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Modulus-686: 380W (4Ω); 220W (8Ω) Balanced Composite Power Amp with extremely low THD

@Koifarm It seems to me that your comments were supposed to be well-intentioned. However, your approach comes across as rather hostile. In this way, you have invited crass responses.

As with any written medium, we're missing the nonverbal communication that might have resolved this sooner. On top of that, as technical people we are liable to get bogged down on details and (temporarily) lose sight of the full story.

I don't want to judge, but maybe my feedback gets perceived as unsolicited as your remarks were too. I find the following resource contains valuable guidelines to prevent conversations straying in unconstructive directions:
https://therulesofcivilconversation.org/

To conclude, may I suggest you lay the subject to rest. It won't be your door the lawyers would be knocking at, and it's unlikely somebody gets fatally electrocuted by an amp that Tom built.
 
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I have addressed all the points that Koifarm brought up. At this point he's just talking to himself without adding anything new to the conversation. I hurt his feelings with my Engineering Done Right tagline. That's really all there is to it.

I follow industry standard practices regarding EMC compliance and electrical safety. End of.

Stop feeding the troll.

Tom
 
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Sorry guys, where are the warnings outside the housing if using a non shielded smps. Where is the insulation class identification? He must be lucky that a customer does not kill him self. I do not believe there was a safety study done before releasing his amp.

What is dangerous is that you refuse to accept you dont know all the safety rules. And I also dont know it.
Thats why there are specialist who can help you.
 
^ Perhaps you are trying to inform politely, but it is simply a communication style or a language difference. However, I'd suggest if you continue to post that you try a change in tone.

If I may...

Are you trying to say something like below?

In my experience and to the best of my knowledge all consumer electronics are required to carry a label on the product noting specific information with regards to the regulations set forth under the Radiocommunication Act (R.S.C., 1985, c. R-2)
I've noted Canadian legislation, but these labels and similar may required for sale or import of certain electronics devices into (country) ...

Then... people with knowledge can openly discuss whether or not that labeling is necessary and/or and any regulatory requirements around the legislation. Tom could certainly have the opportunity to weigh in or not.

In my opinion, one should not assume (and I don't think you are assuming this) that a label indicates compliance or conversely that compliance always requires a label.

That takes a lot longer to type, but I hope it is an example of how a polite discussion may be started vs. implying or openly stating ignorance or violations.

For my own part, I have no idea whatsofrickingever whether that legislation / regulation applies to this product or not... it is just an example of how I might go about asking a question. If I had a similar question of my own, I'd probably ask the most relevant person via PM vs. starting an open debate in a forum.
 
It is very difficult to communicate about these safety issues. I believe you do not have to discus these rules just follow them up. And if you do not like the rules still follow them up and try to get them changed.

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@Koifarm - I think we all agree that it can be difficult to discuss. It is always best to post actual links if practical to ensure context.

FWIW + a bag of ketchup chips, I am inclined to think that some labeling and certification is appropriate for the sale of a completed electrical product in Canada. With that said, I haven't looked at the web page advertising the product nor have I looked at a completed product. So, I am content to say... I don't know. I have supported the compliance for electrical products imported into, sold in, and manufactured in Canada, but my thoughts are irrelevant.

I have seen Tom specifically share what he's done to ensure compliance.

However, that is best left to Tom and his team. If you have concerns re: specifics or even some kind advice for Tom, I've found him an absolute delight. He likely would take any serious advice under consideration and act accordingly based on his extensive knowledge.

Here is what the Canadian government advises consumers... from this site.

https://www.canada.ca/en/health-canada/services/home-safety/electrical-products.html

Electrical products that plug into an electrical outlet must meet Canadian national safety standards and be certified by an accredited certification body.
Always check for certification marks, such as CSA, cUL, or cETL, before purchasing electrical products that plug into an electrical outlet. These marks indicate that the products are assessed and conform to the required Canadian national safety standard.
Do not buy or use electrical products that plug into an electrical outlet without a certification mark.
I'll allow others to continue the conversation, but I hope it is polite, and we can all learn.
 
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do your fully built amps have a CE label (or equivalent for your country) printed on them?
No. The Modulus-686 is a DIY product. I build a couple by hand that I will sell. I make no claims of regulatory compliance, so I'm surprised that this topic seems to have taken on a life of its own here.

Companies can self-certify for CE compliance. Some do that by performing all the necessary compliance tests themselves to make sure the equipment passes. Others, like me, design the circuits so that they should pass. And some just put the CE mark on their equipment and hope for the best.

FWIW, UL certification is not required for the US market even if the corresponding cUL is required in Canada.

Tom
 
No. The Modulus-686 is a DIY product. I build a couple by hand that I will sell. I make no claims of regulatory compliance, so I'm surprised that this topic seems to have taken on a life of its own here.
As I understand it, anything you sell or otherwise bring to circulation must have a CE mark (or equivalent) if it plugs to mains power. At least that's what knowledgable people told me about the regulations in my country. I am not saying this is 100% correct or applies to your situation, but it may well be the case.

Don't get me wrong. I am not saying your amps are not safe (I am pretty sure they are safer than many other electrical devices out there). But I would not be surprised if your fully built amps would be "illegal" without the correct "safety mark". I'd suggest you talk to someone who knows this stuff.
 
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Tom, all producers build their equipment themself. Its about the customer they do not build the offered amps themselves.
Supplying DIY kits is no problem, the customer who buys and use them are responsible for the right/safe use.

I know from my experience that companies who self-certify for CE still have to certify their certifying methods and equipment by a certified body. You stil have to register your products.

It is not the marking that is counting but the system it represents.
The lack of proper markings on a product can be a sign of bad engineering but also the presence of markings is no warranty.
A trustful producer place the right markings on the product and stated references to the certified bodies in his manual.
 
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As I understand it, anything you sell or otherwise bring to circulation must have a CE mark (or equivalent) if it plugs to mains power.
Only if I want to sell it within the EU or import it into the EU. CE is an EU thing. It does not apply in North America.

As I pointed to earlier, I can meet the CE marking requirement simply by slapping a CE sticker on the back of the amp. I'm not suggesting that this is what I would do. Only that I can meet the legal requirements by doing so. Naturally, if I were to slap such a sticker on the amp and someone was to request the compliance test report from me I would be hosed unless I had the product tested and could produce the report.

Adding a sticker won't make my product any more or any less safe. But it would satisfy the requirements for product import and sale to the EU.

Tom
 
These "nowing anything better" guys like the "fish farmer" are exactly the reason for me not to post in German forums.
They are also the reason, why creative and really capable people don't post in German forums anymore and leave them to the trolls.
Anyone knowing something and explaining in best intention, is a red flag for them. Any productive thread gets drawn into complete irrelevance by guys like him..
A process that, over the years, has made the German DIYS "community" completely incompetent.
Which is well received by industry and retailers. It is simpler to sell overpriced products to incompetent consumers.

Electric safety is the cause I do not like to post most of my my projects. I do anything right, but someone doing an incompetent copy could later blame me for his own stupidity.
In Germany any electric product that is sold, has to be emission tested. In theory even a passive one way loudspeaker! So I can build a speaker for my self, but if I sell it to my neighbor have the same responsability like Siemens, Phillips or Samsung. Which makes these manufacturers very happy. That's why they lobby for such regulations.
Our friend got procecuted for selling a device that made it possible to watch pay TV without the part "pay". Because the German law at that time was not covering this kind of theft, they punished him for not complying to electrical norms. He still does not accept he did something wrong and now wants to put others in the same position like him. Some kind of personal problem I suppose. Be mild on him and show some compassion.

PS Concerning German DIYS incompetence, I just found a nice example of a speaker:
https://www.diyaudio.com/community/threads/rcf-21-woofer-lf21n451.405626/#post-7510921
The first non portable Bluetooth speaker ever.
 
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@TioFrancotirador

What do you mean by “SE output connected to Modulus-686?” Why do I ask? The 686 is inherently a balanced bridged output. Both terminals have voltage on them during regular operation. It is not like an SE output where one terminal is held at ground potential, while the other terminal has an output voltage such as his Modulus-86, and 286 designs.

So to answer your question, there is no “half of amp is working” issue on the 686.

And before there is a misunderstanding, one very important consideration is noted in the 686 design document:

Do not connect any of the speaker output terminals to ground. The Modulus-686 is a BTL design, hence both output terminals will provide output voltage.

This is an important point. There are many plate amps for subwoofers (particularly modern Class D) that have an option to use speaker input terminals. They expect to derive their input voltage from an amplifier ‘source’ that has an SE output. If you connect the Modulus 686 bridged balanced speaker output to these types of plate amps, you will/can damage the plate amp.

Best,
Anand.
 
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So I can build a speaker for my self, but if I sell it to my neighbor have the same responsability like Siemens, Phillips or Samsung. Which makes these manufacturers very happy. That's why they lobby for such regulations.
In fairness... at least in the USA, I support that regulations apply to all sales. As an example, have you seen some of the (insert eBay seller here) amplifiers commonly shown around these forums? It is my opinion, and I state no legal grounds, that some of those amplifiers were/are dangerous. They should never have been on the market, and they should be held to the same compliance standards and requirements as (insert big amplifier company). Those laws are in place for consumer protection. Yes, they can be onerous, and they are not often perfect, but they are in place for a reason. We, as DIYers, are fortunate to have some skills to look at a finished amplifier and perhaps judge if it is safe for us to use. The average consumer has no such knowledge. They will likely never open the lid.

I can say with direct knowledge that in the USA many large companies prefer the "no harm, no foul" approach. They prefer to never have a regulation. They lobby against them with big armies of lobbyists. If they hurt someone, they prefer to handle it on an individual basis. They certainly hate recalls. Conversely, many smaller companies prefer detailed regulations b/c they do not have extensive compliance or engineering teams to navigate how to make a safe product / properly labeled product. They would prefer to "be told" how to do it properly. It might be easier and cheaper for them to read a detailed regulation telling them exactly what is required than to pay to learn to do it properly. Many companies, would like to send a prototype to a lab and just be told that it meets requirements and wash their hands. I see this with small toy companies most commonly. That is of course the two extreme ends, and much falls in the middle.

From a consumer standpoint, there should be an expectation that the product is safe to use. Sadly, one of the only ways to tell the consumer that a product is safe is through the use of standardized markings that indicate compliance / safety.

I don't want to imply that it is the same in Germany. I have no knowledge.

My long-winded point is that it is a fine line with some subtlety in the USA.

Back to the regularly scheduled programming re: the amazing Modulus amplifiers. I find regulatory issues fascinating, but I promise that's my last post in this thread re: that area.
 
@tomchr
"Do not connect any of the speaker output terminals to ground. The Modulus-686 is a BTL design, hence both output terminals will provide output voltage."
I understand that this is regardless of source connected to Modulus-686. Be it either: SE (+/G) through pseudo differential XLR cable, where (-) is connected to Ground or true balanced signal +/G/- through differential XLR cable?
 
@tomchr
"Do not connect any of the speaker output terminals to ground. The Modulus-686 is a BTL design, hence both output terminals will provide output voltage."
I understand that this is regardless of source connected to Modulus-686. Be it either: SE (+/G) through pseudo differential XLR cable, where (-) is connected to Ground or true balanced signal +/G/- through differential XLR cable?
That's correct. The output topology of the Modulus 686 amplifier which is a bridged output has no relationship with the input (with regards to the discussion here). The input (to make it easy) is entirely addressed by the circuitry surrounding the OPA 1642 input stage, i.e. it handles the input signal whether it is a pure differential/balanced signal or a single ended one. This is one of the advantages of this type of circuit. Gain also remains the same for both RCA or XLR inputs at either 26 dB (stock) or 20 dB (adjustable by removing a resistor at build/order time).


1700490614539.png


Best,
Anand.
 
OK, I lied. @rolli - That strategy doesn't always fly (at least in the USA). It would largely depend on how complete (all parts vs some) the kit is and the level of complexity / completion required by the consumer along with any instructions provided for assembly and testing. As an example, Tom already sells some of the parts. He has two completed amplifiers he wants to sell. He can't just pull the power cord from the finished amplifier and call it a kit. Are you suggesting he dismantle the two he has for sale and provide a manual? He's already got a separate business that sells completed products. My comments have been related to and still are related only to two very specific amplifiers vs. an overall business model.

I know that's not what you meant, and I know I offered an example that's unlikely and at an extreme. There again ... it's up to Tom to understand the rules for relevant countries and to choose how to react accordingly based on what he knows applies or does not apply in his specific circumstances along with his risk model. He's one of the smartest guys I've ever interacted with. I'm sure he'll handle it.

Last post... really... I pinky swear... on regulatory stuff from me.