Stratus / Ibanez TS-9 Tube Screamer DIY PCB

Stratus - Ibanez TS-9 Tube Screamer Guitar Pedal PCB

$10.00

Available

New version 2 with updated layout! Version 1 documentation can be downloaded here.

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Project overview

Aion Stratus (Ibanez Tube Screamer) PCB, populatedAnother classic that needs no introduction. But 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 buy—and it fits in a 1590B! There are two switches available: one for clipping diodes (with enough pads available for any diode combination you can dream of and “comp cut”/diode lift in the middle), and one that can be used for one of three other mods using jumpers:

  • Fat mod (with three different settings) – read more at AMZ
  • Brightness mod (also with three different settings)
  • “Flat Mids” mod (from the Fulldrive 2)

With the right combination of part values and mods, you can build exact replicas of dozens of Tubescreamer-derived circuits, such as the following:

  • Fulltone Fulldrive 2 (single channel)
  • Fulltone RTO
  • Lovepedal Eternity
  • Landgraff Dynamic Overdrive
  • Clay Jones Overdrive

Component lists are provided for a select few in the build document, but the Tubescreamer is a very inspirational circuit to say the least and there are many more out there.

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Tube Screamer circuit history

The Tube Screamer is easily the most popular overdrive pedal ever created, and accordingly, there’s a lot to say about its origins and history. I am indebted to a few really good sources for the information that follows: Analogman’s Tube Screamer History, an interview with circuit designer Sasumu Tamura[1], and an interview with John Lomas[2], a former product manager at Ibanez.

1979: Maxon OD-808 and Ibanez TS-808

Maxon (Nisshin Onpa) had its origins in pickup manufacturing, but started making effects pedals in 1969.[3] In the mid-1970s, they formed a partnership with Ibanez, who was at that time only a guitar manufacturer, and licensed their designs exclusively to them, though they reserved the right to release them under their own name as well to the Japanese market. They originally released the “OD-808 Overdrive” in 1979.[4] It was not called the Tube Screamer, but is nearly identical except that it uses op-amp input & output buffers instead of the later transistor-based buffers. Both dual op-amps in the pedal are MC1458P, which has nearly identical specs to the 741 used in the MXR Distortion+ but in a dual package. (LM1458 is an equivalent.)

Around that same time, Ibanez was in need of an overdrive pedal to compete with the Boss OD-1 OverDrive, which had been released in late 1977 and had become very popular among guitarists. Maxon licensed the OD-808 circuit to Ibanez, making a few tweaks by dropping the op-amp input & output buffers in favor of the now-ubiquitous transistor buffers, likely as a cost-savings measure since op-amps were much more expensive back then. The result was the 1979 release of the TS-808 Tube Screamer Overdrive Pro.

Interestingly, according to Analogman’s Tube Screamer History[5], some of the very first TS-808s actually had the original Maxon OD-808 circuit, with two MC1458P op-amps. This is probably because Ibanez was in a hurry to get it to market and they couldn’t wait for the new PCB design to be finalized, so they just used Maxon’s existing design for the first run.

1982: Ibanez TS-9 Tube Screamer

In 1982, Ibanez rebranded their series of effects pedals with the “9” suffix (e.g. CP-9, SD-9) and redesigned their enclosures. The TS-808 reappeared as the TS-9 Tube Screamer, dropping “Overdrive Pro” from the name (which curiously would later be reused for the Maxon OD-820 Overdrive Pro). Only three very small changes were made to the circuit from the 808: the 100R and 10k resistors on the output buffer transistor were changed to 470R and 100k respectively, and the op-amp was changed to a TA75558P. This has no real effect on the sound, but does affect output impedance, so it could potentially affect the way it interacts with pedals that follow (or the amp).

The TS-9 would be discontinued in 1985 due to underperforming sales, but not before a variant was released called the ST-9 Super Tube Screamer. This is an extremely rare effect, having only been released in Europe and Japan in extremely limited quantities. In the ST-9, a “Mid Boost” control was added, which controls the frequency of a fixed-gain boost stage that comes before the clipping stage, allowing you to create some really interesting new sounds.

1985 and beyond

In 1985, the 9-series was brushed aside to make room for the “Master Series”.[6] The Tube Screamer actually made two appearances in the Master Series, but under different names. The “MSL Metal Screamer” is an identical circuit topography, but with a capacitor changed to lower the corner frequency from 723 to to 413 Hz, giving it a fair amount more bass.[7] Additionally, the “STL Super Tube” was the same circuit as the ST-9 Super Tube Screamer except that the variable-frequency boost was cut-and-pasted after the clipping stage instead of before.

In 1986, the Master Series was discontinued and the “Power Series” was introduced, more commonly referred to as the “10 series”. The Tube Screamer was restored to Ibanez’s lineup as the TS-10. The circuit was revised slightly and a number of additional parts were added, but mostly related to switching stability and nothing that should affect the tone. If you’re building a true-bypass version, the TS-10 doesn’t have anything new to bring to the table except a 220 ohm resistor in series with the clipping op-amp’s input that doesn’t affect the tone.

While the Power Series continued production until 1996[8], Ibanez introduced the new “Soundtank” series in 1989 in a round black enclosure. The Soundtank pedals were not designed or manufactured by Maxon. The initial run only included newly-designed drive pedals such as the CR5 Crunchy Rhythm and the TM5 Thrash Metal, but later on, they expanded this line to include a wider variety of effects in the same enclosure style, including CP-5 Compressor, the TL-5 Tremolo and of course the TS-5 Tube Screamer, whose only circuit revisions were to the JFET switching. It sounds the same as any other Tube Screamer.

The Sound Tank series was in production until 1999 when the new “Tone-Lok” series was introduced. Again, the Tube Screamer was repackaged as the TS-7 for this series, and there were no circuit changes except a “Hot” switch that increases the gain and volume.

Reissues

The original TS-9 was reissued in 1993 with the TA75558 op-amp and has been in more or less continual production since then. The Ibanez TS-808 was reissued in 2004 in the original enclosure, using the same circuit board as the TS-9s but with the two resistors changed to 808 specs. Maxon also reissued their OD-808 in its original 1979 enclosure in 2004.

In 2002, Maxon and Ibanez parted ways. Ibanez began using another contract manufacturer for the TS-9s, and Maxon released the OD-9 which is nearly identical in appearance to the Ibanez TS-9 except for the logo. Under the hood, it’s been revised to use a new op-amp and to have true-bypass switching via relays. After nearly thirty years, Maxon once again dropped the “Tube Screamer” name and reverted back to just calling it the “Overdrive”.

In 1998, the TS9DX Turbo Tube Screamer was released. This is a hot-rodded TS-9 with three additional modes: Plus, which uses two diodes in series to increase the clipping threshold and increases the capacitor value for more bass; Hot, which uses LEDs for clipping and adds more gain along with increasing bass further; and Turbo, which removes the clipping diodes altogether and adds even more bass.

Which op-amp?

A perennial question surrounding the Tube Screamer is which op-amp sounds best and which is most authentic to the original tone.

The original Maxon OD-808 used MC1458 op-amps, essentially a dual 741, which is much lower fidelity than the ones used in the later Tube Screamers.

The TS-808 was originally released with JRC4558D chips, though some of them had RC4558P, the Texas Instrument equivalent that was the primary chip used in the Boss SD-1.

The original TS-9 used the TA75558P op-amp, and so when it was reissued in 1992, the product team decided to use the same op-amp to make it as authentic as possible. It’s worth noting that some later issues used other chips such as the JRC2043; these are generally regarded as terrible and should be upgraded.

At the end of the day, the JRC4558D is the one most associated with the classic Tube Screamer and the one that most people elect to use when building their own.

1974 or 1979?

Maxon Effects Pedal Release Timeline

Maxon timeline from 1971 through 2002, showing the OD-808 released in 1974.

This is an interesting one:[9] there’s a good deal of Maxon literature, including their European distributor’s website od808.com and the catalog timeline to the right, which indicate that the OD-808 was originally released in 1974. This information has made its way into a number of other sources as well such as Wikipedia.

On the other hand, Maxon’s American distributor’s website indicates it was released in 1979, and the circuit’s designer says in an interview that it was created to compete with the BOSS OD-1, which was released in 1977. In addition, he says he was hired by Maxon in 1974 and his first circuit was the PT999, also released in 1974. It seems like it wouldn’t leave near enough time to design and finalize a hugely innovative overdrive circuit in the same year. Not to mention the fact that there is a very clear circuit-design progression from the MXR Distortion+ to the OD-880, to the BOSS OD-1, to the OD-855, to the OD-808, and putting the OD-808 back five years earlier in the timeline throws everything off—and if I may say so, it gives the designers a little too much credit by removing their direct influences.

So the next step would be to see if we can find any units produced before 1979. All we need is one inside a five-year span… but I can’t find any. The Maxon literature shows two different enclosure styles for the OD-808: a 1590B-size in 1974 and what appears to be the Ibanez style in 1979. Matsumin traced an original OD-808 (the website is in Japanese) with the first style, and while we can’t see any pot codes, the IC batch codes are “J932”, which almost certainly refer to the 32nd week of 1979. There are three more gut shots on Effects Database showing version 1, version 2 and version 3. In the v1 photo, the ICs say “J945” (1979 again), and you can also see the capacitor codes which say “7933” (clearly the 33rd week of 1979). The v2 photo uses a different brand of 1458 chip that says “8001”, probably the first week of 1980, and the v3 photo has a JRC4558 chip with a date code of 0280 which is 1980. (For JRC chips, a 4 digit code means it’s from the 1980s and the first digit is the year.[10] So, if it begins with 0 it’s from 1980.) Note that these date codes only indicate the earliest the pedal could have been manufactured, not the actual year of its manufacture—but that’s all we need here.

Based on the above, my conclusion is that the Maxon OD-808 was designed in 1978-79 and first released in 1979. The original release in the smaller MXR or 1590B-sized enclosure had two op-amps. There were two revisions of the PCB in this enclosure, which are the v1 and v2 photos on Effects Database. Later in 1979, they revised the circuit for Ibanez to create the TS-808 Tube Screamer which dropped down to one op-amp, but they continued production on their small-box OD-808 under the Maxon name. Sometime in 1980, they switched to the Ibanez-style enclosure for their Maxon OD-808 and also switched over to the TS-808 circuit with one JRC4558D op-amp instead of two MC1458Ps.

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Tube Screamer circuit analysis

There’s nothing I can say here that wasn’t already said much, much better in two other places: R.G. Keen’s The Technology of the Tube Screamer, and the Tube Screamer Analysis by ElectroSmash. I can’t top these two sources in technical expertise so I’m not even going to try! Another article worth reading is Tube Screamer’s Secret by BTE Audio.

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Notes & references

  1. State of the Stomp: Maxon’s Susumu Tamura Interview
  2. Green Giant: History of the Tube Screamer
  3. Maxon article on Wikipedia
  4. Maxon’s company history on their website, od808.com, says it was first developed in 1974, but for a number of reasons I don’t believe this is accurate. See the section later on down the page discussing when it was first released.
  5. Tube Screamer History – Analogman
  6. Thanks to Dirk_Hendrik for some info in this section regarding the Master Series and Soundtank series. His knowledge of Ibanez effects beyond the Tube Screamer is second to none.
  7. Other minor changes were made to the input and output buffers of the Metal Screamer, but nothing that affects the tone.
  8. Tonehome: Ibanez Power Series (10 series). Tonehome is the best resource out there for finding the dates of Ibanez pedals.
  9. This thread on freestompboxes.org is an interesting read. It’s a three-page discussion on whether the OD-808 was released in 1974 or 1979. As much as I respect some of the people who fall in the “1974” side of things, I have to disagree.
  10. Analogman and Stinkfoot talk about the date codes in this thread on TGP.