Carver Power Amps


Even though the Carver A-760x magnified current power amplifier was rated at 380 watts per channel into 8 ohms and 600 watts per channel into 4 ohms and lab tested at 500 w/ch at 8 ohms at clipping and 725 w/ch at clipping by Audio Magazine in 1997, it sounds gutless, especially in the bass, compared to a Parasound HCA-3500,etc!
Any opinions on why this is so?
daltonlanny
Carver didn't design the 20,000 tube amps. He just modded a design David Hafler did for him. The mods were minor. Ask him.
Warnerwh, I did not know that the 20k amps were not of BCarver's design. All the worse. From the commercials it seemed as if he was claiming the fame for them. I did not even know that Hafler had anything to do with Tube amp designs. The things people learn at Audiogon. Interesting. Daltonlanny, it is a proven fact that Carvers are beyond overrated....someone stated that Onkyo's were not allowed into a demo test to workers at a electronic retail outlet, all for a reason. Add concrete to its insides and use it as an isolation device.>=)
Paul
Ps: doesn't my dislike for Carver designs show clearly and brightly?
For those of you that still feel that Bob Carver is just another Joe as far as audio design goes, well here it is, from one of the most famous amplifier designers of all time, James Bongiorno:

A few words about the designer, James Bongiorno, and his creation:
"Twenty-Seven years ago James wrote a brochure describing the "Ultimate Amplifier" while at SAE. Of course, every engineer believes that their current work is the ultimate machine. However, it should be understood that this "Ultimate" design could only be as of the moment. The truth is that there never has been nor will there ever be an absolute "ultimate" perfect amplifier. Hard as we try, we get closer and closer but in reality, we’ll never approach perfection. Therein lies the enigma. Who defines what is perfect? What are the rules, the conditions, the standards, etc. The original Ampzilla set a standard, which has been copied, in topological form, for almost the last 30 years. Obviously something must have been right about it in the first place. Subsequently, the Sumo balanced topology has also been copied for the last 10 or 15 years. As we are now entering the new millennium, it is time for another breakthrough in the original tradition defined by the first Ampzilla.

The new Ampzilla 2000 is a radical departure in amplifier topology. Not many designers can make a claim like this. The only other designer capable of true innovation is Bob Carver although his application of technology and marketing go in different directions. Needless to say, James has created something truly new and innovative. All that can be said is, "It’s about time."

The new Ampzilla 2000 uses a completely new variation of the Forward Gain topology to achieve unprecedented improvements in linearity. As a matter of fact, the new circuit is so smooth, that it can be actually listened to OPEN LOOP, WITH NO FEEDBACK. Of course, we aren’t going to make it that way. The PROPER use of feedback is necessary in order to tie down all of the operating points so there will be no variations in performance from unit to unit. The new Ampzilla 2000 uses 12 250-watt output devices per monobloc. This is 3 times more devices than the original Ampzilla. In addition, since it is a monobloc, there is a separate 2500VA transformer for each. In addition, the amount of heat sink radiating area is 3 times greater than the original meaning that there is NO fan. Also, the B+ and B- supply fuses are EXTERNAL. Also, The entire circuit is totally balanced from input to output although there is a totally and uniquely new un-balanced to balanced converter for single ended inputs. Each monobloc has 100,000 ufd of power supply filtering with dual rectification as pioneered in the original Sumo's."

Please note the remark of this world renound amplifier designer regarding Bob Carver. If you are interested in reading the article, here's the link:
http://www.ampzilla2000.com/Amp_History.html
I remember when Carver introduced the Phase Linear 300. "Three Hundred watts! You must be crazy!" is what they said.

But Bob Carver's inventiveness is, I think, best exemplified, not by power amps (although his were certainly different) but by his preamp, particularly the Autocorrelator, which was also available as an outboard unit. I had two (for quadraphonic use). The Autocorrelator was a dynamic multiband filter designed to surpress the noise characteristic of LPs. What made it different from other dynamic filters was the way that the filter gains were controlled. Bob realized that above some surprising low frequency (I seem to remember 2000 Hz) there are no music fundamentals: just harmonics. The frequency bands that will have harmonics are predictable from the signal content in the range of fundamentals. So, in the Autocorrelator, a filter required two things to be opened (gain increased). (1) Signal in that frequency range. (2) Proper harmonic relationship to signal in the fundamental range.

The unit worked quite well for conventional stereo, but for quad, where the inherently inferior L-R signal of LPs (vertical groove modulation) was amplified and broadcast by the rear speakers, the Autocorrelator in the rear channels made a very big improvement. It also had a dynamic rumble filter operating below the frequency range used for gain control, and a Peak Unlimiter (to counteract what recording engineers need to do to stop your stylus from hopping out of the groove).

Clever guy.