EEVblog 1562 - THE 1980's Boombox TEARDOWN - Sharp GF-7600
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Teardown of THE 1980's Boombox / Ghetto Blaster, the iconic Sharp GF-7600
That boombox from the iconic scene with John Cusak in Say Anything playing Peter Gabriel's In Your Eyes
Unboxing: • Sharp GF-7600 Boombox ...
Sony Walkman teardown: • EEVblog #752 - Origina...
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The beat switch is for tweaking the AC bias frequency slightly for times when harmonics of the bias oscillator interfere with AM radio stations. If you're trying to record your favourite station but get an annoying whine but only when you're recording - try a different position of the 'beat' switch. I got through all my life not knowing this but it was @vwestlife's video that told me a while back. Cheers Dave!
Dork! Hehe
Thanks. Never had one that had this switch.
A trap for young players.
@@EEVblog i think it goes back to superhet receiver days, who are you, release the real Dave Jones!
Amazing how many people get that one wrong....
at 6:49 there is a plastic spacer for the tuning knob that fell on the floor not sure if you noticed it or not. Cool BoomBox By the way.
Thanks, found it.
14:10 that switch is to select between record & play. Parts of the circuitry were switched over to share componnets
I believe the little compartment with the small gear for the eject mechanism is intended to contain some grease that slows down the opening of the compartment, effectively providing the soft eject you were looking for.
Yep, seen that in other tape door mechs too, I had one of the "RoboCop" style dual tape deck boxes from the 90s, and the loaders had a plastic gear inside a housing packed with grease.
That slow smooth opening looked so fascinating after oldstyle ones from 70s, just like some door of aliens spacecraft from scifi movie!
It's actually called dampening grease and it is available in a bunch of different viscosities.
At 18:01 there is a "soft touch" door opening mechanism. Usually filled with silicone damping fluid, which has probably migrated out. The "beat cut" switch changes the frequency of the bias oscillator to minimize a beat frequency when recording from AM radio stations (particularly weak ones). Thanks Dave!
I have approx 50 boomboxes so I know what is inside but great show to see all of the design inside. The good thing about "Made inJapan" is that you know it is easy to open and made very service friendly. I have a few Sharp devices and still going strong, also the 90s versions. Sony, JVC, Sanyo, Silver, Panasonic, all made in Japan. But I also have some Philips devices and that is a real different story. They made very nice units but man problem is always the same: Cheese gears. Use of flimsy connectors or not a connector at all, a spagetti of wires.
I think the model you showed is really nice piece, you can see the effort they put into it. Simple, but build quality wise very good. Your unit can run for decades after decades.
The tape door does have a slow eject gear. I bet it just needs some love
Really? Must be completely rooted.
@@EEVblog that's what she said?
They often used a little toothed gear that was suspended in some sort of viscous, grease-like substance to impede the door as it opened, giving the effect of a soft eject. Over time, the grease would dry-out or leak away, and the function would be lost.
@@Oldgamingfart it's called silicone dampening fluid.
@@mornax That's the one!
They were made a lot better back then. rather than the Jaycar reproduction ones with the plastic tape mechanisms inside them that sound terrible and have one PCB board in them. The boombox and stereo amps today look so boring and sound horrible.I wish they would make them look like the did in the 70s and 80s. stereos to today you can have in any colour as long as its in black.📻📻📻
In Spain those were call "loros", parrots. Because some people used to carry them on their shoulders (like a parrot) very loud, while walking on the street, on the beach...
Like a walkman but with the capacity of disturbing everybody 1km around.
Parrot, I like that. It makes sense.
hahaha
In Sweden they were often called "bergsprängare", the Swedish word for rock blaster (the profession), which for once works pretty well when translated to English.
The term seems to have been coined by Hitachi marketing but caught on and was then used for just any system with just a passing resemblance of a Boombox.
3D Super Woofer, surely?
Kids nowdays couldn't lift this over their head with the 10 D batteries, much less hold it there for a whole song.
You mean the 10 year olds? I can easily hold it above my head with the D cell batteries, hence i even have a old radio from grandpa
Lmao, too much soy in the Starbucks
@@309electronics5I wonder what was cost of 10 d-cells then and how those kids earned the cash to buy them. I admit that at the age of 15 I had a similar-sized JVC but never even tried battery power, too expensive. Today, alkaline d-cells in my country start at around 1 US dollar apiece, all the way to almost 5 dollars for the fancy brands.
Wow, mechanics with servo-assisted movements, and at that time a recorder like that was practically junk for us. Instead, having it today is like getting a space saw.
In Christchurch, New Zealand in the mid 70's to late 80's we knew these as ghetto-blasters. Boombox still sounds very strange to me today all these years later!
Same in Canada. Anyone over 40 still calls these ghetto blasters. Used to even say that in the stores.
This teardown reminds me of all the old electronics that I used to tear down as a child in the mid nineties (some without parents' permission)! All those SIL ICs, old school AM frontends etc. The reason for getting into EE is due to the fascinating insides of this type of gear. Thanks Dave!
It's simply not worth looking into a boombox from 1983 and especially 85 and newer. It's all integrated and low end.
The models from the late 70s and very early 80s are the only boomboxes worth getting or even looking inside.
Great teardown. Take that, @Techmoan! :)
We had a few domestic made models of "radiomagnetofon" (radio cassette recorder) here in Poland-not-Portland, and the common name was "jamnik" (dachshund) and later on, boombox. "Ghetto blaster" would never pick up given up the tragic memories of WWII and Holocaust, still fresh among anyone over 40 back then.
We call it 'jezevcik' (dachshund) in Czech too. But not sure if it is just for those dual (side by side) cassette player.
@ I think it's for the long ones, i.e. stereo, probably dual too.
Actually, many Germans and Russians still call them ghettoblasters, especially on Ebay
I'd love a second-channel video where you actually test the speaker frequency response and compare it to the graphic.
Odds are most manufacturers didn't even test the response, they just sourced whatever generic speakers they could find. Also there's a difference between what the amp can output and what the tape mechanism was capable of reproducing (most boombox decks were cheap crap except for the higher-end models)
No one does enthusiasm in electronics like Dave!
All the best stuff is made in Japan...
I had a few of these growing up over the years we used to call them ghetto blasters recently. One of them had resurfaced, and we were our some with some friends. Morgan behold my friend and I said wow that’s a real Guetta Blaster from the 80s. We haven’t seen one of those in years and all of a sudden one of the ladies that was with us. Her feelings were hurt and she snapped. We don’t call it that anymore well I’m sorry about everybody’s feelings but you’re taking away memories and good times so my feelings are equally hurt too. It will be a ghetto blaster to me forever plain and simple.
these commie dems have ruined my country.. the hell with them and there feelings
We called them ghetto blasters too. I know why it's offensive and I don't care, everyone's offended by everything nowadays.
Don't try to play Dire Straits Money For Nothing, the triggering will be unbearable.
@@EEVblogWhy not? "The Chicks were free!"
I recall as kids we used "boombox." We used "ghetto blaster" more in a negative context if someone had a poor-quality boombox... or worse when adults used it to complain about the noise. I grew up in the middle of the USA - the terminology may have differed in other parts.
I think it probably did. As a kid in the UK I always used "ghetto blaster".
@@Silanda Germans and Russians use that word too. But I thought you Brits would call them "Brixton briefcases"
It was nice of them to print the frequency response on both speakers to prevent neck strain (perhaps exacerbated by holding it above one's head for extended periods)
But no numbers!
I'm guessing it's purely fictional anyway. There isn't even a crossover! haha
... ahem.. Now, because this is an engineering crowd:
"Weellll actually..." piezo tweeters measure like a capacitor, which is effectively a first-order high-pass filter, so _technically_ you don't need a crossover. Particularly if the natural treble roll-off of the mid/woof is at the same frequency and slope as the bass roll-off of the piezo.
But, I'm guessing these two drivers don't have perfect and complementary roll-off characteristics, phase, and sensitivity. Nahhh, just wire them in parallel, the piezo won't be too bothered by the LF energy, and that's close enough for rock and roll. Whaddaya want from a pair of speakers in a plastic box, anyway? ;-D
@@nickwallette6201 Those of us who collect boomboxes know it's pretty rare to find a piezo tweeter that still works and produces any audible sound.
Felt guilty, 555 likes, I made it 556. I guess that is dual the likes...
Great idea with the trace fill on the top, you can see the circuit without taking out the board. We called it cassetophone. And the VHS machines were just "video".
"Made in Japan", good old times. None of that china rubbish, right?
Why did they always use organically shaped traces on the board instead of straight lines like today? Even when drawing by hand they could have used rulers and templates to make them straight. Also, primitive CAD already existed in the 80s
The ultimate 'simulcast' was listening to Roy and HG call the state of origin, those overseas or younger than 30 will not understand the cultural significance of this.
Old casette decks are 1000x better than shit they put in them these days when only one factory makes sub par mono players
18:45 you pinched that poor wire again 😢
I used to buy these by the hundreds at Brashs ACT, to sell for Christmas.
They flew out the door, very reliable and rarely came back.
Some Sharp models came in different colors.
AM stereo was "big" in 1985 ...
I've never heard of AM stereo before until this video. Guess it was not so popular in densely populated countries where FM was king and AM was already a relic of the past in the 80s. I don't even recall ever listening to an AM station other than testing whether it worked to begin with.
@stragulus yes I agree. I'm in uk and never heard of am stereo. Guess our decent fm has been around with good Reception since the 60s
There are still AM Stereo stations in the US today, but rare. Check out shango066 who made some video's about it, like this one: th-cam.com/video/I1HIF0toZO8/w-d-xo.html
If you are afraid of copyright strikes while demoing audio gear: Do as Techmoan does and prepare media with TH-cam licenced music.
16:48 Panasonic made a VCR that could switch to the audio line input while recording TV so you could record your TV concert with Hi-Fi stereo sound from the FM radio simulcast.
I wonder how accurate that frequency response curve is, maybe you could check it!
06:45… the knob has to come off, that’s what she said. (C) 2023 EEVblog.
17:50 - NO crossover! ALL the low frequencies were sent to tho those poor tweeters!
Pizeo tweeters did not need crossovers in most cases.
Man I wonder if kids still get to tear apart VCRs these days
This era of boom boxes were really well made. Who ever designed most of them took a lot of pride in their work because some of them were very intricate. The sound quality was usually quite high too. We can't make things like this today. Over time the quality fell through the floor and by the late 90's era the build quality was low and most of them suffered from high noise, hum and distortion. Something that just isn't an issue with any of the units from the 80's.
And the ones built a couple years before this were even better quality. Many were built like tanks. The golden era was 1978-1982. Sadly, quality went downhill after that, due to increased competition, and the rise of the walkman.
Dont sell the peizo tweeters short, they made a big difference for high frequencies.
Hi Dave, I have a Sanyo BOOM BOX when running on 10xD batteries you won't even play a 90 cassette if you go over the volume position where the BAT MAX link is. The cassette drawer has a friction brake for slow tilting, just a little silicone vaseline and the cassette opens slowly.
Nice day 🙂 Tom
Oh man that is a classic. Never had one myself but I remember being jealous when I saw a friend who did have one. I did have a dual deck stereo though but it was a more basic one. I guess it could still quality as a boom box. Later on had one that could play CDs too. Makes me feel old to realize that this is vintage tech now. :P
Battery life was pretty good, that 35W power use is a peak rating, but with normal volume current consumption would have been around 0.5A, depending on mode, with tape being the highest. So with 2Ah NiCd cells around 4 hours, and if you were on radio only around 8 hours of use, though you could easily get 2 days even with flat cells, provided the volume was low. High volume with flat batteries you got motorboating.
I can't see it ever using 35W. Maximum output to the speakers was only 10-12 watts on that model.
Talking of iconic tape machines, I own a Realistic CTR-68. No? Not heard of it? Most people haven't. It's the one used by Hannibal Lecter in Silence of the Lambs. The one in the film has the name "Realistic" scratched off.
AM stereo started Feb 1, 1985 here in Oz (Sydney). Nicely preserved example there but only remember AM stereo car radios, not boom boxes.
Yes! I still have my Sony SRF A200 AM Stereo / FM Stereo portable.Great little radio, but monstorously tight inside to fix. Still listen to it every night. Still 1 AM stereo station broadcasting in QLD.
Almost didn't recognize it without all the banana stickers 😁
Mine was the slightly smaller Sharp GF8080. Removed the batteries and fed from a stabilised mains PSU for a few more watts.
Yes most boomboxes made more power on AC than they did on batteries
I bought my mother a GF7200 (smaller model with similar styling) in the early 80s, to use in her kitchen. When she passed away in 2011 it was still there, being used every day, and working like new. FM radio worked so poorly in her North London kitchen that I added an FM aerial socket when it was new, and used a large aerial in the loft, that also fed the Hi-Fi in the lounge. That was the only time the case ever needed to be opened. It wasn't cheap, but it was great value for money.
*Happy TechMoan noises*
Would have expected a men at work tape
Soldermask with identification was because these were hand assembled, so the little old ladies that put them together could see where the wires went, and then did not get it wrong.
The GF-7600 tape mechanism (11:20) is virtually the same type used in several Sharp models (notably the more popular GF-700 from 1981/82) but with some differences. I mention this because of the take-up idler at the top right and the winding clutch gears in the middle.
It would be interesting to do a teardown on an early 1960s/late 1950s transistor radio--some used steel chassis with sockets for the individual transistors. All hand-wired, of course. There was a huge distrust of printed circuit technology early on.
I used to buy so much D Cells in the late 80s, its unreal :D
I bet Run-DMC sounds much better on these, I guess there's modern versions with Bluetooth? I was born after this era, but always loved the aesthetics of these old boomboxes in all their square glory.
I have the Sanyo M9923. The *actual* boombox from the helicopter scene in Predator, where Little Richard "Long Tall Sally" is played
In Sweden we say "Bergsprängare"
I don't know if it was a London thing but they were often referred to as wog box or ghetto blasters, boom box seems to be a name used posthumously but not really a name of the time.
My father bought Sharp boombox with dual deck we called Tape Recorder and I forget the model in 1983. Sounds amazing for 12 y.o. boy.
Built before planned obsolescence was a thing.
These days even if the hardware lasts they take down the app that is needed to use it and never release the code for user to make their own app..
My high quality Bluetooth portable amp is around 3 years old with a great battery..
Made in Korea wirh screws so I thought when needed i could replace the battery...
Instead its now dead as it needs a custom app(like all such devices) which crashes on the new phones OS version and the company will not update it or release the data needed for an open source version..
So to use it i need a second old phone with an old OS..
I WANT THAT TAPE!!!
Pedantic moment - US boomboxes did not have Short Wave receivers. So, technically that's not same boombox. Although it is very similar.
I'm sure it's actually regional variants of the same Sharp boombox. Boomboxes intended for Asia often do have Short Wave on them. Here in the UK the Sharp GF-7600E (E for Europe) version, it has Long Wave(LW) on it. but only has one SW band covering 6-18MHz. The Japan variant would have FM coverage down to 76MHz.
Low quality presentation. You missed several things that should have been mentioned. Overuse of catchphrases.
Diode with wire hoop, 'heatsink', the diode is maybe a ref voltage or one of them fangled capacitor diodes things in tuners, but guessing as its on the tape deck board its maybe to do with setting a bias voltage for the recording circuitry.
324's are the absolute worst op amp for audio because of the crossover distortion in the push-pull outputs
Yeah but 10% distortion was standard, so no worries!
@@EEVblog LOL ....point taken ....
I didn't have an 80's boombox, but I was able to have a Sony front loader CD boombox with 'megabass'. It wasn't very loud or bassy from I remember when running from D batteries or even from wall power.
Kids today have it so easy with a JBL pvc pipe speaker with super high quality tweeters and some bass drivers with passive radiators...also with a rechargeable lithium based battery.
But most dont know what stereo means - all though these "boomboxes" didnt do anything for sound quality either. Horrible..
Over here in Germany they were called ghettoblasters and they occupy a special place in my heart. I'm still using a CROWN 950 for outdoor listening or just to marvel at as a showpiece with all it's chrome ornaments. Beats any modern bluetooth loudspeaker both in style and sound.
Just a bit of casual racism in Germany.
Here in the UK they were called Brixton briefcases.
@@claptonpond9451 Lovely name that is. Sounds like some witty cockney slang.
One guy carrying the boom box, one guy had a rolled up 36” square of linoleum, a clean t-shirt and a bottle of mop n glo. Hoodies, warm up pants, and a pocket full of cassette tapes cues up to your favorite song. Our neighborhood break dance crew and working on cars with dad is what kept me out of trouble.
80s is gone Music and Electronics,,,The Westerners 80s was Music and Electronics "CRAP",,,These things dont have value (boomboxes) even the good ones,,,is just for cheap entertainement,,,on the other end of spectrum (hifi/highend),,,same thing only they bet on more audio power,,,anyway good video nevertheless
This is not even close to *THE* 1980s boombox. The closes to *"*the*"* boombox of the 80s is the JVC RC-M90.
In fact, they had stopped making anything you could properly call a boombox by 1982/83.
The early boomboxes were very expensive and very well made pieces of audio gear. They made these things because they could. They were cutting edge miniaturization technology. They had very sensitive and very selective tuners. They had high end tape mechanisms. Most used high efficiency speaks with a separate mid range and tweeter on each channel. Though low power, the amplifiers were top notch.
By 83/84/85 they were cheap hollow boxes weighing 1/5th or the originals. High levels of integration. Cheap low end front end. Cheap low end amplifiers. Cheap low end cassette mechanisms. Cheap 5" speakers if you were lucky, more often 4" or even 3" Instead of having 3 distinct drivers per channel, these later ones had a single speaker on each side.
That thing is absolutely not consuming 35 watts. As your on screen note shows, AM stereo started in the early 80s. There are still at least 2 AM stereo stations in the US. KYET Cactus Country 1170 AM is in Arizona and there's another one in Michigan WION. There are probably more, but I am unfamiliar with them. WION was gracious enough to put its AM stereo feed, as received by an AM stereo receiver on the internet.
AM stereo sounds absolutely great. In some ways, it's better than FM stereo. YT user Shango066 has an interview with WION's sound engineer on his channel explaining how the system works.
7:08 That is classic 1980s construction, just not classic boombox construction. Real boomboxes were only made from about 1978 to 1981, maybe early 82.
When the boombox became incredibly popular the prices plummeted and so did the quality. This is a very good example of the massive drop in quality between the early boomboxes and the later ones. Just look at the cheap nastiness of that big hunk of plastic.
WRONG! This is not iconic. Nobody cares about it, only movie buffs. Sharp wasn't even a high end boombox maker, ever.
I had one with detachable speakers when I was little!
I'm only 23 so it was already old when I got it but I totally loved it! I still have it somewhere in a closet in the house I grew up in, but one day I forgot I left it outside. It got rained on and now one side doesn't work anymore unfortunately.
I should really get some electonics cleaner and have a go at fixing it.
Unfortunately when one side stopped working, I, being the stupid destructive 11 year old I was, destroyed the speakers. I could probably design some new better ones and 3D print them though so I can use it again like when I was little.
Remember those - they where horrible... Like almost all ghettoblasters as they were called here in Denmark. A few were decent like the Philips 8644, with 2x30 real watt amplifier og speakers made of wood...
Dave! I just started a job at a new shop doing industrial automation and control work. The problem is nobody has heard of the EV blog! I know you are as surprised as I am. I have your premium digital multimeter and my trusty old fluke 26 mark three in my toolbox. Please produce vinyl Dieker details of the EEV blog logo stat. So I can purchase one from your website about 12 inches wide and 4 inches high in white or black. I would love to display it on my box to raise awareness of your awesome TH-cam channel.
Really nice construction setting this apart from the no-name rubbish that also existed at the time. This can't have been exactly cheap. A shame that we don't get a good idea of how this sounds trying to avoid copyright issues, a well recorded tape with TH-cam library tracks would help.
9:48 Years ago, a fellow electronics engineer told me that MELF stood for Metal Ended Little Fucker. I believed that for years. 😂
I was able to replace belts on one, some were actually totally melted away. Now I can play that famous Peter Gabriel song on cassette from the movie.... Shock the Monkey. LOL Good luck finding this one anywhere. I think collectors have gotten them all. I need a slider switch for the volume though. Have some chrome ones on there from another model for now.
You asked about the name for these: "bergsprängare" in Swedish. Translates to "mountain blaster".
I love how the frequency response charts have no axis labels
Obviously, the vertical axis is amplitude, and the horizontal axis is life goals. :-)
we try to find back your funny australian expression involving "Mario" (like "easy Mario"), what is it?
Whoa. That boombox had everything. I would love to have something like that to use on my PC's line out
Also known as "ghetto blaster" in US/Canada. In fact I have still been caught by my kids using this term
In london in the late 80’s the BBC transmitted digital stereo audio via NICAM. No need for simul-casts
The 5 band equalizer with its special filter chip with gyrators is very interesting
This looks like a copy of the Toshiba RT-S782, which was quite a quality machine for its time
Im a 80's kid never saw the film, never heard of it , it must have been awful and i watched loads of trash teenage rubbish.
My father did repair work for many of the brands of the time, and my dad liked quality of sharp the best.
13:29 - Wow! Jones is amazingly on pitch here! Who knew he could sing?!
When I was at Uni in Atlantic Canada, they were called ghetto blasters. Here in Bermuda, we just called them boxes.
In Sweden we called it "Bergsprängare" = mountain blaster.
are they using a variable capacitor diode for fine tuning
looks like a pot on the bottom of the tuning control ??
Still got my Panasonic 1 from the 90s, worked hard as teenager to save for it.
I've never heard that title before. It was called "Better off dead" here in Australia.
Not only Ghetto Blaster, or Boombox, but also Brixton Briefcase
Ah yes, simulcasts. Sure do remember them. Cheers
A fine example 👍
In Denmark we called it a ghettoblaster back in the '80.
do you know the stories of "finale countdown"? it is very interesting
Most usual failure is the multiple switch play_rec , it gets dirty.
I have the Sharp GF-6060, got one when I was a teenager and used it to play music and load programs onto my ZX Spectrum. Years later I bought another one.....just because!
Mum, Elon Loves to F..... Ire rockets, and people.
Pool video was taken down? Too many armchair contractors?