Are Audio Manufacturers Liable for False Claims, Bloated Spec's?

[jjptkd]

2 minutes ago, RandyH said:

what do you think?   are you satisfied ,,,,, are you keeping the amp or returning it  ? 

I'm very satisfied with my amp it would be hard for me to give it back-- with it I have no desire to "try" anything else. I actually like the fact that it is light weight and doesn't put out a lot of heat plus tube life is supposed to be many times longer than in a typical tube amp, not to mention it just sounds fantastic nice depth and imagining very clear and detailed lots of great solid clean bass snap and way louder than I could ever need it to be in my current space 14x18 room. 

[OO1]

Just now, jjptkd said:

I'm very satisfied with my amp it would be hard for me to give it back-

5 years warranty , that's pretty good

[captainbeefheart]

In that response he states 'depending on the measuring technique' which is what I would be worried about. They never specifically state RMS power, just power, which could be peak power.

 

The bottom line is he never once denies using the 15 watt edcor transformers which jives with the 19 pound weight of the amplifier, and unless the laws of physics have changed this amp cannot produce that amount of power even at 80Hz like he mentions.

 

My guess is we need to ask them how exactly they test for output power and get them in writing to claim the rated output power in RMS.

 

Also someone really needs to ask how they rate the output power and distortion for the different speaker loads given they don't have separate taps for them.

[captainbeefheart]

15 hours ago, Travis In Austin said:

Help me, once again please. 

 

I have watched the threads, this one, the one at ASR (I posted in that about Edcor's liability - zero), and the AK thread. 

 

I understand the manufacturer specs say it's a "75 watt amp." I understand that someone discovered that a "15 watt" Edcor transformer was under the cover.

 

What I would like to try and understand is what relationship the transformer rating bears to the actual output rating of the amp. Does it matter what the power tubes are? What the topology of the amp is? In other words, is it just simple math if you know what the transformer rating it? 

 

 

Peak flux is proportional to the applied voltage and inversely proportional to the frequency and number of turns in the primary. The higher your flux is the more steel you need in the core in order to maintain flux density. The lower the frequency the bigger the transformer gets. Look at sinusoidal signals, say on a scope, I am sure you noticed that for lower frequencies you see more time between vertical divisions. So it takes longer in time for it to complete the full 360°waveform. So you need more energy in the transformer to maintain the waveform for a longer period of time.

 

Tube selection is determined by the impedance ratio or primary impedance from a reflected load. For pentodes there is a sweet spot of load impedance for power vs distortion. For Triodes the higher the impedance the less distortion but lower the output power. And of course depending on your tube selection will tell you how much power out into a load you will have, this dictates the size of the transformer you need to select. The higher the power you have from the circuit the larger the output transformer you will need to accurately produce a 20Hz sine wave. Using an undersized transformer you can clearly see the flux density just falls apart on the trailing edge of the sine wave as it runs out of energy to accurately follow the transfer function of the sine wave.

 

Basically it doesn't matter what topology, power is power and if your circuit can provide 100 watts of power and you decide you want to have low distortion down to 20Hz you need to select a transformer designed for the correct impedance ratio to load the tubes correctly and also one that is rated down to 20Hz for specified power. So say a push pull EL84 circuit is producing 17 watts of power into a 8k  plate to plate load then you look for an 8k:8 output transformer for an 8 ohm speaker that can produce at 17 watts cleanly down to 20Hz. Usually you have a choice of output power and won't find exactly a 17 watt output transformer you select a 25 watt output transformer and you know you will never run out of energy in the output transformer to faithfully produce a 20Hz sine wave at 17 watts power. BTW for 8k:8 that's an impedance ratio of 1000:1 and a turn ratio of 31.6:1. For 17 watts into 8000 ohms we need an applied primary voltage of 373 volts. The secondary into 8 ohms is 11.66v.

 

There is just no way a 15 watt output transformer can do what they claim, it's just impossible as size limits number of turns you can have and the size core you can have.   I truly believe they are using peak power or some odd 'technique' of measuring power.

 

There are books on how to calculate all this to design a properly sized transformer. It's not an easy subject.

[Deang]

My specs are definitely bloated. It’s how I keep my edge. 

[Curious_George]

15 minutes ago, Crankysoldermeister said:

edge = hyperbole

Come on, keep it real.

[Deang]

I thought the expression just meant staying ahead of your competition. I was of course just joking, as I have no bloaty specs. 
 

Nice amp you’re building btw. Great work. 

[jjptkd]

There's been a response on the Jim Clark forum, not sure what's taking ASR so long to test their new amp they've had one in their possession for several days now.

 

They claim there's a special way to test them?
 

Carverfest Amps and how to measure them. A note from Bob. – Carver Stereo Forum

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.

[Khornukopia]

I don't have one of these amplifiers but, am following this thread and reading about the Carver Crimson 275 specs on the other forums too.

 

[captainbeefheart]

14 hours ago, jjptkd said:

There's been a response on the Jim Clark forum, not sure what's taking ASR so long to test their new amp they've had one in their possession for several days now.

 

They claim there's a special way to test them?
 

Carverfest Amps and how to measure them. A note from Bob. – Carver Stereo Forum

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.

 

The only thing that is ridiculous is this response that I don't even believe is from Bob himself.

 

You connect your speakers to the binding posts, which there are only two per channel, kinda hard to mess up. They rate the amplifier into multiple loads but Paul chose 8 ohms to test with so he connected a resistive load between the two output terminals, pretty straight forward and typical testing method. Input different frequencies and measure the output on a scope. Say you measure 16.3 volts on the scope, that's where the peak measure to, you convert that to RMS by multiplying by .7 giving us 11.66v;

 

voltage squared 11.66^2 = 135.95

 

divide by load 135.95 / 8 = 16.99 watts

 

This is all very basic and common amplifier testing that has been done for a very long time. Paul over at ASR did all his testing properly, if he was doing anything wrong by regular standards then it would have been pointed out a long long time ago before this would even get this far.

 

They got caught with their pants down and are doing the classic deflect defense where they simply point blame that people just don't know how to test their 'special' amplifier as if it needs any sort of special method of testing different from the standard methods we all use.

 

The crux of the matter is extremely simple to understand, they use a 15 watt output transformer for a 75 watt circuit. The testing has proven the poor low frequency performance one would expect from doing such a ridiculous thing.

 

I was hoping for a more empathy in their response instead of arrogance and denial. I too have no idea what is taking Amir so long to test the amplifier over at ASR, seriously man we NEED answers NOW!

[captainbeefheart]

Paul showed that his scope was floating, just like the resistor (load) or speaker would be, there is no difference in test results because the output transformer is the problem. Whoever wrote the responses to the questions states that there is magic going on in that tiny output transformer that allows it to get 75 watts at 20Hz yet the sticker on it says 15 watts, pretty sure Edcor knows what they are selling by labeling it a 15 watt output transformer so they are in the clear.

 

Amir just posted and has the amplifier in his possession, it's only a matter of time before we get some definitive answers.

[Khornukopia]

On 1/13/2022 at 12:18 PM, captainbeefheart said:

Amir just posted and has the amplifier in his possession, it's only a matter of time before we get some definitive answers.

He did receive the amp but, at the same time heavy rainstorms caused a lot of water to leak into his house. The amplifier test is on hold.

[captainbeefheart]

3 hours ago, Khornukopia said:

He did receive the amp but, at the same time heavy rainstorms caused a lot of water to leak into his house. The amplifier test is on hold.

 

He posted the review!!

 

https://www.audiosciencereview.com/forum/index.php?reviews/

[the real Duke Spinner]

On 1/6/2022 at 2:22 PM, captainbeefheart said:

In that response he states 'depending on the measuring technique' which is what I would be worried about. They never specifically state RMS power, just power, which could be peak power.

 

The bottom line is he never once denies using the 15 watt edcor transformers which jives with the 19 pound weight of the amplifier, and unless the laws of physics have changed this amp cannot produce that amount of power even at 80Hz like he mentions.

 

My guess is we need to ask them how exactly they test for output power and get them in writing to claim the rated output power in RMS.

 

Also someone really needs to ask how they rate the output power and distortion for the different speaker loads given they don't have separate taps for them.

Aaaahhh ..You might be onto the old IPP scheme Instant Peak Power. 🤪

[Travis In Austin]

8 hours ago, captainbeefheart said:

 

He posted the review!!

 

https://www.audiosciencereview.com/forum/index.php?reviews/

I read it, made several posts about some legal stuff.

 

Is the reviewer's testing methodology, valid? Someone else on the forum has a similar analyzer and caught a couple of mistakes that this reviewer made with noise floors on Class D amps (what test filter to use, misstating it was a "AES" something, etc.). 

 

The reviewer never got it close to 70 watts that I saw. The distortion looks atrocious, but he mentions 3rd harmonic is what he is seeing, not 2nd, and I don't know the significance. 

[MEH Synergy]

4 minutes ago, Travis In Austin said:

I read it, made several posts about some legal stuff.

 

Is the reviewer's testing methodology, valid? Someone else on the forum has a similar analyzer and caught a couple of mistakes that this reviewer made with noise floors on Class D amps (what test filter to use, misstating it was a "AES" something, etc.). 

 

The reviewer never got it close to 70 watts that I saw. The distortion looks atrocious, but he mentions 3rd harmonic is what he is seeing, not 2nd, and I don't know the significance. 

It doesn't test well, it sounds excellent. To be fair, I had a noise problem in my setup running xlr to RCA with A  tube that had rattling inside of it (shipped that way).  Yes, I tested it anyhow and had kind of weird HF ground loop if you will. I blame the shit tube.   Knowing fully that I wasnt using more then a few watts, I REALLY liked the sound of this amp. Really disappointing to see the final reporting... Would never buy one new now based on EXTREME false advertising.... 

[the real Duke Spinner]

On 1/12/2022 at 11:13 PM, jjptkd said:

There's been a response on the Jim Clark forum, not sure what's taking ASR so long to test their new amp they've had one in their possession for several days now.

 

They claim there's a special way to test them?
 

Carverfest Amps and how to measure them. A note from Bob. – Carver Stereo Forum

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.

Carver was always a Liar

[the real Duke Spinner]

10 minutes ago, Travis In Austin said:

I read it, made several posts about some legal stuff.

 

Is the reviewer's testing methodology, valid? Someone else on the forum has a similar analyzer and caught a couple of mistakes that this reviewer made with noise floors on Class D amps (what test filter to use, misstating it was a "AES" something, etc.). 

 

The reviewer never got it close to 70 watts that I saw. The distortion looks atrocious, but he mentions 3rd harmonic is what he is seeing, not 2nd, and I don't know the significance. 

Audio Engineering Society

[Travis In Austin]

1 minute ago, the real Duke Spinner said:

Audio Engineering Society

I think it was AES-17, even I I got the AES part, LOL. 

[Travis In Austin]

Langston @Langston did that testing on same brand and type of analyzer. I will try to find link where he talks about some problems with Amir's testing, nothing major, but interesting the same..