Background
There was a conversation about maintenance and repair of Quad amplifiers – but the discussion turned to the question of plugs.
Dave Plowman
The quality of standard DIN leads and sockets did leave something to be desired – they had a habit of oxidizing and therefore making poor contact when old.
Bernie Newnham
I’ve wondered from time to time, when not swearing at them, what possessed designers to build connectors that are difficult to make and use. Phonos and BNC have been around forever. Mind you – that comment doesn’t apply to Apple, I know why they build special connectors.
Roger Long
If only all plugs were designed by Neutrik.
The DIN plug (German of course) enabled multi connection in one cable, fiddly and never really robust: they were also taken up by B&O and Naim.
The phono is a feeble plug but has taken acceptance as has the dreaded 3.5mm stereo jack.
David Denness, Dave Mundy
And the dreaded SCART, by the French company Peritel, not forgetting the motor car cigarette lighter plug, the 2.5 mini jack, and the 3.5 AV plug (with a vision connection).
I used the 240deg. DIN plug when building my own hi-fi as it made soldering easier! (the 8 pin DIN would have been quite a challenge!)
Pat Heigham
Oh! Good! Another topic to have a general moan about!
Having been used to BBC jackfields where one set up the ins and outs as required (except for LG Studio R – a sound only facility which had F & E multipin connectors for the tape machines – bloody!), I also hate DIN plugs, but I do have nimble fingers and was useful with a soldering iron, so made all my own cables for both home hi-fi and pro sound kit.
Mind you, the DIN plugs required a bench magnifying glass!
I liked to use metal shelled plugs, in some cases having to place the pinned insert into a different make of shell to fit the Quad inputs. The best ones were Preh, without the locking ring, but it was necessary to replace the dome headed screws on the Quad sockets with flush countersunk, and the panel drilled countersunk to accommodate the screws. I think I explained that to the Acoustical people when the
control unit was returned!
I once built a cable to feed the PA’s mono cassette Walkman from the stereo SQN mixer, requiring a combining/buffer pad with three 1/8w resistors crammed into a metal shelled 3.5 jack!
Gold pin plugs solve the oxidisation problem.
Pity that Quad went for DIN sockets over the Far-East manufacturers which had a field of phonos at the back. (No doubt to save space, and on the premise that once connected, it didn’t need to be constantly re-plugged). I used my 44/404 combination as a playback amp, and had Charles Smith (a renegrade SamCine cases guy) make a bespoke case with a trap panel in the top to get at the input switches of the 44, and a panel at the rear, fitted with XLR’s and Neutrik loudspeaker sockets as well as 4mm and bare wire clamp sockets for the L/S outputs.
There are some fairly decent metal shelled phono plugs available, and Canford Audio make several adaptors in multiple combinations. The worst thing about phonos is the lack of a decent cable clamp.
As for SCART – wash yer mouf out! It would have been a contender for multipin ins and outs, if the skirt had been deeper and with a more positive lock. Perhaps our French friends prefer a short skirt and a temporary lock-in!
Peter Fox
If you look at the upgrades for the Quad 33, there is a nice looking option for phono – and its a forest of sockets. No doubt that’s why they went for DIN. I replaced the Tuner to Pre-amp with a 5pin from Maplin but had run a Stanley knife round to trim off a ring of the fancy covering to get a proper insertion.. It was corrosion upsetting the ancient original.
Dave Plowman
In my opinion, it’s not so much a problem with the DIN format of connectors (apart from the speaker one), but the cheap and nasty versions many makers used to save pennies. After all the BBC version of the AKG C451 used the same basic connector, but better made by Tuchel, and others. I’ve used them on my home made solder-station (a locking version, but a standard 5 pin DIN will mate with it) and they’ve been extremely reliable. Body made of a strong plastic and branded Amphenol. Plug has an excellent cord grip and cable support. If I recall correctly, they also come in gold flashed contact versions.
Nick Ware
The secret for easy soldering DIN plugs is to temporarily put a short piece of neoprene sleeve (Hellerman etc) on the adjacent pins to prevent the solder from accidentally flowing to them. To clean the pins, one of those little brass suede shoe brushes works wonders.
The Quad 33 preamp was a bit of a nightmare. Not only the DIN connectors, but the signal was daisy-chained along the row of push button switches, so there were several opportunities for it to go distorted or intermittent. Silver plated switch contacts commonly turned jet black, which wasn’t very helpful and almost impossible to clean. Crackly switch noises could equally be due to leaky coupling capacitors and/or RF induction. The output stage was an emitter follower, and the power supply was single-sided, which would easily result in non-symmetrical clipping.
The early 34 preamps had DIN connectors, but later ones had much better gold plated phonos. For the first time, signal switching was all solid state, so the 34 had no contact issues. The 34 used op amps throughout, running (ISTR) off a +/- 15Volt symmetrical power supply, hence much better headroom, etc. Recommended upgrades today include better modern op amps and replacement of most of the tants and electrolytics.
34 preamps crop up regularly on Ebay and should show an improvement over the 33 that even a non expert would be able to hear. Worth considering if you have an elderly 33!
Dave Mundy
The most unpopular plugs at TC in the 1960s were on the KM54 mic, a very fine thread which was so easy to cross-thread, and on the Beyer M100 which was a very smart looking mic but had a screwed connector. XLRs came from various sources, some good, some not so, but were much preferred to the DINs.
Tony Crake
You get what you pay for with connectors … The "multi" connectors used on OB 7-pair sound cables were made to a "Defcon" spec.(?) and could well resist the "attentions’ of booted riggers! Those DIN connectors used at TVC on mic cables were pretty good with their solid shells but not all XLRs were good… some horrid copies! There are even some "nice" SCART leads but they do cost a lot!
Cables
Discussion turned to some really expensive connecting cables. Bernie found a nice USB printer cable for £1000 – expect it improves printing no end!
Mike Jordan
A website offers a pair of 20cm (yes – really 8” – wouldn’t even reach to the sides of the amp, let alone the speaker) speaker leads for £295 and a pair of 1m (about 3ft) phono leads for £1900.
Alasdair Lawrance
We should start a collection of the value judgements used to justify this nonsense, eg. "…seems to improve the timing and coherence…". What is that supposed to mean? It’s a kind of homeopathy of the hi-fi world.
The point is that you measure the mains by all possible criteria at the input and the output. I doubt if any difference would be found, therefore the cable/plug/fuse/switch makes no difference, definitely not audible. You are then left with voodoo, religion or Harry Potter.
Dave Plowman
But that is exactly what so much of ‘Hi-Fi’ turned into. Use flowery language to describe things you’ve invented – which readers of such things then start to use as if they were true scientific terms. And at the same time, use a journalist with zero technical knowledge who hasn’t the skill or (expensive) equipment to actually measure the things that can be measured, but can write nice prose.
It’s how the press have worked for years. Report something which may have some facts, but is mainly opinion. A reader can’t differentiate, so takes it all as fact. Thus are urban myths born.
David Denness
The trouble is there are Hi-Fi Buffs who, having spent so much money on quasi extra high quality cables, are convinced they CAN hear the difference.
If the average Hi-Fi buff saw how recording studios, radio and television actually originated the material they lavish so much money and attention they would have heart failure.
I know at least one former BBC sound supervisor who could ‘hear the difference’ that the expensive silver mains lead had made. Also the special feed from the consumer unit to his listening room of course!
Tony Crake
There were two OB’s sound men (no names) who were into ‘oxygen free’ LS cables, mains leads and leads to the preamp etc etc etc.
I asked if they had tried 40 amp cooker cable ? They looked suitably scathing !
Dave Plowman
When a serious recording studio uses these posh cables, I’ll be more impressed by the arguments. And when someone re-wires their entire house in it as well as buying a new IEC mains lead. Dunno what you do with the street cable etc, though.
There was at one time a large cash prize on offer for anyone who could reliably tell the difference between ‘ordinary’ phono etc leads and these super duper ones. But in a properly conducted double blind test. And to the best of my knowledge, never got won, which comes as no surprise to me.
The snag is that none of the various claims [for improved cables, plugs, connectors] can be measured, which is not surprising given broadcasters don’t appear to be able to measure simple sound levels.
So they become subjective. And having spent hundreds [of pounds] on a bit of wire you’re sure going to hear the difference.
Hence the only real way is double blind testing.
Speaker wiring can be the exception. If you introduce resistance to a certain point, many will hear it. And some (poorly designed) amplifiers may be sensitive to its parameters too.
Speaker cable isn’t difficult to source. I got a drum of 2.5mm.sq very flexible stuff from TLC ages ago which does nicely. Of course if any cables show, you might choose them on the basis of looks, too.
Pat Heigham
I seem to remember an early hearing test carried out at Wood Norton, where the headphones used to deliver the frequencies to be measured were calibrated, presumably to deliver the same level across the frequency range tested (‘cos they were crap!). Dunno how this was done.
The graph produced from the BBC exercise was so different to that generated by an audiologist I went to, so I remained confused. Maybe a test of all these ‘super duper’ cables and connectors should be carried out in an anechoic chamber, with speakers calibrated, and against common or garden bits of wire.
For a run of speaker cables (about 17 ft from where my Hi-Fi rig sits at one end of the room) I use 4-core mains cable, split out to the two channels at ‘tother end – seems fine! The TV sound goes through the hi-fi, but from my DVD recorders, but I suspect that there are compressors built in to their sound chain.
Remember the Audio Shows at the Russell Hotel? I listened to a demo of a jazz band – the kit was Ampex tape at 30ips through Tannoy Autographs – the big corner buggers. Don’t know what the amps were, but the sound was close to live! Now why do folks spend £1,000s on a vinyl deck, gotta be a con? I have a friend who is a music buff – he doesn’t mind if he’s listening on a good hi-fi system or a tranny – he knows how the music sounds. Maybe the guys buying these space-age, out of this world (or pocket) kit are bamfoozled into not actually listening to the music!
Chris Eames
I have long suspected that these ultra hifi buffs listen to their equipment, and not the music! This reminds me of a cartoon in a magazine (Hifi News?) many years ago. It consisted of a man in front of a pile of very complicated sound gear with the speakers replaced by 2 oscilloscopes. The caption was "But this way I can see it’s perfect"!
Graeme Wall
See (or actually hear) Flanders & Swann’s “Song of Reproduction”. The last line is "… I never did care for music much, it’s the high-fidelity!"
Martin Eccles
Telarc who used to produce great CDs rewired their desk with Monster cable and didn’t use any eq or compression and record direct to disc…
“… Jack Renner … swears by his heavily modified Neotek mixing console, internally rewired with Monster or MIT cables….And Jack insists that the signal path from a microphone feed should be uncomplicated, utilizing the best available components…”
Hugh Sheppard
As late as the 1980s my mother, born in 1906, would visit an older friend for private appreciation of classical music recordings. I stayed for such a session just once, as they were of 78s, but the appreciation of the underlying music was what motivated them, despite the needle hiss and crackle – let alone “It’s time to turn me over”.
Fuses
Mike Jordan
Our old 25W UHF base sets were on a 12v PSU and so took quite a load. A piece of tinfoil wrapped around worked very well.
Another funny:
In BH Switching Centre, we had 3phase D&S behind the racks. One day the house electricians came in to check things through and we asked what would happen if a fuse went. Their reply was “You MUST call us to do it”. We then asked when they were on duty (being an almost 24hr switching centre). Were told they were only on duty daytimes, so we asked what would happen to whole of BBC network if a fuse went outside those hours. Answer came with a handful of fuses!
Nick Ware
A spark who I used to work with used to cut 4" nails into 25mm lengths to put in all the 13Amp lighting kit plugs. Guaranteed not to blow, and cost nothing! There’s nowt so ignorant of electrics as a spark! We once got thrown out of the M&S head-office building in Tottenham Court Road by the House Electrician, who did know his stuff. And rightly so in my opinion.
Geoff Fletcher
We had a jolly lot of sparks at Anglia – one of the best being Gaffer Derek Cork – a.k.a Corky to one and all. I took this candid shot of him in a bit of a momentary quandary about some problem or other one day on a live church service OB, much to his amusement when I gave him a print of it a couple of days later over a pint. I don’t know why, but there is just something about it that makes me smile every time I look at it.
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