i just blew up my behringer sansamp clone

[rmorris]

[quote name='Clive Thorne' post='216366' date='Jun 10 2008, 06:57 PM']If the power supply was rated for 500mA at 12V then, if it was unregulated, the 'no load' voltage would likely be higher than 12V, as someone has already said. Also, if you put a dead short on it then the voltage would drop below 12V, but the current would go well above the 500mA.

If the excess voltage caused one of the solid-state devices to go short, then the resulting current could easily cause a track to burn out. ie the track burning out is probably a symptom rather than the cause.

Even if the supply was regulated then 12v is still 33% above 9V! What would you expect your telly to do if you connected it to 320Vac?

Behringer stuff is cheap, so it's a bit unfair to expect it to be as tolerant as a Boss or something which costs a lot more, and we don't know how a boss would respond to a 33% overvoltage (dont try it!!).



Regards

Herr Behringer[/quote]

I'd still have to say that it's a poor technical design if it's damaged by what is still a relatively low voltage, especially given the environment in which it's likely to be used.
Maybe some of the pedal makers here would like to comment/agree/disagree.

The TV analogy seems a bit misplaced as the absolute voltage/current values are much larger and ac.
However it's worth noteing that TVs still need to survive specified mains surges/transients in order to pass CE regulations.

[PaulWarning]

I fried a Behringer by using a power supply with the wrong polarity, didn't happen with my Zoom 506II, just crap design

[Silent Fly]

I am not a big fan of Behringer and I don't have any commercial relationship with them apart from being a customer.

I am slightly surprised by the comments of this thread.

As we all know, Behringer produces pedals that are inexpensive. They cost far less than the originals and usually they don’t sound too bad (especially considering the price).

A Behringer pedal I have comes with instructions that contain the following specifications:

[i]Power supply: 9V 100mA regulated. Behringer PSU-SB
Power connector: 2mm DC jack, negative center
Battery: 9V type 6LR61[/i]

These are the conditions under which the pedal has been design and should be used. Nobody stops me to use other types of power supply but if I do it, I do it at my own risk.

I agree that some protection on the power supply should be part of the design of a pedal (I include it in all the pedals I design and produce) but equally I don’t see it as fundamental requirement of an as-cheap-as-it-gets pedal.

If I connect a 300W cabinet to a 400W amp and after I played a full volume for one hour one of the cone breaks I don’t complain about the poorly designed cabinet.

I would prefer not to try but I am pretty confident that if I connect my Avalon U5 to a 320V supply instead of the recommended 240V I will damage it. I think that nobody has any doubt that Avalon devices are among the best audio devices on the market.

Last but not least, if any of you has a [url="http://www.lamborghini.co.uk/?section=models&sub_section=5&model=murcielago_lp640"]Lamborghini Murciélago LP640[/url] we can try to use kerosene as fuel and see if the engine is happy after a few miles. Are Lamborghini poorly designed?

Edited October 31, 2008 by Silent Fly

[nick]

[quote name='Silent Fly' post='319272' date='Oct 31 2008, 06:37 PM']I am not a big fan of Behringer and I don't have any commercial relationship with them apart from being a customer.

I am slightly surprised by the comments of this thread.

As we all know, Behringer produces pedals that are inexpensive. They cost far less than the originals and usually they don’t sound too bad (especially considering the price).

A Behringer pedal I have comes with instructions that contain the following specifications:

[i]Power supply: 9V 100mA regulated. Behringer PSU-SB
Power connector: 2mm DC jack, negative center
Battery: 9V type 6LR61[/i]

These are the conditions under which the pedal has been design and should be used. Nobody stops me to use other types of power supply but if I do it, I do it at my own risk.

I agree that some protection on the power supply should be part of the design of a pedal (I include it in all the pedals I design and produce) but equally I don’t see it as fundamental requirement of an as-cheap-as-it-gets pedal.[/quote]

+1
I know of pedals of several other manufacturers including EHX, that have been buggared by incorrect PSU connection.

For what it's worth my Behringer BDI21 is still going strong after nearly two years constant use

[rmorris]

[quote name='Silent Fly' post='319272' date='Oct 31 2008, 07:37 PM']I am not a big fan of Behringer and I don't have any commercial relationship with them apart from being a customer.

I am slightly surprised by the comments of this thread.

As we all know, Behringer produces pedals that are inexpensive. They cost far less than the originals and usually they don’t sound too bad (especially considering the price).

A Behringer pedal I have comes with instructions that contain the following specifications:

[i]Power supply: 9V 100mA regulated. Behringer PSU-SB
Power connector: 2mm DC jack, negative center
Battery: 9V type 6LR61[/i]

These are the conditions under which the pedal has been design and should be used. Nobody stops me to use other types of power supply but if I do it, I do it at my own risk.

I agree that some protection on the power supply should be part of the design of a pedal (I include it in all the pedals I design and produce) but equally I don’t see it as fundamental requirement of an as-cheap-as-it-gets pedal.

If I connect a 300W cabinet to a 400W amp and after I played a full volume for one hour one of the cone breaks I don’t complain about the poorly designed cabinet.

I would prefer not to try but I am pretty confident that if I connect my Avalon U5 to a 320V supply instead of the recommended 240V I will damage it. I think that nobody has any doubt that Avalon devices are among the best audio devices on the market.

Last but not least, if any of you has a [url="http://www.lamborghini.co.uk/?section=models&sub_section=5&model=murcielago_lp640"]Lamborghini Murciélago LP640[/url] we can try to use kerosene as fuel and see if the engine is happy after a few miles. Are Lamborghini poorly designed?[/quote]

It's still rubbish design if 9V polarity reversal causes permanent damage.
It's fairly well accepted that the environment in which a product ( any product ) is likely to be used is relevant with regard to malfunction / damage etc.
And it's obvious that the inadvertent use of a different supply or polarity reversal is a likely event given the same / similar and unidentified connectors commonly used, dark stages etc...
Since 9V is arguably the most common nominal dc voltage then it seems wholly reasonable to expect protection against polarity reversal of a 9V supply or use of an unregulated supply here.
I'm not necessarily expecting it to survive, for example, being fed with 230V ( nominal ) ac mains voltage - it's not a reasonable scenario.

And given that the protection can be simple and low cost ( very very low cost ) then I can't see an excuse even for low cost product.

I have to say that I don't think the analogies given are particularly valid - under what circumstances would you take it into your head to pour kerosene into your Lamborghini ?
And where is this source of 320Vac ?

It's worth noteing that a product running from European ac mains should be able to able to run at significantly above and under the nominal voltage as there is an allowed tolerance on the mains voltage supplied ( +10% / -6% around 230 Vac ? - but I might be incorrect on the actual figures ). Plus should be able to survive various surge transient conditions as defined in emc standards ( there is a sort of opt out for manufacturers but I'll stop now before it gets very nuanced and legalistic :-)

[EBS_freak]

[quote name='Tech' post='132357' date='Feb 2 2008, 12:31 AM']sounds like a cross between dr. who and a poorly conceived porno film.[/quote]

ex-sperminate! ex-sperminate!

[Kev]

Ej-aculate! Ej-aculate!

[Silent Fly]

[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']It's still rubbish design if 9V polarity reversal causes permanent damage.
It's fairly well accepted that the environment in which a product ( any product ) is likely to be used is relevant with regard to malfunction / damage etc.
And it's obvious that the inadvertent use of a different supply or polarity reversal is a likely event given the same / similar and unidentified connectors commonly used, dark stages etc...
Since 9V is arguably the most common nominal dc voltage then it seems wholly reasonable to expect protection against polarity reversal of a 9V supply or use of an unregulated supply here.
I'm not necessarily expecting it to survive, for example, being fed with 230V ( nominal ) ac mains voltage - it's not a reasonable scenario.

And given that the protection can be simple and low cost ( very very low cost ) then I can't see an excuse even for low cost product.

I have to say that I don't think the analogies given are particularly valid - under what circumstances would you take it into your head to pour kerosene into your Lamborghini ?
And where is this source of 320Vac ?

It's worth noteing that a product running from European ac mains should be able to able to run at significantly above and under the nominal voltage as there is an allowed tolerance on the mains voltage supplied ( +10% / -6% around 230 Vac ? - but I might be incorrect on the actual figures ). Plus should be able to survive various surge transient conditions as defined in emc standards ( there is a sort of opt out for manufacturers but I'll stop now before it gets very nuanced and legalistic :-)[/quote]

[size=1][i](I would like to reiterate that I have no personal interests in Behringer. If anything they are my competitors.)[/i][/size]

Regarding what you say, I think we may have to agree to disagree.

Polarity protection and overvoltage protection is an expected part of any pedal design. I think we all agree.

I am not sure about the definition of "rubbish design" though. Without going in the semantic of the English language, personally, the level of design sophistication I expect depends on the amount of money I spend.

If I pay a relative high sum of money for a pedal, I expect it performs above the minimum specifications. How above it depends on the company that produces it and its interest in its reputation.

If I pay the very minimum that I can find, I am happy to compromise on the design and spend a little bit of extra-time checking the connections before powering on the pedalboard.

(Fortunately) Nobody forces us to buy Behringer. We all know that their pedals are not as good as the originals. They don’t sound as good the originals and, yes, they fry if the power supply is not correct. But they are dirty cheap…

Are they rubbish? Maybe... but for the money they cost I think they are good enough.

[Count Bassy]

[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']It's still rubbish design if 9V polarity reversal causes permanent damage.
It's fairly well accepted that the environment in which a product ( any product ) is likely to be used is relevant with regard to malfunction / damage etc.[/quote]

It's designed to a price and performance that is acceptable at that price. If you want Jaguar performance don't buy a mini!

[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']And it's obvious that the inadvertent use of a different supply or polarity reversal is a likely event given the same / similar and unidentified connectors commonly used, dark stages etc...[/quote]

A fact that you and most users are aware of and thus should proceed with due care and attention


[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']Since 9V is arguably the most common nominal dc voltage then it seems wholly reasonable to expect protection against polarity reversal of a 9V supply or use of an unregulated supply here.
I'm not necessarily expecting it to survive, for example, being fed with 230V ( nominal ) ac mains voltage - it's not a reasonable scenario.

And given that the protection can be simple and low cost ( very very low cost ) then I can't see an excuse even for low cost product.[/quote]

I'd agree with that in principal to some extent, but a diode in series will immediatley drop the available voltage for the box to do its work. and putting in some sort of crowbar device would also need a fuse etc, and so add costs.

[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']I have to say that I don't think the analogies given are particularly valid - under what circumstances would you take it into your head to pour kerosene into your Lamborghini ?[/quote]

Under what circumstances would you take it into your head to pour 12Vdc, of either polarity, into your pedal which clearly states 9Vdc?
Picking up the wrong plug on stage and just plugging it is akin to driving your lambo into the petrol station, picking a pump at random, and filling up.

[quote name='rmorris' post='322975' date='Nov 5 2008, 09:11 PM']And where is this source of 320Vac ?

It's worth noteing that a product running from European ac mains should be able to able to run at significantly above and under the nominal voltage as there is an allowed tolerance on the mains voltage supplied ( +10% / -6% around 230 Vac ? - but I might be incorrect on the actual figures ). Plus should be able to survive various surge transient conditions as defined in emc standards ( there is a sort of opt out for manufacturers but I'll stop now before it gets very nuanced and legalistic :-)[/quote]

I only used 320Vac into a telly as it is 230Vac + 30%, ie the same % overvoltage as plugging 12Vdc into a device designed for 9Vdc.

The +10% on the 230V spec is generally to accomodate the UKs continuing use of 240 volts, + some tolerance on that.
You're right about being able to absorb some surges, but I dont think being connected to 30% overvoltage for what must have been quite a few seconds counts as a surge.



Having said all the above, it does seem a shame that pedal manufacturers don't standardise on a 9vdc supply and the same polarity on the same type of connector.

[rmorris]

[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']It's designed to a price and performance that is acceptable at that price. If you want Jaguar performance don't buy a mini![/quote]

Ok - but we are talking about a total failure - and hence total loss of utility here - not merely a reduction in functional performance.

[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']A fact that you and most users are aware of and thus should proceed with due care and attention[/quote]

I'm sure I would be saying that if I were an advocate for a company who's product had been destroyed but shouldn't we be on the side of the musician - experienced or inexperienced - here ?
A £15 pedal destroyed is still a complete loss ( and probably a waste of material resources )


[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']I'd agree with that in principal to some extent, but a diode in series will immediatley drop the available voltage for the box to do its work. and putting in some sort of crowbar device would also need a fuse etc, and so add costs.[/quote]
Yes - but at around 0.6V for a standard diode or 0.3V for a Schottky diode I think it's not really an issue . At least in line with external DC which if unregulated likely supplies a few volts or more over the nominal 9V.
Personally - for the 0.6 / 0.3 V loss I'd put it in line with the PP3 also for those ‘fingers and thumbs’ moments when changing a PP3 in a rush.
The cost really is minimal even when it's multiplied up to retail. I don't think it's necessarily a cost issue - more a design implementation issue in some cases at least.


[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']Under what circumstances would you take it into your head to pour 12Vdc, of either polarity, into your pedal which clearly states 9Vdc?
Picking up the wrong plug on stage and just plugging it is akin to driving your lambo into the petrol station, picking a pump at random, and filling up.[/quote]

Sorry but No.
If the petrol pumps were all the same colour and there was very poor illumination at the filling station then maybe.
But that's not the case.
And in fact misfuelling of cars is a problem and it's not generally possible to fill a diesel model with petrol unless you're really determined to as the nozzles / fuel tank entry guages are deliberately mismatched so that the diesel nozzle won't fit in. You can misfuel the other way - it's probably too late to change that now. The problem was originally seen as being one of petrol into diesel as diesel cars were relatively rare but that has changed to some degree.
However it's worth noteing that there was a move to standardise on the pump colour coding after inconsistencies led to confusion.
I do realise that different voltage ranges are nominally assigned to different plug widths / lengths of DC power jacks but the differences are too small to be reliable in the likely environment of use.
The point is to look at things from the user's point of view rather than the designer / manufacturer.
Alongside that vehicle electrical / electronic systems generally have to meet quite tough standards with regard to electrical faults which they may experience including reverse polarity / double voltage (due to two batteries in series ) and more.


[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']I only used 320Vac into a telly as it is 230Vac + 30%, ie the same % overvoltage as plugging 12Vdc into a device designed for 9Vdc.[/quote]


[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']The +10% on the 230V spec is generally to accomodate the UKs continuing use of 240 volts, + some tolerance on that.
You're right about being able to absorb some surges, but I dont think being connected to 30% overvoltage for what must have been quite a few seconds counts as a surge.[/quote]

Yes - I take the point but while it's the same in percentage / ratiometric terms the potential absolute difference in energy is huge and it's just not a realistic scenario.

[quote name='Clive Thorne' post='326154' date='Nov 10 2008, 06:43 PM']Having said all the above, it does seem a shame that pedal manufacturers don't standardise on a 9vdc supply and the same polarity on the same type of connector.[/quote]

Yes - although I wouldn't want to rule out higher voltages which would allow for 'proper' +4dBu levels .
And it's very difficult to standardise retrospectively on anything.
You could think everything was fine then realise that the typical 'polarity' option connection in the dc lead had been switched for some reason.

All the best.

[rmorris]

[quote name='Silent Fly' post='323311' date='Nov 6 2008, 11:41 AM'][size=1][i](I would like to reiterate that I have no personal interests in Behringer. If anything they are my competitors.)[/i][/size]

Regarding what you say, I think we may have to agree to disagree.

Polarity protection and overvoltage protection is an expected part of any pedal design. I think we all agree.[/quote]

Yes - but I think I'd go further and argue that reverse polarity protection should be regarded as necessary for an effects pedal to be regarded as fit for purpose.
Also overvoltage protection to a reasonable degree.
A pedal running on a typical unregulated supply is likely running well above 9V anyway.
I know Behringer specify use of their regulated 9V supply but let's look at what will happen in reality. There don't seem to be Behringer pedals popping all over the place so I'll assume they are okay with typical unreg' psus. And there is little electronics which is okay with 9V and not , say, 12V.
ICs etc may need 5V or 3.3V etc. so this needs regulation in the pedal anyway. A higher input voltage may result in more heat dissipation but even if this is a problem it's unlikely to result in instant destruction.
Looking under the desk right now I can see supplies of nominal 9Vac . 9V DC unregulated, 12V - all on similar DC jacks which I could probably plug in interchangeably even though they should be segregated with regard to size / voltage.
I really don't want to find myself with a broken pedal due to a simple mistake and I don't want to check with a multimeter everytime I plug in power.


[quote name='Silent Fly' post='323311' date='Nov 6 2008, 11:41 AM']I am not sure about the definition of "rubbish design" though. Without going in the semantic of the English language, personally, the level of design sophistication I expect depends on the amount of money I spend.[/quote]
Shouldn't that be 'semantics' rather than 'semantic' ? ie the noun rather than the verb ?

[quote name='Silent Fly' post='323311' date='Nov 6 2008, 11:41 AM']If I pay a relative high sum of money for a pedal, I expect it performs above the minimum specifications. How above it depends on the company that produces it and its interest in its reputation.

If I pay the very minimum that I can find, I am happy to compromise on the design and spend a little bit of extra-time checking the connections before powering on the pedalboard.[/quote]

fair enough - but my core point is that this needn't be sophisticated design or expensive to implement.


[quote name='Silent Fly' post='323311' date='Nov 6 2008, 11:41 AM'](Fortunately) Nobody forces us to buy Behringer. We all know that their pedals are not as good as the originals. They don’t sound as good the originals and, yes, they fry if the power supply is not correct. But they are dirty cheap…[/quote]

Well I don't really have a particularly poor view of Behringer kit as products. I think someone mentioned EHX also having reverse polarity issues and I'd criticise that also although that situation may be down to historic reasons.
I have a Composer compressor from the days before they went mega-cheap and I'm not complaining that it's not the SSL (or insert your fav dynamics box here ) compressor and also one of their 2 channel 'humbuster' passive transformer boxes. Of course I'm not complaining that the transformers aren't as good as Lundahl / Sowter or whoever but it functions as I need it to when used.
I also have one of their 'Hellbabe' optical wahs - thinking about it there are issues there but not really relevant to the discussion here.

There are ethical / legal / copyright issues with regard to the, shall we say, 'inspiration' behind some of their products which leaves a bit of a bad taste but again not strictly what we are talking about here.

What is interesting is that I read some 'product teardown type' reviews of some Behringer kit a while ago. This was some rack kit rather than fx pedals - and using some well spec'd devices for handling digital
audio. Anyway - it was thought that the analogue stages were less than stellar. Technical investigation showed noticeable noise on the power rails at the op amp pins and an absence of decoupling / bypass capacitors. Caps were fitted and a significant improvement noticed.
Now I didn't hear it myself and I'm always somewhat sceptical about third party reports like this.
But if we accept the observations it does point to problem(s) in the design / implementation / manufacturing process rather than deliberate cost cutting.

Cheers

[Count Bassy]

[quote name='rmorris' post='327185' date='Nov 11 2008, 11:26 PM']I'm sure I would be saying that if I were an advocate for a company who's product had been destroyed but shouldn't we be on the side of the musician - experienced or inexperienced - here ?[/quote]

I don't want to get into a protracted discussion over this, but I just wanted to make it clear that I don't own or use any pedals, and don't own or use anything made by Behringer.

I'm not sticking up for Behringer specifically, or for manufacturers in general, but for the principle that if you don't use equipment according to the instructions (eg connecting the wrong power supply) then it might get damaged or destroyed. While manufacturers could improve their designs to make things more tolerant it is ultimately up to the user to take responsibilty and ensure that it is used correctly.

Perhaps they should print a warning on each pedal saying "Warning: Conecting the wrong power supply might destroy this unit", but this is rather remeniscent of the ridiculous "warning: contents may be hot" on the coffee cups.

[Silent Fly]

[quote name='rmorris' post='327213' date='Nov 12 2008, 12:14 AM'][quote]
Polarity protection and overvoltage protection is an expected part of any pedal design. I think we all agree.[/quote]

Yes - but I think I'd go further and argue that reverse polarity protection should be regarded as necessary for an effects pedal to be regarded as fit for purpose.
Also overvoltage protection to a reasonable degree.
A pedal running on a typical unregulated supply is likely running well above 9V anyway.
I know Behringer specify use of their regulated 9V supply but let's look at what will happen in reality. There don't seem to be Behringer pedals popping all over the place so I'll assume they are okay with typical unreg' psus. And there is little electronics which is okay with 9V and not , say, 12V.
ICs etc may need 5V or 3.3V etc. so this needs regulation in the pedal anyway. A higher input voltage may result in more heat dissipation but even if this is a problem it's unlikely to result in instant destruction.
Looking under the desk right now I can see supplies of nominal 9Vac . 9V DC unregulated, 12V - all on similar DC jacks which I could probably plug in interchangeably even though they should be segregated with regard to size / voltage.
I really don't want to find myself with a broken pedal due to a simple mistake and I don't want to check with a multimeter everytime I plug in power.
[/quote]
We are all entitled to our opinion and I think you made yours perfectly clear.

As I see it, we know Behringer pedals limitations and design oversimplifications. It is up to us as customers decide if we want to buy them or not.

Considering how much they cost, I can live with the risk of frying the pedal. For you this is obviously something more important than it is for me or for other people.

[quote post='327213' date='Nov 12 2008, 12:14 AM']Shouldn't that be 'semantics' rather than 'semantic' ? ie the noun rather than the verb ?[/quote]
English is not my first language so comments to my errors are more then welcome.

[quote name='rmorris' post='327213' date='Nov 12 2008, 12:14 AM']fair enough - but my core point is that this needn't be sophisticated design or expensive to implement.[/quote]
I think I get your point. On the subject, you may find these pages interesting.

[url="http://www.geofex.com/article_folders/mosswitch/mosswitch.htm"]http://www.geofex.com/article_folders/moss...h/mosswitch.htm[/url]
[url="http://www.geofex.com/Article_Folders/cheapgoodprot.htm"]http://www.geofex.com/Article_Folders/cheapgoodprot.htm[/url]
[url="http://electronicdesign.com/Articles/Index.cfm?AD=1&ArticleID=9945"]http://electronicdesign.com/Articles/Index...;ArticleID=9945[/url]

Edited November 12, 2008 by Silent Fly

[rmorris]

[quote name='Silent Fly' post='327581' date='Nov 12 2008, 01:43 PM']I think I get your point. On the subject, you may find these pages interesting.

[url="http://www.geofex.com/article_folders/mosswitch/mosswitch.htm"]http://www.geofex.com/article_folders/moss...h/mosswitch.htm[/url]
[url="http://www.geofex.com/Article_Folders/cheapgoodprot.htm"]http://www.geofex.com/Article_Folders/cheapgoodprot.htm[/url]
[url="http://electronicdesign.com/Articles/Index.cfm?AD=1&ArticleID=9945"]http://electronicdesign.com/Articles/Index...;ArticleID=9945[/url][/quote]

Thanks.
As it happens I've seen the two geofex articles before.
I hadn't seen the third article although I've used fets in a similar manner for a different application.
I prefer the that way of doing things for its relative simplicity and lower parts count compared to the mosfet / bipolar approaches.

Cheers

[rmorris]

[quote name='Clive Thorne' post='327367' date='Nov 12 2008, 10:16 AM']I don't want to get into a protracted discussion over this, but I just wanted to make it clear that I don't own or use any pedals, and don't own or use anything made by Behringer.[/quote]

yes - that's all clear.

[quote name='Clive Thorne' post='327367' date='Nov 12 2008, 10:16 AM']I'm not sticking up for Behringer specifically, or for manufacturers in general, but for the principle that if you don't use equipment according to the instructions (eg connecting the wrong power supply) then it might get damaged or destroyed. While manufacturers could improve their designs to make things more tolerant it is ultimately up to the user to take responsibilty and ensure that it is used correctly.

Perhaps they should print a warning on each pedal saying "Warning: Conecting the wrong power supply might destroy this unit", but this is rather remeniscent of the ridiculous "warning: contents may be hot" on the coffee cups.[/quote]

I agree that a user should be expected not to treat a product recklessly or unreasonably.
But alongside that I think it's fairly well accepted in design and manufacturing that reasonable steps should be taken to avoid damage due to easily foreseeable inadvertent mistakes in use.

Regards