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Sony DPS V55m

4-channel Multi-effects Processor By Hugh Robjohns
Published January 1999

Sony DPS V55m

Sony's new mid‑priced multi‑effects unit boasts four‑channel operation, 200 preset effects algorithms, comprehensive user programming capability, and great sound quality to boot. Hugh Robjohns spins that dial...

Sony might not (yet) have the same kind of pedigree in digital effects processors as, say, Yamaha or Roland, but they do have enormous R&D resources and a company culture of getting their products right. The DPS V55M is the latest in a short line of Sony multi‑effects processors (there are only two in Sony's current model line up). However, they have previous experience with more expensive professional studio processors and reverbs, which have all performed admirably, if not quite developing the legendary status of Eventide or Lexicon.

The DPS V55M is essentially a simplified four‑channel version of Sony's current flagship processor, the stereo DPS V77, employing the same 52‑bit DSP engine to generate realistic reverbs, choruses, pitch‑shifting and a full range of other common effects. However, the real strength of the V55 is in its four inputs and four outputs, which offer a great deal of flexibility including two‑ or four‑input to four‑output surround effects — as far as I am aware, a unique feature at this price level. The machine can also be configured to provide dual independent stereo processing, single stereo processing with a pair of serial or parallel effects processors, or four independent mono processors.

The V55 contains 200 factory presets, many apparently created by a number of top engineers and producers including Roger Nichols, Tom Jung, Snuffy Walden, Joe Chiccarelli, and Michael Bernard, with the provision for another 200 user memories. The effects algorithms include a useful selection of plate, hall and room reverbs, up to 10‑voice chorusing effects, the usual delays, pitch‑shift and harmonisation facilities, a three‑band equaliser, a limiter, compressor and gate, plus rotary speaker, amp simulators, Doppler effects, and even a vocoder.

Setting the machine up is fairly straightforward, and is made easier by the use of a velocity‑sensitive data‑entry wheel and simple control buttons. A very useful effect‑type search facility is included, and for programs with a critical timing element or which require manual triggering, the Enter button can also be used as a tap tempo and trigger function.


Sony DPS V55m

Packaged in a standard 2U rackmounting box with a dark grey front panel, the V55 weighs a mere 3.6kg, so it won't put too much strain your rack frame! The analogue inputs and outputs are all via 20‑bit converters operating at 48kHz sample rates; unlike the V77, however, it has no digital I/O.

The machine has two nominal processing engines, FXA and FXB, and these can be arranged in different ways depending on the input configuration and required effects. The V55 can operate as a four‑channel machine, but in this mode only the FXA processor is functional as all the machine's resources are required to process four channels identically. Nine effects algorithms are available in four‑channel mode including four reverbs, a couple of sophisticated choruses, a rotary speaker, and the vocoder and Doppler effect. As all the machine's total DSP resources are working together in this mode, it gives you the best quality effects.

In practice, I suspect most users would configure the machine for stereo processing for much of the time, even though the quality of the effects is fractionally lower than in four‑channel mode. The two effects engines can be arranged either for dual stereo operation (with one allocated to each stereo channel), or for single stereo operation with the two effects engines working in series, one processing the output of the other (for example, reverb after pitch‑shifting). In this mode, 27 different effects algorithms are available, including five reverbs, two delays, two pitch‑shifters (one a reverse type), one each of chorus, flanging and phasing, two auto‑panners, a three‑band equaliser, an amp simulator and overdrive, three dynamics processors, tremolo, vibrato and wah effects, a vocal‑canceller, pitch roller and a short sampler.

But this is not all the DPS V55M can do. The two effects processing engines can also be split to provide processing for independent pairs of mono inputs, with different processes applied in each channel. Again, it can be configured for four separate mono effects, or two mono chains with two serial effects in each. There are nine algorithms in this mode in various combinations of reverb, chorus, delay, pitch, EQ and compression. Since the same DSP power is now split across four separate effects, the quality of each is reduced slightly further.

Knobs And Buttons

The front panel of the machine has an uncluttered appearance, with the large mains power button (complete with the typical Sony protective fence around the switch) to the left, along with a combi‑jack input connector. Five input level controls are aligned along the bottom of the panel, with a listing of effects algorithms printed above. Just right of centre, the two‑line backlit LCD is mounted above a pair of parameter adjustment buttons, whilst to the right again are six more buttons and a large rotary encoder wheel.

The combi‑jack connector accepts balanced input signals on either a 3‑pole quarter‑inch jack or an XLR. Signal levels down to ‑50dBu can be accommodated (maximum +10dBu) and the handbook states that this facility is intended for microphones. However, the input impedance is quoted as 10kΩ, which seems pretty high for most balanced microphones, yet rather low for an electric guitar. Having said that, it worked OK in both instances for me in the studio using short leads, although I would be wary of cable microphony with long mic leads and a loss of quality and detail with long guitar leads.

Adjacent to the input socket are a three‑position slide switch and a small control knob. The switch determines which signal path the microphone input is routed to: channel 1 only; channels 1 and 2 (the corresponding rear panel inputs are disabled in both cases), or 'rear' which disables the front panel connector in favour of the rear line‑level sockets. The knob below the switch provides a 40dB gain range for the microphone input.

The four larger controls determine the input sensitivity of the corresponding rear‑panel inputs and, assuming common input and output operating levels, the controls range from silence to +12dB with unity gain at the one o'clock position. Above each control knob a tricolour LED flashes red for signals within 2dB of clipping, orange from ‑2 to ‑6dB and green between ‑6 and ‑30dB.

The operational controls are all grouped around the LCD panel, which presents selected information on program numbers, names, effect numbers and types, processing structures and parameter values. Clearly, on a two‑line display it is impossible to show everything at once, and so the information is presented according to the operation in hand.

The six buttons to the right of the display are labelled Bypass, Save, FX Type, System, Exit and Enter — all fairly self‑explanatory, although several have alternate functions. For example, the Bypass button can be reconfigured to mute the output instead of providing an effects bypass, although I would have liked the option to mute the input as well, since this is more useful with reverb programs (allowing reverb tails to die away naturally). Similarly, the FX Type button not only selects a specific algorithm when customising the processing, but is also used when trying to search for a preset program of a specific type — something which is very useful with 200 factory presets and up to another 200 user programs.

The System button accesses MIDI and machine setup parameters. MIDI options include building a table of program change numbers against machine memories, setting the channel number (or Omni Mode), and initiating the bulk transfer of system settings and user memories. The Exit button puts the machine back into normal 'play' mode from any other menu whilst Enter, as well as confirming memory save instructions and the like, is also used as a tap‑tempo button and trigger for some effects.

Judging Effectiveness

The V55 is pre‑programmed with a comprehensive collection of generally very usable effects, although finding your way around them can be a bit of a chore, owing to the usual problem of unrepresentative names combined with the sheer wealth of options. However, familiarity helps a lot, and the effect‑typesearch function is very easy to use. This is operated by pressing the FX Type button twice to enter the search mode, then dialling in the desired effect type number (derived from the algorithm chart on the front panel). The first found program with the desired effect is then presented for audition and, using the two Edit Parameter buttons, alternative programs with the selected algorithm can be recalled and auditioned. When a suitable program is identified, pressing the Enter button loads it and allows its parameters to be edited and the result saved to a user memory.

I was impressed with the depth and warmth of the reverbs, particularly the four‑channel versions which, whilst creating very credible surround sound stages, also seemed to work well with only a stereo output.

If you know precisely what you want, creating an effect from scratch is just as easy. Pressing the FX Type button once allows any desired algorithm to be dialled up by its type number. For the nine four‑channel algorithms, the user is presented with just the one process, while for the remaining stereo and dual mono options the display shows the algorithms running in each of the two processing engines. These can be chosen independently with a press of the Parameter Edit buttons to access each engine prior to selecting the appropriate algorithm. Dual processes are shown with a slash or arrow separating them, representing parallel or serial connection respectively; again, this can be chosen as desired.

According to the manual, the machine is supplied with another booklet called the 'Effect Parameter Guide' which details the programmed effects and the functions of the available parameters for each algorithm. I didn't initially have access to this booklet, but it is a testament to the intuitiveness of the V55 that I did not feel I was missing out. Most algorithms have a manageable handful of parameters and anyone with some experience of multi‑effects processors will find it all very familiar. For example, the reverbs have parameters for on/off, reverb time, pre‑delay, size, spread, hi damp, direct level, effect level and master level — all pretty obvious stuff — and all the other effects are just as instinctive.

In fact the only thing that took me a little while to figure out was how to make the tap‑tempo function work (the algorithms which respond to tap‑tempo or manual triggering are usefully identified in the front panel table). It turned out that the delay time parameter had to be incremented to the next step after maximum (to read 'tap'), or the trigger mode selected to 'tap' rather than 'signal' in appropriate programs. The tap‑tempo mode is very useful indeed (although I would have liked a readout of the resulting delay time), and the System menu allows the tap tempo calculator to be set up to derive various fractions of the tapped timing — either 1/4, 1/3, 1/2, 1, 2, or 3 times.

I was impressed with the depth and warmth of the reverbs, particularly the four‑channel versions which, whilst creating very credible surround sound stages, also seemed to work well with only a stereo output. The dedicated stereo reverbs were also very natural and controllable, though perhaps without quite as much complexity as the four‑channel versions, and I had no reservations about using any of them. They are easy to set up, with the size, spread and hi‑damp parameters giving creative flexibility in fine‑tuning the sound, and the three main versions (plate, hall and room) all provide believable starting points.

The usual clutch of straightforward time‑domain algorithms (repeat delays, phasing, flanging and chorus programs) all performed well and with a wide range of adjustment. I was also impressed with the pitch‑shift algorithms, which produced very smooth results with modest settings, although mechanical‑sounding results were unavoidable when pushed beyond a few tones up or down.

The dynamics processors seemed to be the weakest functions, largely because I found them so difficult to set up. The problem was not in the adjustable parameters — all the expected options were available with sensible ranges, together with some unusual combined functions such as 'sensitivity' in the compressor (which seemed to integrate the threshold and ratio controls). Both the compressor and limiter also include a two‑band equaliser, which is useful. The real stumbling block for me was the absence of a gain‑reduction meter, which made it hard to assess just how hard the machine was working (other than by ear, which can be surprisingly deceptive). With the benefit of my mixing console's metering (the input via an aux send level meter and the output by a PFL of the effects return) I was able to find comparable settings to those on my usual outboard compressors and I found the Sony gave a harder sound with less character, although it often provided greater precision in absolute level control. In reality, I don't believe the dynamics algorithms were intended for stand‑alone mastering‑type applications (despite some of the preset programs' titles) so this test was probably a little unfair. When used in conjunction with some of the other effects to control the processing on a solo instrument, however, they proved more than adequate.


Overall, I liked the V55. It seemed to involve a lot of button‑pushing and knob‑twirling at first, but familiarity brought an appreciation of just how quick and easy it was to edit an existing program or to set one up from scratch — the velocity‑sensitive nature of the rotary encoder was a major asset in this regard. The sound quality is beyond reproach in all cases; the standard time‑domain effects sound very clean on their own, and I rather liked the reverbs for their richness and controllability. I'm not suggesting the machine is on a par with a top‑flight Lexicon for the naturalness of its reverbs, but it is certainly comparable with decent mid‑market models.

The four‑channel surround‑compatibility of the DPS V55M is unique, as far as I know, and makes it an ideal tool for anyone considering surround‑sound production, yet still provides plenty of flexibility for run‑of‑the‑mill stereo work or mono multitrack processing applications. The V55 is a good all‑rounder and won't become redundant with the turn of the millennium, so if you are looking for a multi‑effects machine for surround work, or are just starting out and want a machine you won't outgrow in a hurry (but which is easy to use), I would happily recommend it.


The rear panel is clearly laid out, with all four inputs and outputs accommodated on quarter‑inch jack sockets. These are grouped in stereo pairs (A and B) and if a mono input is required, plugging into the left socket of each group routes the signal to both channels. The rear panel connectors are unbalanced, but small slide switches (one for the inputs and another for the outputs) configure the machine for ‑10dBu or +4dBu operating levels. Strictly speaking, operating at ‑10dBu instead of ‑10dBV means that the nominal signal level will be roughly 2dB too low... but I'm sure that's not going to worry anyone.

The left end of the rear panel carries a pair of MIDI sockets providing a dedicated input, but only a switchable Out/Thru socket. There is also a knob to adjust the contrast of the small front panel LCD. There are no external fuses or mains voltage switching facilities on the rear panel at all, and power is supplied through a captive two‑core mains lead.


  • Four‑channel surround operation.
  • Good sound quality with natural reverbs.
  • Ease of use.
  • Wealth of usable algorithms.


  • No time display with tap tempo.
  • Lack of gain reduction meter.


The V55 is a four‑channel surround‑capable multi‑effects processor with the option of dual parallel or serial processes in stereo and dual‑mono modes. The V55 provides very good sound quality, both technically and aesthetically, particularly in the reverbs.