Modded ART Multiverb,
"re-clocked" with LTC1799 Oscillator Module

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This is an Art Multiverb LT from 1990. It is a very a basic, budget digital reverb and multi effects unit with some really cool fake "plates" and gated reverb sounds. This overclocking / re-clocking mod makes the unit have extremely bizarre, bit-crushed effects for a wide variety of applications by replacing the fixed timing crystal found in the unit with a modern LTC1799 precision oscillator and variable controls.

This is a demo on a dry snare drum track. My signal chain was the snare drum track sent out of Pro Tools into the left mono input of the Multiverb, and then the stereo out of the Multiverb back into Pro Tools. I/O was through Burl Mothership converters.

These are the main controls. I decided to add two "modes" on a switch, which are just two different pots. "Normal" is a 100kOhm audio pot, "Extreme" is 500k for a wider range of adjustment. I also added a power switch to the front panel as the Multiverb is always powered on otherwise.

In the video, I power-cycle the unit when using the "Mode" switch. You CAN switch between them on the spot but then the control buttons no longer function and the unit remains stuck on the preset. I tried putting a big resistor in parallel with the "Mode" switch but I didn't like what it did to the taper of the pots.

I did these mods based on the guide available from Circuit Benders (link below). I made a small circuit board for the LTC1799 oscillator IC based on the data sheet and Circuit Benders adaptation of it. I have a link to order this PCB further down. The trimmer on the PCB is used to fine-tune the clock speed to ensure the control pots on the front panel are actually usable.

As standard practice, I replaced all of the electrolytic caps throughout the unit as the originals were starting to physically bubble and leak. The new power supply caps are wired in kinda funny because I just used the values I had on hand and had to make them fit. I always use electrolytic caps manufactured by reputable companies such as Nichicon, United Chemicon, Rubycon, or Panasonic. I wasn't able to find a schematic for the Multiverb so all replacements were just eyeballed.

Fairly important to note: My unit had a LM2940CT-5.0 voltage regulator which got toasty and burnt up the PCB. I had to re-do some traces with wire becuase of this poor design. I moved it off the board and drilled it to the chassis as a proper heatsink with CPU thermal paste. This tip was lifted from the Circuit Benders guide, as well.

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