Ibanez vintage MSL (Metal Screamer) TS808 modded

I just love the Masters Series (“L”) and Power Series (“10″) from Ibanez ! For a few bucks, you can get a MSL on eBay, full of vintage mojo components ! I like very much my TS10 and I find the MSL lacking “honk”. The adjective “metal” in this pedal is purely marketing, only bandwidth is different from a TS10 (more bass, less honk) …

Ibanez MSL Metal Screamer vintage modded TS808 1The components are “vintage” and full of mojo ;-) … so rather than seek the Holy Grail TS808 several hundred dollars, why not turn this  quite inexpensive MSL into a TS808? The MSL shared with my beloved TS10 the same printed circuit, some components in addition, a different capacitance value in the feedback loop of the op-amp clipping (I suspect of being guilty of the disappearance of honk), and resistance values ​​of the output like TS9 (ie the couple 470R / 100R instead of 100k / 10k to TS808)

Here is Ibanez MSL schematic :

MSL Ibanez Metal Tube Screamer Schematic

and there is a TS808 schematic (thanks to ggg)

Open the door, Hal …

Ibanez MSL Metal Screamer vintage modded TS808 3

Step 1:
Let’s see the polarization of the first transistor. On a TS808, the input stage is biased at V / 2. Here it is a bit higher (R2 / (R2 + R3)) x V, we will fix it. Good thing the jumper J5 is at a potential of V / 2, that’s exactly what we need !

Ibanez MSL Metal Screamer vintage modded TS808 4Jumper J5 stands near the input jack :

Ibanez MSL Metal Screamer vintage modded TS808 5

We will remove R2, R3, and C2 and solder a jumper between the location where was the + of C2 (C2 – R4) with jumper J5. And that’s it :

Ibanez MSL Metal Screamer vintage modded TS808 6
Step 2:
We will now replace C6 82nF capacitor by the appropriate value for TS808: 47nF. I use a good quality Panasonic V-Series (ECQ-V) polyester metallized layer. Polypropylene would be welcome, but they are far too big …

Ibanez MSL Metal Screamer vintage modded TS808 7

Ibanez MSL Metal Screamer vintage modded TS808 8

Step 3 (optional) :
Well well, the presence of electrochimic capacitors (not polarized) 1uF C3 and C10 bother me a lot … I prefer to replace with 1uF Panasonic … let’s do !

Ibanez MSL Metal Screamer vintage modded TS808 9

Step 4 :
We will remove all the stuff before the op-amp, including (according to the diagram): R6, Q6, D4, C4, R7, R8, C5, R11. R11 will be replaced by a 10k, and we will place a jumper between C3 and the input 5 of the op-amp :

Ibanez MSL Metal Screamer vintage modded TS808 10

Ibanez MSL Metal Screamer vintage modded TS808 11(Please note ont this picture C3 and C10 Panasonic ECQ-V 1uF)

Step 5 :
The MSL (such as TS10, TS808 etc..) is not “true bypass”: it uses a flip-flop transistor based. On the MSL, a transistor audio stage was added, we will remove it. This transistor is Q6, so there are two Q6 transistors identified on the Maxon printed circuit (don’t care, we will suppress both anyway) : we will remove the Q6 and R39 and R40 and connect C15 to the emitter of Q1 via a jumper. We will also replace the two output resistors R21 and R22 by “good values”​ (100R, 10k)

Ibanez MSL Metal Screamer vintage modded TS808 12Ibanez MSL Metal Screamer vintage modded TS808 13

Final step :
I replace all coupling resistors and capacitors with carbon comp resistors and capacitors Panasonic …

Ibanez MSL Metal Screamer vintage modded TS808 14Ibanez MSL Metal Screamer vintage modded TS808 15

So how does it sound like ?
Very sweet overdrive, a lot of honk (TS808 720Hz typical frequency), full of sustain and harmonics … a great mod !

Very good reading :
R.G. Keen « The technology of the Tube Screamer » – Steve Cerutti – dolhop at canada dot com : see very interesting document here

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9 Responses to Ibanez vintage MSL (Metal Screamer) TS808 modded

  1. Mike N says:

    Awesome tutorial ! I just finished mine and it sounds great ! Waiting for green paint to dry, and then it’ll be back on duty !! Also, if you ever edit this tutorial….you can make a note that removing C4 “gives up” the .047uf that will go in at C6.
    Once again THANKS for a great lesson !
    Mike

  2. t-geek says:

    Hey, well done, Mike ! Did you mod a MSL ?
    You are perfectly right regarding C4 (47nF) !!!

  3. AyoPasts says:

    Do you have a list of the components needed? and maybe a reccomended site to order from? I know how to solder but i mostly work on car’s, this is kind of a first project like this for me. xD

    • t-geek says:

      Hi,

      See the text, AyoPasts : you will need a 47nF and a 1uF capacitor (I like Panasonic ECQ-V series) and two 10kΩ and one 100Ω resistors.

      You can buy this at mouser.com

      Cheers

      • AyoPasts says:

        Thanks for the reply! I’ve had this pedal sitting in my draw for the longest time and its sweet to finally do something with it, Wish me luck!

  4. Greg S says:

    What is the benefit of step 5? Is there bad tone when the pedal is bypassed? Why did Maxon add the transistor audio stage? I have one of these on the way.

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