Robert keeley Ibanez TS9 Tube Screamer Mod Plus pedal

Robert keeley TS9 MOD plus Tube Screamer

Swapped Components

​The standard op-amp chip (TA75558 or Toshiba) replaced with a Texas Instruments RC4558P chip installed in an 8-pin DIP socket.

​The two output stage resistors (470 ohm and 10k ohm) swapped out for 100 ohm and 10k ohm resistors to match vintage TS808 output specifications.

​Key signal path capacitors changed from stock electrolytic/tantalum parts to high-tolerance metal film capacitors.

​The RC filter capacitor in the gain stage upgraded from 0.047uF to 0.1uF.

​Resistors adjusted in the feedback loop to increase maximum drive capability while allowing the pedal to turn down cleaner.

​The clipping section diodes swapped or modified for asymmetrical clipping.

​The dim stock red LED replaced with a high-brightness blue LED.

​Sound Benefits

​A warmer, smoother high end that eliminates the harsh upper-mid range glare.

​Restored low end and tighter bass response without making the tone muddy or flubby.

​Increased clarity, overall dynamic range, and transparency when playing lower-gain settings.

​A wider range on the drive knob, offering cleaner low-end cleanup and more gain on tap at the max setting.

​A noticeably lower background noise floor and reduced idle hiss.

Pedal never gigged and in mint condition. I'll cover registered postage if within Ireland.