Boss RX-100
A two-channel spring reverb box that Boss quietly slipped into its line while everyone was staring at the digital reverbs.
Overview
The RX-100 is a spring reverb, and it makes no apologies for it. Boss built it with two channels that can run mono or stereo, and it appears in the trade listings of the era as an add-on reverb — a box you bought to give a keyboard rig or a small studio some ambience without springing for one of the new digital units that were suddenly everywhere. The company's own dealer advertising billed it as a "2 Chan. Reverb Box," and one price sheet from the period lists it at £181, while a separate listing puts it at £125. Prices in these dealer sheets bounce around depending on the shop and the year, so treat the number as a range rather than gospel.
What it is, plainly, is a spring tank in a box with Boss's usual no-nonsense enclosure around it. The dealer copy describes it as "mono/stereo in/out spring," which is the whole story in five words: feed it one signal or two, take one signal or two back out. For a keyboard player running a mono rig who wanted to fatten things up, or a home recordist who wanted a real spring sound rather than a digital approximation, that flexibility was the point. It sits in the same catalog era as the DM-100 analogue delay and the BF-2 flanger, and it was clearly pitched at the same customer — the working musician building a rack or a pedalboard on a budget.
The period press took note of it without making a fuss. Modern Recording (January 1981, p.30) covered Boss's spring reverb alongside the rest of the company's line, describing a two-channel unit with totally isolated channels and separate input and output jacks on each — a detail that matters if you're running two different sources through it and don't want them bleeding into each other. That isolation is the practical heart of the RX-100: it's not a stereo reverb in the modern sense of one tank processed into two outputs, it's two channels that happen to live in the same chassis.
Owners report that spring reverb is a sound, not a feature, and the RX-100 delivers the sound faithfully — the boing, the slightly metallic tail, the way a hard transient gets a little splash behind it. It is not a pristine hall. It is not a plate. It is a spring, and if that's what you want, the RX-100 gives it to you with Boss's typical build quality. The trade-off is the usual one with springs: they're mechanical, they're sensitive to being knocked around, and they don't love being shipped. Collectors note that a used RX-100 should be checked for a tank that's come loose or a spring that's been overstretched, because that's the failure mode these things have.
The RX-100 is not a collector's darling in the way the CE-2 or the DM-3 are. It shows up in dealer stock lists and trade-show roundups rather than on pedalboards, and the market for it is narrow — people who specifically want a spring reverb in a Boss enclosure, or who are completing a rack from that early-'80s moment. That narrowness is also its charm. It's a piece of gear that did one job honestly and then got out of the way, and there's something to be said for that.
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