Step Up Transformers….Are they Worth the Trouble?

@lalitk I am not familiar with the Phon' or SUT in use, but I do know the enjoyment to be had entertaining oneself trying out the extent of Permutations that can be created for the Vinyl Signal Path. 

I wish you the best for the next period of your Vinyl Endeavours. 

@lewm Not too long ago, I made known I have been very impressed with the experience had from being demo'd the Paradise Phonostage.

For my bringing the Paradise into the arena of discussion and for referencing the the Builder of 40+ Models choosing a particular RIAA (0.3dB) if remembered correctly. I was subjected to the usual ugliness of written stuff by one forum member at the least. When the Builder referenced the dB i reported on they did claim "this is the value the end user is selecting" ??, food for thought, or all owner / users are no better than Stupid DJ's - not my words ??  

As a show of my not caring about these types of individuals who spiel their ills onto the niceness of a friendly forum, ( I was always advised to Punch the Bully on the nose, rightly or wrongly). I am to continue making a reference to the Paradise, as it is extremely good VFM and will impress many many who encounter it. My own experiences of it in use strongly suggests, especially if individuals are expressing an interest in Branded Phon's up to £10Kish in Value. 

The following info, which is extracted from another forum where the Paradise is under discussion by a few Builders.

Two UK Based Paradise Builders are discussing their builds, One Builder is the above referred to and the other is the producer of a Two Box Model I have also been able to be demo'd and impressed by on the £200K System, where Bake Off's has occurred. These Two Phon's got into the End of Day Line Up to be compared to the Premises Resident Phon' all comers if proven by selection are compared to. 

As your earlier inquiry remains unanswered, this following info might help with some of the info that has been of interest to you.

__________________________________________________________________

Both SPICE simulation and I have reverse RIAA generator and Bruel & Kjaer signal generator plus widerange AC millivoltmeter.
I only simulated it for the Paradise but it can be done more accurately in simulation than in real life as a perfect reverse RIAA generator can be used virtually which is built with +/- 0.00000% accurate parts. This can then allow you to design RIAA networks of extreme accuracy which will be limited only by the tolerance of the real components.
When I design and build phono stages I use the reverse RIAA generator to check the actual response as a "reality check". With many designs the topology is such that if the simulation says the RIAA is spot on then it will be in reality but it can be useful to check that eg the 1% parts used really live up to that spec and that nothing has drifted.
In some designs the accuracy of the RIAA can be affected by the topology and the parts used, I'm mainly thinking of various simple valve phono stages here in which the sample of a particular valve used and how worn it is can all effect the RIAA accuracy.... Not all valve phono stages are affected by this but many of the simpler and more popular ones are.

I've found values to get it within 0.02dB if anyone wants to try it.

Change: 73.5K to 72K, 9K1 to 9K8, 33.3nF to 32.7nF and 11nF to 11.1nF. Leave the 220R shorted or remove and place wire link in. I believe it's generally shorted by most users and if not then it causes a further kick up in HF above about 18KHz....

_________________________________________________________________

I guess the crux of your quote is this: "I only simulated it for the Paradise but it can be done more accurately in simulation than in real life as a perfect reverse RIAA generator can be used virtually which is built with +/- 0.00000% accurate parts. This can then allow you to design RIAA networks of extreme accuracy which will be limited only by the tolerance of the real components."  This comment suggests he has a device that can run a perfect simulated reverse RIAA.  (One question in my mind is what IS a perfect reverse RIAA?  Is it the reverse of the Lipschitz equations, or what is it based upon?) Anyway, notwithstanding the fact that we don't know what model he uses for RIAA, I get it. I find the last paragraph kind of odd; if changing those values improves the accuracy of the RIAA, why not do it in the first place?  Seems easy.  Except of course you have to have exact parts values, else the curve will be off.  And the resistors cannot drift in value when heated. Building these circuits to exacting standards requires a willingness to test parts values rigorously and to be prepared to reject parts that are off even by a small amount.

Dear @herman : I know you by Agon since 15-20 years and I know that even you teach for some years circuit theory.

Again: I’m not chasing numbers. I posted " thousands " of times that my main syatem target is to stay nearer to the recording and to reach that target you need accuracy at each single chain system link and at the end you need " numbers " to look how accurate is " this or that " and not only in the RIAA but in THD or IMD:WE NEED NUMBERS, and like you posted: everything the same lower numbers are better.

I know very well your high knowledge levels but in audio phonolinepreamp designs you need skills too and more important is CREATIVITY because with out this you can’t reach that main target.

Now, been a circuit theory teacher along working in electronics I think that you understand that for the truly sensible output levels of the cartridge signal a short circuit path road for that signal outperforms a longer one: rigth?. Maybe not because in your system you choosed the long path for the cartridge signal. This behavior makes no sense to me knowing your technical background. @lalitk this for me is not " disrespect " not with herman or with any other Agon member never. @mulveling things are that normally I really have serious problems to explain me in english ( " become a demonstration of how NOT to effectively communicate. ) that’s not my native language along that I always try to be direct and always trying to help and not to destroy: I don’t say " look as white " if it’s white and then I say is white. Yes, several times Agoners think that I’m truly agressive because when something seems to me ( first hand experiences. ) is wrong I post is wrong no matter what but I don’t said in that way trying to diminish the other person in any way and I’m sorry for that.

Now and returning to that creativity what my technical friend ( designer ) and partner in the phonolinepreamp manufacturedid it was to " invent/creative " a propietary technique using ( between other things. ) the digital domain audio signal to calibrate in real time each one phonolinepreamp RIAA that allows an overall phono re-equalization accuracy to within +/-0.01 dB, guaranteeing that the musical information decoded by the preamplifier is completely neutral to the input source.

That means accuracy to reach my main system targe. Well this care wit that unit is the care we took in the selection parts that we did it hand tested each part, we don’t let nothing at random everything was measured. Along those chasing " numbers " we made really hundreds of listen tests in several room/system and always testing with the same LP tracks.

At the end what I did it and do in my room/system is not chasing numbers but chasing accuracy and proudly I can say that I achieved and the system has a very high resolution . Next is the link of my virtrual Agon system, yes to long to read it but for me is interesting and explain why it looks here as if I’m chasing " numbers " and why I use transistors instead tubes and why I don’t use any more SUT’s:

On the Quest of Audio Heaven. | Virtual Listening Room (audiogon.com)

Btw, @lalitk it’s a must that the phono stage you choose comes with the RIAA 3.18us pole that’s where the cutting machine stops ( around 50khz-60khz ) to avoid the cutting head burn-in. Not all the phono stages comes with and not all the ones that have it have it with out phase developed " problems ". Nearer to the recording means that the 3.18us most be " there " in your phono stage. Btw, the real issue with my posts in this thread is that what I said goes against what you want it and I don’t posted trying to " hit " you in any way but trying to help trying that you avoid the other gentlemans mistakes/errors because they are wrong ( with all respect ): black is black, no other word .

R.

@lewm I know all about discards due to testing matching, I supplied a substantial amount of monies for the Parts used on the Two Valve Phon's Prototypes of which I have one which incurred further costs by having the End Design voiced to my own preference.

I do believe the individual you have quoted does produce a RIAA that falls into the tight tolerances quoted, by being in a room with the builder, I vaguely remember their description making a reference to the RIAA and on other posts on forums they certainly make reference to it.

On the day a Two Box Paradise 0.02 dB RIAA? and a Four Box 0.3 dB RIAA?  

The RIAA dB's quoted are very likely to have been these, unless the Four Box Builder selects a tighter tolerance for their own Phon's RIAA, than the one they reference as being the purchasers selection, 

On the day, as made known in earlier Posts about the Paradise, the Four Box Model in my view, was the Phon' worthy to be Standalone A/B Compared to the resident £10K Phon' and separating them for which was the better was no easy task.    

As said, this in my view, places the Paradise in a position where for the monies to be laid out to achieve one, gets an individual a Phon' will comfortably hold its own with Phon's from the Branded World that retail at £10K and upwards.

What's not too like if one is a Vendor, Probably a Fly in the Ointment if one is a Retailer.   

“I do know the enjoyment to be had entertaining oneself trying out the extent of Permutations that can be created for the Vinyl Signal Path. ”
@pindac 

That’s been my goal all along! Thanks again for your input :-)