Carver MXR-150 - "Asymmetrical Detector"

[LGLDSR73]

Greetings,

I recently purchased a Carver MXR-150 and when listening to FM noticed that if you engage the 'Asymmetrical Detector' the audio whams out. Gone.

What is the function of this and is what I am experiencing normal when the Asymmetrical Detector' is enabled? I do not know if signal strength comes into play here but it is ~4.5, Stereo and is locked.

Also, I assume that the 'Mute' button (as labeled) is in fact FM Mute?


Many thanks.

 

[coonmanx]

From a website...

ASYMMETRICAL CHARGE-COUPLED FM DETECTION TECHNOLOGY. Carver's patented Asymmetrical Charge-Coupled FM Detector (ACCD) circuit substantially reduces interference caused by multipath distortion and noise present in weak stereo radio broadcast signals. Thus, high quality stereo reproduction can be achieved from FM signals which would produce unacceptably poor sound quality on other equipment. The two patents for the Asymmetrical Charge-Coupled FM Detection Technology will expire beginning in 2000.

I don't believe that the sound should go away from that description. But I'm not sure either.

From Wikipedia...

The "asymmetrical charge-coupled detector" is not the FM detector circuit of Carver's tuners, but rather, as described in U.S. patent 4,457,012 (see below), it is single-ended dynamic noise-reduction processing applied to the noisy left-minus-right component of a weak FM-stereo signal, along with artificial ambience generation to compensate for loss of ambience resulting from the noise reduction.

 

[LGLDSR73]

From a website...

ASYMMETRICAL CHARGE-COUPLED FM DETECTION TECHNOLOGY. Carver's patented Asymmetrical Charge-Coupled FM Detector (ACCD) circuit substantially reduces interference caused by multipath distortion and noise present in weak stereo radio broadcast signals. Thus, high quality stereo reproduction can be achieved from FM signals which would produce unacceptably poor sound quality on other equipment. The two patents for the Asymmetrical Charge-Coupled FM Detection Technology will expire beginning in 2000.

I don't believe that the sound should go away from that description. But I'm not sure either.

From Wikipedia...

The "asymmetrical charge-coupled detector" is not the FM detector circuit of Carver's tuners, but rather, as described in U.S. patent 4,457,012 (see below), it is single-ended dynamic noise-reduction processing applied to the noisy left-minus-right component of a weak FM-stereo signal, along with artificial ambience generation to compensate for loss of ambience resulting from the noise reduction.

Thanks. It is my understanding that it should not mute the FM completely with the signal I am obtaining but I may be wrong.

In any event, he is a frequent contributor to this site, seems like a very nice guy, and I do not anticipate any issues in obtaining a refund. Having just purchased the unit yesterday at ~21:00 I'm not doing another marathon trip at ~$3.60/gallon. If anything aggravates me about this having to go back, it's the cost of the trip as well. I've been unemployed for some 33 months now, so I've got to watch every cent. Hopefully he'll come up here and pickup.

Again, many thanks.

 

[Jon_Logan]

Nah, engaging that ACCD button, should result in almost no change in the sound. It's a very slight effect as I remember. The effect might be greater when tuning stations with lot's of Multipath distortion.

The tuner going silent, when the button is engaged, indicates a problem.

 

[LGLDSR73]

Nah, engaging that ACCD button, should result in almost no change in the sound. It's a very slight effect as I remember. The effect might be greater when tuning stations with lot's of Multipath distortion.

The tuner going silent, when the button is engaged, indicates a problem.

Thanks for your input. I spoke with the seller this morning and he'll take care of it. As I had said, he seemed like a good guy and he is.

Thanks!

 

[audiomagnate]

Nah, engaging that ACCD button, should result in almost no change in the sound. It's a very slight effect as I remember. The effect might be greater when tuning stations with lot's of Multipath distortion.

The tuner going silent, when the button is engaged, indicates a problem.

On weak stations the change is huge on my 900 receiver. They go from unlistenable to great sounding. It's the coolest thing about the receiver, so yeah, you should get it fixed or get money back.

 

[LGLDSR73]

Thanks. The actual fix was simply reversing the lead at the board from the Asymmetrical Detector switch. If only all of life's issues were that simple!