Why Stax moved to dedicated amps -- a speculation
Originally Posted by Goosepond
I wonder if anyone knows why Stax doesn't still produce adapters anymore? Is it because they want to sell more of their amps?
They just moved on with their market. Back in the middle decades of the last century, an amp cost quite a bit of money. It was cheaper making a matching box than a full amp, and probably all their customers wanted to pay for. (I don't know what earspeakers and adapter boxes cost then but certainly they were treated as expensive items; the Stax phones I used in the 1960s at the recording studio my advertising agency owned were kept in a locked wooden box and taken out only when I worked in the studio.) It was probably a smart move on the part of Stax to use pre-existing amps, to make a necessary connecting box as relatively cheaply as possible. Then.
Today a silicon amp, at least, is cheap to make, and the hybrid tube OTL amps Stax makes not much more expensive. Here you should read "cheap" and "expensive" in relative historic terms, and relatively to the high labor and probably wastage costs of making electrostatic earspeaker units. The key cost (next to the case!) is probably the transformer, and that would be the same for an amp and for an adapter box (different kinds of transformers but the cost would be pretty closely related).
Furthermore, it does appear that there has been a change of philosophy at Stax. The cynical might say that this is simply an extension of the line of argument above: that Stax is more responsive to their market, or even follows fashion more closely. Whichever it is, to those of us not overimpressed with the design of Stax amps of old (the design compromises once you understood the topology sat very uneasily with the incredibly high price), the modern Stax amps are impressive (at their respective prices), especially to those of us with tube DIY backgrounds. Underlying this movement, almost dragging the Stax amps into the 21st century by the scuff of their necks, one might reasonably imagine that some opinion-former at Stax decided that the most direct path between source and earphone -- which is clearly not an unknown and possibly unmatched amp PLUS an adapter -- would give the electrostat the best chance to deliver the finest sound. A decicated amp of Stax's own design follows logically, and is made possible at a price the market clearly wants to pay by the advance of electronic time, as described above.
Personally I would like to think that this beneficial sequence happened as the result of hard thought and not just haphazardly because time passing made creeping changes possible.
There will be cries of outrage. There are many here who consider some old Stax earspeaker and its matching adapter box superior to the current crop of earspeakers with their matching dedicated amps. It is possible. However, electrostatic speaker technology has not advanced much in half a century. An electrostat is an electrostat, a nice clear sound. What has advanced is our understanding of how the housing, the cable and the positioning of the diaphraghm in relation to the ear influence the various qualities of the perceived sound. Electrostatic earphone hi-fi is no different from other hi-fi in at least this regard: where cables or other additional elements (all the way up to deliberate EQ) make a difference, it is because of solecisms of design in other aspects of the chain. It thus seems to me likely that, if the owner's amp plus adapter is perceived as superior to the modern amp for driving earspeakers, personal choice or familiarity and adaptation to the quirks of the owner's amp might play a large part. In other words, the adapter box gimmicks some problem right, in exactly the same way that in normal hi-fi a high-capacitance cable can accidentally gimmick mismatched components into giving a "better" perceived sound. But your modern Stax earspeaker already comes engineered with cable that releases the full frequency band of which the factory's recommended matching amp is capable. That is why the amp is matched to it. There is nothing left to gimmick right. (Some other time I will explain why I think that the ever higher frequencies the Stax earspeakers are capable of is a mistake, and why the amp or the cable should be used to filter these down. I mention it now as an example of how hi-fi is never as simple as I, or anyone else, can sometimes make it look by simplifying complex relationships to make a debating point. There is thus in fact something left to gimmick right. But who knows whether the adapter box does the business?)
Don't you just love speculation?
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