Bob Carver reply on the Crimson 275 measurements. Questions?

[Balok 1,408]

26 minutes ago, SteveFord said:

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.

 

 

 

 

 

 

And if the Crimson 275 had been built with a TWO prong IEC, would they still be complaining that it doesn't have a chassis ground?  

[4krow 5,077]

This may seem off topic but it points directly at safety issues. I'll get right to it>> In so many cases, I can think safety actually being the fault to begin with. Working outside, 'they' wanted us to wear safety goggles. You know, the ones that steamed up immediately, no matter the outside temp? Then there were the 3 layers of gloves for high voltage work. 1) cotton 2) rubber gloves over that 3) leather gloves over that! Go ahead, try to use your hands in a meaningful way to work now. The old high voltage testers. The gunsight method was preferred so that you might see the test light pop just as you touched the work being tested. ALL of these were inherently dangerous! BUT they satisfied the experts.

  That 3rd wire may or may NOT be needed for the application. >>>>>>>>>>>>>> "Ground is ground the world around" One of the biggest lies told to us.

[Balok 1,408]

Something else that they brought up at ASR was the fact that the Neutral side was fused rather than the live side.

 

Interestingly, I noticed this;

 

 

 

This is the reviewed unit from the ASR website.  Notice that the earth pin in the picture is at the bottom.

If you go to the Bob Carver website and look at the picture of the Crimson 275 back panel, you will see that the IEC orientation is opposite, with the earth pin at the top!    https://www.bobcarvercorp.com/copy-of-crimson-raven

 

This orientation may affect how the wires are soldered to the fuse and switch.  One would have to open up the units to confirm how it is soldered.  Maybe some units have the live fused and some may have the neutral fused.

 

EDIT:  the unit on the bob carver website is probably actually a picture drawing and not an actual unit so maybe some folks who actually have a unit could say which way the IEC is installed.

Edited January 21, 2022 by Balok

[Yamacarver 664]

1 hour ago, SteveFord said:

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. 

No doubt this type of boilerplate was just copy pasta from another owner's manual. It's very common to find errors in owner's manuals.  After a few too many complaints I was rewarded with the final proofread of all the manuals at a company I worked for.

As long as the amplifier doesn't fall in the bathtub (without a GFCI) I'm sure they are fine.

The last time I checked there still hadn't been a safety notice/recall on the pinto or mustang fuel tank debacle. I'll be damned if I ever trust that company. Lucky dear old dad wasn't taken out by that thick film ignition module in his T-Bird.

 

Edited January 21, 2022 by Yamacarver
Added parenthetical remark.

[SteveFord 1,060]

There's no rhyme or reason as to how they mount those outlets: prong on bottom, prong on top, I've got at least two pieces that have them sideways.

If you're only going to use two prongs quit being so cheap and stick on a two prong connector or just hard wire it in there and then you can complain about no detachable power cord.

Frank Van Alstine was funny, he said he finally put in a detachable power cord socket so you can buy your own fancy one and it can fall right out!

[iamjohngalt 2,064]

On 1/19/2022 at 1:02 PM, B-Man said:

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.

Thanks for posting that link.  I have read Amir's reviews for some other audio gear and they have been reliably accurate for the reviews I have read.

One thing that I have concluded from the methods Amir uses (and the results of the tests) is that there is a lot of discussion about how much difference there is between the results of the tests. 

There is very little mention that the audible difference is negligible (or nil for many people) between a SINAD (at 5 watts 4 ohms) of 113 (best of all gear tested) and SINAD of 78 which the site calls "FAIR."

While accurate, this difference should not have much relevance when an audio enthusiast is comparing gear and making a purchasing decision.  

The test result is as misleading as the specs claimed by many manufacturers trying to make sales to people who have little or no opportunity to hear the gear and make a relevant comparison.

Getting relevant data on audio gear is nearly as difficult as knowing who was responsible for killing JFK.

This Carver site is a notable exception and the administrators and contributors here have my gratitude.

[Balok 1,408]

27 minutes ago, SteveFord said:

There's no rhyme or reason as to how they mount those outlets: prong on bottom, prong on top, I've got at least two pieces that have them sideways.

If you're only going to use two prongs quit being so cheap and stick on a two prong connector or just hard wire it in there and then you can complain about no detachable power cord.

Frank Van Alstine was funny, he said he finally put in a detachable power cord socket so you can buy your own fancy one and it can fall right out!

 

My point was that depending on how the IEC is orientated, it could change how a person wired up the live and neutral.  ie, if you said "pin closest to the fuse is live" and you did 99 that way and then some flunky installed the IEC upside down you may wire the neutral to the fuse without thinking.

I did a quick search for pics on the web and they all look to have the earth pin at the bottom so my observation is probably crackpot anyway.  

I agree that if there is no earth connection, one would probably source two pin connectors for factory product.

 

Lunchtime!

[itchitch 3,997]

I too appreciate (usually) the attempt at moderation here on CS.

Group think and personal attacks have been commonplace on the thread.

Replying with a measured response/question has been interpreted as passive aggressive, egotistical and defensive.

 

Stating that the amp 'sounds good to me' is consistently met with attacks that one is refuting their measurements.

They believe that statement is mutually exclusive.

 

The thread moved from not performing to specifications to lethal.

The "experts"  state "laws" and "standards" with links to IEC etc.

Pretty comical. 

 

"Theoretical" accusations of danger, death and dismemberment run rampant.

 

It would be amazing for someone to make a deal with all of the smart people....

(who have been "building tube amps for 20 years", "owned some tech biz for 30 years", "I'm a lawyer")

Buy an amp.... test your hypothesis. If the chassis is deadly - you will be reimbursed.

I am sure the amp would be damaged but...

If not - retract what you have alleged.

 

There are no aptitude nor personal stability requirements to participate in forums... 

I find short replies to be very revealing and extremely humorous.  "You suck" " What a pos" 

 

P.S.  A "Sherlock Holmes" will make the association - congratulations, you know how to use a search engine  😇

 

 

 

[mbskeam 1,728]

I have been wondering if Bottlehead is this guy....

https://bottlehead.com/

sure seems like he had an agenda, 1st posts were, "look at what I found".

 

PS: I  haven't comment on the "other" sites as I don't want to feed the Trolls

don't feed the trolls....LOL

[oldtexasdog 2,366]

Just a thought, but if I wanted to buy a real nice power cord it seems all the ones I find are made to fit a 3 prong IEC socket. It would be a bummer to find I had a non standard plug at the back of my amp and lets say I am a non DIY person so I would have to pay a crazy amount to have one built? That is of course if I believed the test data that an upgraded power cord would make enough difference in the sound to justify the cost🤑

[Ar9Jim 6,060]

3 hours ago, mbskeam said:

I have been wondering if Bottlehead is this guy....

https://bottlehead.com/

sure seems like he had an agenda, 1st posts were, "look at what I found".

 

PS: I  haven't comment on the "other" sites as I don't want to feed the Trolls

don't feed the trolls....LOL

Yes it is.. I find it curious that the OP has a tube amp business.. I also find it interesting that he has all the time in the world to talk about Bob.. Nothing better to do? Amps to build?

[Ar9Jim 6,060]

The official and only statement from Bob on the ASR forum. He posted this on the site.

 

It has come to my attention that my amplifier design has come under sharp criticism on this forum. I am compelled to say that the 275 is safe as it is wired and assembled, and performs as it was designed. If a customer were to chose to utilize the earth ground pin of the IEC plug (to be connected to the chassis), this can be done at no cost. This design was well considered, and follows a long history of excellent products.

 

The 275 is a powerful, easy to listen to amplifier. I am happy with its design. In fact, this is one of the best designs I have produced. If for any reason a customer is disappointed in the performance or sound quality of this amplifier, they may return it for a full refund. The general reception of the 275 to date has been that of a high quality design, one that does not disappoint in any respect. The performance as it was measured by Amir does not do justice to the sound engineering practices that the 275 represents.

 

I am not going to explain or attempt to refute the reasoning behind each criticism that has been made, the product speaks for itself and stands on its history of satisfaction. This amplifier was not designed to measure the best, it was designed to sound the best, and to do so at an affordable price in relation to products it might be fairly compared to. It is unfortunate for this type of bad press to make such an impression on people not directly familiar with the amplifier.

 

In conclusion, such criticism would be much harder to support in the presence of a 275 playing music. It would be all but impossible to argue that it’s deficient in any way when you experience the actual musical performance. I stand by that. The character of this amplifier is exactly what I wanted it to sound like. For any customer with a 275 wanting to change the grounding or get a refund, email info@bobcarvercorp.com and we can fulfill your needs.

Edited January 22, 2022 by Ar9Jim

[itchitch 3,997]

So damn impressive!

[AndrewJohn 8,184]

I believe Karma is a real thing.

 

Opportunities for Karma, in abundance. 😉 

 

Edited January 22, 2022 by AndrewJohn

[Nahash5150 10,011]

It's not a safety issue. It seems whenever people want to leverage their argument, they bring up safety as a means to diffuse opposition (like uhm, the authoritarian coronavirus policies).

 

So all this is about is a 3 prong socket used as a two prong. I'll give them that. It implies it is Earth Grounded, which could be a selling point? I don't know.

 

It's a meaningless concern, in the context of safety. It's really about presentation. But that can be fixed, so time to move on.

 

I wonder, do these safety nazis get their gear inspected every year for a safety compliance? They should, if they really cared about it. Safety regulations change all the time.

 

[AndrewJohn 8,184]

2 hours ago, Nahash5150 said:

I wonder, do these safety nazis get their gear inspected every year for a safety compliance? They should, if they really cared about it. Safety regulations change all the time.

 

And, do they retrofit the products they designed, produced, shipped (or "tube amp kits" they sold !) to users in past years under previous interpretations of the regulations..., with FREE upgrades and fixes, or offer money-back to users that want/expect regulatory compliant products in perpetuity - forever in the future?

 

 

Edited January 22, 2022 by AndrewJohn

[Nahash5150 10,011]

We can do product  'reviews' and 'measurements' here too.

 

Hell, we can even benchmark their specifications.

[Brian_at_HHH 2,609]

2 hours ago, Nahash5150 said:

We can do product  'reviews' and 'measurements' here too.

 

Hell, we can even benchmark their specifications.

 

But do we typically need to ... or are we smart enough to reserve that for where true, well thought out mods are being made by competent people checking their own work?

[Yamacarver 664]

22 hours ago, itchitch said:

The thread moved from not performing to specifications to lethal

This reminds me of an old childhood story back when they had real lessons behind them LOL.

https://www.worldoftales.com/European_folktales/English_folktale_96.html#gsc.tab=0

He talks about that loose screw as if they all come with one?

Smh

[Nahash5150 10,011]

55 minutes ago, Brian_at_HHH said:

 

But do we typically need to ... or are we smart enough to reserve that for where true, well thought out mods are being made by competent people checking their own work?

 

Honestly, this forum is not built on shitting on people or products.

 

Of course we're allowed our opinions, and sometimes we have complaints, but I think what defines us is that we are fans of audio and promote good experiences.

 

I'm with AJ. Karma is real. It's one of the reasons we don't piss on people here just for the fun of it.

[AndrewJohn 8,184]

On 1/22/2022 at 2:16 PM, Yamacarver said:

This reminds me of an old childhood story back when they had real lessons behind them LOL.

https://www.worldoftales.com/European_folktales/English_folktale_96.html#gsc.tab=0

He talks about that loose screw as if they all come with one?

Smh

 

Finally made time to read this story..., I remember it. Thank you, @Yamacarver. What a great story, and analogy..., thanks for the memory!  It's well worth the read.

 

Anyone living in a house with early "knob and tube" wiring, and there are a LOT of these, (and well, frankly in some areas of the third world or remote locations, this wiring method still exists!)... those dwellers are all doomed, if one believes the "If" statements... of the back-patting "do-gooders" and self-appointed expert arbiters in "mutual admiration societies "... 

 

I thank my parents for teaching me common sense and the Mark Twain / Abe Lincoln lesson so apropos today with the internet:  "Better to remain silent and be thought a fool, than to speak and remove all doubt."

 

(I'm not referring to anyone here on C!, just in case that's not clear.)

Edited January 24, 2022 by AndrewJohn

[Pops Backflow 21]

On 1/22/2022 at 8:38 AM, Nahash5150 said:

We can do product  'reviews' and 'measurements' here too.

 

Hell, we can even benchmark their specifications.

Why not and put this to bed. 

[Nahash5150 10,011]

2 minutes ago, Pops Backflow said:

Why not and put this to bed. 

 

I already did 3 years ago.

 

But that was on the Carverfest kit amps - not a production model. And I don't have a production model, so it's kinda moot now.

[Bigerik 2]

3 minutes ago, Nahash5150 said:

 

I already did 3 years ago.

 

But that was on the Carverfest kit amps - not a production model. And I don't have a production model, so it's kinda moot now.

Are those measurements posted here anywhere?

[Nahash5150 10,011]

6 minutes ago, Bigerik said:

Are those measurements posted here anywhere?

 

Yes. Here is what I posted:

 

 

With KT120's

 

 Bias set at 100mA...         

        
                      

        
            Output Power both channels into 8 ohms: ~60W rms, ~65W at clipping 

        
            THD at max power both channels driven: ~0.9%         

        
            Frequency response: 18Hz - 30kHz +/- 0.5dB         

        
            Single Channel driven into 8 ohms: ~95W         

        
            Mono into 8 ohms: ~130W at 0.5% THD         

        
            Dynamic power both channels driven: ~95W