What is it in old amplifiers, receives that smells?

[DanielT]

Have you experienced that otherwise functioning old amplifiers and or receives can emit a special smell? I can't put my finger, or nose, on exactly describe that type of smell. Kind of smelling warm old electronics.It sort of smells of its age and I know vaguely described.It's not a smell that directly annoys me, but I'm mostly curious about what it is that creates that smell? Smell when the stuff is turned on, that is.
I always check that no dust has collected, for safety reasons, fire risk so it can't create the smell. Are old warm transformers causing the smell?

In addition, I have experienced different smells and even the level of the strength of the smell differs between manufacturers and models. That in itself may depend on how much used, old and worn the stuff is and not so much depending on the manufacturer, model, or?

 

[Blumlein 88]

Even with dusting I've always thought it was mostly dust. Old tube gear seeming to put out more smell. Like you describe not unpleasant, but a smell of age somehow. Maybe some of the old wiring harnesses smell different than old PCB traces and such. Maybe just the different materials off gassing different stuff. Like in this old tubed Fisher receiver showing the bottom of the circuit board.

 

[DanielT]

Regards old electronics in general then there are those who think about this smell and also try to explain what it smells like:

Did 1970s electronics smell back then the same way they do now?

If you open any bit of test equipment from the 1970s, you immediately smell a very distinctive smell, really unlike anything else. Just a vintage electronics smell. New electronics don't really smell like anything. Is there something about vintage electronics that make them smell that way? In the future will current electronics smell like that?

Answer to the question:
Smoke and brominated plastics?

I believe the smell is the result of the oxidation of the various plastics involved. If the plastics have changed the smell will change. I cannot provide you with any other meaningful information.

https://www.reddit.com/r/AskEngineers/comments/baodnf
______

Old electronics and other old smells

I have some older equipment and been in areas with older electronics. And there has always been a smell.
I have tried looking this up but been never able to get a straight answer.
Now I was given an older piece of kit manufactured in the 40s now it has not seen power in over a year so that rules out stuff burning off. And there was that smell when I opened it.

What is this smell? I assume it's various oils and nicotine.

Answer to the question:

Maybe nicotine, but more likely wax, oil and old varnish and other organics which used to be used in electronics manufacture. Rubber, paper.. crazy old electronics!

https://www.reddit.com/r/AskElectronics/comments/htx9s1

 

[DanielT]

Maybe Bakelite was used in old amplifiers, receivers? It can have a special smell. Maybe a little Bakelite smell is emitted when the stuff gets hot?
(that plus the smell of old electronics in itself)

Bakelite Test with Hot Water​

Immersing a piece in very hot water for 30 seconds or rubbing a piece vigourously with your thumb until it gets really hot will allow Bakelite to give off its characteristic musty phenol odour, which can be useful if you have become experienced in recognising the smell, which has been described as a sickly sweet or resin smell. I notice the smell if I am wearing Bakelite beads on a hot day, after a while if I put the beads to my nose I get a hit of that characteristic odour. Once you know it you can't forget it.

Bakelite Test - How to Identify Early Plastics

Bakelite Test - how do you know if your piece is Bakelite or some other plastic? A guide to testing your early plastic jewellery.

www.decolish.com

Bakelite - Wikipedia

en.wikipedia.org

 

[computer-audiophile]

In fact, old and new electronics smell very different. Even if you soldered something in the past, it smelled different than it does today because different chemicals and materials are involved. Hot, dusty tube equipment doesn't necessarily smell unpleasant to me because I was sort of socialised with it in my younger years in physics labs where the racks were full of scientific tube gear.

Today I find the smell of cheap modern electronics from China more toxic and pungent when you open the packaging. Fortunately, it usually fades after the burn-in period.

 

[DanielT]

In fact, old and new electronics smell very different. Even if you soldered something in the past, it smelled different than it does today because different chemicals and materials are involved. Hot, dusty tube equipment doesn't necessarily smell unpleasant to me because I was sort of socialised with it in my younger years in physics labs where the racks were full of scientific tube gear.

Today I find the smell of cheap modern electronics from China more toxic and pungent when you open the packaging. Fortunately, it usually fades after the burn-in period.

Maybe the only time burn-in regarding HiFi can make a difference?

And it was the nose and not the ears that detected the difference.

 

[TonyJZX]

there was a discussion about lead vs lead free solder

i'd imagine whatever the hell they were using even 20yrs ago is vastly different than it is today

 

[MCH]

There is a lot of literature on the subject. Done a quick search and seems that nowadays what is often measured is aromatics. Example:

Evaluation of VOC Emissions from Electrical Components - Fujitsu https://www.fujitsu.com/global/Images/vol45-1-paper14.pdf

However, I know the smell you mean, and it is not like the substances described in the paper above. To me, old electronics smell a bit more to amine-like stuff, so it might be that this other paper that you can download here is more descriptive of your question (pyrazine, dmf...):

High-Throughput Analysis of VOCs From Electronic Waste Emissions

Vocus PTR-TOF can detect a wide range of VOCs for electronic waster emissions in real time. By coupling a high- throughput headspace autosampler, automated analysis of hundreds of samples within one day is achievable.

www.tofwerk.com

In either case, none of the substances mentioned in any of those papers is something that you would want to be exposed to. I would keep my nose away of that stuff.

As many nasty solvents and other stuff has been phased out, i would imagine a newer component will be safer than an old one, specially when we are talking stuff that is like 40 years old or more. But this does not mean new stuff is innocuous. For instance, the solvent of choice for polyimides, that are everywhere in electronics, is still NMP (you can serach wikipedia) and a tiny bit of it is going to be there when the device reaches to you. That said, not long ago, barnishes used in forniture had high percentages of it, and i am sure in some parts of the world still do...

 

[fpitas]

Maybe Bakelite was used in old amplifiers, receivers?

Yes. It was (and some form probably still is) the go-to for consumer grade stuff.

 

[mhardy6647]

Yes. It was (and some form probably still is) the go-to for consumer grade stuff.

Leo Baekeland - Wikipedia

en.wikipedia.org

As a (worthless!) aside, we used to live 15 minutes from Leominster* Massachusetts, famed as the "Plastics City" and one time home of the Plastics Museum (now closed, sadly). Indeed, we used to shop at a shopping center called "Water Tower Plaza" in Leominster that was on the site of (and sported the atavistic water tower from) the old Foster Grant (sunglasses) factory -- set on an erstwhile EPA Superfund site. As an even weirder aside, Leominster was the plastic flamingo capital of the world, and our erstwhile across-the-steeet neighbors once owned the business that made them! Yeah, I know, crazy, right?

National Plastics Center and Museum (Closed), Leominster, Massachusetts

Leominster, the "Comb City" and the place where the plastic lawn flamingo was invented, tells us all about plastic. Opened in 1991, closed in 2008.

www.roadsideamerica.com

In other Central Mass news, Leominster was also the birthplace of Johnny Appleseed -- who was a real guy, if a somewhat eccentric one. The orchards in that part of Massachusetts (including our old hometown, Harvard) are just wonderful, by the way.

Johnny Appleseed - Wikipedia

en.wikipedia.org

And in a presumably unrelated story, Leominster was inundated by torrential rains last week.

Leominster flooding caused up to $40 million in damage to city infrastructure, mayor says

It could take weeks for roads and railways to be fixed.

www.cbsnews.com

But I digress.

___________________
* Leominster is pronounced, to a good approximation, as Lemminsta (with a minor emphasis on the second first syllable). I think it was during the Revolutionary War that Massholes Bay Staters developed truly eccentric pronunciations of some place names as a way to recognize British spies and other outsiders -- a tradition that persists to this day, I might add. EDIT: The state's rather insubstantial and ambiguous road signage also pays tribute to the suspicion that Redcoats are still lurking out there in the woods and fields by the rude bridge that arched the flood. You haven't been really & truly lost until you've been lost in Massachusetts, trust me on this.

 

[computer-audiophile]

I still sometimes like to use Bakelite. Here for example as a carrier plate for my capacitor array in my 1kV power supply for my 211SET Amp.

 

[mhardy6647]

Google Street View of one of my personal favorite MA street signs, located on MA route 111 just a little bit south of the center of Acton, MA (not too far from Leominster...of course!). This one, at least, is accurate. See it there in front of the utility pole on the right side of the screenshot?

 

[frabor]

Define old. I just finished refurbishing a nad 1060 1988. It was cleaned very nicely, washing the metal/plastic parts, complete vacuuming and air compressor blow up scrubbing the bottom of the board with isopropoil till it came clean. It still has the "old" electronics smell

 

[AnalogSteph]

And in a presumably unrelated story, Leominster was inundated by torrential rains last week.

Leominster flooding caused up to $40 million in damage to city infrastructure, mayor says

It could take weeks for roads and railways to be fixed.

www.cbsnews.com

But I digress.

As were Greece (something like 700 l/m², that's like 27.5 inches - at least the fires are out now), Turkey and then Libya (possibly 20,000 dead) as the low pressure zone turned medicane moved southward. High water temperatures = lots of rain, an increasingly common sight.

 

[DanielT]

There is a lot of literature on the subject. Done a quick search and seems that nowadays what is often measured is aromatics. Example:

Evaluation of VOC Emissions from Electrical Components - Fujitsu https://www.fujitsu.com/global/Images/vol45-1-paper14.pdf

However, I know the smell you mean, and it is not like the substances described in the paper above. To me, old electronics smell a bit more to amine-like stuff, so it might be that this other paper that you can download here is more descriptive of your question (pyrazine, dmf...):

High-Throughput Analysis of VOCs From Electronic Waste Emissions

Vocus PTR-TOF can detect a wide range of VOCs for electronic waster emissions in real time. By coupling a high- throughput headspace autosampler, automated analysis of hundreds of samples within one day is achievable.

www.tofwerk.com

In either case, none of the substances mentioned in any of those papers is something that you would want to be exposed to. I would keep my nose away of that stuff.

As many nasty solvents and other stuff has been phased out, i would imagine a newer component will be safer than an old one, specially when we are talking stuff that is like 40 years old or more. But this does not mean new stuff is innocuous. For instance, the solvent of choice for polyimides, that are everywhere in electronics, is still NMP (you can serach wikipedia) and a tiny bit of it is going to be there when the device reaches to you. That said, not long ago, barnishes used in forniture had high percentages of it, and i am sure in some parts of the world still do...

Interesting, I'll check those links.

 

[OldHvyMec]

"The smell" in my older gear it is a slight cap seepage from PIO caps. Bumblebees are the worst. I bring up the old Mac or Marantz valve gear
on a Variac. It can take 3-5 days at VERY low voltage to seal them back up or stop the STINK. 25 VAC for 3 days, 2 days at 50, 1 at 75, and on to 110
and keep it under 117. I have 4-6 pieces that are 60+ years old. Never touched. They work very well at 110vac. I don't push them. A couple of pieces
I have a MX110Z & MC225 look like they were just pulled from box. They took a week to quit stinking. They had set for 15 years or so. More the preamp
actually.

 

[DanielT]

Speaking of Bakelite. This song was a hit (half a hit) in Sweden a number of decades ago. Probably because many people have had a Volvo Amazon in Sweden.

Translation via Google Translate:

I've never been an enthusiast
As for songs about cars
I want to establish that
But then I heard, one day on the radio
Someone was playing
A composition that was about

An old Amazon
With moldings and chrome
Bakelite steering wheel
California white
Genuine galon
In imitation leather
An old Amazon
An old Amazon

 

[DanielT]

Define old. I just finished refurbishing a nad 1060 1988. It was cleaned very nicely, washing the metal/plastic parts, complete vacuuming and air compressor blow up scrubbing the bottom of the board with isopropoil till it came clean. It still has the "old" electronics smell

What is old in HiFi context? A five-year-old DAC considering developments on the DAC side in recent years might be seen as old?

An amplifier, well I don't know. Old, vintage ...25-30 years?

 

[Snoopy]

Even with dusting I've always thought it was mostly dust. Old tube gear seeming to put out more smell. Like you describe not unpleasant, but a smell of age somehow. Maybe some of the old wiring harnesses smell different than old PCB traces and such. Maybe just the different materials off gassing different stuff. Like in this old tubed Fisher receiver showing the bottom of the circuit board.

View attachment 312130

Looking at those electronics it kinda feels insane that this actually works

 

[Mart68]

Unique smells have always fascinated me.

Like new car smell - you can buy sprays and such that claim to replicate it but they don't.

Las Vegas always smells of sulpher, hits you as soon as you get off the plane. L.A either smells of the beach or meat char-grilling.

London doesn't really have a smell, except for the Underground which has a unique smell not replicated on the New York or Paris metros.

I tend to leave the office late when the cleaners are already in. I don't know what products they use but they make the place smell like an American hotel - not a British hotel mind, which smells totally different.

I don't think anyone has ever been able to pin these things down to specifics.