Classic Recording Studio Equipment

Vintage Digital

Ensoniq DP/4 Parallel Effects Processor

Ensoniq were a keyboard manufacturer back in the 1980s, but their legacy seems destined to be their first multi-effect processor, the Ensoniq DP/4. Using their experience from keyboards and samplers, Ensoniq developed their first effects processor in 1992 towards the end of their keyboard era, and to this day, the Ensoniq DP/4 is still sought being after.

Ensoniq DP/4 Parallel Effects Processor Details

As a musician you are required to perform in many different situations, and to be flexible enough to adapt to any musical setting. We believe you should expect no less from your gear, presenting the Ensoniq DP/4. That’s the idea behind the new Ensoniq DP/4 Parallel Effects Processor – flexibility to perform in any situation, extensive programming capabilities and the highest quality sound possible.

To give you this power, we took a unique approach. Based on the concept of parallel processing from the computer world, the DP/4 has 4 discrete processors (called unit(s) A, B, C & D), each capable of producing 24-bit dynamic stereo effects. Each unit is a complete effects device unto itself. – it takes only one of these processors to provide a host of multi-effects.

But with 4 units the Ensoniq DP/4 has the power to produce the highest quality multi-effects without ever sacrificing sound fidelity. This approach also means that each effect you choose has a complete set of programmable parameters, for total control of your sound. The DP/4 has 4 inputs and 4 outputs allowing you to process up to 4 different signals at the same time.

It also has a digital patch bay giving you the flexibility to route signals from mono or stereo sources, in series or parallel configurations. A built-in sub mixer controls signal output, maintaining multiple stereo images with 4 outputs, or even mixing 4 sources down to 2 outputs. This gives you the flexibility to process 1, 2, 3 or 4 separate sources at the same time, with over 30 possible signal flow choices.

Each processor in the DP/4 is capable of producing up to 43 different true stereo effects, as well as 3 additional multi-unit algorithms. These 46 algorithms cover a variety of applications, from world-class reverbs, delays and colouration effects to compression, expansion, ducking and pitch-shifting. The DP/4 has 400 presets already programmed for you, so right out of the box you’re sure to find the type of processing you need.

And one unit in the DP/4 would be a welcome addition to your music making. With the freedom and power that four offer, you’ll be able to bring a quality to your mixing and sound that you only dreamed of. And the ease of having them all under the control of the one interface saves time that is better spent making your music.

The Ensoniq DP/4 gives you total flexibility in routing and processing signals. With 4 powerful multi-effects processors (Units A, B, C & D) and a 4 input/4 output patch bay, there are many ways to configure the Ensoniq DP/4. To make it easy for you to understand, there are 4 basic types of configurations (called Configs) based on how many different inputs, or sources are being used.

Preset Memory
The Ensoniq DP/4 has 400 Presets, so you have lots of sounds to choose from, no matter what type of Config you need to use. There are 4 types of Presets possible, 1 Unit, 2 Unit, 4 Unit and Config Presets, and there are 100 memory locations (50 ROM/ 50 RAM) for each type of Preset.

A 4 Source Config uses four 1 Unit Presets, a 2 Source Config uses two 2 Unit Presets, a 1 Source Config uses one 4 Unit Preset, and a 3 Source Config uses a combination of 1- and 2-Unit Presets. This leaves the Config Preset, which stores the full setup of the DP/4 – a global Preset that can be used to store any possible setup of the DP/4.

The Ensoniq DP/4 has 46 different algorithms, as pictured in the accompanying table. The many powerful reverbs offer a range of ambient spaces, from small rooms to large halls, with plates and a variety of contemporary reverb effects as well. Delays can be achieved up to 6.6 seconds if needed, and the DP/4 allows you to sync delay times to MIDI clocks or to a triggered Tap Tempo.

Rich multi-voiced chorusing, phasing, flanging and combination effects enable you to colour your sound. A rotating speaker algorithm captures all the nuances of a Leslie speaker. A built-in LFO allows the Ensoniq DP/4 to create vibrato, panning, tremolo and other synth-like effects, and you can use a Sine.1Noise generator to create sound effects directly from the Ensoniq DP/4, with no instrument plugged into it.

Guitar players will find a variety of different amp and speaker simulations, as well as a dynamic VCF-Distortion algorithm for great wah-wah pedal effects. In the studio, 4 different pitch shifters, a variety of expanders, shelving and parametric EQ, a Ducker/Gate and an ultra-fast compressor provide all the processing tools needed for record, broadcast and video production work.

Most importantly, each algorithm in the DP/4 can be modulated in real-time by any 2 of 138 possible MIDI or analogue controllers, giving you ultimate control over sound modification or expressive performance. And MIDI Program Changes can be used to change Presets, or even change the complete routing of the DP/4 for totally automated control.

The Interface
Advanced capabilities are nothing if they are not easy to use. Input and output volume is adjusted with dedicated knobs for each of the 4 channels, allowing instant access to these important functions. Peak and signal indicator LEDs are provided to help optimise input signal level.

Each Unit has a dedicated button to select it for loading Presets, editing or bypassing. You can change parameter values easily with the large Data Entry Knob, and a Compare button allows you to audition your current edit against the stored settings.

A large 32-character display provides information about which algorithm/Preset is chosen, non-cryptic parameter access, and even acts as a gain reduction meter during compression modes – a must for critical studio applications. In addition to the back-lit display, the DP/4 has a dedicated 2-character LED that shows the current parameter selected while editing, and also acts as a MIDI indicator to help confirm MIDI reception.

The Sum of Four Parts
Of course, all these features and specs wouldn’t mean a thing if the Ensoniq DP/4 didn’t sound great, but when you hear its world-class reverb, and listen to a sampling of the 400 onboard Presets you’ll realise that you can have it all. The flexibility of 4 signal processors, a digital patch bay and digital submixing, all in one easy-to-use box. The DP/4 Para11el Effects the next generation in affordable effects, from ENSONIQ.


  • A/D – D/A conversion: 16-bit linear
  • Input Level: -12.5 dBVt0 +18 dBV
  • Output Level: +15 dBV maximum
  • Input impedance: IMeg Q
  • Output impedance: 2.6K Q
  • Frequency Response: 2 Hz-18 YO-lz
  • Dynamic Range: 96dB
  • Signal – Noise ratio: -87dB
  • THD+N0ise: (-86dB)
  • Crosstalk between channels: better than -80 dB (1kHz)
  • IM distortion (SMPTE): 0.05%
  • Presets: 400 (200 ROM, 200 RAM)
    • 100 each (50 ROM, 50 RAM) of the following:
    • 1 Unit Presets
    • 2 Unit Presets
    • 4 Unit Presets
    • Config Presets (4 units plus all signal routing parameters)
  • Memory: 512 kbytes
  • Maximum delay time per unit: 1.6 seconds
  • Maximum single delay time possible (no regeneration): 6.6 seconds
  • Dimensions: 482mm x 89mm x 396mm
    Weight: 5.4kg


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The details provided above are drawn from historical documents like advertising brochures or user manuals. They’re shared without bias or review. This info is given solely for your consideration, helping you gauge its usefulness to you.

Ensoniq DP4

There are no samples available at the moment.

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by Rene Kirchner

Sound Quality 90%
Build Quality 95%
Usefullness 95%
Mojo/Funk 95%
Reliability 95%

Had it in the studio from 2003 to 2016. Reliable and user friendly technique and quality. I really miss that thing. One of the best FX all rounder for electronic music studios! Design, Quality and FXs are premium!


by Anonymous

Sound Quality 80%
Build Quality 90%
Usefullness 100%
Mojo/Funk 95%
Reliability 80%

It does everything…four times over. I almost always use all four processors for a single source and get excellent results. A luxury I know since I have three available for use. Typically Vocals and Guitar are the two instruments that can gain from multiple effects. Vocals use a compressor, gating, eq, and reverb, leaving me some other effect to use intermittently such as chorus, echo, distortion, or flanging. Same for guitars. I’ll often use a amp simulator (3 types) and maybe a speaker simulator, leaving me with two other processors for multi-effects such as chorus-delay, or flanger-delay, or dual pitch shifting. You see, there are a lot of possibilities.

I’ve also used it live as 4 compressors – one for each vocal mic, but I found it better to just use two 1U dual compressors for the instant knobs twist and gain reduction LEDs. I have also used it as a dedicated voice processor for live use, and using all four processors in series can even make me sound good!

If you have the mixer, you can use to aux sends for two dual-processor effects, or if you have 4 sends, up to 4 individual effects. Once you understand the routing switching and the switching method of the jacks it’s easy to use 1, 2, or 4 effect in/outs. 3 effect in/out (as in two single and one dual effect) is not really supported, but easy enough to set up with a short patch cable. You just can’t switch it around from the front panel. That’s not so bad though since seldom will you need to change the number of ins and outs on the fly.

Drawback: Great MIDI implementation but sadly the volume control for delay line effects is on the output, not the input, so you will have a harder time queing the exact phrase that should be echoed. You will need a second processor before the delay effect to do that – not a problem if you wanted a second effect in series but it is a limitation.

The rooms and plates sound fine. So does the hall for some things but somehow the hall doesn’t seem so useful to me – I guess it has a bit of a quirky sound. So if you want a really freakin’ good reverb, I’d use the room & plate in parallel or series, or use some of the non-linear (i.e. reverse) reverbs. to me they sound better. The 8-voice chorus is to me a bit much – to smeary or something. I prefer the simpler eq-chorus-ddl effect since it has a cleaner chorus and includes more eq and delay effects that can be used or not.

The system has a lot of programability and that makes this very flexible. As one example, if you have one or up to four inputs, the output of the effect can still remain in stereo. It is mixed internally and output thru jacks 1 & 2, so only two returns are needed. If going mono, just use output 1 and all processors are summed to mono. This is all done with jack switching internally so there is no menu-configuration needed.

Look, I could go on and on with this unit. It has some drawbacks, but it is pretty awesome too. The fact that I have three of these, and continue to use them even now 25 or so years later, should be enough of an endorsement from me.


by Anonymous

Sound Quality 85%
Build Quality 100%
Usefullness 75%
Mojo/Funk 85%
Reliability 95%

Best thing retro design….!


by Jacob Daniel Miller

Sound Quality 85%
Build Quality 100%
Usefullness 100%
Mojo/Funk 70%
Reliability 100%

Fun to use.

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