zod
Well-Known Member
I ended up with a Carver M1.0 about the time audiophile equipment became available to the masses*. This was a whole new world. Didn't know about this until a few years ago when I needed a repair:
In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named then, but revealed later) amplifier at their offices in New Mexico within 48 hours. The Conrad Johnson amplifiers were one of the most highly regarded amplifiers of the day, costing in excess of $6,000 a pair.
Of note that … the challenging amplifier could only be treated as a “black box” and could not even have its lid removed. Nevertheless, Carver, using null difference testing, (null difference testing consists of driving two different amplifiers with identical signal sources and exact levels, but out of phase by exactly 180 degrees.
If the amplifiers were 100% identical, no sound would be heard. If sound was heard, the audio amps had different properties). Bob Carver used "distortion pots" to introduce amplifier characteristics, fine-tuned to null-out any sound differences.
His "motel-room" modified amplifier sound was so similar, Stereophile Magazine editors could not tell the difference between his amplifier and one costing more than $6,000. This amplifier was marketed as the M1.0t for about $400.00. Bob Carver may have single-handedly debunked any number of theories about sound quality by using physics, blind and double-blind testing and unbiased measurements (such as "gold-plated speaker wires sound better than copper wires", etc.).
graph.
www.bobcarvercorp.com
The addicts have a forum:
We have manuals. They are free. However, please consider donating to the site so we can continue to expand our resources.
Hard to find people that work on them for a reasonable price and reasonable time frame. Nobody in Greensboro or Winston could do it. I found an old colleague about 70 minutes away who does beautiful work: http://www.sandhillsavionics.com/
* Engineering uber alles
In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named then, but revealed later) amplifier at their offices in New Mexico within 48 hours. The Conrad Johnson amplifiers were one of the most highly regarded amplifiers of the day, costing in excess of $6,000 a pair.
Of note that … the challenging amplifier could only be treated as a “black box” and could not even have its lid removed. Nevertheless, Carver, using null difference testing, (null difference testing consists of driving two different amplifiers with identical signal sources and exact levels, but out of phase by exactly 180 degrees.
If the amplifiers were 100% identical, no sound would be heard. If sound was heard, the audio amps had different properties). Bob Carver used "distortion pots" to introduce amplifier characteristics, fine-tuned to null-out any sound differences.
His "motel-room" modified amplifier sound was so similar, Stereophile Magazine editors could not tell the difference between his amplifier and one costing more than $6,000. This amplifier was marketed as the M1.0t for about $400.00. Bob Carver may have single-handedly debunked any number of theories about sound quality by using physics, blind and double-blind testing and unbiased measurements (such as "gold-plated speaker wires sound better than copper wires", etc.).
graph.
Carver Challenge | BobCarverCorp.com
www.bobcarvercorp.com
The addicts have a forum:
We have manuals. They are free. However, please consider donating to the site so we can continue to expand our resources.
Hard to find people that work on them for a reasonable price and reasonable time frame. Nobody in Greensboro or Winston could do it. I found an old colleague about 70 minutes away who does beautiful work: http://www.sandhillsavionics.com/
* Engineering uber alles