Dynacord DRP-20 review


German classic from the late 80’s (manufactured in 1989). For those on the other side of the great lake where this company is not so much known, we should mention that Dynacord has been a long time manufacturer for pro audio equipment. Old analogue classics like TAM-21 (flanger/chorus) and VRS-23 Vertical Reverberation System come first in mind (both from the late 70’s – still can be found relatively cheap).

Visually, what makes DRP-20 stand out in every rack is obviously its white face plate, which really looks cool. However, there is also the black face plate version around which has balanced jacks and is less noisy at the output stage (noiseless to be exact). Speaking about ease of use, i gave 5/10 because, it’s one of those devices, where you browse through the menu and tweak with the big knob. Can be time consuming and is not as “hands on” as some other devices, i.e. VRS-23 with one knob per function. Assigning patch names can be real pain in the a**, hence low mark on ease of use. I must admit everything is logically laid out in the unit, and once you get used to it, it’s point and shoot.

DRP-20 is a classic reverb processor made with a true stereo engine, which, on some algorithms can be split to “dual” mode where each line features its own “processor”. The unit features dedicated input and output level knobs with a HI/LO gain button for easy switching from a line level for synths to high gain setting for something like a guitar connected directly into the unit. On top of that, there’s a dedicated “mono input” and “mono output” jack on the front panel which guitarists might appreciate. For the classic studio setup, there are 2 inputs and 2 outputs on the back of the unit.

It is very hard to describe the sound of DRP-20 unless you actually try the unit, in your own setup, with your own gear, etc. I won’t bother describing the “sound” of reverb but rather focus on discussing the unit’s weaker and stronger points. First thing i should point out is that the short room reverb algorithms are definitely not this unit’s specialty. Much cheaper reverbs like Midiverb I and II are far better for the small rooms (ie. drums / percussion work). Luckily there are some really nice multi-taps for small room simulations to compensate for this somehow (intentional or not), but more on that later. Where DRP-20 really shines are the vast spatial reverbs. They sound so lush. And the tails on those are just magnificent! In fact i remember reading many years ago comments from ppl mistaking DRP-20 for Lexicon 480 and Quantec QRS (though this is all highly subjective, still somehow funny anecdote). One thing i know 100% sure, huge reverbs on this unit sound really really good! For some reason there are no much of them in the presets area, so you’ll have to make your own, using the buttons and the dial. Luckily there are more than enough parameters for the reverb, and every major aspect can be precisely set.

Speaking of other good stuff inside, the unit has some nice delay algorithms. One of my favorite is a VCO Delay, where LFO can be used to modulate the time. Since each line can be set independently in time and modulation amount, you can produce everything from wide choruses and flangers to old school delays with modulation (for some 60’s style Sci-Fi movie soundtrack). One very useful feature in the unit is the IN LOOP enable / disable function. Basically, when engaged, all the patches in the unit will have their “original signal amount” set to 0. In other words, all effects will be set to fully wet. This saves a lot of work to someone who’s moving from serial to loop connection or vice-versa, otherwise all the patches would manually have to be reprogrammed.

In Specs
The unit features 32 bit signal processing based around the NEC’s DSP chip. Converters are 16 bit, both the A/D and D/A section. The unit features MIDI for external control of all parameters in real time. Parameters in the unit can be set to either “value” of 0-100% or in classic dB scale which is very useful for both the beginners and the professionals – kudos to Dynacord for that. There are 128 preset locations and another 128 user locations for program storage.

DRP-20 has a total of 26 algorithms or effect structures as they call it. Each structure has its own range of parameters. Structures range from Echos, Reverbs, Plates, Rooms, Echos+Reverbs, Multitaps, Gated Reverbs to the Flanger and Chorus effect. There are also five dual channel algorithms which basically feature echo line on one channel and room or plate on the other channel.

Speaking of Multitaps, last algorithm features 2×11 taps which can produce some really nice room simulations! Those 11 delays per channel are grouped with another channel to form a stereo cluster which can be drawn using cluster time function. It is possible to select one from 9 different clusters for each channel, for some really exotic stereo room effects. Further more, cluster time can be independently set for each channel (L & R) along with the independent feedback amount for each. With some careful programming, a collection of really cool room reverbs can easily be built.

Full list of algorithms:
Two Channel Echo
VCO-Echo Stereo
Plate Reverb
Room Reverb
Echo + Plate
Echo + Room
VCO-Echo + Plate
VCO-Echo + Room
Echo + Live Reverb
L = Echo / R = Plate
L = Echo / R = Room
L = VCO / R = Plate
L = VCO / R = Room
L = Echo / R = Live
Freeze Automatic
Freeze Manual
Plate Reverb & Gate
Room Reverb & Gate
Gated Reverb
Echo + Gated Reverb
Multitap 2×3
Multitap 2×6 Syn
Multitap Presets
Stereo Flanger
Stereo Chorus

Comments (9)

  1. mike

    hi don! i’m searching the whole web for the drp20 programs from ensnareyou. i contacted him but sadly his gear was stolen in 2010. i’m sure you programming it yourself but maybe you happen to have them?
    best regards

  2. Ensnareyou

    I just stumbled across your web site and noticed your DRP20 review. Great effects device, not very well known. I thought I would clarify a few things that many people aren’t aware of. The white faced DRP20 and the later grey faced DRP20/DRP20X were identical in build with the exception of the face plate colors and input/output configurations. The “X” simply denoted XLR connections. Dynacord changed the face plate color when EV/Mark IV took over importing the Dynacord line into the US. When the grey faced units were marketed, they also included a software update which added some new programs, bug fixes, and additional editing and MIDI controls. Older white faced models could be updated to the same specifications as the newer units.

    The output of the DRP20 and 20X was a bit noisy and as such a modification was done to lower their noise floor. Unfortunately some earlier imported grey units and almost all white faced units were shipped without this modification. To get the hardware modification done required sending the DRP20 to EV/Mark IV in the USA or to Dynacord in Germany. EV often did this modification for free and their customer service was excellent. Once upgraded, the DRP20 was very quiet but by no means “noiseless”.

    One major advantage the DRP20 had over other effects devices of the time was the extensive MIDI control of all of its parameters. The MIDI mute function was also of great benefit. While the DRP20 did have a very deep menu to modify these parameters, it was a pretty simple device to use and it sounds excellent. Properly programmed, the DRP20 could compete with any of the big league reverbs of the era. Where the DRP20 really shined was its multi-fx capability and true stereo operation. The DRP20 is the Swiss Army knife of effects devices. While the reverbs of the DRP20 weren’t as unique in character as say an AMS-RMX16, Lexicon 480L, or Quantec, the Chorus, Flange, and Delays were superior. The VCO Delay as you concluded is excellent and can be used to create amazing sound effects. The Reverbs the DRP20 produces are no slouch either.

    The vacuum fluorescent display of the DRP20 was unique and is very easy to read even from far away. The display however ended up being the downfall of the DRP20. When the manufacturer who supplied the displays to Dynacord stopped building it, sourcing a replacement display cheaply enough proved to be near impossible. Sales of the $3,500.00 DRP20 weren’t in high demand and increasing manufacturing costs was out of the question. The 32 bit NEC chip that was the heart of the DRP20 was also quite costly. Rather than continue production of the DRP20, Dynacord discontinued the DRP20 and came out with the lower priced DRP15 and DRP10 models.

    While similar in features, these newer units lacked the processing power and build quality of the DRP20 and were aimed more towards live sound and guitarists. Eventually EV stopped importing Dynacord and their effects devices faded into history. Being that the production of the DRP20 was limited, there are not many of them in existence today.

    The DRP20 remains one of my all time favorite effects devices and I much prefer it over almost every Lexicon device. Learning the inner workings of the DRP20 is necessary though to reap its full potential.

    • Tarkan Sahin


      im searching for information about the Drp 20 and you seem to know this units. Iv been offered a white DRP 20x, which shows strange characters after powering it up. The owner told me that it is because of the low battery. Do you know this problem and is it because of the battery?

      kind regards


    • swissdoc

      Is there a way to check on a given DRP20, if the modification you mention about the noise level has been done?

  3. Chris

    I recently bought a DRP 20, butnit arrived with a cracked VFD 🙁

    Anyone know how to find a replacement?

    • Hi,
      I bought one of these and had the display arrive cracked invisibly so no longer had a vacuum and failed. It was not too hard to get the display from Ebay (Noritake Itron FGS16026 A2 THB) but the fitting was a fiddle due to the construction of the unit. You need a very good desoldering iron too. I removed the display in pieces and then desoldered the pins individually. Great unit though now, really holds its own.

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