Koetsu RoseWood Standard upgrade?

Rauliruegas there are actually some really nice custom options available these days compared to the vintage ones you listed. Transformer cores and such have come a long way in increasing transparency. I would not be over paying for something like Tango, Altec, etc.

Some really nice SUTs from modern winders can be had from Tribute and Intact Audio. Optimized for your cartridge.

SUTs have come a long way recently. Reducing the inductance has made them more transparent. An active stage has to do a lot to the signal and you are actually introducing a lot to the signal path with an active stage. You are introducing another stage of amplification (at best FETs) along with connnecting cables inside the box or outside the box. Most of the connections inside the box are on printed circuit boards, and not point to point wiring. A well designed and executed SUT will convert the current to voltage so the phono stage will think it is seeing a MM cartridge instead of a MC cartridge. Yes, we are dealing with extremely low signals, but you can't make a generalization that SUTs by design are inferior to active stages. I have heard many well designed and executed phono stages. The best active phono stage I had heard in my own personal system was in a KRELL KRC-HR, which I still own and use for comparison. Currently I am using a MM stage from a Liberty B2B with a SUT that outperforms the KRELL, which I am just using right now as a preamp and bypassing the phono stage. What matters to me is what sounds the best. I go to a lot of audio shows and listen to systems at peoples homes. When I substitute a SUT in their system and bypass the MC sections, most of the time, there is a marked improvement in sound. Sometimes not. It is system dependent. I cannot tell you that a SUT is better than an active stage in all cases, just like I can't say that an active stage is better than a SUT in all cases. You have to consider the cartridge and phono stage combo before making that determination.

Dear Dnath: Well, customs options in a SUT is a very old " game " that came almost first from the begin. Examples:

whe Audio technica launched its top of the line LOMC cartridge MC 1000 it appeared along its dedicated AT1000T SUT, Ortofon VLOMC MC2000 appeared along the Ortofon ( dedicated ) 2000T SUT and the same when appeared the cartridges MC3000 and MC5000 but when I bought the Audio Note IO Limited II it came the Audio Note ( silver wired and optimized for the AN catridge. ) SUT.

So that custom mad is nothing new and does not change the SUT/active stage subject.

Of course that I don't heard yet all the SUTs down there but IMHO is unimportant in the whole subject.

You can compare the vintage Denon 1000T SUT against any today SUT and then you will know what I mean or take an Entré one or an Audio Note and the results will be the same. The issue is not that.

I explained some of the why's of SUTs, exist not as the best choice but as the best choice for a phono stage designer with out the right skills/knowledge to design an active high gain unit or for tube electronics designs but certainly not as the best quality performer. In the other side SUT is an unexpensive alternative but not the best one.

All goes around which are your audio music sound reproduction targets and how big is your wallet.

You can make a test the other way around, that's:

listen a top/first rate home audio system ( with active high gain phonolinepreamp. If is a SS electronics design the better. ) with performance characteristics as the ones I posted ( in the other post ) and compare it making only one change: the SUT of your preference ( any. ) and look/listen carefully at both frequency extremes and after you be aware of those differences you will understand why a SUT can't ( today ) even the best active high gain SS stages.

I already posted that I'm not saying that the SUTs sounds bad or totally wrong: NO, what I'm saying is that its quality performance level is a down step over the active high gain stages.
All subjects on audio have its own trade-offs and maybe the more critical trade-off in an active high gain stages is its high price if you want the best but there are several active high gain stages at affordable prices.

Regards and enjoy the music,
R.

Dear Bobsdevices: +++++ " An active stage has to do a lot to the signal and you are actually introducing a lot to the signal path with an active stage. " +++++

this depends of the designer knowledge level and skills. Btw, my phonolinepreamp is a current not voltage design and today there is a trend to design in that fashion.

I think you need to make some comparison tests as the one I mentioned in my post to Dnath.

I think that what you like more are the MM/SUT distortions and certainly could be because you are accustom to or because you are a manufacturer and seller of SUTs and this could makes that your opinion been a biased opinion and not a neutral one.

Btw, I named Krell but never was one of my favorities but even that performs very well.

Regards and enjoy the music,
R.