Carver Crimson 275 Review (Tube Amp)

[LTig]

I just accidentally got this result. Source from REW via Topping 10B to Zen Tour. 48 khz recorded at 96 khz. Signal is 19 and 20 khz at - 60 db. 256 k fft.

View attachment 180546

This is the same signal with this result only using Audacity to generate and play the tone.
View attachment 180558

What are the settings for number of bits and dither in the REW generator?

 

[sarumbear]

Mr. Carver no longer is involved with any company that bears his name. Calling him a felon, when he bears no shame of conviction against his name, is in fact slander.

It would be best for you to stick with what you know personally from experience rather than try to impose your esteemed knowledge of how things work in the UK upon us here in the US. We may share the same language, but we are very different when it comes to how things get done.

Then Mr Carver can sue me. His name and photograph is next to his amplifier.

It is also none of your business!

 

[traderitch]

I made an observation based on what you had been posting. I then create a new sentence and called Mr Carver a felon.

What part of the above you imply is slander to you?

LOL !!!
I love the USA!

Section 4 of POA 1986

 

[amirm]

Let's move on folks...

 

[Blumlein 88]

What are the settings for number of bits and dither in the REW generator?

I moved it to the correct thread. 24 bits with dither.

Master Thread: Are measurements Everything or Nothing?

Why not buy those with your own money, like I do? Because I don't need them?

www.audiosciencereview.com

 

[Zackthedog]

A few things are bothering me about this whole affair. (which I've followed through from a post on another forum) -

1 - I have a few boxes around here with captive two-prong power cords and a couple with detachable cords with two prongs. I've also an earth cheater, which is an adapter that accepts three-pronged power cords and has only two on the output. I use the cheater/adaptor on a sub to remove a ground loop. Are these electronics boxes (DVD player, a receiver, and some other junk), UL/FTC compliant, whereas the Carver box isn't? If so, why?

2 - I've seen only one mention in this long thread of the name E.J. Sarmento (Wyred4Sound). Over a year ago, this was released to the industry press:

"Wyred 4 Sound Announces Exclusive Licensing Agreement with The Bob Carver Corporation and the formation of Glass Audio America, LLC EJ Sarmento – President and Founder of Wyred 4 Sound is pleased to announce the formation of Glass Audio America, LLC for the purposes of manufacturing a complete line of Vacuum Tube and other products under exclusive license from The Bob Carver Corporation. Frank Malitz CEO of the Bob Carver Corporation has been appointed Vice President / Director of Sales and Marketing (National and International) for the newly formed Glass Audio America, LLC. Production of these new products will be in Mr. Sarmento’s newly expanded facilities in Astacadero, California. Frank Malitz will continue his base of operations in Chicago, Illinois".
You can read the full PR here: https://www.monoandstereo.com/2020/01/glass-audio-america-licenses-bob-carver.html

At appears from the above that Mr. Sarmento has manufacturing control over Carver products, hence may have some input on the selection and suitability (or otherwise), of the OT; which seems to be at the forefront of this discussion. If they are manufactured by 'Glass Audio America', a company with ownership connection to the reputable W4S, then I would imagine that Mr. Sarmento would generally object to producing something in his factory that performed contrary to one or more of its key stated performance parameters. Has anyone reached out for comment?

3 - Lastly, are we all entirely comfortable that the test methods employed here are fair*, and that we have sufficient justification, based on the methods employed and the results posted, for what seems to be a public lynching of Carver and this particular product? For example, does the word 'sustained', used/not used, impact the final analysis of these tests significantly, such that its absence in the stated company data casts an entirely different complexion on the whole affair? I'm asking that question because I don't know the answer, but given the serious nature of some of the allegations, aspersions, and inferences, I hope that someone does.

*Fair - I think a lot rests on the interpretation of the word 'fair', in this particular context. Given the wide range of potential loads which might be encountered by any power amplifier, is the particular method used in these tests a fair way to assess the amp's ability to meet its stated power output specifications? Is there an acceptable industry standard for these types of tests, and would the owner/designer of other brands of amplifiers be comfortable having the same assessments made of their own product? I suspect the answer is yes, but I'm asking because I genuinely do not know.

Cheers

For comparison, here's a recent technical review from Stereophile. Baseline testing is typically done at 1 watt, then the amp is put through it's paces. Note the difference in performance between a fixed resistive load and a simulated speaker load. At the end, notice the real-world power measurements into a fixed load. This should give you an idea of how amps are typically measured for performance and what is expected in terms of accuracy of claimed performance.

When the Carver amp claims 75 wpc at 20Hz to 20kHz at less than 1% distortion, you'd rather expect it to at least come close. Of course it doesn't and it really wasn't designed to deliver those specs. That's the nut of the whole problem here.

Audio Research VT100 power amplifier Measurements

Sidebar 3: Measurements A full set of measurements of the Audio Research VT100 was made using its balanced inputs, with selected measurements repeated in the unbalanced mode, as noted below.

www.stereophile.com

 

[EchoChamber]

It's hard to know who to point the finger at. The schematic in the manual calls for the fuse and power switch to be on the same portion of the mains, which they are not in the build. There's also a 120/240 switch that's not present in the production units. The schematic has no mention of incoming earth, so maybe the three pin IEC power entry module was installed in error?

I suspect this amp follows an ancient design that didn’t account for grounding the (metal) chassis and was never updated. To avoid ground loops, the circuit ground could be set to float using a small value resistor or, better yet, using diodes of proper voltage and amp rating, with only the chassis connected to ground. That would provide safety and eliminate potential ground loops.

And of course, there are other ways to eliminate ground loops using signal isolation transformers.

 

[traderitch]

I suspect this amp follows an ancient design that didn’t account for grounding the (metal) chassis. The circuit ground could be floating using a small value resistor, or better yet using diodes of proper voltage and amp rating. With the chassis connected to ground, It would provide safety and eliminate potential ground loops.

And of course, there are other ways to eliminate ground loops using signal isolation transformers.

Still my favorite name...

 

[EchoChamber]

Still my favorite name...

 

[egellings]

That series R-C across the speaker terminals is often called a 'tweeter saver', and at high frequencies, it keeps the amplifier loaded. Some feedback tube amps could oscillate at high frequency when left unloaded, and the R-C pair prevented that. My home brews don't need one, but I installed it anyway, just in case.

 

[AudioResurgence]

Wyred4sound makers of the famous DAC 2v2……it measured really well isn’t it?……..
They also make great $1500 power cable and now the Carver tube amps!
Everything make sense now.

"Wyred4sound makers of the famous DAC 2v2……it measured really well isn’t it?…….." How the heck should I know??
"Everything make sense now."....cool, glad to help.

 

[AudioResurgence]

So you are asking us if an adapter that you called "cheater" is compliant then why the Carver amp isn't?

Please go a head and read what you wrote

"So you are asking us if an adapter that you called "cheater" is compliant then why the Carver amp isn't?"
Actually no, I wasn't asking that. "Cheater" is my term for it. You can buy them at Best Buy. I know it's compliant as a device to disconnect the ground pin. I also pointed out that many electronics components come without a ground pin. The question expressed differently, is: why does the Carver unit require one? I believe paulbottlehead may have already provided the information I was looking for.

 

[Blumlein 88]

If you need to float something for hum reasons you can do it with GFCI adapters meant for outdoor gear and do it safely. Cost $15 or so rather than $1 adapter, but you get protection from electrocution and kill the hum.

You could change the end of the plug like this one:

ELEGRP 4.3 ft. 15 Amp Automatic Reset 2 Prong Portable GFCI Replacement Right Angle Plug G1215PA2 - The Home Depot

The Portable GFCI units (Ground Fault Circuit Interrupters) offer protection for 2 wire or 3 wire appliances and tools to avoid electric shock for people in all work environments. They are perfect for

www.homedepot.com

Or get this beautiful yellow one you just plug on like an adapter.

Amazon.com

You also could install the 3 pin GFCI outlet, and use the cheap cheater then and be protected from electrocution.

 

[EchoChamber]

"So you are asking us if an adapter that you called "cheater" is compliant then why the Carver amp isn't?"
Actually no, I wasn't asking that. "Cheater" is my term for it. You can buy them at Best Buy. I know it's compliant as a device to disconnect the ground pin. I also pointed out that many electronics components come without a ground pin. The question expressed differently, is: why does the Carver unit require one? I believe paulbottlehead may have already provided the information I was looking for.

Just to clarify things, the 3 prong to 2 prong adapters are designed to be used on older electrical outlets and provide a ground solution assuming the rest of the installation is grounded (a precarious solution IMO - better replace the outlet).

It should be used like in the attached image. It is not a “cheater”, quite the opposite.

 

[AudioResurgence]

Just to clarify things, the 3 prong to 2 prong adapters are designed to be used on older electrical outlets and provide a ground solution assuming the rest of the installation is grounded (a precarious solution IMO - better replace the outlet).

It should be used like in the attached image. It is not a cheater, quite the opposite.

View attachment 180596

Thanks. I really didn't need to reference the 'cheater' plug, it seems to have caused a distraction and it wasn't needed to make my point. Didn't want to cause any detour from the more important issues being addressed in this thread. Thanks again.

 

[Blumlein 88]

Just to clarify things, the 3 prong to 2 prong adapters are designed to be used on older electrical outlets and provide a ground solution assuming the rest of the installation is grounded (a precarious solution IMO - better replace the outlet).

It should be used like in the attached image. It is not a “cheater”, quite the opposite.

View attachment 180596

Yes of course. OTOH, I estimate like maybe 1% of them get used that way.

 

[Billy Budapest]

1 - If a product is double insulated, the two prong power cord is OK.

Also, if the case is made out of plastic, then it is considered double-insulated.

 

[EchoChamber]

Yes of course. OTOH, I estimate like maybe 1% of them get used that way.

Oh yeah, it is a horrible solution, a hack. And implies people understand what they need to do to use it safely. Most people will only care about making their 3 prong appliance work on an older 2 prong outlet.

And, in the past, some audio enthusiasts offered it as a solution to solve hum issues. Especially when dealing with tube gear (!!).

 

[BlackTalon]

You replied to a comment I had made... correct?

In the body of your reply to me you stated "You chose to ignore your country's laws."

Are we clear?

Where I come from, 'ignoring' is not 'breaking'. As you say, wording is important...

 

[Larry B. Larabee]

Unfortunately, still wrong. The "rated" voltage of a fuse at least most of the fuses we are dealing with, has nothing to do with arc-over voltage. It is a fuse-vendor specified value and it tied to the interruption current, which together with the voltage rating define a characteristic at the point of interruption. It is to ensure the fuse does not mechanically fail. Arcs internal to the fuse at point of interruption are high energy events and can literally blow the fuse up. When used for secondary protection inside equipment where the fault current is limited, you can use fuses rated much lower voltage than the application safely.

Realistically none of these things will happen. A normal 3AG type fuse won't arc and certainly won't explode. Are the conditions you refer to apply to industrial type fuses of tens or hundreds of amperes. In any case your explanation was too wordy for me to understand. Thanks anyway.