Alesis Quadraverb Patch Editor

| 16-09-2021
[RAND-1-100] Comments

Bob Page, February 12, 1989

This information is presented in the hope that it will be useful, butno warrantees about its accuracy are expressed or implied. I'minterested in any changes/additions you have. Feel free to use thisinformation in any way for any purpose, but please don't pretend youwrote it (leave my name in this document). I'd be happy if you sendme code you write based on this info, but of course that's up to you.

Alesis quadraverb patch editor download

The QuadraVerb 2 comes with a power adapter suitable for the voltage of the country it is shipped to (either 110 or 220V, 50 or 60 Hz). With the QuadraVerb 2 off, plug the small end of the power adapter cord into QuadraVerb 2’s POWER socket and the male (plug) end into a source of AC power. Inside, the QuadraVerb has a quoted frequency response of 16Hz-2OKhz and a dynamic range of 85dB. It contains a custom-designed VLSI chip with 16-bit resolution and 24-bit processing. What all this means is the effects are pretty smooth and the background noise is fairly low.

A MIDI patch editor to help you with your work. QuadEdit is an easy to use, handy midi patch editor specially designed for the Alesis Quadraverb GT effects processor. QuadEdit can load patches. The Alesis QuadraVerb is a 16Hz-20kHz bandwidth stereo programmable effects box with four digital effects (EQ, Pitch Change, Delay, Reverb). The effects can be used in parallel or in serial (or a combination). Selftest: To perform the QuadraVerb's self diagnostics connect a MIDI cable between MIDI in, and MIDI out.

Alesis is currently saying they are not going to release the QuadraVerbinfo 'at this time'. That could mean the 'format' is subject to change,or they are withholding the info until some pet software companies get QVpatch editors to the market, or maybe some other reason, I dunno. In anyevent, I needed the info, so I created it. And on with the show...

Contents:

  • System Exclusive Command Format

QuadraVerb System Exclusive Data Encoding Format

You first need to understand how the QV encodes its data for MIDItransmission. Although all 8 bits of a byte are used internally, theMIDI specification reserves the highest bit for status messages, sothese high bits have to be 'removed' from the data stream. The 8-bitQuadraVerb data is encoded for MIDI transmission into 7-bit data. Theencoding looks like this:

Seven QuadraVerb bytes (each line represents one byte):are transmitted as eight MIDI bytes:Here is a C fragment to decode the data (note that you don't want todecode the SysEx status messsages; they are not encoded):All the info given below assumes the data has been decoded. If you aregoing to send the data back to the QV after editing it, you have to encodeit first. Code fragment left as an exercise for the reader.

Note you have to tell the QuadraVerb to accept MIDI SysEx data before anyof this will work. Although it's possible to instruct the QV to disableSysEx via MIDI SysEx; it's not possible to re-enable it; you have to go doit from the front panel.

A QuadraVerb SysEx command string looks like (in hex): The command codes are: The parameters depend on the command and are discussed below.

To have an external device request a QuadraVerb program dump, send thefollowing MIDI sequence to the QV:where '03' is the 'dump data' command, and 'pp' is the hex parameter:Keep in mind if you're doing many edit/compares on program 27 youprobably want to be dumping the edit buffer, not program 27, as #27 isonly modified once the STORE is done.The format is similar:where 'pp' is the same as in the above description. The data must beencoded before being sent. If you do it right you should send 155 bytesout the MIDI port (including SysEx etc) for an individual program.where 'gg' is the 'parameter group' you want to change:and 'pp' is the parameter number within parameter group (for example in'reverb', parameter number 0 is 'Reverb Type', and the numbers increasethe same as if you used the PAGE UP key).

The 'dd dd dd' string is the value you want in that parameter. It must beencoded, even if it fits in 7 bits. Sometimes the value takes two bytes;in that case they should be sent MSB first, then LSB (this is the oppositeof the HR-16). When one byte is encoded it will become two bytes;likewise two become three. If you're sending two bytes (after encoding)send them first, then 00, then f7.

The QV will also send you these Change Parameter requests every time aparameter is changed using the front panel. If somebody selects the DelayTime parameter and pushes the button to go from 1 to 400ms, you're goingto get 400 of these messages. You will get messages every time the VALUEbuttons get pushed, even when nothing changes (like being in program modeand pressing the down key when you're already at program zero), so beprepared for them.

Alesis Quadraverb Patch Editor Free

You can't send running parameter change requests; each one has to bea separate SysEx message.

A single program has 128 bytes of data. When it's encoded and shippedover MIDI, it's 147 bytes (without SysEx headers). That's why the decodefragment above has that magic number in it.

Unused locations have zeros in them. The EQ bytes change meaningdepending on whether graphic EQ is being used, so both are given.Everything here is listed in decimal.

Graphic EQ parameters, only used in the Graphic_EQ->Delay configuration:Graphic EQ also seems to change all modulation targets to 16Hz boost/cut.

Alesis Quadraverb Patch Editor Download

Here's the complete list, in byte order. Note that all parameters havea 'default' value you can get by pressing both VALUE buttons at the sametime - if you're building a patch editor you might want this info so youruser can hit a button to get the default value for some parameter.

The target numbers are not constant; it depends on what configuration youare using, so you can't always change the target to #48 and know it alwaysmeans your modulator affects Low EQ Frequency. What a pain.A full dump is all 100 programs, end to end. HOWEVER, the MIDI encodingstarts over at each program (that's why you see the i %= 147

Alesis Quadraverb Patch Editor Software

statement inthe decoding fragment above). The edit buffer is not dumped on a fulldump, so after decoding, your data should have 12800 bytes.

Alesis Quadraverb Patch Editorial

No MIDI parameters are ever dumped, and there is no checksum information.I don't know how to get the version of the ROM (without opening the case).