Your opinion on the evolution of amps since 70s?

Both transistor amplifiers and tube amplifiers have seen plenty of evolution since the 50s , 60s and 70s. I have had a hands on experience with both as I ran a consumer electronics repair shop for a number of years during and after college.

With respect to conventional transformer coupled tube amps: the big thing that has changed in pentode based class AB amps is increased filter capacitance in the power supplies! I have rebuilt a number of H/K Citation IIs over the years (one of the very best vintage amps, BTW). Its weakness was its power supply and properly fixed up with new parts and boosted supplies keeps up quite nicely with its modern counterparts. Mind you, to obtain such an amp and fix it up properly will cost you as much as a new amp!

Triode power amplifiers have returned, from the grave we thought they went to during the 30s or maybe during the War. They came back because triodes sound better then pentodes, despite their inefficiencies. High end cares not a whit about that but does care a lot about getting closer to the truth of our recordings. Obviously, single-ended amps reappeared too.

Balanced line applications now exist in tube embodiments and in the home. This too is different and better.

OTLs got reliable and competetive with other amplifier technologies. OTLs were neither reliable or practical in the 70s.

Coupling capacitors, resistors and filter caps have all improved immensely. Just rebuilding a vintage amplifier with newer parts using today's superior materials (non-inductive metal films, Teflon, poloystyrenes, OFCopper, etc, etc.) reaps big rewards. Modern materials sound much better due to better specs (including greater purity).

With respect to transistor amps, they too sound better due to superior materials and better power supply bypassing techniques. High power amplifiers that are also stable are rather commonplace now rather then the exception. Heatsink technologies have improved, thermal feedback means have improved and improved semiconductor devices are commonplace that were only theoretical in the 70s.

Prices have also gone up, but if you figure what inflation has done to the US economy- lets explore that for a moment:

In 1967, a near state of the art system, maybe all Marantz tube gear with a nice set of Dayton-Wright electrostatics, Revox recorder and Empire turntable would have set you back around $3,000, which was about the price of a decent car. Nowadays you pay $20,000 for the same performance (in round numbers) and that gets you entry-level transportation. High End audio today is a good deal.

Another way to look at it: Design a nice,decent box (but not a super fancy one), install a couple of $4.00 volume controls, a couple of switches and some connectors. Now you have a stereo passive volume control. Include the cost of labor to build it, the rent to house the unit while it is being built, dealer markup, shipping and so on (don't forget to include a wage for yourself...) and see how much a simple thing like that has to cost! You are doing exceptionally well or *cheating* if you come up with a retail price of less then $500.00. And that is a passive setup with cheesy controls and no active circuitry!! High end today is a screaming deal. I would not complain about the costs unless you have already walked the talk and seen the expenses that can be involved!

Hi jay_douglas_287@msn.com to some degree you are correct but only for certain parts and materials. In 1970, Teflon parts were astronomical in price- about $1,000 apiece in round numbers, today a Teflon part is a fraction of that. But Caddock resistors and other similar parts did not even exist back then and are quite pricy today. Some Caddock resistors retail for well over $25.00 each. We could use 3 cent resistors and 35 cent coupling caps but the gear would sound bad!

One must also figure the cost of labor and the cost of small manufacturing. If you want something that is stamped out by the 10,000s of units in China, it might be cheap. But if a product is made by hand with proper materials in the US, and only ten of them are made at a time you are simply going to have to pay for it. Its a good bet that the stamped out unit is not going to sound as good too, because by definition less care goes into its existance. You do get what you pay for (although there are shills in any industry).

When I designed our product line I started with the idea of putting the dollars into the performance rather then the cosmetics and that is our ideal today. But we pay the price- often our products are not taken seriously because it *is* less expensive then the competition that it beats! and because we don't have a 1" thick gold panel on the equipment. At the same time though, our stuff is not cheap, because we are only interested in an assult on state of the art, so we have custom built switches, filter caps, resistors and capacitors- this stuff costs very dear even in large quantities. Yes, we could build with lesser materials and parts but now we are not being the best that we can be- which is not what high end audio is all about (hopefully each of us in the industry believes in what we are doing and are building the best stuff that we know how).

If high end audio is shrinking, it is not due to prices, so much as it has to do with public awarness, which is a subject of a different thread.