Gear Change: XoXBox

If you're at all into synths and house music (and, really, why else would you still be reading this blog?) you'll have heard of the XoXBox. I pronounce it "zox-box", please inform in comments if you've heard another way of saying it. It's always interesting to hear people's takes on something that exists, essentially, as a wholly internet-based phenomenon.

The XoX is the apotheosis in a long line of TB-303 emulators, starting with the rackmount bass monosynths of the 90's like the Novation BassStation and the FreeBass FB33 (the latter the more explicit 303 emulator, the former more generic and closer to an SH-101). A friend of mine recently bought an old Roland Alpha Juno 2 from an old skool Brooklyn techno producer (greets to 8-bit, need to get a round and hear more stories one of these days). The Juno 2 has enough proper hoover stabs in memory to back up the claim that it is the original Alpha Juno which Beltram sampled for Mentasm, and the pics he pulled up when I mentioned that I had a XoX (on 8-bit's site, sadly down for maintenance this week) were very interesting. Apparently, there was an earlier attempt at a XoX-style 303 emulator in the early 90s, which was hand-built and almost entirely transistor-based synthesis (think Jupiter 4). The builder passed one over to a brooklyn producer friend who didn't quite know what to make of it, and it languished in his collection for a few years until someone realized what it was. The story ends there, since I, like a fool, never followed up, and dude's site is down. EDIT: hold on a minute, Check This Out.

The XoX itself, however, is effectively the be-all, end-all TB-303 emulator. The design requires the original chips from a 303 or NOS of the same^[1], and the sequencer is designed to act similarly to the original 303 sequencer, though slightly better in the basic version. The arduino(?)-based OS/sequencer can be upgraded via a USB connection built into the basic design of the XoX, which also includes MIDI I/O/T as well as independent DINSYNC, switchable in/out, and CV + Gate outputs. This utterly outclasses the Acidlab Bassline 1 I owned a few years ago, which had severe difficulty syncing via MIDI to my TR-707 and would only work when synced via DIN, and I won't even mention the hilariously terrible programming method (hint: it involved two knobs and an INPUT button). The XoX drops in beautifuly with a MIDI setup, and performs like a dream. Compared with the TB-303, it's a bit like getting an East German BMW from the 60s vs getting a newly produced BMW today. The old one looks nicer, but the new one performs just as you'd like it to.

The configurability of the XoX with new firmware is fairly impressive, although hampered by the original design of it. There are OS upgrades which allow arpeggiation and various other sequencer-oriented re-purposing mods, check this thread on SOKKos (the oldest and most advanced) for more info. There are also several hardware mods which mirror the basic modifications which were often added by 303 users in the 90s, such as the overdrive knob and the filter expanders. However, in a 303 emulator, the most important issue is the accuracy of the sound.

XoXBoxes are known for their variation in sound, just as the original 303s were (though, if you bought a 303, you usually wouldn't question the variation quite so much as with those who buy a XoX). Some of the XoXen have a sound which is very mild even compared to other unmodified XoXes, so you should keep that in mind when shopping for one. There's no way of knowing what the XoX you buy will sound like, no matter who builds it. My XoX was built by a Taiwanese hobbyist who no longer sells them, but it sounded the closest to a vanilla 303 of any XoX I've ever heard. The pop in the filter-envelope reaction to the accents was the most beautiful I've ever heard from anything approximating a 303. The knobs on my XoX were, unfortunately, a bit too slow for my taste. Ideally, they should be like the original 303 knobs, and fast spins shouldn't feel any resistance. Luckily, the standard design of the XoX requires that the circuit boards be fitted well, so the varying button or knob resistance doesn't mean an increased level of wear to the top interface circuit board, and barring truly homebuilt versions, should stand up to a reasonable amount of live performance wear-and-tear as well as whatever you may throw at it in the studio.

One interesting issue I ran into with my XoX lies within my recording setup, which is MIDI-based and relies on a Roland MC-50 hardware sequencer and a Yamaha MJC-8 MIDI router: On two different tracks where I attempted to record the MIDI output of the X0X to the MC-50, there was a strange sense of lag, possibly introduced through lag from the MJC-8 (though I doubt this). The X0X syncs perfectly to a MIDI clock input for it's internal sequencer, which is more than capable of providing for 303-type sync usage. That is, when syncing the internal sequencer in tandem with a MIDI setup, it is bang on to the timing of the track. However, when I recorded the XoX sequence into my MC-50 and set the XoX to MIDI Play, it would drop notes in a strange (but highly usable) way. I think this might have more to do with the firmware than with the ability of the XoX to comprehend MIDI messages when played with an external keyboard. Mine was never upgraded after I got it two years ago, nor did I upload any second party OS to it, so your mileage may vary. Like I said, though, this strange issue of slightly mistimed sequencer messages can be very usable in certain situations, especially when the recorded XoX sequence is sent to another synth with a 303-ish patch.

Though I've sold my XoX recently (for reasons which have nothing to do with the sound/hardware), I'm hopeful of future projects with the same mindset as the XoXBox team had, such as the MB-808. It's a phenomenal approximation of the 303, and no other emulations have come so close to not simply reproducing the sound of the 303, but the interface as well. Drums are another story though, and I think that the next review I'll write up will be on the Korg DDD-1 plus some thoughts on the add-on cards available to it, both the old ones and the newer models which should place it heads and shoulders above the other similarly 12-bit generic drum machines.



[1] I have a theory that at least one plant in China has devoted a few lines to stamping out limited new chips, backed up by the fact that several of the original chips were literally the faulty versions of chips intended for more professional Roland synthesizers (18db filters? really? I've read several sources over the years claiming that either they are all faulty 24db filters or were based on the faulty versions, but given the short production life of the 303 that seems unnecessary) and thus can't possibly be that hard or expensive for an aging through-hole chip factory to replicate on the side.

Further note: The demonstration tracks I've included are my own music, and I'd be happy to describe the synths accompanying the XoXBox for any of them for those who are curious or confused.

Gear Change: Roland DJ-70mkII

This is one of my current keyboards, alongside the CTS-2000. The Roland DJ-70mkII is the final product of the Roland S-series line of samplers, aimed at the strange 90s DJ-consumer market. It consists of the last of the proper S sampler line, the S-760, placed in a high-quality 3-octave keyboard with an enlarged version of the S-760 interface, as well as 8 buttons which can be assigned to samples, a fairly useless phrase sequencer, the usual Roland pitchbender/lfo combination, and a somewhat novel "DJ wheel" which allows you to do a sort of rudimentary scratching on the samples. In reality, the result is a strange combination of the S-760, minus the extra outputs and the video interface, with an Akai S-20, along with the 3-octave keyboard and the DJ wheel.

The keyboard is wonderful, though either as a matter of reaction to the total package or simply due to psychosomatic reaction it feels a little cheap. The interface is, from what I know of the S-760, essentially the same minus the output options (caveat: I've never used an S-760, but I've read a bit). It's extremely easy to create a basic sample, but somewhat odd for a former low-level Akai user such as myself to deal with the structure of patch creation. You can read up on it more on the various sites that explain the S-760, since it seems to be the same to me, and I just haven't had the inclination to explore it properly yet. For a Roland user, this keyboard would undoubtedly be a dream (if it had the outputs and the video interface).

The buttons up top seem superfluous given the keyboard, and the ability to assign any sample to a given key or span of keys, but I guess for the working DJ he may not want to have to worry about hitting the right key (even with gaffer tape?) at the right velocity in the heat of the moment, and would want to simply press a button to play a loop.

The DJ wheel seems to have been based on the ribbon controller on the Yamaha SU10 from a year or two prior to the release of the DJ-70mk1. The SU10 was one of the line of Yamaha MIDI music machines which included the MU5 and the well-received QY10 (and the rest of the QY series), with which it shared a form factor. It boasted a 47 second sampler (much less at higher bitrates/in stereo) in a piece of gear which was about the size of a VHS cassette and included a 4-track phrase sequencer as well as twelve non-velocity pads. It also featured the easiest sampling interface I have ever used, from Akai to Ensoniq to Roland or anyone else, though that may have been made easier by the limited memory space. The relevant side feature, though, was the ability to 'scratch' samples with the built-in ribbon sensor (only one I know of which transmits MIDI, I have to recc this thing again), which essentially chopped up the given sample into audibly small increments and allowed the user to 'scratch' them similar to how one would scratch a record, but in a horrid digital way.

This is what the DJ-70 DJ Wheel aimed to reproduce. The wheel is weighted, though not so much that it feels like the Technics deck which I imagine they were trying to emulate, and this doesn't affect the sound at all apparently, so the effect of weight feels cumbersome given the intent/implementation. Where in the Yamaha SU10 the scratch function was a novelty, the DJ70's wheel is a strangely cumbersome and useless feature which is only novel if one wishes to throw a sample out and listen to it spin down from high velocity. Even a non-weighted but better-implemented algorithm wheel function would have made this a desirable synthesizer. Which brings me to the reason why there are Mark I DJ-70s and Mark II Dj-70s.

When the DJ-70 was originally released in '96 or so, it was aimed at the DJ market with the hope that it would serve as a convenient replacement for the samplers which famously helped house & techno DJs as early as Park & Pickering at the Hacienda and would be priced well enough for current small-time DJs to afford it. The keyboard had 2MB RAM and no SCSI interface, so there was no way for buyers to expand the amount of time they had available in memory for samples beyond a few minutes, and no way of loading in samples aside from a floppy disk drive. It had the editing facilities of the superb S-760, but none of the expandability. Essentially, it was a completely useless product of a company which, I presume, was struggling with a leftover internal bureaucracy in order to find a way to approach the new music which their products had created. Akai had several similar products (the S01, as well as the S-20), as did Yamaha (SU10 among many others) and several other companies. Korg, rejuvenated by their failure in the mid-80s and the continuing success of their alterations to their M01 line, wound up creating the Electribe line with brilliant prescience. I'm digressing.

Roland realized that the DJ-70mkI was completely outdated even by their W30 from 1989, so they updated it as the DJ-70mkII. The mark II included all the features of the mark I, plus a SCSI interface, standard, as well as standard SIMM expansion slots for up to 32MB RAM (it turns off the internal RAM when there is a full 32MB installed). At the time, this still wasn't worth the $1800 pricetag for the DJ-70mkII alone, not to mention the $300 or so it would have cost to max out the RAM and another $250 on top of that for a Zip drive or some Magneto-Optical alternative. Especially not when the S-760 cost about $2200 with the video/digital IO expansion, full RAM, and the standard SCSI & extra four individual outputs. The cost of a cheap second-hand 5-octave MIDI keyboard and a SCSI device unquestionably made the S-760 the better deal as an all-in-one home studio sampler at the time.

At the time, that is. Now, a fully expanded S-760 will usually fetch prices above $250, and the added cost of a MIDI controller plus a mixer and all the stuff you'd normally have had to buy with it in the 90s will set you back at least another $300 in order to use it with a modern PC-based Logic studio. The DJ-70mkII goes for around $125, and the cost of a Zip drive + disks and 2 sticks of 16MB SIMM RAM (if it's even necessary) will bring that up to around $160. Add in a cheap stereo USB Audio interface for another $35 and a USB/MIDI cable for $15, and you've got a hardware sampler plus a MIDI controller which easily outclasses most of the similarly priced 3-octave USB MIDI controller keyboards. Use Logic for sequencing and mixing and the DJ-70mkII becomes a very attractive option for anyone looking to add a bit of hardware to their studio, or add an inexpensive yet extremely powerful sampler to their existent studio.

I've taken to using mine as the sole piece of audio equipment (plus a hardware sequencer) at live performances, since it can handle dozens of samples in memory, and the process of switching between songs becomes as easy as hitting the +1 button on the performance edit menu and hitting play on the sequencer. Anyone who has had to deal with the nightmare of setting up several MIDI keyboards in between bands (or god forbid, CV/gate), the prospect of a single keyboard which will do everything you need and takes about five or ten minutes to set up and go becomes very attractive.

Another point in favor of the DJ-70 series in general is that it has the same spectacular filters sported by the Roland S-series from the S-50 onwards. They're a sort of digital emulation of traditional analog filtering (IE not hard to grasp for anyone who knows Subtractive synths), but they rip. They're nearly capable of self-oscillating resonance, but the sweeps are really where they shine. Literally, they tend to be very bright, but at the same time Roland's samplers have always been known for their unparalleled bass reproduction. The filters are HPF/BPF/LPF switchable, so you can use the HPF with high resonance to give bass hits some real boom, or do the big LPF breakbeat sweeps to do builds and breakdowns, and it can all be automated and controlled via MIDI.

The feature which struck me as most interesting, and the only one I've yet to figure out, is the ability to beatmatch samples to MIDI clock. In theory, this should allow you to sample in a looped beat, and then match it with the internal timestretch to MIDI clock in real time, which was essentially the only major feature of the DJ-70 series that actually made it seem like a fairly good product for a DJ to buy in retrospect. You wouldn't have to worry about matching your sample loops with the track you're spinning, you'd just match the click track off a MIDI sequencer or tap tempo input, and you could create live remixes from your own sample library while mixing in and out of other records/CDs. I haven't quite gotten a handle on it yet, but given the 600+ second maximum sample time of a fully expanded mkII, plus a SCSI sample library and a basic hardware sequencer with half a dozen pre-recorded multi-timbral sequences, you could theoretically run an entire DJ set off of this sampler alone.

The DJ-70mkII is certainly worth a look, but it's best suited to someone with a laptop-based sequencing setup due to the incredible automation possibilities and the output limitations as compared to the S-760. Give the mkI a pass, but if you spot a mkII in good shape for under $150 and you'd like a small keyboard version of the S-50 with a much better interface, it's certainly worth a buy.

Gear Change: Siel DK-70

Before I move on from Siel products, I've got to talk about a synth I truly adore, and am sadly parting with. The Siel DK-70 is an 8-voice DCO analog polysynth in the vein of the Korg Poly-800. It has a built-in two track polyphonic sequencer (real time key-presses only, though it does apparently output MIDI) and a wonderful, though strangely implemented, chord memory function. It runs on 6 D-cell batteries (or C? It's been too long since I used batteries), and has guitar-strap pegs on each end. These are the only part of the construction which are actually made from metal, the case itself being manufactured plastic of a quality similar to a Roland SH-101.

The programming interface on the DK-70 is, again, similar to the Korg Poly-800. The parameters are listed on the upper right of the synth (same as the later CTS-2000, except without the membrane button/menu system), and one selects the parameters to edit via the same membrane push-button phone-style pad that one uses to select a patch. The membrane buttons of the pad, I should mention, are surprisingly high quality given the obvious budget mindset of the design, and have been in good shape on both of the DK-70's I've owned. I compare this to the two Sequential Sixtraks and the Sequential Split-Eight I've had, where the membrane buttons were in absolutely abysmal condition despite the fact that the hardware appeared to have been well cared-for. Age is probably not an issue with the DK-70's interface, although this brings us to the memory issue.

The internal memory of the DK-70 was obviously designed as a consumer keyboard, with the lions share of patch save memory reliant upon a cartridge which was offered with the keyboard, which apparently nobody bought, or at least kept. The internal patch memory consists of 40 preset patches, which are very same-y, though usable if the Siel sound is something you're looking for (i.e. if you bought the thing), and 10 user patches, which are not battery backed-up internally and require that one keep the D-cell batteries in the synth, similar to the Casio CZ-101. Keeping it plugged in via the power supply does not ensure that your patches will be saved. When the 10 user patches are reset, the internal rom refills them with the remaining 10 of the 50 preset patches.

That's not so bad, since the final ten patches of the 50 are quite good with a little editing, and editing is extremely easy for anyone familiar with analog synthesizers. The built-in patches are best described as 'standard analog fare' for 1985, though they do exemplify why Siel and other Italian manufacturers were relegated to a sort of ghetto compared to their Japanese and American competitors. The quality of the piano patches on the DK-70 is horrid even in comparison with the standard synth piano patches of the Korg Polysix from four years prior to the release of the DK-70. Strings, perhaps unsurprisingly given Siel's background with the SCI Prelude, strings are where the DK-70 shines. The oscillators have a warm quality which is immediately comparable to the Korg Poly-61, but the Curtis filters paired with the unique design Siel employed give it a clarity and subdued warmth which totally destroys any possibility of comparison with the Poly-800 in terms of sound. Pair this synth with a cheap 80's reverb unit, and you can create the warmest, most enveloping wall of strings, or the most proper techno bleep bass you've ever heard (especially with the Moog Killer modification on the filter which expands the resonance and gives you knob control for that and the Cutoff).

I've owned two of these, and just sold the last one due to money issues, so let me describe some of the issues I've run into.

First, the power supply is a terrifically oversized 12v ungrounded brick, similar to the bricks which came with the Atari ST 520. It can be very noisy, but since I'm not too familiar with electronics I couldn't explain the factors which contribute to this. My building has a truly terrible electrical system, but behind a surge protector power-strip which shared power with my mixer and most of my other equipment, there was very little noise (caveat: my mixer is a first-gen Makie CR1604, which may have a noise floor above that of the DK-70, or there may be some kind of electrical equivalent of audio frequency cancellation, the correct term escapes me but it's the sort of thing that you deal with when miking a drum kit in the studio). However, when I brought the Siel into the audio studio at my university to allow my friend to use it as backing for a track we were working on, it had a terrific amount of hum. Here again, the caveat would be that I don't know how well that studio is wired and we were using it for something which they apparently never anticipated it would be used for.

Second, the keys tend to degrade over time in a fairly common but strangely unpredictable way. In most of the analog synths that I've owned, keys degrade and fail because the mechanism of the key contacts degrade a very slow rate between the contact and the conductive rubber plunger which the key presses down upon them. It can happen through frequent playing, where the rubber plunger wears down simply through overuse, or, more often, because dust accumulates on the conductive plunger and prevents full contact. However, the DK-70's keyboard is, and I state this having only used two of them, very, very cheap. There seems to be about a millimeter of space between the keys. I've only seen something similar with a quite well-worn Korg Polysix, and on that a simple cleaning of the contacts worked perfectly. With the DK-70, it seems to have been a point of the inexpensive design, possibly reusing a keyboard structure from another more expensive synth. The keys are slightly more mushy than other keyboards, probably due to the cheap feel of the keys themselves, which allows dust to act in different ways on them. A key pressed a certain way will not connect, but if massaged enough or if pressed in a different way will connect perfectly. Further caveat would be that I never bothered to try to clean the contacts, as the DK-70 responds very well to MIDI and I have been using another synth as a controller keyboard the whole time I've owned them. I don't think this problem poses any real issue, and if it does there are several cheap fixes in the case that a simple disassembly and cleaning with a q-tip doesn't work. If you have this problem with this synth or any other, look around for some Wire Glue or Conductive Paint (the former is cheaper and just as effective in my experience).

I would highly, highly recommend the DK-70 for someone in the market for a new analog synth to add to their established MIDI rig. On it's own, it provides wonderful sounds, but sampled it can provide an entire palette of analog-style patches to warp and alter which will sound like nothing which has come before.