As an elderly busker in a hi-vis jacket hammered at a bin-lid drum kit to a tape of old rave hits, his racket only momentarily obscured by the roar of the No.61 bus, Wilba Sandieson looked out from the threshold of Rubadub, the Glasgow record store he has co-owned for nearly 25 years. "This is a place where big changes have always been just around the corner," he said.

Rubadub is bordered by Jamaica Street to the west, the Clyde river to the south, Argyle Street to the north and the Saltmarket to the east—an area that's been the obvious next step in the city centre's "urban regeneration" process for a couple of decades. For whatever reason though, the roughly three-block by ten-block strip remains a half-forgotten anomaly. There are weather-beaten "To Let" signs hanging from the boarded-up windows of abandoned office blocks, cafes advertising two courses for £5, and enormous desolate car parks.

The area has an interesting, frequently murky, and sometimes tragic past. At its south-eastern corner is The Clutha, the pub into which a police helicopter crashed in 2013, killing ten people. A few steps north is a railway bridge that until a year or two ago was still daubed with the words "Pay no poll tax demo, get militant! George Square, 11am, 31st March 1990." Directly beneath it is the overgrown former site of Paddy's Market, a place romanticised as a charming echo of Glasgow's past and demonised as a lawless hive of illegal activity (the truth was somewhere in the middle) until its acrimonious closure by the council in 2009. On the area's eastern side, Jamaica Street (the home of the Sub Club) was named in the 1700s for Glasgow's links with the rum trade, the slave trade, or both.

"We've been hearing ever since we got here that the council were going to redevelop this part next, turn the riverside into an extension of Buchanan Street and so on," Sandieson said, stepping back into the modestly sized unit on Howard Street that Rubadub has called home since 1999. "But we've been here 18 years and it hasn't happened yet." Sandieson, a fresh-faced 57-year-old who joined Rubadub "with a bit of dosh and some business bravado" a few months after it opened, was talking about the local area. But he could just as easily have been talking about the industry that Rubadub has been adapting and readapting to for the past 25 years.

Rubadub became a touchstone in the techno world almost from the moment Martin McKay, a man with a sharp eye for the bottom line and a knack for one-liners, opened the doors at the store's first location, in the town of Paisley, on August 10th, 1992. Richie Hawtin, Carl Craig, Andrew Weatherall and John Acquaviva were early fans of the shop, among a list of people who would regularly make the ten-mile trip west of Glasgow to visit whenever they were in Scotland. (The celebrity customers McKay and Sandieson preferred to talk about were Frank Bruno—"he lived in Glasgow for a summer and loved buying headphones"— Brad Pitt, Gary Barlow, and ZZ Top.) Sometime in the middle of the '90s, Adam X coined the idea of the "axis of techno," which grouped Rubadub with Hardwax in Berlin, Sonic Groove in New York City and FatCat in London as the four stores in the world doing the most to push quality techno. Working at Rubadub has influenced many DJs, producers and promoters, Jackmaster and Denis Sulta being two of the most prominent examples.

Sandieson is jovial and sharp, a product of Rubadub's quick-witted, no-nonsense culture and the tough environments—1960s Glasgow and 1970s Paisley—in which he grew up. "I still think I'm a lot harder than I am," he laughed, recalling a day in the mid-'90s when he wandered into the South Side of Chicago on a mission to visit Barney's Distribution, prompting a local police unit to screech up and evacuate him from the area. A naturally bold businessman, he joined in 1993 with an expectation common to many of Rubadub's central figures: to be there for a couple of years at most.

Back in the summer of 1992, McKay's cofounder was Alan Gray, a friend he had grown up with in Barrhead, a town on Glasgow's southwestern outskirts, a few miles to the south of Paisley. Gray had recently been made redundant; McKay had been working in a secure but tedious role at Strathclyde Regional Council, spending his days "looking out the window and wishing I was listening to records instead." Seeing an opportunity in Gray's redundancy, they scraped together "a set of decks and a thousand pounds" and leased a unit, a former massage parlour in a dingy but unthreatening Paisley backstreet. They filled the shelves with stock from man-with-a-van local distributors with names like Great Asset, Mo's Music Machine, Pinnacle and Greyhound, and opened for business.

The records Rubadub sold at first ran the gamut, as McKay explained, from "proper techno to not-so-proper techno," the latter largely comprising "colourful hardcore records that people sometimes just bought for the pictures." The compilation Virtual Sex, which came with a free set of 3D glasses, was a popular seller. Records from Hawtin and Acquaviva's Plus-8 and IntelliNET labels also did well, as did those from the Dutch imprint Eevo Lute Muzique, especially As The Leaves Fall From The Trees by the label's cofounder Wladimir Manshanden. Manshanden turned up in the shop one day years later, and McKay delighted in telling him how important his record had been to him and Sandieson.

The early 1990s were a time when many of the basic processes behind running a record store were unrecognisable from today—a time of fax machines spewing release lists onto the floor, of hours spent listening as distributors played records down crackly phone lines, and of reps driving across the country in vans stacked with vinyl. "That was just how you had to do it then," said McKay. "You'd have someone from Mo's Music Machine or wherever drive to the shop, and you'd go out and look in the van and buy whatever you fancied."

What set the shop apart was simple: it stocked house and techno records that nobody else in the UK except for FatCat had in significant numbers. "The mission at the beginning was just to get records out there," said Sandieson, who already knew the store well as a punter and a friend by the time he joined. "Before Rubadub started you could get records from Detroit and Chicago here but you'd have to be really fast and really lucky because they ran out almost immediately. Only one or two copies of a lot of things would actually make it up to Glasgow because London distributors would leave shops here at the bottom of the list when it came to the better titles. We thought to ourselves, 'These records are really good, I'm sure the guys making them would like to sell more of them.' So we took the plunge and started contacting artists and labels direct instead, ordering 100 or 200 copies of records we liked rather than whatever handful we could get from the distributors in London. A lot of the records sold out quickly in those numbers. Some of them we're still trying to sell now," he chuckled.

In late 1993, the owners of the Koh-i-Noor curry house a couple of streets away decided to open the basement space underneath the restaurant for club nights. They asked Rubadub (McKay and Sandieson, and later Barrie Watson and Euan Magennis, McKay's DJ partner to this day), to play there every Thursday night, then promoted them to Saturdays a few months later when it became clear that their big Thursday crowds were no fluke. Helped by some influential word-of-mouth (Weatherall was a fan of the club, and was one of its most-booked guests alongside Underground Resistance and Alex Knight of FatCat), 69 became known as the best place to hear new techno, house and electro in Glasgow. Busloads of people from the city made the short journey west every Saturday for a decade, and, when Rubadub changed their residency, did the same once a month for a decade after that.

The club finally closed at the end of 2016, though has since reopened under new management. "It was great to have a place where we could immediately play out everything that we loved that had come into the shop that week or that month. Having one fed into the other, and both helped the other to be successful," said McKay. "We'd always know if we were running over at the end of the night because the Koh-i-Noor's manager, Abdul, would come steaming through the bar and throw a pint glass at us."

Sandieson and McKay are no-nonsense guys who see their world as a series of small, undramatic events rather than something shaped by big moments. Even they, though, can't underplay the importance of the "pilgrimage" Sandieson made to Detroit and Chicago in 1994, not long after he joined the business. "That was really important," he said. "Our friend Chris Abbott [who ran Infonet, Creation Records' techno offshoot] knew Mad Mike and took me to [Underground Resistance's distribution hub] Submerge to meet him. I was green as fuck at that time, to be honest, but I looked around and decided I should spend pretty much all of the money we had on stock there. Stuff from Transmat, 430 West, KMS and the like. I bought a lot of back-catalogue stuff as well as new things, and having that back-catalogue stock on an ongoing basis became another thing that set us apart.

"I had a bit of a past in retail, and my mum and dad had an ice cream van. My dad's attitude was always, 'What do you want? I don't have that now but I'll have it tomorrow.' I suppose I brought that approach to the table, so I didn't bat an eyelid at spending a load of money there, and came back with a lot of great records to fill the shop with.

"Being there also really opened my eyes to how things were in the US at the time," Sandieson said. "Almost nobody there was playing or promoting the amazing, fresh music that was coming out of the Detroit and Chicago ghettos. Maybe it was a race thing, but whatever it was, they missed the boat, and people like us in Berlin and London and Glasgow ended up being the ones who took that wave of new music to an audience outside the places where it originated."

On the same trip, Mad Mike introduced Sandieson to a host of other important Detroit figures, including Derrick May. "Derrick's a real people-person," Sandieson smiled. "He invited me over to his house as soon as he met me, and I looked through the records he had and chose what I wanted. Then he said, 'Do you want me to sign them for you?' That had never crossed my mind before, but I thought, aye! We made the signed copies of his records a pound dearer than the normal versions when I got back to Scotland."

Around that time, it became fashionable to paint Glasgow as a British or European answer to Detroit. McKay had a blunt response to all that: "Glasgow's fuck-all like Detroit. You can't compare the two—Detroit is a totally different world. There is a musical connection of some sort, and people here love music from there, but the other social factors—poverty, post-industrial decline and the rest of it—that people try to connect the two cities on exist on a completely different scale there."

McKay's steady stream of laugh-out-loud stories and quips ("I'm playing ghetto golf at five," he told me one day as we tried to schedule a meeting) and his self-deprecating take on Rubadub's longevity mask a sharp business brain backed by a staggering knowledge of the music he deals in. Affectionate stories abound about his eye for business—at 69 he would sometimes charge the DJs he'd booked a fiver to get in, just like the punters. It's obvious that his financial sense and his work ethic have been crucial to Rubadub's longevity.

"We might gently mock Martin's eye for the purse strings," said Aleks Jurczyk, a towering, moustachioed figure in his mid-30s who for the last decade has been Rubadub's much-loved resident synth expert. "But it's propped the business up in leaner months. Both Martin and Wilba are very savvy people—they like to give the impression of being chaotic, but they're both fucking sharp. A shop in any industry, let alone this one, doesn't stay open and thriving for 25 years because of luck. They both have great heads for business, and they've made excellent choices with the people they've brought in over the years.

"Take Lisa, who does the logistics stuff at the warehouse. She's not immersed in electronic music culture in the slightest, she's just really organised and good at what she does. Wilba spotted her working in a pub in a sleepy village by the seaside. They never stop looking for ways to improve things." McKay and Sandieson's hiring nous has resulted in a remarkably low staff turnover. "It's an amazing place to work, but it also makes you completely unemployable elsewhere," laughed Jurczyk. "I honestly can't begin to imagine where else I would go and work now, the culture shock would be too much."

Rubadub began taking on staff a year or so after opening. Hip-hop was a major part of the business at that time, and the shop's first two hires, Marc Donaghy and the late Ewen Armstrong, were swiftly christened "Hip-Hop United" and tasked with looking after that side of things. This habit of assigning team names to new crops of Rubadub employees meant Jack Revill (Jackmaster), Calum Morton (Spencer) and a couple of others were called "Blazin Squad" in the early 2000s. "They'd come into the shop and do dance routines," McKay said. "The routines were different every time and they clearly worked hard on them to try to impress us. Which they did."

Barrie Watson, one of the shop's first and most loyal customers, joined soon after Donaghy and Armstrong, again expecting to stay just a couple of years. (He stayed for eight.) Watson remains a much-loved figure there, instrumental in building the connections that allowed the store to cut out distribution middle men and bring in records by Drexciya, DJ Assault, Aux 88, Direct Beat, 430 West, DJ Godfather and countless others. (McKay recently returned to Detroit and went to see his old friend DJ Godfather play. McKay eventually caught up with him backstage, and Godfather excitedly introduced him to the room: "Hey everybody, this is Martin! He's the first guy who ever brought ghettotech to Ireland!")

With the shop established in Paisley and valuable contacts in Detroit, Chicago and Berlin solidified, a move to Glasgow became the natural next step. Virginia Galleries, a three-floor pre-Edwardian tobacco exchange located just off Argyle Street, was the perfect place, and Rubadub took a unit there in 1995. "The Galleries was a great location for us," said Sandieson. "It was full of wee shops trying to be self-sufficient and keep away from the mainstream, so it suited us down to the ground. It had a great vibe, and we all fed off each other's uniqueness." The Virginia Galleries and Paisley stores operated in tandem for a year. Business in Glasgow was so good that Rubadub took a second unit at the Galleries in 1997, the Paisley store having been closed the previous year "to unite the clans."

A combination of high demand for vinyl and a new strength of focus brought on by the birth of Sandieson's first child made the mid-to-late-'90s a boom time for Rubadub. "On Saturdays there was a queue out the door and queues at the listening booths," remembered McKay. "It was really vibrant." The biggest-selling record in the store's history, Erik & Fiedel's Donna, sold by the hundreds in 1997, embodying a moment of unparalleled buoyancy in the shop and the industry. The IDM boom, led by labels such as Skam, Rephlex and Nature, was happening too, and Rubadub was well-placed to be the primary outlet for "the Glasgow record-buying public's endless hunger for this weird electronic music." Sandieson's second child was born in 1998, instantly making him even more serious and business-minded: "Basically, I needed to keep a closer eye on the bottom line. Some people here had mixed feelings about it, but for me it was clear: we had to make sure we sold stuff in decent enough volumes to allow our passion to continue. We were doing just that though, so things were great."

Richard Chater, cofounder and elder statesman of the Numbers collective, spent the 1990s on the outside looking in, before Sandieson and McKay created a job for him, "techno consultant and label support," in 2004. "Before I started working in the shop I was picking up these records that I honestly felt a lot of Glasgow and the UK didn't know about," Chater said. "Rubadub was like a secret society that wasn't actually a secret—it was open to anyone who was into music and had a sense of humour. Bar the 313 and IDM lists there wasn't much on the web back then, and the records we'd buy from Rubadub were mostly not written about in the mainstream dance press. So it was pretty amazing to have a place I could just pop into after work on a Friday and hear the new Anthony Shakir or Monolake blasting out, or pick up Dopplereffekt's Infophysix and then find out it had been made by one half of Drexciya.

"The bigger house and techno clubs in Glasgow weren't playing these records at the time," he said. "So the shop and the weekly parties at 69 were our main means to find out about them. Having the shop as an influence meant you could join the dots between different strands of music—we were getting experimental electronica on labels like Skam, Sähkö and D.U.B, techno from UR, Transmat and Metroplex, KDJ, Sound Signature, Direct Beat, Dance Mania, Viewlexx, Nature, Erik & Fiedel/MMM and Soundhack, and ghettotech and booty stuff by people like DJ Assault and DJ Godfather. And because Rubadub also stocked older records, we also had access to the dub, reggae, disco and 1980s electro that was the precursor to all of it."

October 1998 brought a development as pivotal as any in the business's history. Marks & Spencer, who had (and still have) a huge store immediately adjacent to the site of the Virginia Galleries, began work on an underground loading bay. The digging impacted on the structural integrity of the Galleries, an old building in an area already prone to subsidence. Tales of shopkeepers running from the place as it sank were untrue—what did happen happened in the dead of night. But the facts were stark and potentially ruinous: the building had suddenly subsided by between 10 and 14 inches, and overnight the place became a guarded no-go zone for the shopkeepers whose stock was lying inside.

"It was months before a lot of the people there were able to get their goods back, and only a few of the shops managed to recover and reopen elsewhere," said McKay. Sandieson and McKay returned to the building with a van in the early hours, paid off the night watchman, and snuck up the back stairs to raid their own shop, retrieving a huge amount of stock and giving themselves the chance to start over elsewhere. They spent the next six months trading from a temporary space on King Street. "We had to dig deep in every way to survive that," said Sandieson. "But we managed it, and ended up using the insurance pay out to help buy the unit on Howard Street in 1999."

The years since 1999 have been a time of unprecedented change in the ways people buy and consume music, and record stores around the world have closed en masse. But if Rubadub has ever been at risk, it has never looked like it from the outside. The agility of the business allowed it to foreground its distribution business in the early 2000s, a move that that has been crucial in weathering its most trying moments in the years since.

Rubadub had periodically dipped a toe into distribution through the 1990s, supplying to shops in Glasgow and elsewhere, such as the still-active Underground Solush'n in Edinburgh and Strawberry Bazaar in Auchterarder, a small village halfway between Stirling and Perth. Now though, it became a central part of the business. Rubadub's warehouse is a ten-minute train ride from Glasgow Central, in a bleak industrial estate in the southwestern suburb of Hillington. The place is enormous—"future-proof" said Sandieson—and alongside the ceiling-high racks of vinyl and equipment, it also houses a vast office space, an industrial kitchen and a screen-printing area run by Lindsay Todd (AKA House Of Traps), the owner of Edinburgh's Firecracker Records. Labels including Mood Hut, Novel Sound, Rhythm Section, Proibito, Apron Records and Echospace are among the hundreds that now entrust themselves to the bespoke approach Rubadub has become known for.

Chater, alongside Pete Letton and Mark Maxwell, plays a particularly important role in this side of Rubadub, and he talks about it with passion and clarity. "We like to treat each label and release as its own little island. Sometimes when a record comes in it just flies, and all we have to do is facilitate it getting from the plant to the shops. But at the same time there are labels that need a bit of TLC to help them get their records to people's turntables, and we're more than down to help with that, whether it means help with promotion, with getting their releases mastered, or whatever.

"We're music fans first and foremost, so our motivation in doing this comes from seeking out music that really excites us," he said. "That usually comes to us quite organically from labels or friends getting in touch, but sometimes it's through our own digging online or the connections we make through our personal endeavours, whether it's Numbers, Dixon Avenue Basement Jams or any of the other projects the people here have. Although we're deeply serious about honouring the music we grew up with, it is even more vital for us to continue pushing new, forward-thinking sounds and styles, and we've found the distribution business is a great way to do that."

At the store, the looming figures of Jurczyk and Dan Lurinsky are the most instantly recognisable of the staff, but there's a strong additional cast. Every one of them, as Sandieson proudly noted, is involved in DJing, producing or promoting. Mark Maxwell, who has a role in distribution as well as running the shop's website, used to work with John Peel, and counts Ron Morelli and Will Bankhead as fans of his DJing. Becky Marshall co-runs the So Low night and label with Optimo's JD Twitch and two others, while Ryan Martin, who joined as a teenager in 2010 and is now the store's main buyer, co-runs the All Caps label and night. Sam Wilson, who looks after the mail order department, runs a night called Silver Dollar Club, while the shop's newest recruit, Jedd Gillies, has recently begun making his own beats. ("Once he'd settled in he asked us if we knew his dad's records," Chater said. "Turns out his old man used to record for the Chicago label Guidance in the '90s.")

Pete Letton, head of distribution and an ever-smiling presence at the warehouse, put out his debut 12-inch a few months ago and next year will release his second through Rhythm Section. Hector Barbour, AKA Denis Sulta, worked at the store from the age of 16 until last year, although, like Jack Revill, he still retains his @rubadub.co.uk email address. "We took Hector on after he was turned down by McDonald's," laughed Sandieson. "We got him in part-time and he turned out to be great. Sometimes we'll have someone come from nowhere like that and just be a breath of fresh air to the place, and it's always a brilliant surprise when it happens."

"Working at Rubadub has opened me up to a whole world of music I might never have heard otherwise," Ira Osbourne, the shop's youngest member of staff and its "first-ever real apprentice," told me. "It's the perfect place to be if you want to have the widest possible contact with electronic music and with other people making and promoting it in this city. It's allowed me to meet countless new people, many of whom I have worked with or intend to work with at some point, and it also lets me expose nights I do to new audiences who I'd probably struggle to reach in other ways."

Along with the distribution business, selling production gear has been a major factor in Rubadub's success. The gear business was set up and run by Jason Brunton until his departure last year, but putting Jurczyk at the helm—the antithesis of the "moody record store guy"—has been a masterstroke. Jurczyk is effortlessly knowledgeable about all of the gear Rubadub sells, but his expertise on modular synths, a growth industry that Rubadub has fuelled as much as it has tapped into, is world class.

"Modulars and semi-modulars are my thing," Jurczyk told me. "So when I joined about ten years ago we started getting them in. Before that there was only one guy in the UK selling them, but they began to get more and more popular just after that, so we came on to it at just the right time, I think. The current buzz around them will die down eventually, but even mainstream pop acts are using them these days, so I think they're here to stay." Jurczyk is intimately linked with the tiny community of companies, such as Tony Rolando's Make Noise, who design and build these machines. Jurczyk said they resemble small record labels in the way they operate, rather than big electronics manufacturers.

Rubadub's gear business is another way it has helped bring Glasgow's music scene, with its stream of exciting new producers and great parties, to its current position. Overlapping with this has been the dramatic broadening of Glasgow's cultural mix since the millennium, and the Howard Street store has been happy to see the changes.

"The majority of the people coming in during the first few years were white Scottish guys," McKay told me. A wave of migration from eastern Europe in the early 2000s brought new, enthusiastic customers, eager to add records and equipment to their new lives in Scotland. Migrants from Africa, the Middle East, Asia and elsewhere have followed, many of them becoming loyal customers and using equipment and records bought from Rubadub to start music projects, run club nights or open venues, which has further enriched the city's nightlife. "In Glasgow everyone involved in music is involved with each other, to a greater or lesser extent," Jurczyk said. "And the general attitude here is that anyone who wants to join in can join in. Go to a night at the African-Caribbean Centre in Ibrox or the Kinning Park Complex, for example, and you can see that happening, and the benefits of it, really clearly."

McKay and Sandieson have always been happiest working in the background, quietly changing things when needed, and otherwise "keeping a wee air of mystery." At the shop, Lurinsky and Jurczyk told me about the one bit of press the pair did in the first years of the shop, a small article in Jockey Slut that is part of a semi-legendary scrapbook of Rubadub-related ephemera from down the years. "The pair of them look like Howard Marks or something," Jurczyk giggled. "They've got big moustaches and they're wearing dark glasses and these really thick cable-knit jumpers. I don't know if they were deliberately trying to conceal their identities but that's certainly what it looks like."

This kind of humour runs deep at Rubadub. Putting a caustic or self-deprecating spin on old stories seems to be a way for its main figures to preserve its history without being overly sentimental. Also in the archive are the old photo IDs of 69's patrons from the days when it was a private members' club. "The fashion and hairstyling in there is unbelievable, it's a real rogues' gallery," Lurinsky said. "You look at it and think, Fucking hell, these were our regulars."

These days, a healthy spread of styles sell well in the store. On one of my last visits, I realised I hadn't listened to any records in the shop since moving away from Glasgow several years ago. I spent an afternoon at the turntables on the mezzanine at the back of the shop, listening to new records by As Longitude, Naum Gabo, Powell and LAPS, as a steady stream of people of all ages strolled in, chatted with the staff and each other and dug for records.

"The last 25 years have been amazing for lots of reasons, but the best thing of all has been seeing people discover the shop, start buying gear or records, and end up making great music of their own, or becoming a great DJ, or running a label," said McKay. "So many times we've been able to watch as someone has gone from being a young kid walking in for the first time, to us eventually selling their records. I like to think that's happened because we've managed to make the shop a resource and a community, and not just a place to buy things."