Has anybody heard the new Audio Research LS 27?

But that IS the point isn't it.

In Audio Research's defense, any quality audio manufacturer has the right to improve their products as state of the art parts and technology improves. It is in their best interest to do so. You try a new design and you learn from it. It either works or it fails, in which case you move on and try something else. High end manufacturers that do not improve their products over time won't last long as it's extremely competitive.

Just a quick question here..Onhwy61, Have you ever designed a solid state of tube line stage or the power supply that goes to that line stage?? I love how people dismiss what's involved in the design of a product.If you had never designed a piece of audio gear then you have no point of reference and your comments are without merit. So here's the deal, when you have sat down for hours at a time and listened to 10 different manufacturers resistors and capacitors in only one small part of the circuit and played the same song over and over again at 2am ( when the line voltage is stable and quiet) and do this for months at a time till you voice the product correctly, then you can come back and tell me it's easy. Audio manufacturers should be given props for continuing to work on their designs thereby advancing the audio state of the art.

Yes there are many things you can do with an SP-10 to improve it, but some of the limitations are with the 6922's themselves. Most of the new ARC line stages use 6H30's which frankly are better tubes with regard to dynamics and voltage swing then a 6922 or a 12AX7. It's simply newer technology. The Russian's never stopped designing new tubes. That doesn't mean all new technology is better, but in this case the 6H30 is superior, as are the newly developed power supplies utilizing more linear transistors in the newer line stages.

Agreed. If you don't keep reinventing yourself you will be quickly passed by the competition.

This is exactly what happens when a car manufacturer comes out with a new model every year. That's why some people buy used cars in order for someone else to take the depreciation 'hit'. Are people pissed because once they drive their new car off the lot, it depreciates a few grand? They are not. They realize models change every year. Prices go up and more options and accessories become available for the new model. That's the way it is. The marketing model exists for any electronics product and even cars as stated above. If you don't wish to precipitate in the purchase of new products, try buying something used next time.

Again, I have a hard time with people complaining that they use the same circuit or similar circuits year after year. As a Warranty Repair Station for ARC, I can say without question their circuits change as do the parts they use. If people need to complain about this they can build their own line stages. It is not an easy task. Some people sure know how to beat a dead horse.

Granted, there are not thousands of ways to amplify a signal. Circuits change when designers have the insight to use a SOTA device in a new way. In tube design it would be utilizing a new tube. The circuit topology has to change to take advantage of it. True you have less design options wih tube products then transistor. Bipolar transistors give way to j-fets at preamp inputs thereby lessening noise. Some of this is semantics. What is your definition of a circuit topology change? Are you aware of the fact that the way you lay the circuit board out, the circuit board material, and the thickness and width of the traces can make or break a potential design. It is true that if a designer finds that a particular circuit in a product like a power supply sounds particularly good, (yes power supplies do have a strong effect on an audio circuit), they might use it in another design. You have to remember that it's the whole package, not just individual parts or circuit topology that make up the sound of the unit your listening to. Some manufacturers actually remove or update parts as they become available after the first design because it sounds better or gives better reliability. That's not being cheap, that's improving performance and that would be a circuit topology change. In fact a new manufacturer of amplifiers has just come out with a new output transistor circuit that doesn't utilize emitter resistors. That to me is a new circuit design. I don't think someone like Nelson Pass or John Curl would say there had been little change in line stage design over the past 40 years. When new parts come out, circuits change. Everyone is entitled to their opinion.