in Ensoniq DP Pro

Ensoniq DP/Pro FX unit

I just scored a cheap DP/Pro. Only the battery was dead and that was easily replaced.

The DP/2 and DP/4 boxes always draw favourable comments for their ‘quality grunge’. The DP Pro is the less talked-about, but it uses the later generation ESP2 chips (24bit). I have no reference for comparison but I am surprised at how noise-less this box is. Great!

Initial run through the factory presets revealed the best digital reverbs I’ve yet heard, and they are extremely tweakable. This will be a slow-burne – it will tale a while to know this box, but I already know that it will pay dividends. I see lots of synthesis potential.

Manual can be found here.

The factory battery was soldered in place but easy to get at. Emboldened by my first soldering forays, I managed to remove the factory battery quite easily by heating the legs and pulling. I replaced it with a battery holder – just by re-heating the existing solder joints and pushing it in.  Popped-in the battery and voila – a perfectly functioning unit.

The exact battery type is BR2330, available at Farnell,  but you will probably get away with using any similar 3v coin battery (at your own risk though!).

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  1. Hi, How did you get to the bottom of the bottom of the board to de-solder/solder in the new batt? I have my DP/Pro open now but can’t get the board out. Mostly due to the XLR jacks and the extension on the input level knob–not sure how that comes apart. Thanks!

  2. Hi Phil – hope you got it back together in one piece 😛

    I removed the battery from topside – the board looked too messy to disassemble.It wasn’t necessary – I just touched my soldering iron off the battery legs and pulled it out.

    I replaced it with a standard coin battery holder by simply re-heated the existing solder blobs and pushed the holder in. Now the battery (BR2330) can be changed in future without the need for an iron.

    Good luck!

  3. I have wider spaces going after tweaking but still missing ‘complex wide’ open spaces… any ideas. not worried about grain..i like it

  4. hi, i have brought the DP/4+ back to life. It looks like someone tried to change the converters and it blew the transistors and caused track damage to the PCB. Preliminary views; it sounds fuller and bigger than the DP/pro. The presets are definitely more exotic. I need to test the reverbs out and I think the DP/pro is quieter with a better analog section.

    • Hi Raj,

      Sorry to hear of your DPpro troubles. I have been intrigued by the DP4+ also but I can’t justify the purchase right now.

      TBH I haven’t touched my gear in some time as I recently started a business and it sucked-up most of my 2012 time. However I did treat myself to a new mixer for christmas and I have some spare time over the coming weeks so I’ll be working with the DPpro and reveal any findings/examples.


      • hi, let me know where you get with your DP/Pro.
        When i exchanged emails with Jon Dattoro he mentioned that he considered that the detune was his favourite effect on the DP4. He said it was achieved: It ‘…by adding the input signal to a slightly pitch-shifted replica…’

        I’m going to have a look at this, next time I fire-up both the DP4 and DP/Pro

      • Hi stim, Finally fixed my DP4+, i know its been a while but i had to learn all about D/As, op-amps and get myself a surface mount heat gun. Anyway playing through the presets the phasers seem meatier, the reverbs deeper. In fact,i have found i have to use the DP/Pro with sends but the DP4+ sounds great as an insert effect. Going to do some more exploring. Certainly, they are two very different Fx boxes

        • Hi Rajah,

          Good news about your unit – you had to replace your op-amps? Scary stuff 🙂
          I also picked-up a DP/4 (problem-free luckily) and I agree – I much prefer the sound of the DP4 over the DPpro. The reverbs have a nice gritty edge, and I also am loving the distortion – one of the best digital distortions I’ve heard. I understand now why this unit was so popular with the techno crowd.
          I may sell the DP pro. It’s a pain to program it. I only use it for chorus really.

      • Hi Rajah,

        – I much prefer the sound of the DP4 over the DPpro


        – The reverbs have a nice gritty edge, and I also am loving the distortion – one of the best digital distortions I’ve heard. I understand now why this unit was so popular with the techno crowd.

        Agree and its got Daft Punk all over it including their Tron release and anything else from their stable, i’m thinking Kavinsky’s outrun.

        – I may sell the DP pro. It’s a pain to program it. I only use it for chorus really.

        May do the same. Now that i have had more a play on the units and studied the schematics some more (i know), i think i know why the DP4 sounds better. There is gain staging and summing going on inside the unit, hence all those Op-Amps, whereas with the DP/pro I think it goes A/D and D/A pretty much. The Dp/Pro can sound cleaner but for keyboards and guitars the DP4+ is much better especially as you can chain 4 fx blocks. Its the closest you will get to eventide without breaking the bank. The algorithms are different and the DP4+ is much closer to the Lexicon 224. I do want to pick up a SPX2000 so the DP/pro may go. Also i need to save for the Oto fx devices which are on the way for Q4.

        By the way people complain the DP4 is noisy but i don’t think its that noisy or at least its noisy in a good way.

      • hi, having explored the Dp4+ some more i think the ‘noise’ that some people refer to, is ‘broadband’ noise from the Reverb algorithms. The Dp/Pro is less noisy in this respect also I think the Chorus on the Dp/Pro is nicer, smoother. They are very different units with completely different algorithms and character

  5. Raj,
    I think you’re going a little deep on the theory for me. In the DP/Pro I was looking for decent quality configurable small-room reverbs on the send bus. I think I have that.

    In particular I like the reflection modeler a lot – it seems to give me the best results so far, and it’s easy to go out of the park.

    But I’ve spent most of my time recently making resonators. I.e feeding a medium delay onto a multi-tap with very short delay times. Feeding it the thinnest of noise impulses has produced Interesting and unexpected results so far. I’ll make some recordings…..

  6. Hey, i have 3 DP4+s right now, having received 2 units to repair. Both had Bad DC Offset and one had a shut down channel. I now a great deal more about how to fix these units and the values you need to see at various test points. Will be publishing a write up soon. Separately, I have a DP2 on the bench and note it has a delta-sigma DAC so it will have a very different sound to the DP4 and the Dp/pro. I’m thinking it will be more like an Effectron.

  7. I have dp2 and dp/pro and they have similar sound. Dp/pro is easier to program.
    Dp/pro make some small click on the right channel. Do you have advices about it?