Step Up Transformers….Are they Worth the Trouble?

Tubes units normally have really high RIAA deviation 20hz-20khz some witn a swing over 1 db and why is important this deviation?: because we are talking of a curve where any discrete frequency deviation affects around 2 octaves in that RIAA curve and the deviations exist almost in all discrete frequencies in that  RIAA . You can use tubes in any place but phono stage due that in reality makes a damage ( sever ) to that cartridge MUSIC signal. In theory the RIAA eq. in a phono stage should has 0 deviation ( only through digital we can reach that 0 deviation. ) to avoid added signal fully colorations and SS in this regards is better aproach.

Dr. Stanley Lipshitz wrote an article that shows all the math for producing a proper RIAA curve. If you do the math the curve will be accurate and this has nothing to do with tubes or solid state.

The Link is to a Thread produced by a Forum Member on another for and one who I have a lot of trust in what they report.

In this case they are making known a experience had using different Phonostages in comparison, as well as using SUT's on a Phonostage Model that have been referenced on this forum recently as being a state of the art design costing $30K.

A extended read is the least the link is able to offer.

https://www.whatsbestforum.com/threads/my-next-phonostage-boulder-2008-or-ch-precision-p1-or.26346/

Dear @atmasphere  :  " this has nothing to do with tubes or solid state. " 

Ok, then is a huge coincidence that all SS  units outperforms in that regards  tube units and according what you posted I can infere that all those tube designers has not the technical knowledge levels and skills.Just incredible that so low level in tube designers. Could be a " shame " for them.

R.

'All' or most that you know of?

At any rate, I have to agree with you that 'knowledge levels and skills' is an issue. People seem to get into this sport out of desire rather than if they have the education or not.

If you take the time to read Dr. Lipshitz's paper you will see that it has nothing to do with the kind of amplification. If the electronics are designed according to the math in the paper it will have correct EQ.

the today top phono SS stages has A RIAA deviation of at least 0.1db and lower than that, mine is 0.011 and FM Acoustics 0.05.

chasing numbers like this is a fool's errand. There are so many errors introduced in so many stages of the process that these small deviations do not matter.

Everything else being equal then of course go for the better measurement, but everything else is never equal ... so how does it sound? That's really all that matters..

regarding SUTs and loading , someone much more knowledgeable than me (Dave Slagle) advocates for choosing an SUT ratio to get the gain you need, then loading it on the input side to get the load you need, DO NOT rely on the reflected impedance of the phono stage. The problem with this approach is that most phono stages use the arbitrary 47KΩ load, which is usually not the ideal. It should usually be much higher. That is the Emia approach which has proven to be audio nirvana for me... not chasing measurements.