Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

Article Group:
Echo Unit Supplement

Ursa Major 8X32

Digital Reverb

The Ursa Major 8X32 is quite unlike the other units in this supplement because it is one of the few computer-based digital delay systems that produces reverberation. Since a natural space such as a large room, studio or concert hall each have their own complex pattern of reflected sound waves, the 8X32 has four basic reverberation programs that simulate these different environments, with fast and slow mechanical plate effects, a medium size concert hall, and a large echoing space having a phenomenal decay time of 20 seconds!

The control panel is suitably sophisticated for a unit of this price and, as well as giving visual signal monitoring, allows 64 user settings to be stored with comprehensive modification of the basic characteristics of any selected program.

Reverberation is simulated by three independent processing stages - first, the direct sound has 'Early Reflections' that give body to the sound and define the space size; second 'Initial Reverberation' forms the more distinct cluster of immediate reflections, and finally a dense indistinguishable mass of reverberation over a variable decay time is created. Each of these stages usually overlap as in a real acoustic space.

Early Reflections

Three delay taps create the Early Reflections and each delay program has a preset delay value for them which can be increased up to 98mS by using the +/- buttons below the long red LED display on the left side of the panel. The display shows the increase you set immediately above the buttons. Similarly, the level of Early Reflections can be set from 1 to a maximum 8 steps. The echoes are much cleaner here and only give slight colouration to the waveform.

Initial Reverberation

Initial reverberation is made from a cluster of 10 delays and this too has +/- buttons for increasing the preset delay up to 98mS, with volume level adjustment from 1 to 8, both shown on the display above. The left and right reflections are quite different and are complex waveform transformations that change for each of the four basic program settings.

Final Reverberation

The decay time for the dense final reverberation can be set in increasing increments that vary for each program: Plate I .0-5 secs, Plate II .0-7 secs, Hall .0-8 secs, and Space .0-20 secs.

An interesting bonus hidden in the 8X32 is that with zero decay time, the Early Reflections and Initial Reverberation controls can produce short delays for fattening vocals by doubling. You can also detect a stereo balance that is a left to right 'slap'. Longer delay times show complex waveforms with highlighting of harmonics for each program.

There are also two other 4-button sections on the panel with LED indicators for controlling low and high frequency decay. LF decay can be set to slope off at 20, 50, 100 and 200Hz while HF decay can filter off at 1k, 2k, 5k and 8kHz. These are not provided as you might think to tidy up the sound with noise or rumble and so on, but are made to act only on the final reverberation - keeping the Early Reflections and Initial Reverb at full bandwidth and thus retaining the clarity. These controls are most useful for adjusting the character for the reverberation to the particular instruments in use. For example, cymbals can be cut out of the final reverberation by setting HF decay at 5, 2 or 1 and bass drum booming is removed by setting LF decay to 100 or 200.

At the centre of the front panel is an LED display that shows both input (by a vertical row) and reverberation (by a sloping row), calibrated from -36, 30, 24, 18, 12 and 6dB to 0dB 'overflow'. Like any digital system input, a maximum input is desirable without reaching the overflow point, although the unit's tolerance to strong peaks is very good.

Two other controls provide Input Mute on or off for straight through signal, and Reverb Clear for emptying the memory of decaying sounds instantly. The latter actually resets to 0.2 decay time and also takes part in saving program settings.

Program Storage

Up to 64 'registers' can be stored in the non-volatile memory which is more than enough for most purposes. This is done by dialling 2 digits with buttons numbers 0-9 as shown in the right-hand display. Once a stored program is recalled, you can modify the panel controls as you wish and load the new program into another register. The moment a control is changed, edit mode is indicated by two dots either side of the program number. A-B comparison of original and edited programs is easily done and a safety locking feature stops other people corrupting your programs at a performance.

Reverb Types

1. Plate. This simulates the reverberation produced by a plate device with a small, fast diffusing surface and its sound is bright and effective for percussion or adding body to a vocal or group sound.

2. Plate II is like a larger plate whose smooth reverberation diffuses more slowly and has a more stable ring to it.

3. Hall. This is very good indeed for true concert hall effect - solo instruments take on their correct acoustic image without any harshness but more 'rippling' reflections are present during long decays. The sound is rich and complex, with high frequencies decaying more rapidly than low or middle frequencies.

4. Space. This unit would be quite good enough with a maximum Hall decay of 10 secs, but to have this final program extending the decay to 20secs has to be heard to be believed. It's an unnatural effect that's more like drifting into space to infinity and can be very impressive with electronic music.


Top layer of circuitry (with second layer mounted underneath).

A remote unit is available that duplicates the panel controls and program updates are likely to be issued from time to time. The CPU board will be updated for automated mixdown or remote computer control (RS232 interface) via a rear 15 pin connector. Left/right inputs and outputs are via XLR-3 sockets. Both are active differential types with inputs summed together before processing and outputs balanced. The unit is 19" rack mounting, measuring 3½" high and 15½" deep.


This word has to be used for the 8X32, although I'm tempted to say that for its price tag of just under £4,000, it deserves to be. The front panel display presses in unusually on its foam backing for no apparent reason, although general construction is up to professional standard. Its dynamic range is 80dB, which is quite acceptable for a delay machine, although some criticism is made by others about its limited bandwidth - only 8kHz, from its sampling rate of 20kHz. I personally found this no problem at all. In practice, the 8X32 has to be highly-rated and its high cost must be due to the large number of IC components and its original and authentic software-derived programs.

The Ursa Major 8X32 is distributed in the UK by Feldon Audio, (Contact Details). Feldon Audio also hire out the 8X32 for £75 a day. Ask them for their hire leaflet, mentioning E&MM please.

Previous Article in this issue

Enter The Time Domain

Next article in this issue


Electronics & Music Maker - Copyright: Music Maker Publications (UK), Future Publishing.


Electronics & Music Maker - May 1983

Echo Unit Supplement

Gear in this article:

Studio FX > Ursa Major > 8X32 Digital Reverb

Gear Tags:

Digital FX


Previous article in this issue:

> Enter The Time Domain

Next article in this issue:

> KORG SDD-3000

Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Please Contribute to mu:zines by supplying magazines, scanning or donating funds. Thanks!

We currently are running with a balance of £100+, with total outgoings so far of £1,046.00. More details...

Small Print

Terms of usePrivacy