Amplifier Input Impedance

I should keep my mouth shut because I'm ignorant, but I have read that it's hard to design a SS amp with high input impedence and still get enough power or maybe rate the amp with higher power. I know Levenson has cheated so to speak on their imput impedence ratings which are sometimes only half as high as they claim.

I have to try again. I have the same complaint on low impedence SS amps and have spent years trying to match preamp to amp. I think that the lower the input impedence, the more gain the amp has which in turn degrades sound quality. For better SQ you want low gain in amp and pre. So if company X wants to make a 200w amp, it is easier accomplished by making the amp low impedence at the input. But I don't have the technical knowledge to prove this or discuss it.

And I haven't had to deal with this issue since I got my hk990 integrated. It has a variable gain setting for the active pre which doesn't address the issue of amplifier input impedence directly (and hk doesn't say what the amp's input impedence is and hopefully hk has matched pre and amp), but it does provide a tool that affects impedence in regard to the speakers so that gain can be adjusted according to the speaker demands. If you had speakers that were 16 ohms which you could get with autoformers, a SS amp would have a lower power output.

But again I have the same complaint. Amps get gain and hence power depending on their input impedence. I'm sure someone can explain this better.

It is true that the Hovland has a pretty nasty output impedance which is just as unforgivable as exceedingly low input impedance monster amps. My point is only that this hobby hs quite enough challenges in producing great musical sound in the home, so why do some designers complicate matters with silly impedance design.

For example, the Bryston "Flagship" 28B SST2 mono blocks spec at 15,000 ohms. The Aragon Iriduim, same input impedance. These are just two examples (not trying to beat-up on these companys); there are many many other examples.

Most solid state amps are designed to work with typical all SS pre-amps/systems, not higher out impedance tube pre-amps.

I think its that simple.

With ongoing popularity of tube gear in high end audio, some lines are designed with higher input imepdance to work well with tube pre-amps as well. But it is a niche market so still not as common as would be the case otherwise.

Impedance matching is important for optimal sound quality,but many might not notice otherwise or care. Plus practically its really only a significant issue when a higher out impedance tube pre-amp is involved.

How much power are you looking for ?

Good Listening

Peter