Active FETs vs. Step-up phono stage designs

Dan_ed got that right...

Its been my experience that you don't want semiconductors at the input of a phono stage- they just don't have the same low level detail as an all-tube phono section.

I don't like transformers for the same reason- they limit bandwidth and loose detail.

But noise is also an issue. If I had to compromise (meaning that I can't use a phono section that is all-tube, is quiet enough yet has the needed gain), I think I would go with an SUT before using semiconductors. I guess I don't like the semiconductor sound (brighter due to emphasis of odd ordered harmonic distortion, lacking in tubes and SUTs).

Atmasphere,
Would it be correct to say all-tube phono preamps are rather rare?

Hadn't really thought about that! We make two... it might be interesting to take a poll.

Aesthetix is all tube gain stages I believe. I believe they are all tube gain stages. I do think the mm with SUT is perhaps the "standard". However, there can be more work involved with getting SUT loading optimized. Not a big thing, just a bit more work involved.

In my case, the phono stage I use has a FET mc gain stage that is configured conservatively. I.e., most of the gain is realized through the MM stage. I can run my XV-1s through my MM stage. Obviously, it sounds much better through the mc inputs, but I think that gives an idea of how much gain is applied at each stage.

I leave the discussion now since Actusreus is really looking for designer input.

There is no general rule for a specific Design. You will find good ones, you will
find bad ones, you will find right ones, you will find wrong ones and every
designer will tell you why he went that way and not the other one....:-)
To design a good Phonostage which sounds like the real thing is quite a task,
specially when you need higher gain. The main problem today is profit and
good parts are simply expensive, see resistors, caps, wire and so on and when
everything will be tested in a lab, the costs can ruin the mark up. Hyping is
more cost efficient and it works also pretty good today.
I used for a lot of years high gain transistor stages, now I am with SUT's based
units. Here it is the comparable problem, the normal SUT's are in general cheap,
lousy and horrible from the datas. But the price counts. Top SUT's which have
excellent datas, superior channel separation and uncolored sound, they exist,
but no one buys them. Too expensive for "High End" units. No matter how much
money you are willing to spend, you don't get it. Professional Users, yes, they
do, but they tell the manufacturer what datas they want to have and they pay
the price for it..