Ibanez / Stratus TS-9 Clone Pedal Repair

What do we have here? This pedal is completely custom inside and out.  Who made it?  And why does it not work?  Can the Unbrokenstring Crew decipher this jewel and get it working again?
Matt received this as a gift after a live show, from an appreciative fan.  It has an honored place on his pedal board.

 

Google is of absolutely NO help deciphering any of this text.

 

Very nice circuit board!  This is a Tube Screamer circuit, with several types of LEDs and diodes selectable in the clipping circuit.  Nearly every aspect of the circuit topology is ‘bend-able’ in this pedal.  Very cool!

 

This unit uses a very nice, high-quality Burr Brown operational amplifier chip and precision components throughout.

 

Our principle problem is immediately apparent.  See the broken wire on the output jack?

 

We have another broken wire on the switch.  Solid (unstranded) wire is easy to work with, but is prone to cracking and breaking more quickly than stranded wire.  But solid wire is widely used in the pedal building world.

 

Stratus is a supplier of ‘build your own clone’ pedal kits.  Their catalog confirms that this is a Tube Screamer clone.  Oh, and we found more broken wires.

 

The common ground circuit at the output jack relies on the conductivity of the enclosure.  When the enclosure is painted, as this one is, one can have an intermittent electrical connection.  Here, I’ve removed the jack to scrape some paint and add a toothed lock washer for better connection to the pedal enclosure.

 

This tool is handy to keep jacks from turning while the nut is tightened.  These are designed for hollow-body guitars, but work almost anywhere a quarter-inch jack is found…  for instance, here.

 

I wonder whose cat this is?

Thanks for reading all the way to the end!

CONTACT – David Latchaw EE
281-636-8626

Ibanez TubeScreamer Pedal Repair

Steve said that his Keeley-modded Tube Screamer pedal had quit.  Could the Unbrokenstring Crew bring it back to life?

This pedal is in great shape cosmetically!

Robert Keeley made a few circuit changes that are well-documented on the Web.  This pedal has those changes.

The battery box has its own lid.

The bottom of the pedal is shielded with the metal screen seen in the center.

A die cut sheet of black insulative material protects the circuit board from the metal shield.

Let’s get it all out of the enclosure so that we can work on it.

We’ve applied battery power and connected up to my Marshall Stack.  The original problem is still with us.

An oscilloscope probe verifies that the dual operational amplifier is defective.  Part of the Keeley mod specifies a Texas Instruments 4558 dual op amp.  This IC is socketed, so replacing it is trivial.

Here is an example of the softly clipped audio that the Tube Screamer delivers to the amp input.

Reversing the disassembly procedure is all we need to do to get this cool little pedal back together again.  We’re done.

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE
281-636-8626