The Waldorf Microwave XT is a 1998 rackmount wavetable synthesizer built around 44 continuous rotary encoders and a Motorola DSP56303. It runs two wavetable oscillators per voice across 64 ROM wavetables, ships 10 voices expandable to 30, and trades on the Reverb Price Guide between €782 and €2,256 across 69 completed orders.
Key takeaways
- Reverb’s guide puts a good-to-mint XT at €782 to €2,256 across 69 orders; recent sales run €900 to €2,556.
- The manual names 13 filter types. The XT has no comb, formant or peak filter, and no 24dB high pass.
- The 30-voice upgrade is a user-installable 20-voice card, but it only fits mainboard revision #3 running OS 2.29 or later.
- There is no reverb on board. Plan an external send.
What is the Waldorf Microwave XT?
The Microwave XT is Waldorf’s 1998 rackmount wavetable synthesizer, and it exists because the Microwave II had the same engine buried under a menu-driven front panel. The XT put 44 continuous rotary encoders on the front (Sound on Sound) and turned a menu-diving module into something you could actually play.
Those encoders are the whole point. They are continuous rather than absolute, so loading a patch does not cause parameter jumps when a physical knob position disagrees with the stored value. Alongside them sits a 2 x 40 character backlit LCD and 20-bit converters, up from the Microwave II’s 18-bit.
It never pretends to be analogue.
Wavetable scanning gives you timbres that move in ways a filter sweep cannot imitate, and the digital signal path keeps them bright and slightly brittle, which is the character people are still paying for twenty-eight years later. It sits in a specific pocket of synthesis history, too. Where the Roland D50 layered samples against synthesis and the Kawai K5000 went additive, the XT bet everything on scanning through wavetables in real time, then gave you a physical knob for every part of that journey.
Production ran from 1998 until Waldorf AG’s insolvency on 5 February 2004 (Wikipedia). Waldorf has never published unit numbers, so treat any specific production figure you see quoted elsewhere with suspicion.
What is inside the sound engine?
Each voice runs two wavetable oscillators plus a ring modulator and a noise source, drawing on 64 ROM wavetables and 32 user slots. Every wavetable is a list of 64 individual waves (Microwave II owner’s manual), and sweeping through that list is what produces the XT’s signature evolving textures.
| Released | 1998 (line ended 2004) |
| Polyphony | 10 voices, expandable to 30 |
| Oscillators | 2 wavetable oscillators per voice, plus ring modulator and noise |
| Wavetables | 64 ROM, 32 user, 64 waves per table |
| Processor | MC68331 microcontroller, Motorola DSP56303, 10.24 MHz crystal, 40 kHz sample rate |
| Filters | 13 named types (see below) |
| Modulation | 16-slot matrix plus 4 modifiers, 2 LFOs, 8-stage loopable wave envelope |
| Memory | 256 patches, 128 multis, 64 card patches |
| Multitimbral | 8 parts, each with its own arpeggiator |
| Effects | Chorus, Flanger 1 & 2, Autowah BP/LP, Overdrive, Delay, Amp Mod. No reverb |
| Display | 2 x 40 character backlit LCD |
| Audio input | Mono, routed through the filters and effects |
Compiled from the Sound on Sound review, Vintage Synth Explorer, the Microwave II owner’s manual, and The Usual Suspects’ hardware teardown.
Most people underuse the 8-stage loopable wave envelope, which is a shame. Unlike an ADSR it has independent level and time per stage, so pointing it at wavetable position gives you rhythmic timbral movement that cycles on its own clock rather than following note velocity.
User wavetables load over sysex, which is how most people get custom material onto the machine. If you want to see the same idea running on modern hardware, I have covered loading your own wavetables into the Akai MPC and the Ensoniq Fizmo transwave sounds that get close to this territory from a different direction.
Which filters does the Microwave XT actually have?
The manual enumerates 13 named filter types (Microwave II manual, p.54), while Sound on Sound’s review counts twelve. Either way, three filters commonly attributed to the XT are not on it: there is no comb filter, no formant filter and no peak filter. The comb filter belongs to the Waldorf Q and microQ.
| 24dB Low Pass | Four-pole, the steepest classic lowpass |
| 12dB Low Pass | Two-pole, gentler slope |
| 24dB Band Pass | Narrow band emphasis |
| 12dB Band Pass | Wider band emphasis |
| 12dB High Pass | The only high pass on the machine |
| Sin(x) to Low Pass | Trigonometric shaping ahead of a lowpass stage |
| Waveshaper | 12dB lowpass plus shaping driven by the current wavetable |
| Dual Low/Band Pass | Two responses in series |
| FM Filter | Oscillator 2 modulates the cutoff. Bell and metallic tones |
| S&H to Low Pass 12dB | Sample rate reduction before filtering |
| 24dB Notch | Steep band rejection |
| 12dB Notch | Gentler band rejection |
| Band Stop | Rejects a band while passing the extremes |
Two are worth going out of your way for: Waveshaper and FM Filter. Waveshaper distorts using whichever wavetable is loaded, so its character changes as you scan. The FM Filter turns the cutoff into a modulation destination for Oscillator 2, which is where the XT’s metallic bell tones come from.
Is the 30-voice expansion worth it?
Ten voices is the stock configuration and it runs out faster than you expect in eight-part multi mode. The upgrade is an Encore Electronics card carrying two extra DSP56303 chips, taking you to 30 voices total, and it is user-installable with no soldering (Encore Electronics). It is not a factory-only job, whatever you may have read.
Compatibility is the catch.
Mainboard revisions #1 and #2 have no expansion slot at all. If you are buying specifically to expand later, ask the seller to photograph the board revision before you pay. A rev #1 machine is not upgradable, and no amount of money fixes that.
What does a Microwave XT cost in 2026?
The Reverb Price Guide puts a good-to-mint Microwave XT between €782 and €2,256, calculated across 69 completed orders for the 1998 orange rackmount. Individual sales scatter widely inside and above that band, which tells you condition and configuration matter more than the headline range suggests.
Here is what people actually paid, seven verified transactions from Reverb’s public history:
Source: Reverb Price Guide transaction history, retrieved 20 July 2026. Prices exclude shipping and tax.
Look at the spread rather than the average. A good-condition unit went for €900 in January 2026 while an excellent one cleared €2,556 four months later, so condition is worth roughly a factor of three here. And an excellent unit sold for €1,110 in the same month as that €900 example, which means patience matters as much as condition.
Worth knowing before you negotiate: the five XTs listed on Reverb the day I checked were asking €1,400 to €2,799, against a sold band that starts at €900. Asking prices on this synth sit consistently above what it actually clears for. Offer accordingly.
Keyboard versions are a different market entirely, and a much thinner one. Reverb carries no price guide entry for the Microwave XTk at all, because too few change hands to compute a range from, which means anyone quoting you a firm XTk figure is extrapolating from a handful of listings, not reading data. The same caveat applies to the 30-voice machines: they appear rarely enough that each sale sets its own price, and a seller who knows what they have will price accordingly. Budget patience instead of a number.
What should you check before buying one?
Four things account for most of the trouble on a machine this age, and only one of them is genuinely electrical. Start with the mainboard revision, because it is the one check that cannot be undone afterwards: Encore’s expansion card fits revision #3 running OS 2.29 or later and nothing earlier, since revisions #1 and #2 have no slot at all.
- Mainboard revision. Ask for a photograph before you pay. A revision #1 machine you bought hoping to take to 30 voices will sit at 10 forever, and no amount of money changes that afterwards.
- Nextel paint. The orange coating is widely reported to go sticky and flake with age (donsolaris). Ugly, but cosmetic, not electrical.
- Encoders. All 44 see heavy use. Test every one.
- LCD. Backlight failure is commonly reported on displays of this vintage, so check the screen comes up readable, not merely lit.
Budget for reverb while you are at it, because the XT has none. At this price point do not pair it with the cheapest box you can find: something like the TC Electronic M300 sits better alongside a synth in this class, though the Yamaha REV500 will do the job if the rack budget is already spent.
Waldorf’s black Shadow edition is reported at 666 units, though that figure traces to dealer listings rather than anything Waldorf published, so treat it as folklore with a good hit rate. Reverb’s price data covers the orange rackmount only, so I have no honest basis for telling you what a Shadow is worth.
Who actually used a Microwave XT?
Only two attributions survive scrutiny, and both are worth stating precisely. Sound on Sound’s October 2005 studio feature on Massive Attack photographs the band’s keyboard rack, and the caption identifies a Waldorf Microwave XT sitting alongside a Moog Prodigy and a Roland Juno 60 (Sound on Sound).
Stronger still, because it comes straight from the manufacturer: Waldorf’s own artist page quotes Tim Hecker directly: “I’ve had both a Microwave XT and a Quantum” (Waldorf Music). For an ambient producer whose work lives on slowly mutating texture, the XT is an obvious fit.
Beyond those two, be careful. A lot of XT credits circulating online do not survive a check. Vince Clarke’s documented inventory lists the 1989 Waldorf Microwave, a different instrument entirely, and Ferry Corsten’s studio shows a Waldorf Q. Those two Waldorfs get confused constantly, and the confusion propagates.
How does the XT compare to the II, the XTk and Xenia?
Its predecessor, the Microwave II (written Microwave 2 about as often), shares the same engine and voice architecture. Only the interface really differs: the II routes you through a menu, the XT gives you 44 encoders. If you program by ear and tweak constantly, that difference is the entire purchase decision.
Waldorf added a keyboard in 1999. That Microwave XTk carries 49 keys with velocity, channel aftertouch and release velocity, and its keybed is synth action, not weighted. Sound on Sound quoted it at £1,449 including VAT when they reviewed it in March 2000 (Sound on Sound).
If you want the sound without the hardware, Xenia from The Usual Suspects emulates the DSP56300 chip itself rather than modelling the output, covering both the Microwave II and the XT. It is free, and it needs a user-supplied original firmware ROM to run. I have written a full review of Xenia and how to install it if that is the route you are considering.
One correction worth making, because it is repeated widely: Waldorf’s Largo plugin is not an XT emulation. Largo descends from the Blofeld and Q, and carries 128 waves per wavetable against the XT’s 64. The Blofeld is the closer relative, and Waldorf’s own spec sheet confirms it includes the Microwave II/XT/XTk wavetables (Waldorf Music).
Soundbanks and patch resources
With 256 patch slots on board and a further 64 on card, the XT holds a serious library, and sysex is the only route sounds travel in or out. Waldorf still hosts the original factory banks for the whole Microwave II/XT/XTk series, which is the sensible starting point before you go hunting through user collections.
- Official legacy sound banks from Waldorf
- A large user collection at Preset Patch
- Paul Nagle’s XT patches at Audiobombs
- Soundtower’s uWaveEdit, an editor and librarian for patch management
Programming guides and wavetable references
Carbon111’s archive is still the best free XT programming resource on the web, and it covers ground the manual does not: how to squeeze a third LFO out of the 16-slot modulation matrix, how to build a patch that browses all 64 ROM wavetables, and how windowed sync produces formant shifts the filters alone cannot.
- A quick tour of the Microwave II/XT for getting oriented
- The Microwave II/XT Cookbook, Waldorf’s own programming guide
- An extra LFO from modifiers, squeezing a third LFO out of the mod matrix
- Wavetable browser patch for auditioning every table quickly
- Wavetable reference charts, a visual guide to the built-in tables
- Formant shift through windowed sync and the waveshaping workshop
Frequently asked questions
The five questions below come up most often, and the short answers are: roughly €782 to €2,256 depending hard on condition, ten voices as standard, identical in sound to the Microwave II, no onboard reverb, and the XTk is the same synth with 49 keys bolted on.
How much is a Waldorf Microwave XT worth?
The Reverb Price Guide puts a good-to-mint Microwave XT between €782 and €2,256, based on 69 completed orders. Recent sales cluster across that whole span: seven transactions since February 2025 ranged from €900 for a good-condition unit to €2,556 for an excellent one, so condition swings the price by roughly a factor of three.
How many voices does the Microwave XT have?
Ten voices as standard. An Encore Electronics expansion card adds two more DSP56303 chips for 30 voices total, and it installs without soldering. The card only fits mainboard revision #3 running OS 2.29 or later, so revisions #1 and #2 cannot be expanded at all.
Is the Microwave XT the same as the Microwave II?
They share the same synthesis engine and voice architecture, so they sound the same. The difference is control. The Microwave II hides its parameters behind a menu, while the XT exposes them across 44 continuous rotary encoders. You are paying for the front panel, not the sound.
Does the Waldorf Microwave XT have reverb?
No. The onboard effects are chorus, two flangers, autowah in bandpass and lowpass, overdrive, delay and amplitude modulation. There is no reverb algorithm on the machine, so you will need an external send or a plugin if you want space around XT pads.
What is the difference between the Microwave XT and the XTk?
The XTk is the 1999 keyboard version of the same synthesizer. It carries 49 keys with velocity, channel aftertouch and release velocity, using a synth-action keybed rather than a weighted one. The sound engine is identical, so choose between them on format and price alone.
The verdict
Nothing since has quite replaced this thing, and that is why it holds its price. Wavetable synthesis is everywhere now, in Serum, in the Blofeld, in Xenia, but the combination of this engine, these converters and 44 encoders under your hands produces a specific kind of bright, restless texture that soft synths approximate rather than reproduce.
Buy on condition and mainboard revision, not on colour. Budget for an external reverb. And if you only want the sound, Xenia costs nothing and gets remarkably close.
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