Bob Carver reply on the Crimson 275 measurements. Questions?

[Bigerik 2]

8 minutes ago, Nahash5150 said:

 

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         

Thanks very much.  
 

[ZappaPatton 703]

On 1/21/2022 at 8:31 AM, B-Man said:

I agree with your EG thought process but unfortunately UL, CE and others disagree - 

Skil has made 15 amp, 120 volt metal cased UL certified circular saws for indoor/ outdoor use with no ground prong for decades.

 

There are countless metal cased non-earth grounded Underwriters Laboratories certified tools and appliances.

 

My apologies but I am confused at how Underwriters Laboratories disagrees with @Nahash5150?

 

 

 

[ZappaPatton 703]

On 1/21/2022 at 10:13 AM, SteveFord said:

There's no rhyme or reason as to how they mount those outlets: prong on bottom, prong on top

Prong on top came from industrial installations with metal receptacle covers.

 

Should the cover plate screw vibrate out causing the metal plate to fall and guillotine the prongs of an electrical cord, a prong down install would be catastrophic, whereas a prong up installation would be of no significance. 

 

In residential applications with decorative stainless, copper, bronze, ect. duplex receptacle covers the receptacles should be inverted to prong up orientation.

[B-Man 4,763]

14 hours ago, ZappaPatton said:

Skil has made 15 amp, 120 volt metal cased UL certified circular saws for indoor/ outdoor use with no ground prong for decades.

 

There are countless metal cased non-earth grounded Underwriters Laboratories certified tools and appliances.

 

My apologies but I am confused at how Underwriters Laboratories disagrees with @Nahash5150?

 

If you look into the requirements of construction you mention for those Skil tools you will see that the Crimson amp does not comply with that methodology. That is why they would not receive a UL certification in their current implementation.

[Yamacarver 664]

15 hours ago, ZappaPatton said:

Prong on top came from industrial installations with metal receptacle covers.

 

Should the cover plate screw vibrate out causing the metal plate to fall and guillotine the prongs of an electrical cord, a prong down install would be catastrophic, whereas a prong up installation would be of no significance. 

 

In residential applications with decorative stainless, copper, bronze, ect. duplex receptacle covers the receptacles should be inverted to prong up orientation.

That's an interesting tidbit, I was thinking of getting some brushed stainless outlet covers. The problem I have with an upside down outlet is  that molded plugs with a right angle point the wire up instead of down and may fall out easier.

 

I think what people here are referring to is the third pin on the IEC receptacle mounted on the amplifier. Apparently some are mounted up and some are mounted down and this would switch the polarity of the other two pins as presented to the person wiring the chassis. 

I've never seen one but from looking at the pictures I get the impression that a two prong IEC receptacle would be compatible with either a two or three conductor cord.

Whereas the reverse would not be possible. 

[Daddyjt 8,637]

I remember, in my youth, when my buying decisions were based on stats and specs. It’s sad when there are entire forums dedicated to stats and specs, and no mention of actual listening.  I don’t have a dog in this particular fight (I don’t even care for tube amps) - just pointing out that no one is talking about how the amp actually SOUNDS…

 

Oddly, my “awakening” to the less-than relevant nature of specs came in car audio, when I swapped a “200 watt” Jensen amplifier ($150) with the 45 watt Rockford Fosgate Punch 45 ($300). The difference was profound both in sound quality and power. It took quite a bit of convincing from a buddy of mine to shell out the $300 (not a small sum in the late ‘80s) for a measly 45 watt amp. And I’m sure Rockford would have sold many more of these amps (initially at least) if they had marketed them as “200 watt” - but as it played out, the lowly Punch 45 (and 75 & 150) became legendary. 

[ZappaPatton 703]

1 hour ago, Yamacarver said:

That's an interesting tidbit, I was thinking of getting some brushed stainless outlet covers. The problem I have with an upside down outlet is  that molded plugs with a right angle point the wire up instead of down and may fall out easier.

 

I think what people here are referring to is the third pin on the IEC receptacle mounted on the amplifier. Apparently some are mounted up and some are mounted down and this would switch the polarity of the other two pins as presented to the person wiring the chassis. 

I've never seen one but from looking at the pictures I get the impression that a two prong IEC receptacle would be compatible with either a two or three conductor cord.

Whereas the reverse would not be possible. 

 

1 hour ago, Yamacarver said:

That's an interesting tidbit, I was thinking of getting some brushed stainless outlet covers. The problem I have with an upside down outlet is  that molded plugs with a right angle point the wire up instead of down and may fall out easier.

 

I think what people here are referring to is the third pin on the IEC receptacle mounted on the amplifier. Apparently some are mounted up and some are mounted down and this would switch the polarity of the other two pins as presented to the person wiring the chassis. 

I've never seen one but from looking at the pictures I get the impression that a two prong IEC receptacle would be compatible with either a two or three conductor cord.

Whereas the reverse would not be possible. 

You are exactly right, that is what would happen with an IEC socket.

[Nahash5150 10,011]

UL certification is not a requirement.

 

Since Bob Carver Corp sells them through 'showrooms' and now recently, directly from the factory, UL cert is entirely optional.

 

Look - UL does a lot of good things, but it's also a shrewd business model. Not much different than NFPA for fire code. Both organizations are full of egg heads that look for ways to stay relevant in order to keep the testing and verification dollars coming in...

 

Neither entity has any legal authority to tell manufacturers what to do or consumers what to buy. They are simply a 'third party' that gives clout to the integrity of a product, and thus, makes the product much easier to sell in a competitive market.

 

It's local governments that determine the legality of manufacture and use. NFPA defers to the 'authority having jurisdiction' as the only, and final say in how a Fire System is installed. If the AHJ says 'follow NFPA 72 blah blah', then that is what you do. If the AHJ doesn't specify, then as a company you follow the NFPA guidelines to cover your ass (if anything happens, you can at least claim you followed the code, even though that code might not have been legally required).

 

Local governments could simply say the same thing about UL - 'all appliances must be UL listed to be used in this building'.

 

Now it's a legal issue. 

 

So, does your local government require some kind of certification for the appliances you use in your home? If not, then the UL requirements don't mean anything!

[Balok 1,407]

2 hours ago, Daddyjt said:

  I don’t have a dog in this particular fight (I don’t even care for tube amps) 

 

 

 

I reckon you best be gettin' a dog, Mark.   

 

 

 

[Yamacarver 664]

NicoCatBlackDeGailloAkaTheDarkness

5.0 out of 5 starsVerified Purchase

TWO PRONG FTW

Reviewed in the United States on May 27, 2021

these bois are tight. tight af. will blow away any 2 prong receptacle you currently have in your rental. BUY THEM NOW.

 

I was wondering when these were phased out but I guess they weren't LOL.

[Ar9Jim 6,056]

December 12 2023.

UPDATE:

 

After the closing of the company that owned license to Bob Carver's designs and products from 2019 to 2021, I asked Bob if he was willing to take one more swing at audio together, to combine our strengths and repair the damage to his legacy from the previous attempt.

 

In Feb 2022 Bob Carver LLC was founded as the IP holder and BC Audio was founded as the manufacturer. A start-up while facing headwinds from a typhoon of negative feedback related to the Crimson 275 has been tough to say the least. Seeing the legacy of a brilliant man who has given his life to improving our listening experience, tarnished by the previous attempt was gut wrenching for me personally. I know Bob Carver the man vs the unfair insinuations and allegations being made about his intent and design of the Crimson 275. Bob is all about customer satisfaction as the main reason for doing this work.

 

Bob offered refunds for 30 days at that time in 2022 and then extended it to 90 days. Bob also offered to change the chassis ground at no charge for those who wanted the change. We still offer that change at no charge if the customer sends it in. Bob profited nothing from the previous attempt but stood behind his name like the good man that he is.

 

What I've learned about the Crimson 275's produced from 2019 to 2021, after having many come in for the updates:

 

The grounding on the Crimson 275 is actually quiet safe. Similar to the audio components you own from the 1980s without safety grounded plugs (sometimes not even polarized) and metal chassis, or the millions of tube amplifiers made before the 3 prong plug was even invented. A full short potential was 6 volts at only mA of current  Not even a tingle.

 

Very few Crimson 275s had a polarity issue. Maybe one builder on one day. The vast majority had no issue, judging from the build dates on either side of the poor review specimen that have came in for ground changes.

 

The transformers used are the exact parts Bob specified for the 275. The 15w Edcor are a Carver design from over a decade earlier. The 275 is a type of performance to weight ratio experiment. Building a great sounding 75w @ 1K tube amp weighing less than 20lbs for less than $3K, being serviced and Made in the USA was the target. The previous license owner did not change the Bob Carver designated parts. The Black Magic 275 uses the same parts with a few manufacturing updates..

 

Specs gone wrong

 

As a dealer, I had no doubt about the power output of the Crimson 275 from experience. Customers had positive feedback comparing to others of 3 times the 275s power rating. 

 

If you notice, tube amplifier power ratings by most any company, you will generally find the power rating stated at 1Khz as standard practice, in comparison to solid state specs that generally state a 20Hz to 20Khz bandwidth quantifier in the spec..

 

The reasoning for this is the older tube amp designs being soft on bass. Still today, many tube amps tend to roll off in low frequencies, so they state power at 1Khz..  The Crimson 275 power spec should have been stated as 75w @ 1Khz like a tube amp, not 20Hz to 20Khz like a solid state. I suspect this was a salesman spec error but I was not involved and can't say for sure. 

 

The RAM 285 is one of few tube amps that can make it's full power to below 20Hz, so the power rating on the RAM 285 is not an error, but instead of 19lbs it weighs 56lbs.

 

Bye for now.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

Edited December 26, 2023 by Ar9Jim