally as well, otherwise you’ll change the bass response of the circuit. Since R5 and C4 form a simple R-C filter, you can use the R-C filter calculator at AMZ to tweak the values. For instance, the stock TS-9 circuit has a corner frequency of 720 Hz with R5 at 4.7k and C4 at 47n (0.047uF). If you wanted to drop the 4.7k resistor to, say, 3.3k, you’d enter 3300 in the Resistor field and enter 720 in the Corner Frequency field, and hit Calculate to find the new value of C4 (in this case, 0.067uF). Since capacitors come in standard values, you’ll have to settle for the nearest available value, which is 68n. If you want to change the gain range of any variants described below, start with their listed values for R5 and C4 in order to preserve their corner frequency. Bypassing the buffers: A couple of TS variants such as the Lovepedal Eternity and Fulltone RTO use the core Tube Screamer circuit without one or both of the buffers. To bypass the input buffer, omit R2, R3, Q1 and C2. Jumper the pads marked “BUF BYP” inside C2. To bypass the output buffer, omit R11-15, Q2, C8 and C9. Jumper R11 and connect pin 1 of the Volume pot to the pad just above the normal pad (this is ground instead of reference voltage). If using the recommended PCB-mount pots, you’ll have to bend the leg back and upward a little bit, but it will fit without any trouble. Next, you’ll want to jumper the pads marked “BUF BYP” inside C8 which connects the Volume pot directly to the output of the circuit. TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 3 Diode Clipping Options Lovepedal Eternity, Marshall Bluesbreaker Close-up of silkscreen. (Square pad pairs are always connected.) Zendrive LED clipping Landgraff Dynamic Overdrive (asym- metrical silicon on top, LED on bottom) MOSFET clipping JFET clipping Fulldrive 2 (Silicon top, MOSFET bottom) Stock TS-9 (symmetrical clipping) Boss SD-1 (asymmetrical clipping) TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 4 Schematic (Stock Circuit Values) T U O k01 D N u1 51R G 9C 5088 R14 100R 2N k01 V Q2 D 9 N + 31R G k015 R ds. V 21R mo n001 S5 S2SW2 can be used for a number of different Use jumpers to assign mods to the switch. S8 JRC4558D IC1A7uCR1111 1k38ACkL0O02V1 1 VR 0 2 2 3 2 R1 1k W 2 S M 3 1 TONE20kW 32 C6 220n R092R2 GND M1 6 3 1 7 4 S S S S S k 1 k01 1C5 220n 1B 47 RX R V 8R D CX4 100n 3B 2B GN R7 1k 10n CX5 D 8 5 5 RC4 C1B7 D5 D9 1 J I p15 D2 D6 2 kAVE 3C 500DRI 5 6 4 8 3 D D 11C 10uF k01 D3 D7 VR VR 4R u1 1 3 51k R6 k01 8 8 81R 9V Q12N502C P2 71R k01 + k015 CLI C4 47n 7k4 R 8 01C 47uF4 GNDVR 2RR1 1k R3 10k GND CX2 22n F1F2 5R V CX6 100n n22 CX3 68n F3 1C 2M2 9V 2004N1 DPR GND + 1D N I 6 R 1R 74 7k4 MDMEL5 WS V9+ RDEL TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 5 Variations Fulldrive 2 MOSFET, single-channel version Resistors Capacitors Semiconductors R1 1k C1 22n Q1 - Q2 2N5088 R2 510k C2 1uF film IC1 JRC4558D R3 10k C3 51pF D1 1N4002 R4 10k C4 100n 2 D2 1N914 R5 3k3 2 C5 220n D4 1N4005 R6 22k C6 220n D6 1N34A R7 1k C7 1uF film D7, D8 2N7000 R8 10k C8 100n D3, D5, D9 jumper R9 220R C9 10uF R10 1k C10 100uF 25v Potentiometers R11 1k C11 100uF 25v Tone 25kB R12 510k CX1 10pF Drive 500kA 2 R13 10k CX5 10n 1 Volume 100kA R14 100R R15 82k Other R16 jumper R17 10k SW1 SPDT center off R18 10k SW2 SPDT RX1 47k 1 Build Notes 1 To be exactly like the original, you’ll want to use the switch for the Flat Mids mod: include RX1 & CX5 and connect the Mids jumpers. 2 These are the stock values for the first channel, but I’d recommend doubling the gain range to compensate for the fact that you don’t have the second high-gain channel available. You can either do this by using a 1-meg Drive pot or by changing R5 to 1.5k and C4 to 220n. I wouldn’t go much higher than this because it makes the single Gain knob difficult to dial in. 3 The original unit uses a 25kB for the Tone control, but this was likely due the fact that 20kW pots were hard to come by when the Fulldrive was first developed. I’d recommend using a 20kW here since you’ll have finer control over the tone. The entire tonal range will still be there. TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 6 Landgraff Dynamic Overdrive / Clay Jones Overdrive (same circuit) Resistors Capacitors Semiconductors R1 1k C1 20n (22n is OK) Q1 - Q2 2SC1815 1 R2 510k C2 1uF film IC1 JRC4558D R3 10k C3 51pF D1 1N4002 R4 10k C4 220n D2 1N914 R5 1k C5 220n D4 1N914 R6 10k C6 220n D6 LED R7 1k C7 1uF film D8 LED R8 10k C8 100n D3, 5, 7, 9 jumper R9 220R C9 10uF R10 1k C10 100uF 25v Potentiometers R11 1k C11 47uF 25v Tone 25kB R12 510k Drive 1MB R13 10k 1 If using a 2SC1815 (E-C-B), you Volume 100kA will need to twist the C and B legs R14 100R around to fit the E-B-C pads. But a R15 10k 2N5088 would also work fine here. Other R16 jumper R17 10k SW1 SPDT center off R18 10k Boss SD-1 (true bypass) Resistors Capacitors Semiconductors R1 10k C1 47n Q1 - Q2 2N5088 R2 470k C2 18n IC1 RC4558P R3 10k C3 (omit) D1 1N4002 R4 100k C4 47n D2, D3, D4 1N914 R5 4k7 C5 (omit) D5 jumper R6 33k C6 27n R7 10k C7 1uF film Potentiometers R8 18n capacitor 1 C8 47n Tone 20kW R9 470R C9 1uF film Drive 1MB R10 10k + 10n 2 C10 100uF 25v Volume 10kB R11 4k7 C11 47uF 25v R12 1M R13 10k 1 Yep, a capacitor. R14 1k R15 100k 2 There’s not enough space on the board for both of these. I recommend soldering the 10n capacitor in the resistor’s place and then soldering the R16 jumper resistor across the lugs on the bottom of the board. However, you can R17 33k also just solder the capacitor across the top of the resistor. R18 33k TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 7 Lovepedal Eternity (Original) Resistors Capacitors Semiconductors R1 (jumper) C1 56n Q1 - Q2 (omit) 1 R2 (omit) 1 C2 (omit) 1 IC1 LM1458 2 R3 (omit) 1 C3 (omit) 1 D1 1N4002 R4 1M C4 220n D2, D3, D4 1N914 R5 1k C5 150n D5 (jumper) R6 10k C6 150n R7 1k C7 22uF 25v Potentiometers R8 (omit) 1 C8 (omit) 1 Tone 5kB R9 470R C9 (omit) 1 Drive 100kA R10 1k C10 47uF 25v Volume 100kA 1 R11 (jumper) 1 C11 47uF 25v R12 (omit) 1 R13 (omit) 1 1 See “Bypassing the buffers” above in the Mod section and follow the R14 (omit) 1 instructions to bypass both of the buffers. Lug 1 of the pot must be bent R15 (omit) 1 and connected to the upper pad (ground instead of Vref). R16 390R 2 The exact type of IC is unknown, though the general consensus is that R17 10k it’s probably an LM1458. Many others have been tried and the OPA2604 R18 10k or NE5532 have both been reported to sound great in this circuit as well. Lovepedal Eternity (“Burst” Edition) Resistors Capacitors Semiconductors R1 (jumper) C1 47n Q1 - Q2 (omit) 1 R2 (omit) 1 C2 (omit) 1 IC1 LM1458 2 R3 (omit) 1 C3 (omit) 1 D1 1N4002 R4 1M C4 100n D2-D5 1N914 R5 3k3 C5 220n R6 20k C6 150n Potentiometers R7 1k C7 10uF 16v Tone 5kB R8 (omit) 1 C8 (omit) 1 Drive 500kA R9 330R C9 (omit) 1 Volume 500kA 1 R10 1k C10 47uF 25v R11 (jumper) 1 C11 47uF 25v R12 (omit) 1 R13 (omit) 1 1 See “Bypassing the buffers” above in the Mod section and follow the R14 (omit) 1 instructions to bypass both of the buffers. Lug 1 of the pot must be bent R15 (omit) 1 and connected to the upper pad (ground instead of Vref). R16 330R 2 The exact type of IC is unknown, though the general consensus is that R17 10k it’s probably an LM1458. Many others have been tried and the OPA2604 R18 10k or NE5532 have both been reported to sound great in this circuit as well. TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 8 Fulltone RTO (Robin Trower Overdrive) Resistors Capacitors Semiconductors R1 1k C1 22n Q1 (omit) 1 R2 (omit) 1 C2 (omit) 1 Q2 2SC1815 2 R3 (omit) 1 C3 51pF IC1 LF353 R4 1M C4 100n D1 1N4002 R5 4k7 C5 220n D2 jumper R6 18k C6 150n D3, D5 2N7000 R7 1k C7 1uF film D4 BAT41 R8 10k C8 100n R9 220R C9 10uF Potentiometers R10 1k C10 47uF 25v Tone 25kB R11 1k C11 10uF 25v Drive 1MB R12 510k Volume 100kB R13 10k R14 100R R15 100k 1 Input buffer is bypassed. See “Bypassing the buffers” above in the Mod section and follow the instructions to bypass the input buffer only. R16 (jumper) R17 10k 2 If using a 2SC1815 (E-C-B), you will need to twist the C and B legs R18 10k around to fit the E-B-C pads. But a 2N5088 would also work fine here. Mad Professor / BJFE Little Green Wonder (with different tone section) Resistors Capacitors Semiconductors R1 5k6 C1 47n Q1 2SK170 3 R2 1M C2 1uF & 5k6 1 Q2 (omit) 2 R3 10k C3 100pF IC1 TLC272CP R4 27k C4 220n D1 1N4002 R5 2k C5 100n D2, D4 Green LED R6 5k6 C6 47n D3, D5 jumper R7 2k C7 1uF film R8 10k C8 100n Potentiometers R9 470R C9 10uF Tone 20kW R10 2k C10 100uF 25v Drive 500kB R11 5k6 C11 100uF 25v Volume 50kB R12 (omit) 2 R13 (omit) 2 1You’ll need to cram a 1uF cap and a 5k6 resistor in series in this single spot. It might be easier to do this from the bottom of the board so you have more space. R14 (omit) 2 R15 (omit) 2 2 See “Bypassing the buffers” above in the Mod section and follow the instructions to bypass the output buffer. Lug 1 of the pot must be bent and connected to the upper pad. R16 47R R17 27k 3 If using a 2SK170, reverse the orientation from the PCB silkscreen. R18 27k 4 The LGW uses a dual-pot tone control to control the bass as well as the treble. This version does NOT have that. I recommend using the Fat Mod to help compensate, but you might also need to tweak some values in the tone section (C5, C6 and R9). TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 9 General Build Instructions These are general guidelines and explanations for all Aion Electronics DIY projects, so be aware that not everything described below may apply to this particular project. Build Order When putting together the PCB, it’s recommended that you do not yet solder any of the enclosure-mounted control components (pots and switches) to the board. Instead, follow this build order: 1. Attach the audio jacks, DC jack and footswitch to the enclosure. 2. Firmly attach the pots and switches to the enclosure, taking care that they are aligned and straight. 3. Push the LED1 into the hole in the enclosure with the leads sticking straight up, ensuring that the flat side is oriented according to the silkscreen on the PCB. 4. Fit the PCB onto all the control components, including the leads of the LED. If it doesn’t fit, or if you need to bend things more than you think you should, double-check the alignment of the pots and switches. 5. Once you feel good about everything, solder them from the top2 as the last step before wiring. This way there is no stress on the solder joints from slight misalignments that do not fit the drilled holes. You can still take it out easily if the build needs to be debugged, but now the PCB is “custom-fit” to that particular enclosure. 6. Wire everything according to the wiring diagram on the last page. 1 For the LED: You can use a bezel if you’d like, but generally it’s easier just to drill the proper size of hole and push the LED through so it fits snugly. If you solder it directly to the PCB, it’ll stay put even if the hole is slightly too big. Make absolutely sure the LED is oriented correctly (the flat side matches the silk screen) before soldering, as it’ll be a pain to fix later! After it’s soldered, clip off the excess length of the leads. 2 Note on soldering the toggle switch(es): It will require a good amount of solder to fill the pads. Try to be as quick as possible to avoid melting the lugs, and be prepared to feed a lot of solder as soon as the solder starts to melt. I recommend waiting 20-30 seconds between soldering each lug to give it time to cool down. “RPD” and “LEDR” resistors The resistors marked “RPD” and “LEDR” are generally not original to the circuit and can be adjusted to preference. “RPD” is the pulldown resistor to help tame true-bypass popping, while “LEDR” controls the brightness of the LED. I generally use 2.2M for the pulldown resistor and 4.7k for the LED resistor. Sockets Since double-sided boards can be very frustrating to desolder, especially components with more than 2 leads, it is recommended to use sockets for all transistors and ICs. It may save you a lot of headaches later on. TS-9 TUBE SCREAMER / STRATUS OVERDRIVE (V2) 10