Heathkit AD-27

A 1960s quest to play music in stereo leads to the purchase of a Heathkit hi-fi

“I’d never spend a hundred and thirty quid on a record player,” Gavin scoffed in contempt when I told him what my Heathkit stereo had cost, “especially when I had to make it myself.”

Such derision was painful coming from one of my best friends, but he did have a point. £130 in 1970 was today’s equivalent of around £1,750 in terms of prices, and possibly twice that in terms of earnings, so it was indeed a worrying amount to spend on just “a record player”.

Gavin’s dismissiveness should not have been a surprise. To begin with, he did not seem very musical going by what I’d heard of his hymn singing in school assembly. Secondly, his main interest was animals. If he had managed to save £130 he would have expanded his menagerie of amphibians, reptiles and cage birds. I would have quipped just as quickly that I’d never spend a hundred and thirty quid on a twittering flock of Java sparrows, especially then to have to feed them and clean out the bird mess.

I've always liked music. When my mother did her housework to Housewives’ Choice on the Light Programme in the nineteen fifties, all the songs went straight into my head and stayed there (e.g. almost at random: Mitch Miller’s ‘Yellow Rose of Texas’; The Four Lads’ ‘Standing on the Corner’; Eve Boswell’s ‘Pickin’ a Chicken’; Michael Holliday’s ‘Story of My Life’; Perry Como’s ‘Delaware’;  ... ). And later through the nineteen sixties pop explosion I recorded hours of LPs and singles on my reel-to-reel tape recorder. I learned to play guitar and clarinet, and even began to like classical music.

The attraction was always the music rather than the words. I could never understand the appeal of the tuneless Bob Dylan or the droning Leonard Cohen, and when performers came along who were more concerned with how they looked than how they sounded, they left me cold – I’m thinking here of posers such as David Bowie and Marc Bolan. I belatedly came round to appreciating Bob Dylan’s genius, and even Leonard Cohen’s, but in 1970 I would have always gone for the spectacular musicianship of The Who or Jethro Tull any day.

It therefore seemed entirely justifiable to spend a large sum of money on audio equipment – not a “record player” but ‘hi-fi’ – high fidelity stereo, the high quality reproduction of sound. Something of similar quality would be costly even today, despite the shrinking price of consumer electronics over the intervening decades.

People forget now that when the early Beatles and Rolling Stones records came out they were in single channel mono rather than binaural stereo, played in most homes on simple self-contained Dansette-type record players. Mine was a Philips, but basically the same – it had a built in amplifier with a single loudspeaker, the turntable speed could be adjusted for 33 rpm LPs (later called albums), 45 rpm singles and the old 78 rpm records, and it had a drop-down autochanger which allowed around half a dozen records to be played automatically in succession. The sound quality was not all that great.

My first LPs were all monophonic: ‘The Hits of the Animals’ (an export version bought in Belgium), Georgie Fame’s ‘Sweet Things’ and Gustav Holst’s ‘The Planets’. I didn’t own any others for some years  because I could lend these out in exchange for others to record on tape. LPs began to appear in stereo during the latter half of the nineteen sixties, but as they were downwards compatible most people continued to play them on mono equipment. I first heard true stereo at a friend’s house and was thrilled by the way Jimi Hendrix’s guitar floated ethereally across the room from one speaker to the other.

Shure phono cartridge and stylus, with boxes (these are from later in the 1970s).

When I got the Beatles White Album in 1968 it was in stereo, and I wanted to know what it really sounded like. I bought a Shure stereo phono cartridge – the cartridge is the part that holds the stylus underneath the head of the record player arm – and wired it up so that one stereo channel played internally through the record player as usual, and the other externally through my tape recorder. It worked, but not very well. The aeroplane at the beginning of the first track, ‘Back in the U.S.S.R.’, did just about fly across the room in front of me, but it wasn’t all that convincing. Trials with other bits and bits and pieces of equipment fared no better.* It might have been stereo but it was certainly not high fidelity. After a while I gave up and went back to mono. As my uncle put it, “Good mono is better than bad stereo.” There was nothing for it but to save up for a proper system. It had to wait until after I started work.

Before the nineteen seventies, ‘hi-fi’ was an expensive minority interest and proper systems were expensive. One of the first affordable products was Alan Sugar’s Amstrad 8000 stereo amplifier which cost £17, but Sugar himself now admits that it wasn’t very good – possibly no better than my own first faltering trials. Hi-fi also still came as a collection of separate units – a turntable or record deck, a radio tuner, a tape deck, a pre-amplifier, an amplifier and loudspeakers – interconnected by a confusion of wires hanging behind in a spaghetti-like, dust-collecting tangle. Integrated music centres which came along around 1973 avoided some of this wiring mess, but their sound quality at first still tended to be poor. It was some time before consumers began to look for higher quality.

My Heathkit AD-27 Stereo Compact

Before these things came to market, the most cost-effective way to get high fidelity stereo was as a build-it-yourself kit – a collection  of wooden cabinets, chassis parts, printed circuit boards and electronic components. I bought a Heathkit AD-27 stereo centre comprising a stereo tuner/amplifier (Heathkit AR-14) and integrated record deck (BSR McDonald 500A), together with large Heathkit speaker cabinets containing bass and treble loudspeakers.

It took several weeks to put it together. One problem for me was that there were around a hundred and forty resistors of around sixty different values identified by colour-coded bands: green-blue-brown for 560 Ω (ohms), grey-red-brown for 820 Ω, yellow-violet-orange for 47 kΩ. Now, as previously posted, distinguishing red from brown from orange from green from grey is no simple matter for me, but I managed by sorting them into piles and checking I had the correct numbers of each according to the list of components. It’s a wonder I did it right, but I did.

Extracts from Heathkit AD-27 documentation
See links at end of page to download full manuals from Google docs

For the next few weeks I soldiered on with my soldering iron, mounting resistors, transistors, capacitors, diodes, chokes and other components on to printed circuit boards. I screwed together the metal chassis and wired in the boards, power supply, knobs, switches, sockets and other parts. I sometimes worked on it in the early hours of the morning. One night my dad walked wondering why the light was on, and seeing a stream of smoke rising from the soldering iron said in surprise, “Oh! Are you having a cig son?”

The speakers came flat packed and had to be put together. The back used a surprisingly large number of screws. One of the bass speaker cones had to be sent back and replaced because it rattled.

When at last it was finished it didn’t work. Despite re-soldering all the joints I wasn’t getting anything like the correct voltage readings at specified points on the circuit boards. I sent it back to Heath of Gloucester for attention, and for a nominal charge they quickly fixed it. Whether the problem was my fault is unclear because although they carried out more re-soldering, they also had to replace a faulty component.

On its return, I installed the unit in its wooden cabinet and switched it on, and it worked. My ‘good mono’ uncle rushed round to witness the moment, and as the full orchestra came in and rose to a crescendo near the beginning of the Peer Gynt Suite, without any sign of distortion, he gave me a thumbs up sign and said, simply, “It’s a good ‘un.” And it was. It had a wonderfully rich, warm tone.

It malfunctioned once more when about four years old, and I couldn’t mend it. I sent it back to Gloucester a second time and again they replaced a component and re-heated some of the joints. As well as making wonderful equipment they gave wonderful service.

It gave me years of enjoyment. Even my dad started buying records to listen to on his Thursday half-days off.  I was a bit put out to find Bing Crosby, Vera Lynn and Mrs. Mills among the LPs in my record box.

Despite the expense and derision, the Heathkit was well worth the money. But the fortune Gavin spent on animals was a much better investment. I never became a rock star but he later became a vet.


Here are a couple of YouTube videos of AD-27s, although the first one is in a completely different cabinet and you have to look near the end for a good view of the deck.

* In due course all the bits and pieces of equipment got thrown away: my Philips reel-to-reel tape recorder, an almost identical two track machine acquired for nothing from a friend who no longer used it, my uncle's old Grundig tape recorder, an extension loudspeaker and belatedly the Heathkit around 2003 after spending years in the loft. People are now interested in these things again, and I wish I still had them. I have a photograph from a wet morning in spring, 1978, showing my old record player, an extension loudspeaker and my uncle's old Grundig tape recorder waiting forlornly at the side of the road for their fate with the dustmen.

Links to Assembly Manuals and Related Items on Google Docs

The Heathkit AD-27 was based on the Heathkit AR-14 stereo tuner/amplifier.
Specification Sheet - Heathkit Kit Builders Guide - Invoice and miscellaneous items

AD-27 Assembly Manual (manual number 595-1134 dated 28th March 1969).
The circuit diagram which folds out from page 115 contains very small text so I have scanned it at higher resolution.
Assembly manual - Amendments and additional Information - Circuit Diagram

Berkeley Loudspeakers (model SCM-3, manual number 595-G590-01 dated 10th September 1970).
Assembly manual - Amendments - Additional information 

 

In praise of bicycles

“That’s a nice lamp,” the older boy said as he approached me in the dusk at the end of the back lane near the bomb-buildings. I was on my three-wheeler trying out the bright new bicycle lamps I’d been given for my birthday, white at the front, red at the back.

“Can I look?” he asked, and without waiting for an answer reached down and slid the white lamp upwards from its bracket in front of the handlebars. “A really good lamp,” he smiled, examining it closely and seeing how far it could shine, “and a new one too.”

I smiled back gullibly. He glanced around furtively and then ran off along the street, lamp in hand, the beam moving up and down on the wall with the movement of his arm. I watched in disbelief as he disappeared around a corner, and started to cry loudly. My mother came running out of the house and took quite a time to calm me down. I had just been introduced to the world’s wickedness, a crime victim at the age of four. We never saw the lamp again.

“Would you recognize him if you saw him?” she asked. I didn’t know what ‘recognize’ meant.

In the flat streets where I grew up, the roads belonged to bicycles. Everyone had one, and nearly everyone used them, at least some of the time, as their main everyday transport. Four times a day, when the women rode to and from the clothing factory, or the children to and from the schools, or the men to and from the railways, docks and shipyard, they packed the roads three and four abreast - four times a day because most people went home for their ‘dinner’. With no room to overtake, motor vehicles, the few there were, had to crawl along at bicycle speed. When the railway gates closed, cars, vans, lorries, buses, and even motor cycles had to wait patiently behind as many as forty or fifty cyclists who had zig-zagged through to the front of the queue. Who needed a motor vehicle when you could cycle everywhere effortlessly on level roads? Even when it was raining a bicycle cape kept you dry, a shaped waterproof sheet draped over your arms, back and shoulders down to the pedals, with just a hole for your head. Better to be an unfashionable yellow rhinoceros than a soggy wet dog.

My three wheeler came at the start of my bicycling years after graduating from pedal cars. I rode along the pavement at the front of the house, bumping rhythmically over the slabs like a train on a railway track, and returned round the back, past the bomb-buildings, along the smooth concrete surface of the back lane where once a rag and bone man’s horse deposited a stinking pile of manure that kept me away for a couple of weeks until it dried and turned white.

They resurfaced the road at the front, and the loose chippings drifted down the camber to collect in the gutters. I gathered them up in a little tray fixed to the back of my bike, and took them to my mother’s uncle who mixed them with cement to make himself a new front door step. He glanced furtively up and down the street before lifting them inside, the same look as the boy who had stolen my lamp, receiving stolen road stone from a four year old thief. That step is still there after sixty years, as good as the day he built it.

For safety, I ‘helped’ my dad paint white panels on the rear mudguards, just as legally required then on grown up bikes. But my first accident was due to lack of experience rather than lack of visibility. I thought I could reverse my tricycle square against the high wall of the lane and lean back comfortably against it, but the tricycle rolled forwards and I fell backwards cracking my head on the concrete. More crying. My mother came running out of the house horrified by the red pool of blood collecting on the ground. Perhaps a helmet would have saved me, but even if they had been invented then they certainly had not yet been declared ‘essential’ by the health and safety squad.

I moved excitedly up to a two wheeler at around seven or eight, a second hand one. My mother puffed up and down the road behind supporting the saddle, struggling to keep up, and then, in an instant, she was no longer with me, and with a surge of elation I knew I could do it. A year or so later, my dad took me to the cycle shop to order a spanking new bike. That was a good business to be in; there were around half a dozen bicycle sales and repair shops in the town.

My new bike was bigger and fabulously modern, a Raleigh of course. I chose one with the latest straight handlebars rather than the traditional backwards-pointing ones, white mudguards, calliper brakes rather than rods, a front wheel dynamo for the lights, and a three-speed Sturmey Archer rear hub, much simpler to operate than the derailleur gears on racing bikes. You didn’t really need gears on our flat streets except to accelerate quickly and go faster. 

Apart from the usual minor scrapes and grazes I only remember falling off properly on two occasions. The first time, not long after learning to ride, I hit a large stone while following my dad along the river back. My bike stopped dead throwing me forwards over the handlebars, landing on my back in soft grass after a perfect mid-air somersault. I got on my bike again and caught up my dad who had no idea I hadn’t been behind him all the time. The second time was more serious. I stood on the pedals to accelerate, the gear slipped, the pedal gave way and I dropped painfully down on to the crossbar and lost control. I was still moving forwards when my face hit the road, scraping off a strip of skin from chin to forehead, lucky not to break my nose. I looked quite a sight for the next couple of weeks.

No one ever expressed any concerns about young children riding around the streets and lanes on tricycles, or older children around town on two wheelers, nor when we went on longer rides in the school holidays. Around ten miles away was Skipwith Common, the location of R.A.F. Riccall, an abandoned wartime airfield where crews were trained to fly Halifax bombers. Nature was already beginning to reclaim the buildings and runways, and it was a great place to explore. It remains a diverse natural habitat today.

Slightly further was Selby, where the London to Edinburgh railway line crossed the Ouse at the northern end of the station platform, and every train, no matter how important, had to slow down to rattle across the swing bridge at forty miles an hour. A constant procession of powerful main line steam engines with evocative names passed through all day in both directions, enabling me to cross off now long forgotten A4 ‘streaks’ such as ‘Silver King’, A1 Pacifics such as ‘Bongrace’, Britannias such as ‘Rudyard Kipling’, and some of the new English Electric diesels. It was a trainspotters’ paradise.

Skipwith and Selby always seemed much further away on the way home. Around half-way back was a playground in a grassy field, which always provided a much needed rest. If you saw that road now, with its stream of fast cars and heavy lorries, you would be appalled at the idea of eleven and twelve year-olds riding off for the day.

Most of us were thus thoroughly accustomed to busy traffic long before it was decided we needed to take our cycling proficiency tests.* We practised in the army drill hall with long strips of canvas rolled out to represent roads and junctions. I put my new knowledge into use straight away, waiting at the crown of a road to turn right from a minor road into a major road. Unfortunately, it was at the same moment a large lorry wanted to turn right into the road where I was waiting. “The lorry has priority” I told myself confidently, so continued to wait at the crown of the road. The driver wound down his window and told me in no uncertain terms to “get out of the bloody way”. So much for the theory.

As for the practice of being able to control our machines, I suspect we could have taught the instructor a few things. Riding slowly and weaving between cones was simple. We could have shown him the finer skills of carrying two people on one bike and how to look cool while riding along nonchalantly with hands in pockets. Two of my schoolmates could even swap bicycles while riding along without either of them getting off or stopping.

We passed our tests one mild Saturday afternoon in April on the deserted roads of the industrial estate. I proudly received my badge and certificate and quietly went back to my old streetwise ways. But I always maintain that our road-wise experience and natural understanding of things like gears, momentum, acceleration, braking and centrifugal force, gave us a head start when it was time to learn to drive.

In due course my ‘new’ bicycle really became too small for me, but it stayed with me for many years. It saw me through six years in Hull, another pancake flat place. Once when I’d chained it to a bike rack, I returned to find someone had helped themselves to the Sturmey Archer back wheel and had to walk home. I thought of my stolen front lamp from an earlier time. The wheel and hub were surprisingly inexpensive to replace; it always amazes me how cheap bicycle parts are in comparison with car parts of similar complexity.

Not so long ago I took my family to see the place I grew up. At the motorway exit roundabout we stopped to wait for a large middle aged man on a bicycle labouring slowly against the rain and wind, oblivious to the queuing traffic. He was wearing a flat cap and a brown gabardine mackintosh belted over a blue boiler suit, his baggy trouser legs secured at the ankles by bicycle clips. It could have been my dad from sixty years ago. My children laughed out loud at this solitary remnant of the droves of cyclists who used to block the roads four abreast.

“It’s Fungus the Bogeyman,” they shrieked.

“You are now entering my home town,” was all I could think to say.


* Andrew Petcher's Age of Innocence blog has similar recollections of the cycling proficiency test.