# Sequential Circuits MAX

MAX, Sequential Circuits @ 07 February 2019

“This Synth has been modified with the addition of the following features:

• 100 sounds, all downloadable, located in battery-backed RAM

• Note storage increased from about 500 to about 3200

• Unison mode added.

• Three sets of 100 factory sounds in EPROM: 80 Max + 20 Six track Unison factory sounds, 100 Six Track factory sounds, and 100 Multi-Trak factory sounds (without chorus or velocity sensitivity, of course)

• CC parameter changes to current program can be saved to program 99, then copied to any other program

• MIDI receive buffer increased from 64 bytes to 128 bytes

• Removed code that reduced volume of subsequent notes if CC change received while MIDI note with low velocity playing. This a code bug in the original EPROM.

These features were added by upgrading both the EPROM and the type/amount of RAM. The Max shipped with a 128K EPROM and two 2Kx8 SRAM chips. This modified Max has a 256K EPROM and a single 32Kx8 SRAM chip (only 16K is used). The modification is a small PC board which holds the EPROM and NV SRAM. This board plugs into the existing EPROM socket on the Max. Five additional wires connect from the Max main board to the new memory board. In addition, the two SRAM chips on the Max main board have been disabled. See more info by googling “Sequential Circuits MAX Mod Page – Tauntek”

-Power Adapter


The original NON-Modded Sequential Circuits Max was designed as a companion to the Six-Track, Multi-Trak and possibly the C64 personal computer. It relied on MIDI messages for parameter changes, having no on-board way to vary them. It came with 80 “factory sounds” in EPROM, and storage for 20 more in RAM, which could be used after downloading via MIDI. Two “songs” or sequences could be recorded and either stored in RAM or dumped to MIDI. No battery back-up was provided for RAM, so all song data and the 20 programs were lost when the unit was powered down.

Synth is in great working condition. Guaranteed to be operational. Returns accepted if Synth is not working as described.
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