Recording Tricks: Digitech TSR-24S, TSR-24

Digitech TSR-24S, TSR-24 reverb/effects

  • Update the TSR-24 to TSR-24S

This underrated reverb/effects unit was made with two versions. The TSR-24 (True Stereo Reverb, 24 bit) was replaced by the TSR-24S. The "S" version adds many new algorithms and increases the maximum delay time. Owners of the TSR-24 can upgrade to the "S" model with version 2.0 of the system software, which was still available from Digitech as of March 2003.

Contact Digitech to buy the 2 chips to make it a 24S (details below). It might take some digging to find/buy the chips since these reverbs have been out of production for a while. Make sure you get the 24S manual, since there were a bunch of new features, and make sure you recieve two chips. Also available is (was?) the PPC-200 expander module to increase memory and add more algorithms.

Here are the details from when I ordered the TSR-24S chips in December 1994. Item #s 72-3076-09V2.00 (EPROM #1) and 72-3076-10V2.00 (EPROM #2) aka "TSR-24S V2.00.00 EPROM 27C020-15". On the packing slip, I noted that chip #1 is the one that goes "closest to the transformer." I assume that this means the power supply.

For more info, contact Digitech, or peruse their user forums.

Here is an upgrade report from Steve Devito, who says that the hardest part was "to get the Digitech guys to listen to me on the phone, alas after 3 weeks of trying they got it right." After that, he successfuly upgraded his unit (March, 2003). Here's how:

Note that you will lose all your presets by doing this upgrade. If you want to keep them, consider a bulk MIDI dump or individual program dump. (I don't know, though, if older TSR-24 programs will seamlessly load back into a TSR-24S.) Or, write down your most important settings on paper.

Take the screw (above the T of TSR) on the back panel off.

Take the three screws on each side off.

Take the screw on the top of the unit off.

Take the four hex nuts out (7/64" hex-head).

Remove the cover panel

Locate the chip that should read V1.01 TSR24. This slot should be marked E0(U30) on the board

Remove this chip.

In the now empty slot align your v.2 chip # 1

DO NOT PUT THE EPROM IN BACKWARDS! This can damage the TSR24 unit.

This is a tight squeeze so take time to ensure that all the pins are properly aligned to the slots that will receive them.

Make sure that the "half circle" notch on the top of the chip is facing toward the rear panel of the unit.

Gently push the chip into place.

Locate the slot that should be marked E1 (U33).

Insert chip #2 into this slot using the same method as chip #1.

(don't leave your tools inside the unit)

Close up the unit

Power up the unit with the number 1 access key depressed. Then after a small asterisk appears in the upper left hand corner of the display push the program up arrow button. This will reset the algorithms to their factory presets for v2.0. The display should read "Resetting... Please wait..."

That's it!

For a quick test, hit access key 4 to see if it brings up the tuner. If so, you should be upgraded.

Stock for the upgrade chips is running low so hurry if you want to do this. (as of 2/26/2003)


- Do not lift the unit by the front panel while the cover is off, it feels loose and could break.

- As with any electronic equipment, make sure you are static - grounded before opening and operating on the unit.

Thanks, Steve!!

  • reinitialize to factory presets

WARNING: this will erase all user-stored presets! To renitialize to factory presets: hold Acess1+ Power up. Then press Up Arrow.