Carver Crimson 275 Review (Tube Amp)

[Travis]

Only one correction I would make to that - the safety ground is related to the electrical safety requirements of CE, not the EMC (as long as emissions and susceptibility can be passed without it).

Class 1 (grounded) or Class 2 (double insulated) are mandatory for compliance. No wiggle room. You can't test for double insulation - you have to prove it by design. It can be quite challenging to get right.

But my point is the fact that this particular amp is or isn't UL rated, or EU certified, is of zero significance in the context of how it was raised when the amp was first reviewed and discussed, and even again here recently.

Many people said, and I think Amir even mentioned in the review "there are no ratings on the back of the amp." Good to point out for sure, but there was a common misconception that audio amps, good ones, would be UL rated. I think I even mentioned at the time, go look at the back of your amp and let us know. Some posted photos. Many were posting that no EU or UL rating was further evidence of, well, something. For a short time some were saying that "it's a requirement that" it is grounded a particular way. I asked back then, and just mentioned it again a day or two ago, there is no requirement in the US for anything on an audio amp. Early on there was one or two EE's that kept saying, "it's required" but they couldn't point to a Federal, State, or local law that required a manufacturer of amps to do it a certain way. Because there isn't any. Electrical codes do, and only require rated amps in very specific circumstances.

There was all of these great arguments about the suspect specifications, the FTC problems, the design problem on the grounding, there wasn't a need to try and make an additional point that had a faulty foundation: "It must be grounded, that's a requirement." Not in the US it isn't. "Well they market in the EU." Haven't seen any evidence of that. But that means nothing, they could have an EU version of their product, that is done all of the time. This review was on a amp sold in the USA.

The last point I wanted to make was that an CE certification, which many back peddled to as a backup position (well it isn't CE certified) is nowhere near what is required to get a UL or CTA rating, These were all red herrings to the major issues at hand. The company was having major issues, the marketing people seemed to have cooked the books, if it hadn't been reviewed who knows how long this would have gone on.

Something I just realized, Amir reviewed the 350W Amp in August. It didn't have a screw loose, it didn't blow fuses, but it was noisy and distorted to an extreme. But if it sounds good, or if Bob says it sounds good, for a lot of people that's enough. I don't know if that had a 3 prong plug, if so, how it was grounded. Would like to see if someone knowledgeable has looked at that. I also can't recall if it had a CE sticker on the back. Again, whether it does has no bearing on whether it is a good amp in terms of the parameters of the typical testing done as ASR.

 

[antcollinet]

That may very well be. I know that I see ads for "EU Certification" all the time, it is a design review, not product testing.

No, it isn't.

It is compliance with standards. Many of the standards require testing for many things.

If you certify CE, and your product kills someone, and you are found not to be compliant, and negligent in that lack of compliance - there is a significant chance that a senior engineer or other person involved in sign off will be going to prison.

In a previous life, the organisation I worked for spent millions recalling a product because there was a tiny violation of clearance distance inside the insulation system of a transformer.

 

[solderdude]

That may very well be. I know that I see ads for "EU Certification" all the time, it is a design review, not product testing.

Nope. See answer @tonycollinet

Devices (in several classes) have to comply to certain standards.
Several tests have to be done and when one passes these tests and have documented the results a manufacturer can put CE marking on it and can sell it in the EU.
The manufacturer can test it themselves (if they have the required test equipment) or have it done at a certified test facility.
A CE mark indicates the device complies to EU law/rules for that type of device.

 

[Speedskater]

As I mentioned earlier, few if any hi-fi amplifier manufacturers get UL certification, or other NRTL certifications like CSA or ETL. Why, because you have to submit six samples for testing and you do not get them back. So McIntosh, Benchmark, NAD, Yamaha, Mark Levinson (I know for sure) do not get UL certification. There is no requirement in the US that an amplifier have UL (or similar NRTL certification).

The USA does not set the requirements for AC powered products. Each "agency having jurisdiction" (State or city government) is free to select which NEC & UL rules to enforce. Most "AHJ"s use the entire NEC code (with a few additions or subtractions) but are behind on the latest (3 year) update. The "AHJ"s decisions are laws.

From a UL point of view, amps and other hi-fi components are appliances. UL has books on appliance safety specs.

Most "AHJ"s require all AC powered things in a residence to have a safety certification.

 

[fpitas]

Yeppers. The tetrode kink led to the development of the beam tubes and pentodes -- there were also some some interesting IP/patent issues (as I recall) which is, again IIRC, at least part of the reason we had a proliferation of sort of similar, but sort of different power output tubes (e.g., the 6L6, the EL34 and its kith and kin).

The kink an sich.

See that wiggly-wooglie little disturbance at low plate voltages in the curves? That's the kink.

https://www.researchgate.net/figure/Typical-family-of-curves-of-a-tetrode-Notice-the-kink-that-appears-in-the-curves-for_fig18_319877861

Yes, as I recall Philips got the patent on the pentode. So, somebody invented beam power to get around that. Which is good, because they do different things.

 

[dfuller]

Yes, as I recall Philips got the patent on the pentode. So, somebody invented beam power to get around that. Which is good, because they do different things.

Yep, Philips got the patent. EMI (GEC) and RCA made the beam tetrode in response.

 

[atmasphere]

There was all of these great arguments about the suspect specifications, the FTC problems, the design problem on the grounding, there wasn't a need to try and make an additional point that had a faulty foundation: "It must be grounded, that's a requirement." Not in the US it isn't. "Well they market in the EU." Haven't seen any evidence of that. But that means nothing, they could have an EU version of their product, that is done all of the time. This review was on a amp sold in the USA.

The reason an ungrounded amp built on a metal chassis might get docked is pretty simple. If it gets damaged it can be a lethal shock hazard. The silliness of this is its so easy to prevent!! If this amp had been grounded correctly but were lacking UL approval and/or the CE mark would have of no consequence in the context of the review.

 

[Travis]

Nope. See answer @tonycollinet

Devices (in several classes) have to comply to certain standards.
Several tests have to be done and when one passes these tests and have documented the results a manufacturer can put CE marking on it and can sell it in the EU.
The manufacturer can test it themselves (if they have the required test equipment) or have it done at a certified test facility.
A CE mark indicates the device complies to EU law/rules for that type of device.

That may be, but audio amps do not need to be tested to get a CE cert. only a design review by a 3rd party certifier. That's just a fact. In addition, and this some how keeps getting lost in here, a CE sticker doesn't mean squat compared to a UL or CTA sticker.

 

[Blumlein 88]

This CE, UL etc has been hashed out about 5 times already in this thread. Bottom line, is the Carver amp this thread is about is electrically not up to modern design safety. If you insist on having one you can make it safe by using it with a GFCI plug. Or sending it back for Carver to fix.

Is this not enough already?

 

[Travis]

The USA does not set the requirements for AC powered products. Each "agency having jurisdiction" (State or city government) is free to select which NEC & UL rules to enforce. Most "AHJ"s use the entire NEC code (with a few additions or subtractions) but are behind on the latest (3 year) update. The "AHJ"s decisions are laws.

From a UL point of view, amps and other hi-fi components are appliances. UL has books on appliance safety specs.

Most "AHJ"s require all AC powered things in a residence to have a safety certification.

How misinformed you really are. I said that electrical codes are what controls what needs to have a NRTL (like UL) in about 15 prior posts in this thread going back to the beginning. I stated there was no federal, state or local law that says an amplifier needed to be grounded in a particular way, or that it be rated. I also said it is electrical codes in a jurisdiction what set out when an particular electrical appliance or device needs to have a rating, and what specific condistions/type of use. You are correct, the jurisdiction chooses which sections of the NEC (and which version, they seldom update to the latest version right away). The building/electrical code required by the state or local government requires a rating for electrical and electronic devices installed in certain commercial settings, and for a residence it is usually permanently installed in the structure. Ceiling speakers for example.

This isn't rocket science to figure out, it's pretty easy if you are an electrical engineer, an electrical contractor, or in building design or construction. How are electrical codes enforced in the US, whether at the state or local level? If you know the answer to that, or can figure it out, you will know why things like amplifiers, cd players, HT receivers, DACs, preamps, are NOT required to be UL or other NRTL rated in the typical residence application.

UL doesn't consider amps to be appliances. There is a standard specifically for audio and video equipment used in residential and commercial settings. UL has a book of specs just on amplifiers. They consider them to be, well, amplifiers. that are used in environments like movie theaters, outdoors, near swimming pools, etc. They are tested vigorously, to complete failure. The building codes, NEC, state and local, do not require typical audio amplifiers or HT receivers to have a safety certification. Benchmark, a very well-regarded brand here for amps, pre, and DAC, no UL rating. Same with dozens and dozens of other very highly regarded and expensive amplifiers. Many commercial amplifiers, like Crown, offer UL-rated amplifiers because the NEC requires them in places like movie theaters.

"Most "AHJ"s require all AC powered things in a residence to have a safety certification." No they don't. Most AHJ's require permanently installed AC (or DC) powered things in a residence to have a NRTL certification. Like electric ovens and ranges, installed microwaves, wired smoke alarms, etc. (Don't know what you mean by safety certification unless you mean an NRTL certification like UL.)

Here is a real, real easy one. Go to your kitchen, and look at anything that is plugged into the wall: Kitchenaid mixer, Nespresso coffee maker, toaster, blender, and how many have a rating? Probably none. How about your wife's 1500 watt Dyson hair dryer, nope. What about a Dyson hand dryer that is attached to a wall. Yep. (They use ESL lab, not UL, which is fine for the NEC). Can you find those products that are UL rated? Yes. They are generally the "commercial version" of that product. I bet the recessed lighting is UL rated, ceiling and inwall speakers are UL rated, Subzero fridge/freezer yep, built-in icemaker, yep.

But maybe I'm out of step, out of touch. That's certainly a possibility. Please tell me, I have asked others here that say they are in the business or related profession where they would know about this and they have said the NEC or other codes don't require a UL/NRTA certification for an audio amplifier in a home in the US or Canada (CTL certification). Maybe there is a city or county/parish out there that has an electrical code that says home audio amplifiers shall be NRTA certified, or maybe the NEC was recently amended to require that, please cite or quote the relevant section. We also need to let people in those jurisdictions know that their audio amps (which are probably not NRTL rated) are in violation of the local codes. Maybe those in states with old codes can get some good deals on some equipment from those in states with new codes where everyone will be getting rid of their amps and other things to comply with the code in their jurisdiction.

Can you, or anyone, please point out part of the NEC that requires that a home audio amplifier, preamp, DAC, etc. needs to have a NRTL rating/certification to be used in a home (not outside, not permanently installed)?

By the way, audio and television devices are UL 6500, commercial audio is in the 800s I believe.

 

[Travis]

This CE, UL etc has been hashed out about 5 times already in this thread. Bottom line, is the Carver amp this thread is about is electrically not up to modern design safety. If you insist on having one you can make it safe by using it with a GFCI plug. Or sending it back for Carver to fix.

Is this not enough already?

You would think, but probably not.

Never ceases to amaze me that a community forum that prides itself on science, objective data, being skeptical of subjective or anecdotal information throws that all out the window when it comes to the most easily verifiable things like electrical codes, or whether there are UL ratings on amps that were highly rated. About every 30 or 40 pages someone comes along and repeats the myth about UL ratings, "good amps will have a safety certification." No they won't, because they are not required to have one.

It still won't be enough.

I think there should be a rule if you want to talk more about that issue you have to take a photo of the pack of your amp(s)/receiver/integrated/HT so everyone can see if it is UL or other NRTL certified.

 

[Travis]

I'm sort of interested in the legal mandates in USA regardiing electrical safety of consumer kit.

Here in in Europe (even still in the UK) we have CE certification - which covers both safety and emc requirements - being a legal mandate - with all the standards that state what is required to meet that.

As far as I can see, the standards in USA have pretty much the same requirements - but I can't find anything clear about the legal mandate for meeting those standards. As far as I can see it is legislated at the state level (which doesn't help clarity), and it seems that most states require compliance with NEC standards of one version or another - but it is far from easy to work out.

Are you (or anyone else) aware of any clear references?

So on electrical, it is the version of the NEC that the state or local jurisdiction adopts. Most states there is a lag behind the most current version of the NEC, or certain sections. You see this when it will impact the cost of housing (GFI and other breakers for example).

The NEC specifies when something like an amplifier needs to have a Nationally Recognized testing Laboratory (NRTL) certification. It is very limited (same in Canada). Movie theaters, outdoors, and near water are the most common situations where plug in devices have to be rated. Things that get installed at part of the home, in-ceiling recessed lighting, in-ceiling speakers, etc. are all rated.

There is nothing equivalent to CE certification in the United States or Canada. If it is going to be safety tested, it has to be done by an independent lab, and submit six samples, for destructive testing. They also do follow-up testing to renew the rating. There is no provision in the NEC to accept a product that is CE rated.

There is a federal agency called the Consumer Product Safety Commission. They require that all products intended for children (toys, clothing) be tested, and if imported, that a Certificate of Compliance be filed.

For products not specific for children, you have to check their regulations to see if testing is required. Here are some examples of some things that are required:

The following list of mandatory standards comprises CPSC regulations that contain the requirements for a reasonable testing program in the particular standard:

• 16 CFR part 1610, Standard for the flammability of clothing textiles
• 16 CFR part 1203, Safety standard for bicycle helmets
• 16 CFR part 1204, Safety standard for omnidirectional citizens band base station antennas
• 16 CFR part 1205, Safety standard for walk-behind power lawn mowers
• 16 CFR part 1209, Safety standard for cellulose insulation
• 16 CFR part 1210, Safety standard for cigarette lighters
• 16 CFR part 1211, Safety standard for automatic residential garage door operators
• 16 CFR part 1212, Safety standard for multipurpose lighters

As someone previously mentioned, we leave it to personal injury lawyers to find dangerous products, drugs, etc. and go after them. If the CPSC gets enough complaints about a particular product they can force a recall. f

 

[solderdude]

That may be, but audio amps do not need to be tested to get a CE cert. only a design review by a 3rd party certifier. That's just a fact. In addition, and this some how keeps getting lost in here, a CE sticker doesn't mean squat compared to a UL or CTA sticker.

Incorrect.
One does not have to put a CE marker on the device BUT all electronic devices intended for consumers DO need to comply to CE norms.
This amp may well comply to class-II. It would have to be tested for this and must comply to CE standards when sold to consumers in the EU.
It does not have the proper IEC inlets for that, there is no class-II symbol on it. The used IEC plug suggests it is a class-I product but is NOT a class-I product simply because safety ground is not connected to the chassis (metal parts that can be touched).

As far as we know NO such test reports are available and likely have not been done either.

The fact that Bob offers to have the ground pin connected on request says enough as well...


The amp may well be safe to use though and might even be 'properly grounded' when connected using RCA plugs. That does not take away the fact that the used 'method' of providing ground lift is not correct.
When ground lift were the goal the IEC pin should have been connected to the chassis and audio ground should not have been tied to the chassis.
Would you agree with this or do you have a different opinion ?

 

[antcollinet]

That may be, but audio amps do not need to be tested to get a CE cert. only a design review by a 3rd party certifier. That's just a fact. In addition, and this some how keeps getting lost in here, a CE sticker doesn't mean squat compared to a UL or CTA sticker.

It really isn't true. At all. If you are using a third party certifier - they will want to see all the test results, as part of the certification process.

The main reason to use a third party isn't to make it easier - it is to demonstrate due diligence through independent review.

 

[amirm]

Benchmark, a very well-regarded brand here for amps, pre, and DAC, no UL rating.

They most definitely do. Here is the safety compliance page from manual:
Safety
Product: Audio Amplifier, Audio Equipment, Stereo Audio Amplifier
Model: AHB2
Part Number: 500-18000-xx0
Parameters:
 Rated Input Voltage: 100-120 Vac; 220-240 Vac
 Rated Frequency: 50/60 Hz
 Rated Input Current: 8A
 Protection Class: I
Tested according to:
 CAN/CSA C22.2 60065/A1:2006
 UL 60065:2007
 EN60065/A12:2011
Certification Mark:


Ul600065 is precisely for home electronics. Above certification was performed by TUV NA as NRTL.

 

[amirm]

Here's the tuv mark:

 

[Blumlein 88]

You would think, but probably not.

Never ceases to amaze me that a community forum that prides itself on science, objective data, being skeptical of subjective or anecdotal information throws that all out the window when it comes to the most easily verifiable things like electrical codes, or whether there are UL ratings on amps that were highly rated. About every 30 or 40 pages someone comes along and repeats the myth about UL ratings, "good amps will have a safety certification." No they won't, because they are not required to have one.

It still won't be enough.

I think there should be a rule if you want to talk more about that issue you have to take a photo of the pack of your amp(s)/receiver/integrated/HT so everyone can see if it is UL or other NRTL certified.

The topic of this thread is designed in a way that violates a basic electrical safety issue. That is it.

If you want long discussions about intricacies of UL ratings I suggest starting a thread on this topic. Continuing here it's just obscuring the issue on the Carver 275.

 

[Speedskater]

One of the main reasons that many modern low powered audio components use a wall-wart power supply is to avoid the need for a 'UL' marking.

 

[pma]

Why does this s..t product attracts that much attention? The worse the more interesting?

 

[fpitas]

Why does this s..t product attracts that much attention? The worse the more interesting?

Everybody loves a train wreck.