the guitar room
the amp room
the effects room

 

Ibanez Tube Screamer

the green monster

Short history

The first Tube Screamer is the venerable TS-808 Overdrive Pro, introduced somewhere around 1979-1980 (I don't have an exact date here). There were predecessors (OD-850 and OD-855), but the 808 was the first one to be named "tube screamer", so that's where we start. Almost all of the TS-808s used either the JRC 4558D or the TI RC4558P chip. These pedals are very expensive these days, unless you come across one at a garage sale of course. Ibanez recently reissued this pedal, using the same components (pcb and pots) as in their reissue TS-9, but using the right output section and a (new) JRC4558D IC.

 

Around 1982-83 Ibanez introduced the "9" series, with a completely redesigned exterior, and the TS-9 Tube Screamer was born. The main differences from the 808 were a few resistors in the output section (presumably to make the pedal mate better with transistor amps), different pots (design, not value) and op-amp chip. A few TS-9s had the JRC 4558 chip, but most were shipped with either the JRC 2043 or the TA 75558. Original TS-9s are starting to get real expensive as well, but in Sweden you can still find them at about the same price as a new reissue unit.

Note: The "9" series also contained the TS-9s bigger brother: the ST-9 Super Tube Screamer. Essentially a TS-9 with a "mid boost" control, painted dark metallic green. Not to be confused with the later TS-9 DX. The TS-9 circuit was also used in the UE-300 mains-powered floor multi-effects. I used to own one, and of course I sold it... and how I regret it now! I wonder where it is now? Hmm... Anyway, read more about the UE monster here.

 

Just a few years later - in 1985 - the "9" series gave way for the "Master Series" - which looked just like the more well known "10" series, but with mostly black casings. Interestingly enough, Ibanez didn't carry the Tube Screamer over to the Master Series - they kept the oh-so-rare Super Tube Screamer instead, tweaked it a little (the pre-distortion mid boost circuit was moved to become a post-distortion mid boost) and called it "Super Tube" (STL). In 1986 Ibanez replaced the Master series with the "Power Series", which is the one also known as "10", and the TS-10 Tube Screamer Classic was born. The TS-10 can be had for a lot less than a 9, and will sound close enough, if not just as good. They are harder to mod to 808 specs, though, as the TS-10 not only had component value changes (like the "9") but also several new components that weren't there before. The input/output jacks are mounted directly on the pcb, with no support from the box, and will eventually fail. It's still a great pedal, and not too expensive. You might even get it cheaper than that, if you find one that's broken. Nine times out of ten, it's the jacks that have failed - if you remove them carefully, you'll be able to glue them on to the pcb before you solder them back in. Fixed! BTW, this construction weakness (or bargain opportunity, depending on how you see it) goes for the whole "10" series.

 

The later "Soundtank" series (the one that was supposed to look like a tank, but mostly reminds me of a bug) also had its version of the TS: the TS-5 Tubescreamer. Apparently (I haven't heard one myself) it sounds darker than the others, and therefore not as appealing. They are cheap enough, though, so buying one just to have it won't clean you out. It has the same weak spots as the "10" - pcb-mounted jacks that just poke out of holes in the enclosure, without support. This one also has its pots mounted the same way, plus the enclosure itself is plastic... Apparently, in its first incarnation the Soundtank series had metal enclosures. The series then consisted of six (!) different od/dist/fuzz boxes, and nothing else! The second time around, when the TS-5 first appeared, they switched to plastic. I guess this is why you don't see many Soundtanks around - they're all busted up...

 

Even later (and still in production) is the TS-7 Tubescreamer. This is the one with the "gain" switch and the funky "pop-up" pots. From what I hear, this one is pretty good, and easy to mod as well. It belongs to the "Tone-Lok" series (no doubt referring to the pots being "locked down" when not in use). Most of the TS-7's have a JRD4558 op-amp (instead of the JRC version) which apparently doesn't help the pedal very much. Later versions of this pedal have the JRC4558D, but I don't have any particular date when that change happened. Nevertheless, it's a good deal if you want to try out a 'screamer' without having to shell out for a TS-9.

 

Then came the reissue TS-9 Tube Screamer, which is a more or less exact copy of the early '80s pedal, and in 1998 the TS-9 DX Turbo Tube Screamer appeared - a TS with three added modes. Both of them use the TA 75558 chip exclusively. In 2002, Ibanez took over the production of these pedals from Maxon - possibly because Maxon decided to reissue the 9 series on their own. The latest model is the reissue TS-808, which basically is a RI TS-9 with an 808 style case. It uses the same circuit board, pots and components as the TS-9, and apart from the cosmetics, the only differences are the two output resistors (which are changed to 808 values) and the op-amp chip (current production JRC4558D). It looks cool, though, so I predict it will sell well.

Update: around 2006-2007, the Ibanez TS-9 and TS-9DX started shipping with the current production JRC4558D, possibly because the TA75558P isn't RoHS certified and therefore can't be used in equipment destined for sale in Europe. So since then, brand new TS-9's are even closer to the reissue TS-808.

For a detailed look at the NOS vs current production op-amp debate, go here.

 

Cousins

Few guitar effect circuits has been more copied throughout history, and here are just a few:

 

How do I mod it?

As stated above, the main differences between the TS-9 (original and reissue) and the TS-808 are the output resistors and the op-amp chip. Modding a TS-9 to 808 specs means replacing the resistors and the chip, and that's it. Of course, Ibanez has already done this with their reissue TS-808, but you can easily mod yours to the same spec. First off, you need to find the right chip - the JRC4558D and RC4558P (which were the main chips used in the TS-808) are still in production, and will cost you next to nothing at an electronics store. There are also NOS (New Old Stock) JRC4558D chips floating around for sale - op-amps that were produced in the good old days, but never got used. Now, a big part of the reason why a '79 TS-808 sounds the way it does is because it's been in use since then. Over time and use, electrical components start to deviate from their original specs. On the other hand, while a NOS part may be the same age as the '79 808 mentioned above, it has a main difference - it's never been used. That puts it (in my book) a lot closer to the new op-amp than the one that's been in use since 1979.

There are differences between the various chips, of course, and you can read the full story here. The short version is that the RC4558P you will find in some of the better-sounding TS-808's is still in production, and sounds exactly the same as the old parts (minus the 20 years of use, of course). The JRC4558D that is being produced today is not exactly identical to the NOS JRC4558D chips available - the factory moved from Japan in the mid-to-late 80's, and chances are that their new production line are different from the old one, making the chips sound slightly different.

If you absolutely have to have "the real thing", and don't want the RC4558P, you have two options:

  1. Locate a japanese transistor radio from the early '80s in the attic and take it apart. Inside you'll probably find a whole bunch of JRC4558D chips, properly used and age-treated.
  2. Pay up for a NOS unit

The third option would of course be to just go to Mouser and get the reissue one. It might sound ever-so-slightly different, but... I prefer it over most of the others anyway, including the RC4558P, and if your pedal is a reissue TS-9 with the TA75558P, you will definitely notice an improvement. Anyway, whatever you do, make sure you fit an IC socket - that way you won't damage the chip, and you can pop in different IC's as you please.

Suitable IC's for a TS-9 are:

But honestly, the op-amp chip is not by a longshot the big defining factor in the Tube Screamer sound. The famous overdrive doesn't happen there at all, but in the clipping diodes, so don't take the chip thing too seriously. Of equal importance when doing the 808 mod is the fact that the output section of a TS-9 differs slightly from the 808 - two resistors needs changing. Replace the 470 ohm resistor with a 100 ohm, and the 100 Kohm with a 10 Kohm. That's it. I'd detail it a bit clearly for you, but there's no need - it has already been done way better than I would have. Just check out this great photoessay at Tonepad.com.

 

Other mods

Dating a TS-9 back to 808 specs isn't the only way to make it sound better. One thing that always annoyed me was the lack of bass response - it seemed that the only time the TS-9 sounded at its best was at loud levels. Like it or not, a big part of the Tube Screamer sound is that it actually doesn't distort the lower frequencies at all, it just lets them past the distortion circuit. A capacitor/resistor network restricts the low end going into the clipping stage, and at current values (4.7K/0.047uF) it starts to roll off at around 750Hz. Change this cap for a bigger value, say a 0.1uF, and you'll lower the corner frequency to about 340 Hz, enough to give yourself more bass. This will also make the pedal "growl" a bit more on the lower notes.

More/less gain - the resistors in the distortion network can be changed to give you more gain at the higher end of the pot, and less gain at the lower end. In between you'll find all your old sounds. This will make the pedal more useful, both as a clean(ish) boost and as a distortion device. Be careful, though, as any resistor value changes in a res/cap network (such as the one described above) will also change the frequency response of the network. For instance, if you lower the value of the 4.7K resistor, to give yourself more gain, you will also have to raise the capacitor value accordingly to keep the same frequency response. In other words: a 2.2K resistor needs a 0.1uF cap to keep the standard bass rolloff. To get the added bass response as described above, but with the extra gain the 2.2K resistor provides, the cap would have to be 0.2uF (or thereabout - find the closest standard value).

"Brown" mod - not really a mod per se, as it doesn't change the circuit, but it's still an option preferred by some. From what I've gathered, it involves replacing five key resistors (sorry - I don't know exactly which ones) using '60s style carbon composition resistors, claimed to have a smoother, rounder sound than modern carbon or metal film types. This resistor type is no longer in production - due to excessive noise and too much variation between components, they were phased out long ago. Do they really sound better, or is it just another "mojo"? You be the judge - at least now you know the theory involved.

Asymmetrical clipping - in a TS-9 the diodes do the actual distorting. If you replace one of them with another type of diode, the distortion will sound different, as the "up" and "down" part of the wave will clip differently. You can also try adding a diode in series with one of the others, giving you two diodes in one direction and one in the other. This will increase the amount of 2nd order harmonics (one octave up) in the sound, and make the overall louder. But you don't have to install extra diodes to get the clipping out of sync - changing one of them for another type will do that too. Different diodes can dramatically alter the overdrive character. LEDs in general clip later than than silicon diodes, producing a cleaner tone with more dynamics and output. Germanium diodes go the opposite way - they clip earlier than silicon, producing more drive and saturation.

Boss SD-1 to 808 specs - The SD-1 is very much like the TS-9, and can be modded into a poor mans' TS-808 quite easily. The main operational difference is that the Boss unit uses asymmetrical clipping, while the Ibanez doesn't. The story is that Apparently Roland/Boss had the asymmetrical clipping idea patented. I don't know if this was ever true, but to this day the two companies have stuck to their designs. A 808-style SD-1 will have a bit more gain and grit than a modded TS-9, due to different pot values and such, but for the money it's a great deal. However, changing the SD-1 circuit completely into an 808 is a bit more involved, but the point of this simple mod is to make the SD-1 better, not to make it imitate another pedal...

 

Don't feel confident enough to mod your own pedals? On the "Soldering 101" page there are a few tips and tricks. Also, in the links section there are links to people who will gladly do the job for you. If you live in my area (Sweden or the European Union at large) I can do all these mods (and more) for you. Just click the logo and you're there!

 

© 2002 - 2009