3.5mm jack plug/socket standards?

[Terry Pinnell]

I've posted separately about distortion problems with a newly-built
stereo amplifier. Isolating that was hindered because I was also
getting some noise due to loose plug fittings.

Input and output is via 3.5mm stereo jack plugs and sockets. I find
that the fitting is very critical; the slightest movement outward of
the plug loses one or both channels.

Looking closely at four types of plug I have on hand, I note some
differences in dimensions, particularly in the lengths of the ground
and middle sections.
http://www.terrypin.dial.pipex.com/Images/JPscompared.jpg

Shouldn't all 3.5 mm stereo plugs reliably fit all 3.5 mm stereo
sockets? If so, why are the dimensions therefore not a more
tightly-met standard?

 

[Genome]

I've posted separately about distortion problems with a newly-built
stereo amplifier. Isolating that was hindered because I was also
getting some noise due to loose plug fittings.

Input and output is via 3.5mm stereo jack plugs and sockets. I find
that the fitting is very critical; the slightest movement outward of
the plug loses one or both channels.

Looking closely at four types of plug I have on hand, I note some
differences in dimensions, particularly in the lengths of the ground
and middle sections.
http://www.terrypin.dial.pipex.com/Images/JPscompared.jpg

Shouldn't all 3.5 mm stereo plugs reliably fit all 3.5 mm stereo
sockets? If so, why are the dimensions therefore not a more
tightly-met standard?

The crap you buy from Maplin and such like is exactly that. Cheap, nasty and
probably hand made.

When Sony et al design product they use buying power to get what they
specify so it's all nice and snug.

3.5mm isn't exactly proffesional stuff so don't expect great things. Use
phono's instead. Not necessarily better made but the fit will be snugger and
you can always sprange it a bit for a tight fit.

DNA

 

[Paul Burridge]

I've posted separately about distortion problems with a newly-built
stereo amplifier. Isolating that was hindered because I was also
getting some noise due to loose plug fittings.

Input and output is via 3.5mm stereo jack plugs and sockets. I find
that the fitting is very critical; the slightest movement outward of
the plug loses one or both channels.

Looking closely at four types of plug I have on hand, I note some
differences in dimensions, particularly in the lengths of the ground
and middle sections.
http://www.terrypin.dial.pipex.com/Images/JPscompared.jpg

Shouldn't all 3.5 mm stereo plugs reliably fit all 3.5 mm stereo
sockets? If so, why are the dimensions therefore not a more
tightly-met standard?

Just had similar problem using 3.5 phono and socket for 9V DC power
feed into a project. With the socket/plug in series; the rail voltages
were 8V/0V. When hard wired directly thereby bypassing the
plug/socket; the voltage was back up to 9V again. No amount of
twiddling with the fit and cleaning the surfaces would get rid of that
residual resistance in the connection so I've hard wired the power in
permanently. Problem sorted.

 

[Leon Heller]

I've posted separately about distortion problems with a newly-built
stereo amplifier. Isolating that was hindered because I was also
getting some noise due to loose plug fittings.

Input and output is via 3.5mm stereo jack plugs and sockets. I find
that the fitting is very critical; the slightest movement outward of
the plug loses one or both channels.

Looking closely at four types of plug I have on hand, I note some
differences in dimensions, particularly in the lengths of the ground
and middle sections.
http://www.terrypin.dial.pipex.com/Images/JPscompared.jpg

Shouldn't all 3.5 mm stereo plugs reliably fit all 3.5 mm stereo
sockets? If so, why are the dimensions therefore not a more
tightly-met standard?

Use good quality plugs and sockets. Rendar's are very good, if expensive.

Leon

 

[Terry Pinnell]

Use good quality plugs and sockets. Rendar's are very good, if expensive.

Thanks both. But I'd still be interested in comments about the
standards.

 

[N. Thornton]

3.5mm jack is what you get on bottom end equipment, typically
connected to whats basically fuse wire. Its not pro stuff. Thats its
place in life. There are always poor quality products about, if you
want a relatively good one, buy one thats relatively good.

Thanks both. But I'd still be interested in comments about the
standards.

like what?


Regards, NT

 

[Terry Pinnell]

3.5mm jack is what you get on bottom end equipment, typically
connected to whats basically fuse wire. Its not pro stuff. Thats its
place in life. There are always poor quality products about, if you
want a relatively good one, buy one thats relatively good.

I wouldn't describe my 400 UKP (700 USD) Pocket PC as 'bottom end
equipment'. And I imagine there's a *lot* of expensive equipment
sporting 3.5mm jack sockets, largely because of compactness
requirements.

like what?

Like some basic facts, including what tolerances are allowed.

 

[Ralph & Diane Barone]

I wouldn't describe my 400 UKP (700 USD) Pocket PC as 'bottom end
equipment'.

I'm sure there's not more than $10 worth of audio related components in
your Pocket PC, so it COULD be described as bottom end audio gear.

And I imagine there's a *lot* of expensive equipment
sporting 3.5mm jack sockets, largely because of compactness
requirements.

Yes and no. When you get into the high end, sometimes compactness is
sacrificed for reliability. XLRs and 1/4" phone jacks start showing up,
and RCA jacks and 1/8" phone jacks start to disappear.

 

[John Woodgate]

I read in sci.electronics.design that Terry Pinnell <terrypinDELETE@dial

Thanks both. But I'd still be interested in comments about the
standards.

I posted this but it seems to have disappeared:

I read in alt.binaries.schematics.electronic that Terry Pinnell
[email protected]>) about '3.5mm jack plug/socket standards? -
JPscompared.jpg', on Sat, 31 Jan 2004:

Looking closely at four types of plug I have on hand, I note some
differences in dimensions, particularly in the lengths of the ground and
middle sections.
http://www.terrypin.dial.pipex.com/Images/JPscompared.jpg

Shouldn't all 3.5 mm stereo plugs reliably fit all 3.5 mm stereo
sockets?

Yes, they should.

If so, why are the dimensions therefore not a more tightly-met
standard?

There IS a standard, IEC 60603-11, whose introduction was very long
delayed by a spat between Japanese interests (with a world-wide market)
and US interests (with no market to speak of). It didn't help that two
British manufacturers also introduced totally incompatible versions.

All plugs and jacks that conform to the standard should work together.

 

[Tim Shoppa]

Just had similar problem using 3.5 phono and socket for 9V DC power
feed into a project.

The 3.5mm plug has always seemed totally inappropriate for power
connections. It is nearly guaranteed to short out when you insert
or remove it. While most wall-warts will withstand this abuse
without a hitch because of their high internal resistance, it just
seems wrong to me.

No amount of
twiddling with the fit and cleaning the surfaces would get rid of that
residual resistance in the connection so I've hard wired the power in
permanently. Problem sorted.

OTOH there are many good polarized connectors out there which are quite
suitable for power. The only problem is lack of agreement as to which
polarization convention for those coaxial plugs :-(, but we have workarounds


Tim.

 

[Terry Pinnell]

I read in sci.electronics.design that Terry Pinnell <terrypinDELETE@dial


I posted this but it seems to have disappeared:

I read in alt.binaries.schematics.electronic that Terry Pinnell
[email protected]>) about '3.5mm jack plug/socket standards? -
JPscompared.jpg', on Sat, 31 Jan 2004:


Yes, they should.


There IS a standard, IEC 60603-11, whose introduction was very long
delayed by a spat between Japanese interests (with a world-wide market)
and US interests (with no market to speak of). It didn't help that two
British manufacturers also introduced totally incompatible versions.

All plugs and jacks that conform to the standard should work together.

Thanks, John.

 

[John Woodgate]

I read in sci.electronics.design that Tim Shoppa <shoppa@trailing-

OTOH there are many good polarized connectors out there which are quite
suitable for power. The only problem is lack of agreement as to which
polarization convention for those coaxial plugs :-(, but we have
workarounds

That, too, is now standardized, with + in the middle, but go talk to a
brick wall.

 

[Paul Burridge]

The 3.5mm plug has always seemed totally inappropriate for power
connections. It is nearly guaranteed to short out when you insert
or remove it. While most wall-warts will withstand this abuse
without a hitch because of their high internal resistance, it just
seems wrong to me.

Agreed. Just another expedient in my case...

 

[Paul Burridge]

I read in sci.electronics.design that Tim Shoppa <shoppa@trailing-


That, too, is now standardized, with + in the middle, but go talk to a
brick wall.

I wouldn't trust that convention - checking first rules.

 

[Frithiof Andreas Jensen]

[email protected] (N. Thornton) wrote:

I wouldn't describe my 400 UKP (700 USD) Pocket PC as 'bottom end
equipment'.

Depends on your posisiton in the value chain does it not?

It may well be that you paid GBP 400 for about GBP 75 worth of product -
thats delivered on the dockside in the UK btw. Off-factory, in China, it
will be less than that!

Remember, "the price" is merely whatever one can take the customer for
without him taking undue offense ..... or why *else* do you think that f.ex.
the now-oldish T68i cellfone retailing at better than GBP 200 only about a
year ago is still available in multitudes at only GBP 20 now - it is not
because someone suddently decided to loose money on that sale!

And I imagine there's a *lot* of expensive equipment
sporting 3.5mm jack sockets, largely because of compactness
requirements.

Sony f.ex. buys millions of connectors; they can demand good specs and
therefore their stuff performs.

Like some basic facts, including what tolerances are allowed.

Whatever you like, I assume - I do not think there *exists* a meaningful
standard for 3.5 mm jacks etc.

 

[N. Thornton]

I wouldn't describe my 400 UKP (700 USD) Pocket PC as 'bottom end
equipment'. And I imagine there's a *lot* of expensive equipment
sporting 3.5mm jack sockets, largely because of compactness
requirements.

Compactness encourages compromises. As an audio connector 3.5mm is
bottom end, but compactness is sometimes more important. With
computers, cost cutting is harsh too: if they can use a 3.5 and it
works, they will. Even if your PC were top end, that doesnt preclude
it from using bottom end connectors.

Like some basic facts, including what tolerances are allowed.

John Woodgate might correct me on this if I'm wrong, but as I
understand it, what is allowed is determined by case law, and
primarily revolves around what works and doesnt injure people. IEC
specs are good things to use, but I would assume that connectors not
meeting them are allowed. And equally connectors that do meet them are
also not allowed in many apps.

Regards, NT

 

[John Woodgate]

I read in sci.electronics.design that N. Thornton <[email protected]>

John Woodgate might correct me on this if I'm wrong, but as I understand
it, what is allowed is determined by case law, and primarily revolves
around what works and doesnt injure people.

'Allowed' is a big word. In practice, what is allowed is what no-one
complains about.

IEC specs are good things to
use, but I would assume that connectors not meeting them are allowed.

We often have to point out to zealous standardizers that the IEC does
not have a gaol, but does have a goal. It works by persuasion.

In the case in point, though, someone has complained, and he is not
alone. It's simply daft for people to make connectors that don't meet
the IEC standard.

And equally connectors that do meet them are also not allowed in many
apps.

I don't know about that. What have you in mind?

 

[N. Thornton]

I read in sci.electronics.design that N. Thornton <[email protected]>

In the case in point, though, someone has complained, and he is not
alone. It's simply daft for people to make connectors that don't meet
the IEC standard.

Unfortunately daftness doesnt stop quite a few people.

I don't know about that. What have you in mind?

A 3.5mm jack can meet the highest of standards, it still wont be
allowed if its carrying mains power. Just as one example of why
meeting IEC specs doesnt guarantee allowabililty. A more likely
example might be where the connector would usually be suitable, but
wouldnt for some less obvious reason, eg... trying to think... I know,
if 3.5s were used on stage audio kit a judge might well uphold the
claim that they werent suitable for job since they dont survive the
normal expected level of abuse in that app.


Regards, NT

 

[John Woodgate]

I read in sci.electronics.design that N. Thornton <[email protected]>

A 3.5mm jack can meet the highest of standards, it still wont be allowed
if its carrying mains power. Just as one example of why meeting IEC
specs doesnt guarantee allowabililty.

Doesn't meet IEC 61984 on connector safety.

A more likely example might be
where the connector would usually be suitable, but wouldnt for some less
obvious reason, eg... trying to think... I know, if 3.5s were used on
stage audio kit a judge might well uphold the claim that they werent
suitable for job since they dont survive the normal expected level of
abuse in that app.

Doesn't meet IEC 60268-12.

You happen to have chosen two examples where IEC standards exist that
would be violated. But of course there are cases where a given connector
should not be allowed, even if there is no standard that specifically
disallows it. There was one example, I recall. Audio amplifier power
consumption is measure at 1/8 of rated output power. This amplifier took
1.8 A, so it was fitted with an appliance connector rated at 2 A. But of
course at full output power it drew far more than 2 A. The certification
body was disturbed to find that IEC 60065 (before the days of ENs)
didn't disallow this. The BSI committee suggested that an appeal to the
common sense of the designers might work, and it did.

 

[Walter Harley]

Use good quality [3.5mm] plugs and sockets. Rendar's are very good, if

expensive.

Do you have a US source for those? I've been searching for decent quality
3.5mm stereo jacks for a product I manufacture, to no avail. The 3.5mm
connectors I've been able to find are uniformly crap.

I see that Rendar seems to have been acquired by Schurter; but none of the
Schurter distributors I can find (Avnet, Digikey, Mouser, Future, ...) seem
to carry their audio connector line.

I have emailed Schurter, but any leads anyone could give me would be much
appreciated.