Classic Recording Studio Equipment

Vintage Digital

Yamaha SPX90 Multi-Effects Processor

The Yamaha SPX90 was released in 1985 as an affordable multi-effects processor for the masses. It remains today a true classic digital effects processor. It is also the most looked at effects processor on this website.

Yamaha SPX90 Multi-Effects Processor Details

When the Yamaha SPX90 Multi-Effects Processor was released way back in 1985 no one would have expected it to become a classic, probably not even Yamaha themselves who continued to release better specified models year after year.

Regardless of the improved noise floor, wider bandwidth and stereo inputs of the later models, it is the Yamaha SPX90 that remains the sought-after Yamaha effects processor.

The Yamaha SPX90, developed through a fusion of cutting-edge acoustical research and digital technology of the time, was created with the intention of offering musicians and home recording enthusiasts a diverse selection of captivating effects.

The Yamaha SPX90 Digital Multi-Effect Processor utilises highly refined LSI (Large Scale Integration) technology to create natural reverberation. Not only is its assortment of 30 preset effects comprehensive enough to suit most studio and performance applications, the SPX90 also allows you to create up to 60 additional effects and store them for instant recall.

The Yamaha SPX90 can create effects far beyond mere reverberation, though that in itself is of a truly superior quality. A variety of echo, delay, and special effects – each with comprehensive parameter and adjustments – can be accessed at the touch of a switch. And as the Yamaha SPX90 is MIDI-compatible, it can be programmed to apply separate reverberation effects to a variety of MIDI compatible instruments.

The Yamaha SPX90 Digital Multi-Effect Processor will prove extremely useful in a variety of applications: acoustic electric, PA, MIDI instrument, and home recording systems.

The Yamaha SPX90 is equipped with a selection of 30 outstanding preset effect programs. The Yamaha SPX90 offers incredible sonic flexibility, as each effect type comprises its own set of parameters. These parameters can be adjusted to suit your tastes and the tonal characteristics of your music equipment.

The Yamaha SPX90 offers incredible sonic flexibility, as each effect type comprises its own set of parameters. These parameters can be adjusted to suit your tastes and the tonal characteristics of your musical equipment.

We therefore recommend that you examine each preset effect program and observe how these parameters affect the sound. You will soon discover many new and exciting applications for the Yamaha SPX90’s preset effect programs. 

Programs & Parameters
The preset programs in the SPX90 fail into the following types: REV (Reverb), ERI and ER2 (Early Reflections), DELAY, ECHO, MOD (Modulation), GATE, PITCH, FREEZE, PAN, VIBRATO and PEO (parametric equaliser). Each of these program types has a specific selection of programmable parameters.

“Parameters” indicates the separate, individual functions that make up each effect. There are two types of parameters in the SPX90: “invisible” parameters (non-programmable, fixed-value parameters) and programmable parameters (those you can edit or modify).

Effects Available

  • Reverb, ER1 and ER2, Reverb and Gate
  • Delay, Echo, Delay Vibrato
  • Flanging, Chorus, Phasing, Pitch Change
  • Freeze (Sampling)
  • Gate, Compressor, Auto Pan, Triggered Pan, Parametric EQ


The Yamaha SPX90 remains a beloved effects processor among audio professionals and enthusiasts even today, decades after its initial release. Known for its versatility and robust performance, the SPX90 offers a wide range of effects, including reverb, delay, chorus, and flanging, making it an indispensable tool for both studio and live sound applications. Its straightforward interface and reliable operation ensure that users can quickly dial in the perfect sound without hassle.

Additionally, the SPX90’s high-quality audio processing, dynamic range, and minimal distortion contribute to its enduring reputation for delivering clear and professional audio effects. Whether for musicians, sound engineers, or producers, the Yamaha SPX90 continues to be a go-to unit for its consistent quality, ease of use, and impressive sonic capabilities.


  • Number of Input Channels: Unbalanced x 1 (Phone Jack)
  • Nominal Input Level: -20 dBm/+4 dBm, Selectable
  • Input Impedance: 10 k-ohms
  • Level Control: Volume, Max. Gain +12 dB
  • A/D Conversion
    • Sampling Frequency: 31.25 kHz
    • Quantisation: Linear 16 Bit
    • Band Width: 20 Hz to 12 kHz
    • Number of Channels: 1
  • D/A Conversion
    • Number of Channels: 2
    • Sampling Frequency: 31.25 kHz
    • Quantisation: Linear 16 Bit
    • Band Width: 20 Hz to 12 kHz
  • Number of Output Channels: Unbalanced x 2 (Phono Jack)
  • Nominal Output Level: -20 dBm/+4 dBm, Selectable
  • OutputImpedance: 600 ohms
  • Output Mixing: Direct Signal, Effect Signal
  • Presets (ROM): 1~30
  • User Memory (RAM): 31~90 (Non-Volatile)
    • All parameters except Input Level can be memorised
    • Key On triggers the program 18, 19, 20, 28 and 29
  • MIDI Channel: 1 to 16, OMNI (4 banks), Program Number (1 to 128)
    • Note on/off is recognised only for pitch change A, D and freeze B
  • Dynamic Range:
    • Reverb: more than 75 dB
    • Delay: more than 81 dB
  • Distortion:
    • Bypassed Signal: less than 0.01%
    • Effect Signal: less than 0.03%
  • Band Width:
    • Bypassed signal: 20 Hz to 20 kHz
    • Effect Signal: 20 Hz to 12 kHz
  • Power Consumption: 20W
  • Dimensions: 480mm x 45.2mm x 285mm (18-7/8″ x 1-3/4″ x 11-1/4″)
  • Weight: 3.2 kg (7 lbs)


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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.

Yamaha SPX90

The Yamaha SPX90 Reverb Impulse Responses for Altiverb are a complete package of this classic Yamaha effects units reverb presets. A total of 8 reverb patches are included. The recording of these impulse responses was done with very careful calibration, through a Focusrite digital audio interface, and recorded into Harrison Mixbus 32C.


by Simon Alexander

Sound Quality 75%
Build Quality 90%
Usefullness 80%
Mojo/Funk 70%
Reliability 95%

When the SPX came out in 1985, I grabbed one straight away. It was roughly half the price of a Rev 7 and did a similar job, but with a few additions of pitch shifting and a crude short sampling mode that I can’t remember if the option to control by midi was available. The reverb and multi effects were the main attraction for me and it did those very well. Infact when put in comparison to the Rev 7’s reverb, it’s very close indeed. I still have two SPX’s in my studio today and occasionally they get used on percussion sounds, but are only relegated to secondary use because I have a lot of other reverbs to choose from. As a general summary, they are well worth the money they go for today.


by Anonymous

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

My first piece of outboard gear was a Yamaha REV7, and the SPX90 was the second. The SPX I still have and use, and it has been at the heart of some of my best mixes. Sure some of the programs are “grainy” or “bright” but many of them sit perfectly and the Symphonic is worth the price of this unit alone. (The REV7 was traded to a friend for a 1968 sparkle-top Rhodes Suitcase, and while I miss the reverb, I was the winner in that trade, no question.


by Luca Marenco

Sound Quality 80%
Build Quality 90%
Usefullness 80%
Mojo/Funk 100%
Reliability 70%

Lovely old-looking rack, it has a bunch of warm-sounding, old-school reverbs which, summed with its other delays and psychoacoustic effects make a good unit even nowadays, specially if you search those old ’80/’90 warm, soft sound. I recommend it for genres like Rock, Funk, Electronic and for some cool sounding Jazz; its too hot-sounding for stuff like metal. Overall a good fx (also cheap!) to have in your rack.


by Alexis Peña

Sound Quality 85%
Build Quality 95%
Usefullness 80%
Mojo/Funk 85%
Reliability 95%

A pesar de ser tan antiguo sigue siendo muy funcional aún hoy en día, es ideal para lograr ese color vintage en la reverb en las voces, esto acompañado con unas buenas etapas de compresión y retardo logran un sonido muy particular. En las percusiones también es bastante útil y en particular me encanta el efecto de chorus, me parece muy bien logrado y natural. En general para ser un equipo diseñado en 1985 sigue siendo un buen equipo aún, muy bien pensado.

Despite being so old, it is still very functional even today, it is ideal to achieve that vintage color in the reverb in the voices, this accompanied by good compression and delay stages they achieve a very particular sound. On percussion it is also quite useful and I particularly love the chorus effect, it seems very well done and natural to me. In general, for a team designed in 1985, it is still a good team, very well thought out.


by Jota

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

One of the first reverb rack units that I ever used, it sounds fantastic, and it have the most useful chorus effect ever.

Used it? Leave your rating and review

4 Responses

  1. I have a question about the sound samples:

    the dry drums (for example) are stereo and the wet reverb samples are also stereo.
    how did you do that with a mono input? two units for left and right maybe?

      1. In cubase, I send a mono drum track to the spx and the sound is immediately skewed to one side, causing a severe imbalance between left and right. I have connected the L and R of the spx to the two inputs of the audio interface respectively.
        Can the master tell me what to do?
        Thank you.

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