Carver Crimson 275 Review (Tube Amp)

[SIY]

SIY,

I have no financial interest (other than owning a variant) in these amplifiers.

My intentions have been clearly stated throughout this discussion.

I take claims of catastrophic safety issues seriously.
BC has responded to the claims that there is no protection if If a high voltage wire were to touch the inside of the chassis:
"The B+ fuse will blow"
The "what ifs" are beyond the scope of the review and were not tested.
(I have never disputed the measurement results).

I appreciate the discussion about other amps that is scattered throughout this thread.

Again you are projecting such animus.
I am not sure why someone of your esteem on this site, a technical expert, must resort to name calling.
(I do find some humor in the 'likes' by the people in your responses - complicity of character)

Uh huh.

 

[LTig]

What's especially egregious in this case is that the safety changes recommended are apparently easily done and inexpensive.

Obviously the producer has decided that the costs of grounding the chassis of all produced units weigh higher than the costs if one of his customers is hurt or killed in case of error. However small the chance is that this happens - it shows quite a disrespect to the well being of his customers, especially regarding the minor costs of grounding the chassis in the first place (I'd say less than 1 US$ per unit including assembly, for a dealer price of 2.5kUS$).

 

[SIY]

Obviously the producer has decided that the costs of grounding the chassis of all produced units weigh higher than the costs if one of his customers is hurt or killed in case of error. However small the chance is that this happens - it shows quite a disrespect to the well being of his customers, especially regarding the minor costs of grounding the chassis in the first place (I'd say less than 1 US$ per unit including assembly, for a dealer price of 2.5kUS$).

If the grounding scheme is as poorly engineered as the rest of this disaster, the safety ground might have been omitted because of hum.

 

[Blumlein 88]

I've said it before, maybe he needs to ship one of these to each owner. With an explanation it makes his amps safer. Plus a sticker to put on the back saying only use with GFCI protected outlets.

 

[Greg P]

I think how often something might occur is quite relevant-- do I have a greater chance of being struck by lightning or winning the lottery than getting shocked by this amplifier or is it just a matter of time?

One reason very, very few people are struck by lightning is because when it occurs, most people take shelter. For instance, I won't go out fishing in my boat if thunderstorms are in the forecast. Same thing holds true for electronic gear: there are safety standards that are followed in most cases, present amp under discussion excepted.

 

[Xulonn]

Unimpressive

¡Tu tambien!

 

[Rottmannash]

He's lying, or someone is generating these posts in his name. I am really saddened to see this.

I too wondered if it was truly him posting...

 

[Blumlein 88]

One reason very, very few people are struck by lightning is because when it occurs, most people take shelter. For instance, I won't go out fishing in my boat if thunderstorms are in the forecast. Same thing holds true for electronic gear: there are safety standards that are followed in most cases, present amp under discussion excepted.

The Sad Story Of The Man Struck By Lightning 7 Times - Grunge

It's a distinction likely no one would want. Both terrible and fascinating, Roy Cleveland Sullivan holds the world record for "Most lightning strikes survived."

www.grunge.com

Man struck by lightning 7 times in his life, and survives all of them.

I was surprised in the article (don't know the source) that over an 80 year life the odds are 1 in 15,300 of being struck by lightning. That is more than I would have guessed.

Closest I've come is working on a very slightly elevated structure as a storm (which turned out to have a tornado overhead my location) rolled in. A co worker with long hair said "woah look at me". All of his hair was standing on end. I said we have to get the hell off of here. We just got the ground next to this structure when it was hit with a huge lightning bolt.

 

[Chazz6]

Hello, Bob here. Here are my replies to your questions. ...

3. Are the Edcor 15w OPTs part of the design? Yes. They work quite well driving loudspeakers. In combination with back EMF feedback, and our DC restorer tracking bias supply, the ability of a tube amp to increase voltage with increases in impedance at low frequencies is inherent in my design. Together, these make music as a system.

The sentence "In combination with..." is beyond my technical understanding but it arouses my carnival-talk sensor.

In any event, the reply does not address the fact that with a 15W output transformer, the vendor claims this is a 75W amplifier. Either don't publish a power rating and say why (like Frank Van Alstine sometimes, an independent designer-seller for whom I have great respect), or publish a true, standard RMS at 1 kHz power rating and explain how the amp can supposedly drive power-hungry speakers.

 

[thunderchicken]

What you have to think about is how many products are made. even if the chances are one in 10,000 against. That means for every 10,000 products shipped, one becomes dangerous to touch, and someone can be killed by it.

And it doesn't matter if there are only ever 1000 of these particular amps made. The regulations apply to ALL products so that none of them become unsafe through easily mitigated faults.

Put simply - if one of these amps ever kills someone by failing to be compliant with known best practise, there is a good chance of someone going to prison.

EDITED TO ADD
Prior to retirement I was required to attend a number of product electrical safety awareness trainings. In the USA as I understand it, even where UL standards are not legally mandated, it doesn't matter. If you kill someone with your product, you will be required to show that your product met "state of the art" requirements. In other words if it is generally accepted that you protect people by earthing metal enclosures, or by providing effective double insulation, and this is what most manufacturers do (so state of the art) - then you are going to be in serious trouble if you don't.

Probably not prison, but definitely exposing yourself to a product liability claim. It would bankrupt a producer, but not jail anyone.

 

[Larry B. Larabee]

If the grounding scheme is as poorly engineered as the rest of this disaster, the safety ground might have been omitted because of hum.

Grounding the chassis costs nothing.
Certainly the ground is omitted to eliminate hum and nuisance service enquiries from the customers.

I've said it before, maybe he needs to ship one of these to each owner. With an explanation it makes his amps safer. Plus a sticker to put on the back saying only use with GFCI protected outlets.

I don't think gfci outlets are activated if you touch an energized component and you aren't grounded.

I too wondered if it was truly him posting...

ASR pretty much confirmed it is BC.

There's always the chance that the 275 will try to amplify that 60hz ac signal on the chassis and we know how well it is capable of doing that, so there's your primary fuse blows under fault condition protection mechanism. Problem solved.

 

[mhardy6647]

If the grounding scheme is as poorly engineered as the rest of this disaster, the safety ground might have been omitted because of hum.

I suspect this is a very real, perhaps even likely, scenario.
It's been in the back of my mind since the original admonitions regarding how to properly test the amplifier, way back when (feels like a lifetime ago).

 

[atmasphere]

Grounding the chassis costs nothing.
Certainly the ground is omitted to eliminate hum and nuisance service enquiries from the customers.

Had the amps been wired correctly thet would have a better noise floor, ground loop immunity and electrical safety all at once. But its not the first time I've seen legacy circuits show up in new equipment; pardon me for saying this but IMO there is far too little proper engineering practiced in high end audio today.

 

[solderdude]

I don't think gfci outlets are activated if you touch an energized component and you aren't grounded.

A GFCI already activate when there is an unbalance of around 5mA between L and N. Note that there is always a small imbalance (due to leakage) anyway so they can trip sooner or later but guaranteed at 30mA (for household).
When the current is lower than that you just get a firm jolt and how annoying and dangerous that is depends on the path the current takes through a human body.
Normally, when someone is touching the L wire currents may well be higher than 5mA. A 22k resistance at 110V is already enough.
For industrial purposes the trip current can be 100mA

 

[Blumlein 88]

I don't think gfci outlets are activated if you touch an energized component and you aren't grounded.

True, but then you are in no danger. GFCI outlets interrupt the circuit if there is a 5 milliamp imbalance between ingoing and outgoing current. So if you touched it ungrounded then nothing happens. Without a path for current to flow you aren't electrocuted. If you create a path of greater than 5 milliamps then the GFCI trips and it saves you. It provides protection from electrocution just as the 3rd pin safety ground does. It does it via a different mechanism.

Now I'm not championing an unsafe design, but if anyone has this Carver Crimson or if they have old tube gear that only had two wires, using a GFCI outlet can provide them with much more safety than they currently have.

Also these work if you live in an older home that only has two wire wiring systems. So they provide you with much of the safety from electrocution that a 3rd pin ground would. I think few people are aware of this.

 

[antcollinet]

Probably not prison, but definitely exposing yourself to a product liability claim. It would bankrupt a producer, but not jail anyone.

Individuals (including individual engineers - though this is unlikely) can be found to be criminally negligent and face jail time. At least they can in EU. Not sure about USA, but product liability jeopardies tend to be higher over there.

 

[SIY]

But its not the first time I've seen legacy circuits show up in new equipment; pardon me for saying this but IMO there is far too little proper engineering practiced in high end audio today.

"Oh, boy, another Mullard 5-20!"

 

[Laserjock]

If this were properly grounded and called the Carver Crimson 215 would it make my Revel M106 sound as good as the Wilson Tune-Tots?

 

[MakeMineVinyl]

We really should ship thousands of these unsafe amplifiers to Ukraine so that they can be thrown at invading forces to shock them into retreat - probably more lethal than many other munitions, and probably cheaper too. An added bonus is that the 15w transformers make them light enough to chuck over long distances, making them far superior and more practical than a vintage McIntosh MC275 would be for this use.

 

[Greg P]

The Sad Story Of The Man Struck By Lightning 7 Times - Grunge

It's a distinction likely no one would want. Both terrible and fascinating, Roy Cleveland Sullivan holds the world record for "Most lightning strikes survived."

www.grunge.com

Man struck by lightning 7 times in his life, and survives all of them.

I was surprised in the article (don't know the source) that over an 80 year life the odds are 1 in 15,300 of being struck by lightning. That is more than I would have guessed.

Same here.