Bob Carver reply on the Crimson 275 measurements. Questions?

[Ar9Jim 6,056]

Hello,

 We made Bob aware of the controversy, from what will prove to be faulty measurement technics for the 275 on some forums by an individual. WRF (Wayne) having built and tested one of the amps in the original post has been great trying to educate. 

 

Bob gave me this letter as a response to post. I'll post it here and then ask Bob to answer any questions The Carver Site members may have first. We can/will repost the answers to your questions to the other sites.  Not to sound bitter (because Bobs not) but I don't wish to draw clicks to their site. Better to draw attention here. 

 

Bob is busy designing a cool new amp called the 2180. 2x180 watts with 2-KT120 per channel. In most tube amps, the grid voltage is 1/2 the plate voltage. Bob has been working with a different voltage ratio between plate and grid with hand wound transformers. The prototype hand wound transformer made 200 watts driving one channel . The prototype factory production transformer should be ready for Bob and his assistant to test in 2 weeks.. 

 

I'll gather the questions on Mondays and give them to Bob for a reply.. Here's the note from Bob and his reply to a couple popular questions I had ask.

 

                                                                                          Crimson/Raven 275

 

The current 275 is the best amplifier that I’ve ever designed.  It is extremely powerful and it has a smooth and sweet musical voice.  I have been building and designing amplifiers for approximately 50 years in my lifetime and in those 50 years I’ve been attacked and I’ve been vilified for my designs. My designs have also won many accolades and many awards and I’m very happy about that.

 

Designing amplifiers has been my life’s passion and I cannot imagine doing anything that’s more fun or intellectually challenging or more rewarding.

This amplifier has enormous power, an enormously wide frequency response and the best sound that I’ve ever been able to produce in my almost 30 years of amplifier design and building.

 

I can remember walking on the pathways at the University of Washington with Tim De Paravicini and we had  beautiful, beautiful talks about amplifiers, loudspeakers but mostly about amplifiers. Amplifiers were our passion.

 

My amplifier knowledge today, when I compare it to my early knowledge, I find that my early knowledge was as scarce and meager kind. But no longer. This new amplifier design is my very best work. I have given it a voice that is large and a voice that has detailed imaging within the larger voice and it’s what I’ve always strived for.

For now this is Bob Carver signing off. Thank you

I invite any and all questions. So if anybody has a question or several questions, please just ask and I will answer.

 

 

 

QUESTION: Bob, how can a 75 watt tube amp use such small output transformers and be lightweight ?

 

ANSWER: I've always designed amplifiers that had lots of power and lighter weight than others designs. The transformer size can be made smaller by using fine wire and specified materials. There is no magic, because it adds inefficiencies in other ways like power, but the design has more than enough power. 

 

 

QUESTION: Bob,  A guy is claiming a 275 makes 17 watts with strange distortion numbers any thoughts?

 

ANSWER: Thats ridiculous, a 75 watt amp.. Isn't it obvious? It is being test wrong or its damaged.. My amps can be difficult to test, difficult to get the grounding correct. I've been dealing with people testing my designs wrong and getting grounding errors effecting measurements, most of my life. 

 

 

 

QUESTION: Bob is it fair to say that you design amplifiers for reproducing music into dynamic loudspeaker loads, more so than focusing on reproducing sine waves into load resistors?

 

ANSWER: There is some truth to that. My amps can perform way above there power rating for a time, a time being several seconds. 

 

 

MORE QUESTIONS, ASK HERE..   The Carver Site is the place for answers. Have fun. Enjoy!   Sincerely,  Jim Clark.

 

 

 

 

 

 

 

 

Edited January 7, 2022 by Ar9Jim

[Nahash5150 10,011]

Bob has an account here. Just FYI. He may need to be reminded!

[Ar9Jim 6,056]

9 hours ago, Nahash5150 said:

Bob has an account here. Just FYI. He may need to be reminded!

He knows, Greg.  Bob is focusing on designing new products and little else right now. He seldom looks at emails or phone calls. If he answered emails and phone calls, that would take all his time away from doing what he loves.  Personally, I spend little time on forums. A cup of coffee in the morning and thats about it.  

 

Bob sent me his reply in a voice mail and asked me to transcribe it and post it.  So that is why I'm here relaying his message. Whatever I can do to help him from being distracted, so he can stay in his creative mindset, enjoying his days, I will do at his request. Humbly, its an honor, but not one that I enjoy.

 

 Thanks for letting me post the reply here. Your site is largest of the Carver themed site so maybe the controversy can bring in more members and clicks. 

Most times, these "bad" moments have good hiding in them.  

Edited January 8, 2022 by Ar9Jim

[Nahash5150 10,011]

3 hours ago, Ar9Jim said:

He knows, Greg.  Bob is focusing on designing new products and little else right now. He seldom looks at emails or phone calls. If he answered emails and phone calls, that would take all his time away from doing what he loves.  Personally, I spend little time on forums. A cup of coffee in the morning and thats about it.  

 

Bob sent me his reply in a voice mail and asked me to transcribe it and post it.  So that is why I'm here relaying his message. Whatever I can do to help him from being distracted, so he can stay in his creative mindset, enjoying his days, I will do at his request. Humbly, its an honor, but not one that I enjoy.

 

 Thanks for letting me post the reply here. Your site is largest of the Carver themed site so maybe the controversy can bring in more members and clicks. 

Most times, these "bad" moments have good hiding in them.  

 

It was a joke Jim.

[SteveFord 1,060]

On page 2 of the Owner's Manual it says not to defeat the purpose of the grounding plug and to connect the amplifier only to an outlet with a protective grounding socket.

This is not hooked up on either the CarverFest or production 275s, the third prong has nothing attached to it.

Are you planning on providing a safety upgrade to actually put this grounding plug into operation?

 

 

[Ar9Jim 6,056]

Reply from Bob after testing for shock hazards as described on some forums.

 

"We know that the 275 is perfectly safe the way it is currently wired. If you want it grounded another way, send it in and we can rewire it so the earth ground connects directly to the chassis,  We will pay shipping both ways. We stand behind the product and its quality."

 

Edited January 20, 2022 by Ar9Jim

[Yamacarver 664]

I just read somewhere that earthing more than one piece of equipment can cause the ground loop hum and this holds true on my system with the addition of the three pronged pro amp.

[Nahash5150 10,011]

This EG topic was very heated when we were building the kits.

 

Some people insisted that the EG be connected, even after Bob told them not to.

 

Earth Ground is NOT always safe. Furthermore, almost all audio equipment is NOT Earth Grounded.

[wrf 3,829]

Much ado over nothing.  Below is a view into the IEC socket of a Sunfire Symphonic Reference amp.  Note the missing ground pin.  Fuse has since been repaired, right @PMAT

 

[Brian_at_HHH 2,609]

Thank you, Jim.

 

I think it was (certainly should have been) painfully obvious to anyone with enough neurons to form a synapse, that there was something fundamentally wrong with those tests.  Anyone who does testing of any sort on a professional basis knows that if your test results are entirely out of whack with observed reality, you need to re-examine how you are testing, and not blindly hold to results that don't make sense.

 

For one thing, nobody is going to produce a tube amp with 4xKT120's that only puts out 15-17 watts.  I'm not even sure you could design one, unless, perhaps, you leave most of the tubes unwired...

 

This, sadly, is another example of where common sense has largely been lost thanks to so-called internet "experts."

 

FWIW, I'm now the proud owner of a shiny pair of Crimson 275's, and plan to enjoy their ample, clean, wonderful sounding tube power for many years.

[Nahash5150 10,011]

But Steve is selling his now?

 

I'm walking away from this topic. This is blowing up my own neurons...

 

[itchitch 3,997]

2 minutes ago, Nahash5150 said:

I'm walking away from this topic

 

I really hope you don't....

 

[Nahash5150 10,011]

1 hour ago, itchitch said:

 

I really hope you don't....

 

 

I am. I'm tired of it. I have never seen so much babble about a single freaking amplifier ever. The controversy just keeps spinning right back to where we started! Over and over again.

 

@wrf knows as much about it as I do. He may still have the patience for it...but I suspect his won't last much longer either.

 

I still own two. I even used one of them to drive the 900W 4 ohm Tekton MOABS and it performed just fine. Sometimes I wonder just what the hell people are expecting from their amplifiers. It isn't a PA system - it's a little 55W per channel tube amp!

 

I'm not trying to be an ass but my patience has a limit. I talk to people all over the world about audio everyday. In most cases, people enjoy relatively standard set ups - a set of good speakers and a Carver amp or two with a couple of sources and a preamp.

 

But some people want their stuff to sound like a rock concert (which average about 150,000 watts of power). Or, they expect a 40 year old Carver to keep up with a modern class A amp that costs $30,000 (true story).

 

So I don't understand people and never will. But I do understand when I've had enough.

 

And I've had enough of the Carver275 'controversy'.

 

Also - EGing everything is just a CYA nowadays thanks to the rabid (and very unfair) liability with products.

[B-Man 4,763]

I'm not trying to be a dick here but I want to throw out two things about the Audio Science Review web site review of the Crimson 275:

 

1. Amir is a sound, knowledgeable guy who has tested untold numbers of amps, etc. He has the knowledge and equipment to test amps properly and is a Bob Carver fan in general.

 

2. The overall tone of the site and the review of the 275 is that it does not meet the specs that are printed in the documentation. That is the main beef they are talking about.

 

If there is an issue with his testing method it should be addressed. If not then it really looks bad for the Crimson 275 when judged by the published specs. I personally like how both of mine sound but the focus of the review is that the claimed output power is 75 watts into 4 or 8 ohms - and that appears to be a great stretch when reviewing the results of his testing efforts. The amp he tested blew the power fuse well before achieving anywhere close to the claimed power levels. The other area that is causing criticism are the tiny output transformers - they saw the 15 watt labels and immediately jumped to their own conclusions. To be fair to them all of the tube amps they have tested over the years that do produce 75 watts per channel are much heavier because of the large power and output transformers. For example, the McIntosh MC275 delivers 75 WPC, into 4, 8 or 16 ohms, 20-20KHZ, 0.5% THD max, 105db S/N ratio. It weighs 67 lbs. In comparison the Crimson 275 weighs 19 lbs.

 

You can read Amir's testing and evaluation here: https://www.audiosciencereview.com/forum/index.php?threads/carver-crimson-275-review-tube-amp.29971/  Unfortunately the unit he received had a loose screw floating about inside the chassis. That could have presented itself as an issue if he had not found it during his inspection of the amp.

 

I would be interested in seeing what the actual power and distortion measurements are when tested "properly" while using the full 20-20KHZ audio bandwidth, presented like the McIntosh specs I mentioned earlier.

[avguytx 226]

I've read in some other forums where people are putting in to return theirs.  I am not a technician and cannot make claim to Amirs tests but, in looking the broad range of tested amps, and to see where this one falls, something is up.   Can anyone else properly test one of these amplifiers or is that documented somewhere from an outside source?   Was there something wrong with the one sent to him?  I fully realize that we don't hear based on "specs" but somewhere the validity of that testing needs to be addressed.  And that test coming from someone who is a Carver fan from way back.

 

I think the world of Bob and have know him since the late 80's and was a Sunfire Rep with the company I was with (from 2001 till 2009) till they went under in 2009.  We had various events in the territory called "A Night With Bob Carver" which were heavily attended.  Not to mention I have a picture of him with my signed M-1.0t and also a DTL-200 that he graciously looked over years ago and helped to get working.  He was always a pleasure to spend time talking with.

[Ar9Jim 6,056]

On 1/18/2022 at 9:33 PM, Ar9Jim said:

Reply from Bob after testing for shock hazards as described on some forums.

 

"We know that the 275 is perfectly safe the way it is currently wired. If you want it grounded another way, send it in and we can rewire it so the earth ground connects directly to the chassis,  We will pay shipping both ways. We stand behind the product and its quality."

 

Just an update to the statement..  It is interesting how many new units from other brands I have noticed here with 2 prong cords.. Brand new, metal cases..  There must be a world wide audio conspiracy going on here.. OMG... ASR is gonna save the freaking world...   The world is eternally in their debt..   Also I heard a press release is coming today. If it goes to dealers first, I'll post it here first.

Edited January 20, 2022 by Ar9Jim

[B-Man 4,763]

Yeah, those idiots obviously don't understand grounding and why and where it is applied. I shake my head at stuff like that - have they looked at the two prong power cords on 99% of consumer electronics sold in the US?

 

Unreal...

 

EDIT - After making more time to read the thread they are also bringing up the true "safety" grounding aspect. As in if there is a wire break, a switch failure, etc. how the lack of insulation inside or the lack of a chassis ground can create a dangerous situation for the end user. From a CE or UL perspective this can be a liability issue. I am curious to see how it is addressed, if it is at all.

[Nahash5150 10,011]

Okay so I can't walk away for good...

 

QUESTION:

 

Am I at risk for working on electronic equipment? I am required to open up high voltage appliances, and in many cases, test them before I know what is wrong with them. Does this impose significant risk to my life?

[Ar9Jim 6,056]

1 hour ago, Nahash5150 said:

Okay so I can't walk away for good...

 

QUESTION:

 

Am I at risk for working on electronic equipment? I am required to open up high voltage appliances, and in many cases, test them before I know what is wrong with them. Does this impose significant risk to my life?

Very little risk at all. You are expert in your field and know how the system functions.  Lack of knowledge is dangerous. 

[Ar9Jim 6,056]

Bob made a comment that I thought summed the situation well.

 

” I have built conventional designs of amplifiers, that test great by conventional test standards, and have avoided  controversy with those, but to be honest, those designs are kind of boring.” Bob Carver.

 

[B-Man 4,763]

1 hour ago, Nahash5150 said:

Okay so I can't walk away for good...

 

QUESTION:

 

Am I at risk for working on electronic equipment? I am required to open up high voltage appliances, and in many cases, test them before I know what is wrong with them. Does this impose significant risk to my life?

 

I'm glad you are still here. 

 

Technically, yes - you are at some level of risk. Who among us hasn't been "bit" at least once by our friend the electron? Is it likely you will be seriously injured with your knowledge and experience? No.

 

They are talking about it from a mechanical failure inside the amp perspective. I'm not defending their stance, other than to say that if someone bought one and it had a floating screw inside (ironically that is what happened with the retail unit they purchased to test) that has the hot side shorted to the chassis it could end up being a bad scenario for the end user. Not likely fatal but a definite issue nonetheless. A lawyer's paradise for sure...

[Nahash5150 10,011]

44 minutes ago, Ar9Jim said:

Very little risk at all. You are expert in your field and know how the system functions.  Lack of knowledge is dangerous. 

 

But I'm still at risk. I have been shocked before, and accidents can still happen. Even worse, I've had damaged units catch fire and blow up large cap capacitors. Expert or not - electronics in general are hazardous.

 

My point is, you can't make anything 'safe'. There's always a way to make anything dangerous. If regulators, such as OSHA, ever wanted to shut down companies they could easily do it. That is why there is a reliance on a) the written law, and b) rules and regulations. There is such a thing as acceptable risk, because there is always risk.

 

What it really comes down to is liability. Ultimately, the manufacturer is always liable, no matter what regulation or standard they follow. According to the law, it doesn't matter if an amplifier is UL or CE or compliant in every way to the written law and regulations. If someone is injured or killed using your product, you will be responsible - period.

 

Personal liability is one matter, but business liability is quite another.

 

A business's only real recourse is to have good insurance. Following regulations won't save you, it just decreases your chances of being brought to court by mitigating the chances of an accident ever happening.

 

You cannot call anything that uses line power 'safe'. You cannot legally claim that because line power is by default hazardous usage.

 

So the 'safety' discussion is just a loop without any end.

 

 

[Nahash5150 10,011]

7 minutes ago, B-Man said:

 

I'm glad you are still here. 

 

Technically, yes - you are at some level of risk. Who among us hasn't been "bit" at least once by our friend the electron? Is it likely you will be seriously injured with your knowledge and experience? No.

 

They are talking about it from a mechanical failure inside the amp perspective. I'm not defending their stance, other than to say that if someone bought one and it had a floating screw inside (ironically that is what happened with the retail unit they purchased to test) that has the hot side shorted to the chassis it could end up being a bad scenario for the end user. Not likely fatal but a definite issue nonetheless. A lawyer's paradise for sure...

 

Okay fine. Then if the chassis is grounded and you touch a faulty power cord and get exposed to the hot with one hand, and you're grounded with the other hand, you could get fucked.

 

EG is not automatic safety. In many ways it is far more dangerous.

[B-Man 4,763]

I agree with your EG thought process but unfortunately UL, CE and others disagree - and I bet the legal review of any issues would fall back to looking at those agency listings, electrical codes, etc. I'm not arguing for their thought process - I'm more interested in what Bob Carver Corporation is going to do, if anything, about the situation. I saw a note that said Bob agreed to pay shipping both ways to have anyone's amp re-wired to utilize a chassis ground at no charge but there isn't any mention of this on the Crimson 275 web page.

[SteveFord 1,060]

The issue is there's a 3 prong receptacle on the amplifier and it specifically states in the owner's manual not to use a cheater plug, make sure to plug it into a 3 prong outlet for safety reasons. 

A kit amp for enthusiasts is one thing, a production model is a different animal.

That's what the ruckus is about.