Krell Connect Media Streaming Player Preview

I agree that is a nice looking amp. But I'm going to stand by my statement.

The first amp to deliver class A performance without high quiescent current was the Quad 405, which Peter called Current dumping or feed forward bias if you will. In 1976 Nelson Pass patented his sliding bias circuit. The goals were the same. There has always been a lot of debate as the whether Nelson Pass infringed Peter's patents. I think it is fair to say that most who have looked critically at the issue feel he did.

In any event 1500 watts per channel is a lot of power. One has to question the wisdom of feeding that amount of power to a speaker with a passive crossover.

So I use current dumpers that are 250 watts per channel. I get the same power. If I had paid full price that would have cost me $4.5K. But I bought them gently used and it cost me under 3k. Also I am not feeding 1500 watts to a passive crossover.

The bottom line is that I would bet my amplification is the equal of that Boulder at a fraction of the cost.

The build quality of my Quads is very high and the part count much less due to the inherent elegance of Peter's designs. I think that contributes greatly to the extreme longevity of his amps.



So I still think this is an example of a dead end approach at the price asked. Any minute improvement, which likely does not exist over a more sensible approach can not possibly be justified by the cost.

So I'm going to chalk this up to another example of audio sillyness.

This is important as it intimidates the music lover. It has a lot, but not all to do with the fact, that a significant proportion of the population had reasonable component audio systems and now much fewer do.

This is having an impact on the quality of source material. This is especially true in the steaming sphere, which is going audiophile at a snails pace. The only streaming site I know of with audiophile audio quality, and yes I use that term with reluctance, is the Berlin Philharmonic site. With their really good HD picture and 350 kbs AAC audio stream from custom designed and built servers, they are way ahead of the pack.

A couple of weeks ago I astounded some visitors with a viewing of the first movement of the Brahms piano concerto No. 2. It knocked the proverbial socks off so to speak. These superbly recorded and filmed performances are works of art, and fully justify the price of the yearly season ticket.

I'm working hard to try and help our two professional orchestra, both now with locked out musicians, to increase revenue, with the same approach. The biggest barrier is lack of an audience with the equipment to realize the benefit so they can really enjoy high quality productions.

Audio sillyness, or fraud really, at the dealer and manufacturer level puts them off, and they feel they will be had. I don't think there is a dealer in these Twin Cities who would sell the music lover honestly. Inappropriate equipment would be selected more often than not, and they would try and sell them on funny wire and terminations. Most now sense it and stay away, or walk out. For every sucker, there are actually probably a 100 who know they are being had, and their right.

Peter Walker foresaw this problem and now the new owners if his great firm indulge in this practice.

I have challenged Quad on this and they tell me they are not taken seriously unless they also offer the funny wire.

That means that the music lover who wanted to really enjoy music in the home at a fair price are now turned away and only the gullible kooks are left. This is a sad state of affairs we have come to.

I have to say this site is a beacon of home in this, and vigorously confronts this nonsense.

An amp can deliver good performance, look good in and out and not cost anything like 205K. That is absurd, unjustified and turns off the music lover who wants to enjoy the musical, and now the AV arts, on fine equipment at a fair price.

Yes but right now, there is a Saudi Prince just loving his new $205k Boulder amps being driven by his iPod

I have. It seems to me the concepts are very similar. It was never tried in court, and I never discussed it with Peter, but he never pursued it. To me from the circuits I believe there was an infringement of patents. However the language used to describe the function of the circuits is very different.

To be honest I was unaware of the use of micro controllers in these types of circuits.

However the invention of a circuit that gives class A performance without the disadvantages has to go to Peter Walker.

This concept has not been used nearly enough, especially as the patents have expired. I firmly believe these designs do sound better than the ubiquitous A/B designs. In Peter's designs they are a lot more reliable also.

The sad fact is these designs could produce much cheaper high quality amps with lower heat output.

Just look at the part count of the Emotiva amps. They could produce cheaper more reliable amps with this type of topology. Peter's amp boards are small enough they could be used in receivers and would produce a lot less heat and better results all round.

I can't find the reference to the use of micro-controllers in sliding bias circuits. I know I read it somewhere, but Google isn't helping me right now.

I think you're being too idealistic about the way the patent office should work. Derivative patents are common and perfectly legitimate in the system, for better or for worse. Since Pass cited Walker in his filing, so the patent office actually did that analysis, it would seem the use of your term infringement is reaching. (I have no idea whether Pass included the citation or the patent office did. It is probably irrelevant anyway.) Perhaps you are letting emotion overcome reality here because of your relationship to Walker.

Sliding bias circuits look to me to be completely unrelated to using a small Class A amp to modify the output of a lesser amp. FWIW, I think the sliding bias strategy looks superior; it doesn't try to emulate the performance of a Class A amp, a sliding bias design is a Class A amp with more efficient operation.